Patent Application
20150054467
The present invention relates to a battery control device.
As shown in
Patent Document 1: JP A-2011-205827
In a system as shown in
Against the background discussed above, an object of the present invention is to provide a battery control device that can achieve power saving while ensuring safety.
According to one aspect of the present invention, a battery control device which monitors charge/discharge control, by a charge/discharge control portion, of a battery unit including a secondary battery in order to protect the battery unit is provided with: a communication portion which communicates with each of the battery unit and the charge/discharge control portion; and a control portion which sets as a target operation mode either a normal operation mode in which communication is conducted continuously in the communication portion or an intermittent operation mode in which communication is suspended intermittently in the communication portion, the control portion executing communication in the communication portion according to the target operation mode. Here, while the target operation mode is the intermittent operation mode, when a predetermined cancellation condition is fulfilled, the control portion switches the target operation mode from the intermittent operation mode to the normal operation mode.
According to the present invention, it is possible to provide a battery control device that can achieve power saving while ensuring safety.
Hereinafter, exemplary embodiments of the present invention will be described specifically with reference to the accompanying drawings. Among different drawings referred to, the same parts are identified by the same reference signs, and in principle no overlapping description of the same parts will be repeated. In the present specification, for simplicity's sake, symbols and signs referring to information, signals, physical quantities, states, members, etc. are occasionally used with the names of the corresponding information, signals, physical quantities, states, members, etc. omitted or abbreviated.
The power conversion circuit 12 includes a plurality of switching devices comprising field-effect transistors, insulated-gate bipolar transistors, or the like, and executes power conversion operation under the control of the power conversion control portion 11. The power conversion operation includes charge operation and discharge operation.
In charge operation, the power conversion circuit 12 converts the output electric power of the power block PB1 into desired direct-current electric power, and supplies the obtained direct-current electric power via the breaker portion 22 to each battery unit BU. The power block PB1 is an electric power source that outputs either alternating-current electric power or direct-current electric power, and includes, for example, a commercial alternating-current electric power source or a solar cell unit. Each battery unit BU is charged when receiving direct-current electric power based on the output electric power of the power block PB1.
In discharge operation, the power conversion circuit 12 receives the discharge electric power from each battery unit BU via the breaker portion 22, and converts the received discharge electric power into desired direct-current electric power or alternating-current electric power to feed it to the power block PB2. The power block PB2 is, for example, a load that consumes electric power, and is driven by the output electric power from the power conversion circuit 12. The power conversion circuit 12 can also feed the output electric power of the power block PB1 to the power block PB2 directly without passage through a battery unit BU (in that case, predetermined power conversion can be performed).
The power conversion control portion 11 controls the operation, including power conversion operation, of the power conversion circuit 12. The power conversion control portion 11 can thus be said to include a charge/discharge control portion for controlling the charging and discharging of the battery units BU.
The battery management portion 21 communicates with each battery unit BU across a communication line CLB, and communicates with the power conversion control portion 11 across a communication line CLS. The battery management portion 21 receives, from each battery unit BU, battery status data (see
The breaker portion 22 comprises a breaker (current breaker) interposed between, in series with, the battery module 31 of each battery unit BU and the power conversion circuit 12, and is either in an on state or in an off state at a time. When the breaker portion 22 is on, each battery module 31 is connected to the power conversion circuit 12, so that each battery module 31 can be charged and discharged via the power conversion circuit 12. When the breaker portion 22 is off, the electric path between each battery module 31 and the power conversion circuit 12 is disconnected, so that no battery module 31 can be charged or discharged via the power conversion circuit 12. Instead of a breaker, any other component, such as a self-control protector (SCP) or a mechanical relay, that can disconnect the above-mentioned electric path according to a signal from outside can be used to build the breaker portion 22. The electric path between each battery module 31 and the power conversion circuit 12 comprises a power line PLB, which is an electric path between each battery module 31 and the breaker portion 22, and a power line PLS, which is an electric path between the power conversion circuit 12 and the breaker portion 22. The breaker portion 22 is in principle kept on, and accordingly, in this embodiment, unless otherwise stated, it is assumed that the breaker portion 22 is kept on.
With reference to
Between the battery module 31 and the pair of power input/output terminals POUT, there are interposed, in series, a current sensor 33, for measuring the value (hereinafter referred to as the battery current value) of the current passing through the battery module 31, and a fuse 36 such as a self-control protector. Across both terminals of the battery module 31, a voltage sensor 34 is connected in parallel. The voltage sensor 34 measures the value (hereinafter referred to as the battery voltage value) of the voltage across the battery module 31. The battery voltage value is the terminal voltage value of the battery module 31, that is, the value of the potential difference between the positive electrode of the secondary cell located at the highest-potential end and the negative electrode of the secondary cell located at the lowest-potential end in the battery module 31. The potential difference between the positive and negative electrodes of each secondary cell in the battery module 31 (that is, the voltage value for each cell in the battery module 31) can also be measured to be included in the battery status data. The battery module 31 is provided with a temperature sensor 35. The temperature sensor 35 measures the temperature (hereinafter referred to as the battery temperature) of the battery module 31. The battery temperature is, for example, the surface temperature of the pack enclosing the plurality of secondary cells in the battery module 31, or the temperature at a particular spot in the battery module 31.
The battery current value, battery voltage value, and battery temperature measured by the sensors 33, 34, and 35 are fed to a unit control portion 32. The unit control portion 32 generates battery status data (battery status information) based on the measured battery current value, battery voltage value, and battery temperature, and transmits it to the battery management portion 21. For each battery unit BU, such battery status data is generated and transmitted to the battery management portion 21.
Each flag in the bunch of battery status flags has an initial value of 0. For convenience' sake, operation for substituting a value of 0 or 1 in the flags in the bunch of battery status flags is referred to as flag setting operation. In each battery unit BU, the unit control portion 32 performs flag setting operation on each flag in the bunch of battery status flags based on the battery current value, battery voltage value, and battery temperature from the sensors 33, 34, and 35. The flag setting operation on the flags in the bunch of battery status flags can instead be performed by the battery management portion 21. In that case, based on the battery current value, battery voltage value, and battery temperature in the battery status data from a given battery unit BU, the battery management portion 21 can perform flag setting operation on each flag in the bunch of battery status flags for that battery unit BU.
In a case where the battery block BB comprises a plurality of battery units BU, the plurality of battery units BU can be connected together in any way. The following description, however, assumes the following configuration: as shown in
The battery management portion 21 is connected to each unit control portion 32 via the communication line CLB. Here, a total of n unit control portions 32 in the battery units BU[1] to BU[n] are preferably connected together in a daisy-chain configuration or the like and then to the battery management portion 21. Adopting this configuration makes it possible to handle the battery status of the plurality of battery units BU constituting the battery block BB as a bunch of battery statuses, and this makes more accurate control possible. However, the battery block BB can instead be so configured that the plurality of unit control portions 32 are integrated into a single unit. In that case, even when a plurality of battery units BU are used, the battery management portion 21 has only to handle a single target of communication, and this advantageously helps simplify the control.
The power line PLS comprises a high-potential-side power line PLS(+) and a low-potential-side power line PLS(−). The power lines PLB(+), PLB(−), PLS(+), and PLS(−) are connected to breaker terminals 53, 54, 55, and 56, respectively. Between the breaker terminals 53 and 55, a breaker switch 51 is interposed in series, and between the breaker terminals 54 and 56, a breaker switch 52 is interposed in series. A state where the breaker portion 22 is on is a state where the breaker switches 51 and 52 are on and hence the power lines PLB and PLS are connected together. A state where the breaker portion 22 is off is a state where the breaker switches 51 and 52 are off and hence the power lines PLB and PLS are disconnected from each other. A main control portion 60 can, under a predetermined condition, apply a voltage V[12] (described later) to a coil 57 via an unillustrated breaker trip circuit to turn off the breaker switches 51 and 52. On the other hand, the unit control portion 32 of each battery unit BU can, when a fault (such as overcharging) occurs and it is serious, output a STOP signal, and also when this STOP signal is output, the breaker portion 22 is turned off. By referring to the state of a three-terminal switch 58 of which the state changes in coordination with the breaker switches 51 and 52 being turned on and off, the main control portion 60 can recognize the on/off state of the breaker portion 22. The breaker switch 52 can be omitted, in which case the breaker terminals 54 and 56 can be connected together directly without passage through a breaker switch 52.
The power line PLS is connected, via the breaker terminals 55 and 56 and a switch 66 comprising a field-effect transistor or the like, to a converter 63. The on/off state of the switch 66 is controlled by the main control portion 60. When the switch 66 is on, the voltage between the terminals 55 and 56 is, as an input voltage VIN, applied to the converter 63. When the switch 66 is off, the voltage between the terminals 55 and 56 is not supplied to the converter 63 (thus, VIN=0). When the breaker portion 22 and the switch 66 are both on, the converter 63 converts the input voltage VIN into a voltage V[12] having a predetermined voltage value (for example, 12 volts DC) and outputs it to a communication power supply circuit 64. The communication power supply circuit 64 converts the voltage V[12] into communication supply voltages and outputs them to communication portions 61 and 62. The communication portions 61 and 62 are driven by, as their driving voltages, the communication supply voltages. In the example shown in
The main control portion 60 comprises a CPU (central processing unit) or the like, and is driven by, as its driving voltage, the voltage VMAIN. The main control portion 60 controls the operation of the communication portions 61 and 62 for communication, and controls operation within the battery management portion 21 in a centralized fashion. The communication portion 61 communicates with each battery unit BU (that is, each unit control portion 32) connected thereto via the communication line CLB. The communication portion 62 communicates with the power conversion control portion 11 connected thereto via the communication line CLS. From each battery unit BU, the main control portion 60 is previously notified of an ID number unique to the battery unit BU, so that the communication portion 61 can communicate with a desired battery unit BU with the help of its ID number. The battery management portion 21 supplies each battery unit BU with the output voltage V[12] of the converter 63 for the driving of the unit control portion 32 of the battery unit BU.
A temperature sensor 67 measures the temperature at a predetermined spot in the battery management portion 21 (for example, the temperature of the circuit board on which the main control portion 60 is mounted, or the surface temperature of the housing of the battery management portion 21), and conveys the measured temperature to the main control portion 60. A non-volatile memory 68 comprises an EEPROM (electrically erasable programmable read-only memory) or the like.
The communication by the communication portion 61 (that is, the communication between the battery management portion 21 and any battery unit BU) and the communication by the communication portion 62 (that is, the communication between the battery management portion 21 and the power conversion control portion 11) can each be full-duplex communication independent of the other. In this embodiment, it is assumed that they are each half-duplex communication independent of the other. Under the control of the main control portion 60, half-duplex communication by the communication portion 61 and half-duplex communication by the communication portion 62 are conducted independently of each other. As is well known, when half-duplex communication is conducted between two blocks, not both blocks can transmit or receive simultaneously; while one block is transmitting a signal, the other block has to receive the signal. The half-duplex communication by the communication portions 61 and 62 can be conducted, for example, in compliance with the RS-485 communication standard. In the half-duplex communication by the communication portions 61 and 62, a master-slave method is adopted. Specifically, in the communication by the communication portion 61, the battery management portion 21 (that is, the communication portion 61) is designated as a master, and any battery unit BU (that is, the unit control portions 32) is designated as a slave. On the other hand, in the communication by the communication portion 62, the power conversion control portion 11 is designated as a master, and the battery management portion 21 (that is, the communication portion 62) is designated as a slave.
With reference to
The communication portion 61 executes basic communication operation in which it transmits a command including a data request command to a plurality of battery units BU sequentially and receives in reply to the command a response signal from the plurality of battery units BU sequentially. Basic communication operation serves as communication operation for acquiring battery status data; as shown in
More specifically, in basic communication operation, the communication portion 61 delivers a command 311 having an ID number “1” added to it to the communication line CLB. Of all the battery units BU[1] to BU[n], only the battery unit BU[1] corresponding to the ID number “1” responds to the command 311, and the unit control portion 32 of the battery unit BU[1] returns a response signal 312 including the latest battery status data in the battery unit BU[1]. After receiving the response signal 312, the communication portion 61 delivers a command 313 having an ID number “2” added to it to the communication line CLB. Of all the battery units BU[1] to BU[n], only the battery unit BU[2] corresponding to the ID number “2” responds to the command 313, and the unit control portion 32 of the battery unit BU[2] returns a response signal 314 including the latest battery status data in the battery unit BU[2]. In a case where n=2, when the communication portion 61 has received the response signal 314, it concludes one session of basic communication operation. In a case where more battery units BU are provided, basic communication operation includes similar communication operation for the other battery units BU.
The communication portion 61 performs basic communication operation periodically, at predetermined time intervals INTB (for example, at intervals of one to several seconds). The main control portion 60 stores the battery status data received by the communication portion 61 in a buffer memory 70, comprising a DRAM (dynamic random-access memory) or the like, provided in the battery management portion 21 (for example, in the main control portion 60). Here, so that only the latest battery status data on each battery unit BU may be held in the buffer memory 70, the battery status data stored in the buffer memory 70 can be updated every time new battery status data is received.
Independently of the communication by the communication portion 61, the communication portion 62 receives a command 321 including a data request command from the power conversion control portion 11. In reply to reception of the command 321, the communication portion 62 transmits a response signal 322 including processed battery status data to the power conversion control portion 11. The processed battery status data (the contents of the response signal 322) is generated by the main control portion 60 based on the latest battery status data stored in the buffer memory 70. The processed battery status data is data obtained by converting the latest battery status data on the n battery units BU into a predetermined data format, but can instead be the latest battery status data, as it is, on the n battery units BU. Unless a communication fault or the like is present, such a command 321 is transmitted periodically at predetermined time intervals INTS (for example, at intervals of one to several seconds) from the power conversion control portion 11 to be received by the communication portion 62, with the result that a response signal 322 is transmitted periodically at the same time intervals INTS from the communication portion 62 to the power conversion control portion 11.
The main control portion 60 monitors whether or not a fault has occurred in the battery block BB, the battery management portion 21, and the breaker portion 22 in the electric power system 1. Faults monitored by the main control portion 60 include a fault due to overcharging (overcharging fault), a fault due to overdischarging (overdischarging fault), a fault due to an overcurrent (overcurrent fault), a temperature fault, a sensor fault, and a communication fault. All these can be understood as faults in the battery unit BU or in the battery management portion 21.
A fault due to overcharging is, for example, a state where the battery voltage value of any battery unit BU remains over a predetermined reference voltage value VTHU for a predetermined length of time or longer. A fault due to overdischarging is a state where the battery voltage value of any battery unit BU remains under a predetermined reference voltage value VTHL for a predetermined length of time or longer (VTHU>VTHL). A fault due to an overcurrent is, for example, a state where the battery current value of any battery unit BU remains over a predetermined reference current value ITHU for a predetermined length of time or longer. A temperature fault is, for example, a state where the battery temperature of any battery unit BU or the temperature measured by the temperature sensor 67 stays out of a predetermined temperature range for a predetermined length of time or longer.
A sensor fault can be a fault in the sensors 33, 34, and 35 in any battery unit BU, and can also be a fault in the temperature sensor 67. For example, a state where the battery current value, battery voltage value, or battery temperature measured by the sensor 33, 34, or 35 falls outside predetermined ranges of current, voltage, or temperature is understood as a fault in the sensor 33, 34, or 35. For example, a state where the temperature measured by the temperature sensor 67 falls outside a predetermined temperature range is understood as a fault in the temperature sensor 67.
A communication fault can be a first communication fault which is a communication fault between the battery management portion 21 (that is, the communication portion 61) and any battery unit BU or a second communication fault which is a communication fault between the power conversion control portion 11 and the battery management portion 21 (that is, the communication portion 62). A first communication fault can be, for example, a state where, in reply to a command (for example, 311 or 313) from the communication portion 61, no response signal (for example, 312 or 314) from a battery unit BU is received by the communication portion 61. A second communication fault can be, for example, a state where a command 321 expected to be transmitted periodically from the power conversion control portion 11 is not received by the communication portion 62 for a predetermined length of time or longer.
Based on the battery status data received from each battery unit BU, the temperature measured by the temperature sensor 67, and the communication status in the communication portions 61 and 62, the main control portion 60 integrates a request or notification related to the charging or discharging of the battery module 31 into a response signal 322 which the main control portion 60 transmits to the power conversion control portion 11. Specifically, based on the battery status data received from each battery unit BU and the temperature measured by the temperature sensor 67, the main control portion 60 checks whether or not an overcharge fault, overdischarge fault, overcurrent fault, temperature fault, or sensor fault is present. Moreover, based on the signal reception status in the communication portions 61 and 62, the main control portion 60 checks whether or not a first or second communication fault is present. The main control portion 60 generates a charge enable/disable signal 341 and a discharge enable/disable signal 342 reflecting the results of those checks, and integrates them into a response signal 322 (see
The signals 341 and 342 are each a flag that has a digital value (logical value) of either 0 or 1 at a time. A signal 341 having a value of 0 acts as a charge enable signal to enable the charging of the battery module 31; a signal 341 having a value of 1 acts as a charge disable signal to indicate the necessity to disable the charging of the battery module 31. A signal 342 having a value of 0 acts as a discharge enable signal to enable the discharging of the battery module 31; a signal 342 having a value of 1 acts as a discharge disable signal indicating the necessity to disable the discharging of the battery module 31. For example, in a case where a charge disable flag (see
When an overcharge fault, overdischarge fault, overcurrent fault, or temperature fault is present in a battery unit BU, from the perspective of protecting the battery unit BU, charge operation and/or discharge operation should be stopped. On the other hand, when a sensor fault or communication fault is present, due to inconveniences such as the inability to accurately recognize the status of the battery units BU as the target of protection, it is undesirable, for safety reasons, to continue charge operation and/or discharge operation. Accordingly, on occurrence of a fault, the main control portion 60 substitutes “1” in either or both of signals 341 and 342 in accordance with the type of the fault present, and thereby requests the power conversion control portion 11 to disable charging or discharging. If a received response signal 322 includes a charge disable signal (that is, a signal 341 having a value of 1), the power conversion control portion 11 controls the power conversion circuit 12 so that charge operation is stopped immediately; if a received response signal 322 includes a discharge disable signal (that is, a signal 342 having a value of 1), the power conversion control portion 11 controls the power conversion circuit 12 so that discharge operation is stopped immediately.
The generation and transmission of a charge disable signal or a discharge disable signal by the battery management portion 21 corresponds to first protection operation for the battery units BU. When a charge disable signal is transmitted during charge operation, or when a discharge disable signal is transmitted during discharge operation, the battery current value is supposed to quickly fall to zero (or substantially zero), but this may not happen if the power conversion circuit 12 has a fault or the power conversion control portion 11 is not operating properly.
With this taken into consideration, the battery management portion 21, after transmitting a charge disable signal or a discharge disable signal, executes second protection operation, which can be understood as additional protection operation. The second protection operation will now be described. In second protection operation, the main control portion 60 monitors a target current value ITG, and if the magnitude of the target current value ITG does not fall to or below a positive predetermined value ITH even a predetermined length of time THTIME after the timing of the transmission of a charge disable signal or discharge disable signal by the communication portion 62, the main control portion 60 can turn the breaker portion 22 from on to off. If, the predetermined length of time THTIME after the above-mentioned timing of the transmission, the target current value ITG is equal to or less than the predetermined value ITH, the main control portion 60 can keep the breaker portion 22 on. In a case where a charge disable signal is transmitted from the communication portion 62, the target current value ITG is the battery current value during the charging of any battery unit BU, and can be the sum of, or the average of, or the maximum value among the measured battery current values during the charging of the battery units BU[1] to BU[n]. In a case where a discharge disable signal is transmitted from the communication portion 62, the target current value ITG is the battery current value during the discharging of any battery unit BU, and can be the sum of, or the average of, or the maximum value among the measured battery current values during the discharging of the battery units BU[1] to BU[n].
Immediately before turning the breaker portion 22 from on to off in second protection operation or the like, the main control portion 60 can save the latest battery status data received from each battery unit BU in the non-volatile memory 68. By exploiting the so saved data, it is easier to investigate what has caused the breaker portion 22 to turn off, facilitating restoration operation.
As will be understood from the above description, the battery units BU themselves have no charging/discharging control function, and rely mainly on the power conversion control portion 11 and the power conversion circuit 12 for charging/discharging control. The power conversion control portion 11 and the power conversion circuit 12 can be such as are incorporated in devices called power controllers, and such a power controller can be combined with a solar cell unit as an example of the power block PB1 to build a solar cell system (in that case, the power block PB2 is, for example, a load or an electric power system). In a possible application of this type of solar cell system, a battery unit is added to build a solar cell system having a power storage function. In one practical example of such an application, a battery unit BU can be additionally connected to an existing, separately provided solar cell system. When a solar cell system having a power storage function is considered as a whole, power conversion control is important which encompasses, for example, charge/discharge control and, with respect to the solar cell system, power generation control and reverse power flow control. However, apart from that, protection of the battery unit BU is also important. In particular, for example, in an application where a battery unit BU is connected to an exiting solar power system, relying on the exiting solar power system for protection of the battery unit BU leaves concerns about the stability of protection. With this taken into consideration, in this embodiment, the battery management portion 21 is provided as a mediator between, at one end, the power conversion control portion 11 and the power conversion circuit 12 and, at the other, the battery unit BU, so that the battery management portion 21 plays a central role to realize a protection function (first and second protection operation) utilizing communication.
The battery management portion 21 (main control portion 60) operates in one of a plurality of operation modes, and the operation mode in which the battery management portion 21 is actually operating is called the target operation mode. As shown in
The plurality of operation modes as candidates for the target operation mode include at least a normal operation mode and an intermittent operation mode, and in different operation modes, communication proceeds in different manners.
When the normal operation mode is set as the target operation mode, the battery management portion 21 performs normal operation. In normal operation, the communication portions 61 and 62 conduct communication on a continuous basis. The communication operation by the communication portions 61 and 62 described previously with reference to
When the intermittent operation mode is set as the target operation mode, the battery management portion 21 performs intermittent operation. In intermittent operation, the communication by the communication portions 61 and 62 is intermittently suspended. Specifically, when the target operation mode is the intermittent operation mode, as shown in
The main control portion 60 makes the communication portions 61 and 62 conduct communication in a manner complying with the target operation mode. Specifically, when the target operation mode is the normal operation mode, the main control portion 60 keeps the switch 66 (see
For example in a time zone when completely or almost no discharging or charging of the battery unit BU is expected to take place, the power conversion control portion 11 can instruct, by transmitting a mode request signal 361, the battery management portion 21 to perform intermittent operation. As shown in
The above-mentioned plurality of operation modes can include any operation mode other than the normal operation mode and the intermittent operation mode. For example, they can include a hibernation mode. When the hibernation mode is set as the target operation mode, the main control portion 60 keeps the switch 66 off until a particular input is fed to the battery management portion 21 from outside (for example, until a particular signal is fed from the power conversion control portion 11 to the main control portion 60).
In the configuration example shown in
Even in a period when intermittent operation is performed, in active periods, as in normal operation, the communication function and the protection function (first and second protection operation) of the battery management portion 21 are active. In sleep periods, however, the communication function of the battery management portion 21 is inactive, with the result that the protection function achieved by utilizing the communication function is inactive. It is therefore advisable, with a view to securing the safety of the battery unit BU, to control whether or not to perform intermittent operation and what to perform in it according to the situation at hand.
Some application examples related to intermittent operation will be described below. Unless inconsistent, any part of the description given thus far applies equally to the application examples presented below. Unless inconsistent, any of the plurality of application examples presented below can be combined with any other.
A first application example related to intermittent operation will be described. In intermittent operation, lengthening sleep periods helps enhance the power saving effect, but excessively long sleep periods, since these are periods when the communication function and the protection function are inactive, can lead to slack control for safety. With this taken into consideration, in the first example of application example, when the intermittent operation mode is set as the target operation mode, the main control portion 60 sets at least one of the active duration and the sleep duration variably (such that it can be varied) based on battery status data. In the following description, for the sake of simple designation, the operation performed by the main control portion 60 to achieve variable setting of at least one of the active duration and the sleep duration will be referred to as variable setting operation. The battery status data used in variable setting operation can be the latest battery status data that the main control portion 60 has acquired via the communication portion 61 prior to variable setting operation. The main control portion 60 can perform variable setting operation at the start of intermittent operation, or can perform variable setting operation with any timing during execution of intermittent operation.
With respect to the active duration, a reference duration REFACT (for example, five seconds) is prescribed, and with respect to the sleep duration, a reference duration REFSLP (for example, 25 seconds) is prescribed. The reference durations REFACT and REFSLP can be durations specified by the power conversion control portion 11. For example, the power conversion control portion 11 can, when transmitting an intermittent operation request signal REQINT (see
As battery status data, the battery current value of each battery unit BU can be used. The battery current value represents the current value in the charging or discharging of the battery module 31, and can have a zero value, a positive value (charging), or a negative value (discharging) (the same applies to the other application examples described later). In a case where the battery current value is used as the battery status data, the main control portion 60 sets an evaluation current value based on the battery current value of each battery unit BU. In a case where n=1, the evaluation current value equals the absolute value of the battery current value of the battery unit BU[1]. In a case where n≧2, the evaluation current value equals, for example, the sum of, or the average of, or the maximum value among, or any one of the battery current values of the battery units BU[1] to BU[n].
The main control portion 60 compares the evaluation current value with a predetermined threshold value ITHA1 (ITHA1≧1). If the evaluation current value is equal to or less than the threshold value ITHA1, the main control portion 60 sets the reference durations REFACT and REFSLP as the active duration and the sleep duration as in the initial state. On the other hand, if the evaluation current value is larger than the threshold value ITHA1, the main control portion 60 increases the active duration alone, or decreases the sleep duration alone, or increases the active duration and in addition decreases the sleep duration relative to the initial state. Here, as the evaluation current value increases, the amount of increase of the active duration and the amount of decrease of the sleep duration can be increased. Needless to say, increasing the active duration relative to the initial state means increasing the active duration from the reference duration REFACT, and decreasing the sleep duration relative to the initial state means decreasing the sleep duration from the reference duration REFSLP.
If the evaluation current value is equal to or larger than a predetermined threshold value ITHA2 (ITHA2>ITHA1), the main control portion 60 can set the sleep duration to be zero. That is, even when the communication portion 62 receives an intermittent operation request signal REQINT, the target operation mode can be set for the normal operation mode so that normal operation is performed.
As battery status data, the battery temperatures of the battery units BU[1] to BU[n] (hereinafter referred to as the n battery temperatures) can be used.
The main control portion 60 checks whether or not each battery temperature falls within a predetermined temperature range TMPRNG. If all the n battery temperatures fall within the temperature range TMPRNG, the main control portion 60 sets the reference durations REFACT and REFSLP as the active duration and the sleep duration as in the initial state. On the other hand, if, among the n battery temperatures, there is any battery temperature (hereinafter referred to as a deviated temperature) that falls outside the temperature range TMPRNG, the main control portion 60 increases the active duration alone, or decreases the sleep duration alone, or increases the active duration and in addition decreases the sleep duration relative to the initial state. Here, as the deviated temperature deviates further from the temperature range TMPRNG, the amount of increase of the active duration and the amount of decrease of the sleep duration can be increased. That is, when the deviated temperature is higher than the upper limit temperature of the temperature range TMPRNG, as the difference between the deviated temperature and the upper limit temperature increases, the main control portion 60 can increase the amount of increase of the active duration and the amount of decrease of the sleep duration. Likewise, when the deviated temperature is lower than the lower limit temperature of the temperature range TMPRNG, as the difference between the deviated temperature and the lower limit temperature increases, the main control portion 60 can increase the amount of increase of the active duration and the amount of decrease of the sleep duration. In a case where n≧2, the deviated temperature that determines the amount of increase of the active duration and the amount of decrease of the sleep duration is the maximum or minimum value among the n battery temperatures, and is the battery temperature farthest from the temperature range TMPRNG among the n battery temperatures.
The temperature range TMPRNG is, for example, part (around the center) of a prescribed operatable temperature range of the battery module 31. If, for example, any of the n battery temperatures deviates even from a predetermined temperature range TMPRNG2, the main control portion 60 can set the sleep duration to be zero. That is, even when the communication portion 62 receives an intermittent operation request signal REQINT, the target operation mode can be set for the normal operation mode so that normal operation is performed. The temperature range TMPRNG2 contains, and is wider than, the temperature range TMPRNG. The temperature range TMPRNG2 can be identical with, or part of, the above-mentioned operatable temperature range.
As battery status data, the remaining capacity data of the battery units BU[1] to BU[n] (hereinafter also referred to as the n remaining capacity data pieces) can be used. As mentioned previously, remaining capacity data is data indicating the remaining capacity or SOC of a battery module 31. As is well known, the SOC of a battery module 31 is the ratio of the capacity remaining in the battery module 31 to the full-charge capacity thereof. In a case where remaining capacity data is a value indicating the remaining capacity, a capacity range (described later) is a range defined in terms of “A·h (amperes per hour)” or the like; in a case where remaining capacity data is a value indicating the SOC, a capacity range (described later) is a range defined in terms of “%.”
The main control portion 60 checks whether or not each remaining capacity data piece falls within a predetermined capacity range CPRNG. If all the n remaining capacity data pieces fall within the capacity range CPRNG, the main control portion 60 sets the reference durations REFACT and REFSLP as the active duration and the sleep duration as in the initial state. On the other hand, if, among the n remaining capacity data pieces, there is any remaining capacity data piece (hereinafter referred to as a deviated remaining capacity data piece) that falls outside the capacity range CPRNG, the main control portion 60 increases the active duration alone, or decreases the sleep duration alone, or increases the active duration and in addition decreases the sleep duration relative to the initial state. Here, as the deviated remaining capacity data piece deviates further from the capacity range CPRNG, the amount of increase of the active duration and the amount of decrease of the sleep duration can be increased. That is, when the deviated remaining capacity data piece is larger than the upper limit value of the capacity range CPRNG, then, as the difference between the deviated remaining capacity data piece and the upper limit value increases, the main control portion 60 can increase the amount of increase of the active duration and the amount of decrease of the sleep duration. Likewise, when the deviated remaining capacity data piece is smaller than the lower limit value of the capacity range CPRNG, then, as the difference between the deviated remaining capacity data piece and the lower limit value increases, the main control portion 60 can increase the amount of increase of the active duration and the amount of decrease of the sleep duration. In a case where n≧2, the deviated remaining capacity data piece that determines the amount of increase of the active duration and the amount of decrease of the sleep duration is the maximum or minimum value among the n remaining capacity data pieces, and is the remaining capacity data piece farthest from the capacity range CPRNG among the n remaining capacity data pieces.
If, for example, any of the n remaining capacity data pieces deviates even from a predetermined capacity range CPRNG2, the main control portion 60 can set the sleep duration to be zero. That is, even when the communication portion 62 receives an intermittent operation request signal REQINT, the target operation mode can be set for the normal operation mode so that normal operation is performed. The capacity range CPRNG2 contains, and is wider than the capacity range CPRNG. The SOC equivalent values of the upper and lower limits of the capacity range CPRNG2are, for example, 100% (or 100%−Δ) and 0% (or 0%+Δ) respectively (where Δ represents a predetermined value fulfilling 0<Δ<0.5).
As battery status data, the battery voltage values of the battery units BU[1] to BU[n] (hereinafter also referred to as the n battery voltage values) can be used. Being terminal voltage values, battery voltage values vary with remaining capacity data, and thus allow operation similar to variable setting operation based on remaining capacity data.
Specifically, the main control portion 60 checks whether or not each battery voltage value falls within a predetermined voltage range VRNG. If all the n battery voltage values fall within the voltage range VRNG, the main control portion 60 sets the reference durations REFACT and REFSLP as the active duration and the sleep duration as in the initial state. On the other hand, if, among the n battery voltage values, there is any battery voltage value (hereinafter referred to as a deviated voltage value) that falls outside the voltage range VRNG, the main control portion 60 increases the active duration alone, or decreases the sleep duration alone, or increases the active duration and in addition decreases the sleep duration relative to the initial state. Here, as the deviated voltage value further deviates from the voltage range VRNG, the amount of increase of the active duration and the amount of decrease of the sleep duration can be increased. That is, when the deviated voltage value is higher than the upper limit value of the voltage range VRNG, then, as the difference between the deviated voltage value and the upper limit value increases, the main control portion 60 can increase the amount of increase of the active duration and the amount of decrease of the sleep duration. Likewise, when the deviated voltage value is lower than the lower limit value of the voltage range VRNG, then, as the difference between the deviated voltage value and the lower limit value increases, the main control portion 60 can increase the amount of increase of the active duration and the amount of decrease of the sleep duration. In a case where n≧2, the deviated voltage value that determines the amount of increase of the active duration and the amount of decrease of the sleep duration is the maximum or minimum value among the n battery voltage values, and is the battery voltage value farthest from the voltage range VRNG among the n battery voltage values.
If, for example, any of the n battery voltage values deviates even from a predetermined voltage range VRNG2, the main control portion 60 can set the sleep duration to be zero. That is, even when the communication portion 62 receives an intermittent operation request signal REQINT, the target operation mode can be set for the normal operation mode so that normal operation is performed. The voltage range VRNG2 contains, and is wider than, the voltage range VRNG. The upper limit of the voltage range VRNG2 corresponds to a voltage level equal to or close to an overcharge voltage level, and the lower limit of the voltage range VRNG2 corresponds to a voltage level equal to or close to an overdischarge voltage level.
Variable setting operation based on battery current value, battery temperature, remaining capacity data, and battery voltage value has been discussed separately. The main control portion 60 can perform variable setting operation based on two or more of indices comprising battery current value as a first index, battery temperature as a second index, remaining capacity data as a third index, and battery voltage value as a fourth index. For example, the main control portion 60 can perform variable setting operation based on two or more of the first to third indices, or based on two or more of the first, second, and fourth indices. Also in cases where variable setting operation is performed based on two or more indices, the active duration or the sleep duration can be varied according to the relevant indices.
In the first application example of intermittent operation, and also in a second and a third application example of intermittent operation which will be described later, the battery status data is assumed to include all of the first to fourth indices; the battery status data, however, can instead include only any one, two, or three of the first to fourth indices. The main control portion 60 can perform variable setting operation by using one or more indices included in the battery status data.
Insertion of sleep periods signifies disablement of the communication function and the protection function, and this is undesirable from the perspective of protection. However, so long as the charge/discharge current equals zero or is sufficiently low, reasonably long sleep duration or a reasonably short active duration is not considered to pose a serious problem. The same is true when the battery temperature falls around the center of the operatable temperature range, or when the remaining capacity data or the battery voltage value is well away from the overcharge or overdischarge level. However, when the charge/discharge current is relatively high, or when the battery temperature is relatively close to the upper or lower limit of the operatable temperature range, or when the remaining capacity data or the battery voltage value is relatively close to the overcharge or overdischarge level, it is preferable to avoid inactivation of the communication function and the protection function as much as possible, and to monitor the battery status as frequently as possible. On the other hand, power saving resulting from intermittent operation is highly beneficial. By performing the above-described variable setting operation with such factors taken into consideration, it is possible to achieve a satisfactory balance between battery protection and power saving (it is possible to achieve power saving while ensuring the safety of the battery unit BU).
In the example described above, the active duration can vary only in the increasing direction relative to the reference duration REFACT, and the sleep duration can vary only in the decreasing direction relative to the reference duration REFSLP. However, in a case where, based on at least one of the first to fourth indices mentioned above, no serious problem is expected to be likely in terms of safety, the active duration can be decreased to be smaller than the reference duration REFACT, and the sleep duration can be increased to be larger than the reference duration REFACT. For example, in a case where the above-mentioned evaluation current value is equal to or smaller than the threshold value ITHA1 then, as the evaluation current value decreases, the active duration can be decreased to be smaller than the reference duration REFACT, and additionally or alternatively the sleep duration can be increased to be larger than the reference duration REFSLP.
A second application example related to intermittent operation will now be described. Unless inconsistent, any part of the description given thus far including the description of the first application example of intermittent operation applies equally to the second application example. As described previously, the target operation mode is in principle set according to a mode request signal 361 (see
Operation for checking whether or not an inhibition condition is fulfilled is called inhibition condition check operation.
The operation mode setting portion 101 can perform inhibition condition check operation based on battery status data. The battery status data used in inhibition condition check operation can be the latest battery status data that the main control portion 60 acquires via the communication portion 61 at the timing that inhibition condition check operation is performed. As battery status data, a battery current value, a battery temperature, remaining capacity data, or a battery voltage value is used.
In a case where, as battery status data, the battery current value of each individual battery unit BU is used, then, according to the method described above in connection with the first application example, the operation mode setting portion 101 compares the evaluation current value with a predetermined threshold value ITHB (ITHB≧0). The operation mode setting portion 101 can determine, if the evaluation current value is equal to or smaller than the threshold value ITHB, that no inhibition condition is fulfilled and, if the evaluation current value is larger than the threshold value ITHB, that an inhibition condition is fulfilled.
In a case where, as battery status data, the battery temperatures of the battery units BU[1] to BU[n] (the n battery temperatures) are used, the operation mode setting portion 101 checks whether or not each battery temperature falls within a predetermined temperature range TMPRNG. The operation mode setting portion 101 can determine, if all the n battery temperatures fall within the predetermined temperature range TMPRNGB, that no inhibition condition is fulfilled and, if any of the n battery temperatures falls outside the predetermined temperature range TMPRNGB, that an inhibition condition is fulfilled.
In a case where, as battery status data, the remaining capacity data of the battery units BU[1] to BU[n] (the n remaining capacity data pieces) are used, the operation mode setting portion 101 checks whether or not each remaining capacity data piece falls within a predetermined capacity range CPRNGB. The operation mode setting portion 101 can determine, if all the n remaining capacity data pieces fall within the predetermined capacity range CPRNG, that no inhibition condition is fulfilled and, if any of the n remaining capacity data pieces falls outside the capacity range CPRNG, that an inhibition condition is fulfilled.
In a case where, as battery status data, the battery voltage values of the battery units BU[1] to BU[n] (the n battery voltage values as n terminal voltage values) are used, the operation mode setting portion 101 checks whether or not each battery voltage value falls within a predetermined voltage range VRNGB. The operation mode setting portion 101 can determine, if all the n battery voltage values fall within the predetermined voltage range VRNGB, that no inhibition condition is fulfilled and, if any of the n battery voltage values falls outside the voltage range VRNGB, that an inhibition condition is fulfilled.
The operation mode setting portion 101 can perform inhibition condition check operation based on two, three, or four of four indices (first to fourth indices) comprising battery current value, battery temperature, remaining capacity data, and battery voltage value. For example, in a case where the four indices are used, only if the evaluation current value is equal to or smaller than the threshold value ITHB, in addition all the n battery temperatures fall within the temperature range TMPRNGB, in addition all the n remaining capacity data pieces fall within the capacity range CPRNGB, and in addition all the n battery voltage values fall within the voltage range VRNGB, it is determined that no inhibition condition is fulfilled; otherwise, it is determined that an inhibition condition is fulfilled.
With the above-described inhibition condition check operation based on battery status data, in a situation where the communication function and the protection function should better be kept active, as in a case where the charge/discharge current is relatively high, switching to intermittent operation can be inhibited. This ensures the safety of the battery unit BU.
The operation mode setting portion 101 can perform inhibition condition check operation based on whether or not a fault is present in a battery unit BU or in the battery management portion 21. Specifically, when the communication portion 62 receives an intermittent operation request signal REQINT, the operation mode setting portion 101 checks, based on the battery status data received from each battery unit BU and the temperature measured by the temperature sensor 67, whether or not a fault due to overcharging (overcharging fault), a fault due to overdischarging (overdischarging fault), a fault due to an overcurrent (overcurrent fault), a temperature fault, or a sensor fault is present, and also checks, based on the signal reception status in the communication portion 61, whether or not a first communication fault is present. As described previously, a temperature fault can be a temperature fault in the battery module 31 based on the temperature measured by the temperature sensor 35 (see
If any of an overcharge fault, an overdischarge fault, an overcurrent fault, a temperature fault in the battery module 31, a temperature fault in the battery management portion 21, a sensor fault, and a first communication fault is found to be present, the operation mode setting portion 101 can determine that an inhibition condition is fulfilled; if none of those errors is found to be present, the operation mode setting portion 101 can determine that no inhibition condition is fulfilled.
With the above-described inhibition condition check operation based on presence/absence of a fault, on occurrence of a fault, that is, in a situation where the communication function and the protection function should be active to curb aggravation of the fault, switching to intermittent operation can be inhibited. This ensures the safety of the battery unit BU.
As shown in
The power conversion control portion 11 transmits to the communication portion 62 an update signal AUPDATE for updating the software SFTA. The update signal AUPDATE includes a signal requesting the updating of the software SFTA and the code of the updated software SFTA. When an update signal AUPDATE is received by the communication portion 62, according to the contents of the update signal AUPDATE, the main control portion 60 updates the software SFTA by using a predetermined boot loader program. Likewise, the power conversion control portion 11 transmits to the communication portion 62 an update signal BUPDATE for updating the software SFTB. The update signal BUPDATE that corresponds to the software SFTB in the battery unit BU[i] is represented by the symbol BUPDATE[i]. The update signal BUPDATE[i] includes a signal requesting the updating of the software SFTB in the battery unit BU[i] and the code of the updated software SFTB. When an update signal BUPDATE[i] is received by the communication portion 62, the main control portion 60 transmits, via the communication portion 61, the update signal BUPDATE[i] to the battery unit BU[i]. On receiving the update signal BUPDATE[i], the unit control portion 32 in the battery unit BU[i] updates, according to the content of the update signal BUPDATE[i], its own software SFTB by using a predetermined boot loader program.
During execution of updating operation for the software SFTA (operation for updating the software SFTA), execution of basic communication operation is stopped, and thus the protection function exploiting basic communication operation is inactive. Likewise, during execution of updating operation for the software SFTB (operation for updating the software SFTB) in the battery unit BU[i], generation of battery status data in the battery unit BU[i] and transmission of battery status data from the battery unit BU[i] to the communication portion 61 (in other words, reception of battery status data from the battery unit BU[i] by the communication portion 61) is stopped, and thus the protection function according to battery status data of the battery unit BU[i] becomes inactive. In a state where the protection function is entirely or partly inactive, it is undesirable to permit switching to intermittent operation, which may further diminish the protection function.
With this taken into consideration, the operation mode setting portion 101 can perform inhibition condition check operation based on whether or not updating operation for the software SFTA or SFTB is being executed. Specifically, the operation mode setting portion 101 can determine, during execution of updating operation for the software SFTA or SFTB, that an inhibition condition is fulfilled and, except during execution of updating operation for the software SFTA or SFTB, that no inhibition condition is fulfilled.
With the configuration described above, during execution of software updating operation, during which time the communication function should not be inactive, switching to intermittent operation is inhibited. It is thus possible to update software properly without unduly lowering the safety of the battery unit BU.
A third application example related to intermittent operation will now be described. Unless inconsistent, any part of the description given thus far including the description of the first and second application examples of intermittent operation applies equally to the third application example. It may occur that, while intermittent operation is being performed according to an intermittent operation request signal REQINT, a situation arises where continuation of intermittent operation is undesirable. With this taken into consideration, in the third application example, when the target operation mode is the intermittent operation mode, the operation mode setting portion 101 constantly monitors and checks whether or not a predetermined cancellation condition is fulfilled. Unless a predetermined cancellation condition is fulfilled, the operation mode setting portion 101 maintains the intermittent operation mode as the target operation mode. On the other hand, if a predetermined cancellation condition is fulfilled, regardless of the reception status and received contents of the mode request signal 361 in the communication portion 62, the operation mode setting portion 101 switches the target operation mode from the intermittent operation mode to the normal operation mode. Thus, when the target operation mode is the intermittent operation mode, if a predetermined cancellation condition is fulfilled, even when a mode request signal 361 requesting switching of the target operation mode to the normal operation mode (that is, a normal operation request signal REQNOR) is not received by the communication portion 62, the operation mode setting portion 101 switches the target operation mode from the intermittent operation mode to the normal operation mode. Thus, for example, in a situation where the top priority is ensuring safety, it is possible to forcibly return to normal operation, leading to enhanced safety. Here, a state where a mode request signal 361 requesting switching of the target operation mode to the normal operation mode (that is a normal operation request signal REQNOR) is not received by the communication portion 62 can be a state where the communication portion 62 has received an intermittent operation request signal REQINT and has thus been requested to maintain the target operation mode in the intermittent operation mode, and a state where, due to a second communication fault, a mode request signal 361 itself is not received by the communication portion 62.
Operation for checking fulfillment/non-fulfillment of a cancellation condition (that is, operation for checking whether or not a cancellation condition is fulfilled) is called cancellation condition check operation. During execution of intermittent operation, the operation mode setting portion 101 can constantly check fulfillment/non-fulfillment of a cancellation condition.
The operation mode setting portion 101 can perform cancellation condition check operation based on battery status data. The battery status data used in cancellation condition check operation can be the latest battery status data that the main control portion 60 acquires via the communication portion 61 at the timing that cancellation condition check operation is performed. The operation mode setting portion 101 can perform cancellation condition check operation every time the latest battery status data is acquired via the communication portion 61.
Cancellation condition check operation based on battery status data can be similar to inhibition condition check operation based on battery status data in the second application example. The operation mode setting portion 101 can perform cancellation condition check operation based on at least one of a battery current value, a battery temperature, remaining capacity data, and a battery voltage value included in battery status data. The specific operation of inhibition condition check operation based on battery status data described previously in connection with the second application example can be applied to cancellation condition check operation based on battery status data. In that case, “inhibition condition” and “inhibition condition check operation” in the description of the second application example have simply to be read “cancellation condition” and “cancellation condition check operation” (that is, on the assumption that an inhibition condition being fulfilled is the counterpart of a cancellation condition being fulfilled and that an inhibition condition not being fulfilled is the counterpart of a cancellation condition not being fulfilled). Accordingly, when the previously-mentioned evaluation current value is higher than the threshold value ITHB, it can be determined that a cancellation condition is fulfilled.
With cancellation condition check operation based on battery status data, in a situation where status monitoring and protection of the battery unit BU should better be performed constantly, as in a case where the charge/discharge current is relatively high, forcible switching is performed to normal operation, where status monitoring and protection of the battery unit BU can be performed constantly. This ensures the safety of the battery unit BU.
The operation mode setting portion 101 can perform cancellation condition check operation based on whether or not a fault is present in the battery units BU or in the battery management portion 21. Specifically, during execution of intermittent operation, based on the battery status data received from each battery unit BU and the temperature measured by the temperature sensor 67, the operation mode setting portion 101 checks whether or not a fault due to overcharging (overcharging fault), a fault due to overdischarging (overdischarging fault), a fault due to an overcurrent (overcurrent fault), a temperature fault, or a sensor fault is present. Moreover, based on signal reception status in the communication portions 61 and 62, the operation mode setting portion 101 checks whether or not a first or second communication fault is present. As described previously, a temperature fault can be a temperature fault in the battery module 31 based on the temperature measured by the temperature sensor 35 (see
The operation mode setting portion 101 can determine that a cancellation condition is fulfilled if any of an overcharge fault, an overdischarge fault, an overcurrent fault, a temperature fault in the battery module 31, a temperature fault in the battery management portion 21, a sensor fault, a first communication fault, and a second communication fault is found to be present. The operation mode setting portion 101 can determine that no cancellation condition is fulfilled if none of those errors is found to be present.
With the above-described cancellation condition check operation based on presence/absence of a fault, on occurrence of a fault, that is, in a situation where the communication function and the protection function should be activated to curb aggravation of the fault, forcible switching is made to normal operation, where those functions are constantly active. This ensures the safety of the battery unit BU.
During execution of intermittent operation, the operation mode setting portion 101 can monitor whether or not an update signal AUPDATE or BUPDATE[i], which can be transmitted from the power conversion control portion 11, is received by the communication portion 62 so that, based on whether or not either is received, the operation mode setting portion 101 performs cancellation condition check operation. Specifically, the operation mode setting portion 101 determines, if an update signal AUPDATE or BUPDATE[i] is received by the communication portion 62, that a cancellation condition is fulfilled and, if neither is received, that no cancellation condition is fulfilled. A state where an update signal AUPDATE or BUPDATE[i] is being received by the communication portion 62 can be understood to include a state where operation for updating the software SFTA or operation for updating the software SFTB in the battery unit BU[i] is actually being executed according to the update signal AUPDATE or BUPDATE[i].
As discussed previously in connection with the second application example, during software updating operation, the communication function should be kept active. With a configuration where reception of a signal for software updating evokes forcible switching to normal operation, it is possible to update software properly without unduly lowering the safety of the battery unit BU.
In a case where the entire system including the power conversion control portion 11, the power conversion circuit 12, and the battery unit BU is designed comprehensively, the power conversion control portion 11 can control whether or not to execute intermittent operation to suit the situation at hand with a view to, for example, ensuring the safety of the battery unit BU. However, as mentioned previously, an implementation is also possible where a battery unit BU is additionally connected to an existing solar cell system or the like. In such an implementation, for example, it can occur that “the power conversion control portion 11 simply checks the current time and requests intermittent operation on the assumption that hardly any charging or discharging is performed in a midnight time zone (in reality, however, charging or discharging can be performed, and a fault such as an overdischarge fault can occur). Thus, it is sensible not to heed instructions from the power conversion control portion 11 alone in providing protection for the battery unit BU. The operation for inhibiting switching to intermittent operation in the second application example and the operation for cancelling intermittent operation in the third application example contribute to achieving such protection.
Embodiments of the present invention allow for many variations and modifications within the spirit and scope of the technical concepts recited in the appended claims. The embodiments described above merely present examples of how the present invention can be implemented, and the senses of the terms used to describe the present invention and its features are not limited to those in which the terms are used in the description of the embodiments. Any specific values mentioned in the above description are merely examples, and, needless to say, can be changed to many different values. As notes applicable to the embodiments described above, notes 1 to 5 are given below. Unless inconsistent, any of the notes below can be combined with any other.
The switch 66 can be omitted so that, when the breaker portion 22 is on, the voltage resulting discharging of the battery unit BU is supplied as the input voltage VIN to the converter 63 all the time. In that case, the main control portion 62 can control the communication portions 61 and 62 such that communication operation (transmission operation and reception operation) by the communication portions 61 and 62 is stopped in sleep periods. For an enhanced power saving effect, however, it is preferable to provide the switch 66.
All or part of the components of the electric power system 1 (see
In the embodiment described above (see
A device including the battery management portion 21 and the breaker portion 22 can be referred to as a battery control device. A system including the battery management portion 21, the breaker portion 22, and the battery block BB can be referred to as a battery system. The communication portions 61 and 62 can be regarded as constituting a single communication portion for communication with the power conversion control portion 11 and each battery unit BU. A device including the power conversion control portion 11 and the power conversion circuit 12 can be referred to as a power conversion device.
The present invention can be applied also to an electric power system provided with a plurality of breaker portions 22 and a plurality of battery blocks BB. In that case, a single power conversion circuit 12 can be used to handle the plurality of breaker portions 22 and the plurality of battery blocks BB. In an electric power system provided with a plurality of breaker portions 22 and a plurality of battery blocks BB, one battery management portion 21 can be provided for each pair of one breaker portion 22 and one battery block BB, or one battery management portion 21 can be provided for each set of a plurality of breaker portions 22 and a plurality of battery blocks BB.
1 electric power system
11 power conversion control portion
12 power conversion circuit
21 battery management portion
22 breaker portion
31 battery module
60 main control portion
61, 62 communication portion
101 operation mode setting portion
BU battery unit
PB1, PB2 power block
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-073479 | Mar 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/057121 | 3/14/2013 | WO | 00 |
