Patent Application
20160233560
The present invention relates to a power storage system using storage batteries and a maintenance technology including preventive maintenance thereof.
Large scale power storage systems capable of charging/discharging a large capacity of power by connecting a plurality of storage batteries serially and in parallel have been developed as power storage systems. A power storage system charges storage batteries by feeding from a power system, a photovoltaic power generating system, and the like and supplies stable and necessary power to a load in a load facility by discharging from the storage batteries. Application examples of a large scale power storage system are to perform peak cut and peak shift of load power consumed in load facilities such as buildings and factories and leveling of natural energy such as sunlight.
As storage batteries to be used for a power storage system, lithium-ion storage batteries are used instead of conventional lead-acid storage batteries. Depending on conditions such as capacity density and mass, lithium-ion storage batteries are often more advantageous than lead-acid storage batteries. Unlike lead-acid storage batteries, in case of lithium-ion storage batteries, it is necessary to continuously monitor states of the storage batteries such as voltage in order to ensure soundness. That is, a power storage system is provided with a function of monitoring states of the storage batteries.
The above function determines and detects states of the storage batteries such as a normal state, an abnormal state, or a warning state by monitoring to transmit signals in accordance with the detections. For example, when it is determined that the voltage of the storage batteries is outside the range of use, a signal indicating an abnormal state is output, and when it is determined that it is close to a threshold value within the range of use, a signal indicating warning is output. The power storage system outputs an alarm when states of the storage batteries such as an abnormal state or a warning state are detected and partially stops operating the system with respect to a portion including the corresponding storage batteries in the detected states, that is, the charging/discharging function.
In the power storage system, a maintenance person performs maintenance works such as checking malfunctions of the portion including the corresponding storage batteries in accordance with the alarm based on the above signal. The maintenance person then eliminates the malfunction, ensures safety, and resumes operations of this portion. Works of the maintenance person include maintenance actions such as periodic maintenance checkups, diagnosis, and examination of storage batteries in the above states such as an abnormal state or a warning state and replacement of parts.
A prior-art example related to power storage systems is Japanese Patent Application Laid-Open Publication No. 2012-244843 (Patent Document 1). Patent Document 1 discloses a configuration of providing terminals for replacing storage batteries in a storage battery system in which a plurality of storage batteries are connected serially and in parallel.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2012-244843
In the prior-art power storage system, when arranged to monitor storage batteries such as lithium-ion storage batteries as described above, operations of the system, that is, charging/discharging functions are stopped in units of storage battery groups including the corresponding storage battery/storage batteries in accordance with signals of detection of states such as an abnormal state or a warning state due to failures or degradation of the storage batteries. Maintenance works including preventive maintenance by a maintenance person are performed in a state in which operations in units of storage battery groups are stopped. Therefore, the stopped states in units of storage battery groups continue until malfunctions of the storage batteries are eliminated by the maintenance works. The storage battery groups cannot be utilized for charging/discharging during the stop time. Such a stop time in the storage battery groups occurs also for storage batteries in a normal state other than the storage batteries in an abnormal state.
When the stop time of operation in units of storage battery groups of the power storage system becomes long as described above, a problem in that the convenience for users is lowered is caused. Prior-art power storage systems including Patent Document 1 are not provided with means for coping with stop times of storage battery groups based on monitoring of the storage batteries described above, and there is room for improvement with respect to convenience.
It is an object of the present invention to provide a technology capable of reducing a stop time of operation in units of storage battery groups during maintenance works including preventive maintenance of storage battery facilities and enhancing an operation rate of the entire system with respect to the above-described power storage system.
Representative embodiments of the present invention are a power storage system and a maintenance method including preventive maintenance of the power storage system, and they are characterized in that they include configurations as indicated below.
A power storage system according to one embodiment includes one or more relay panels connected to one or more power control devices; a plurality of storage battery panels connected to the relay panels and equipped with one or more storage batteries; and one or more maintenance devices connected to the relay panels when performing maintenance works including preventive maintenance by a maintenance person, in which the storage battery panel transmits a first signal in which based on monitoring of a state of the storage battery, the state thereof is detected or determined to the superordinate relay panel, the relay panel transmits a second signal based on the first signal to the superordinate power control device, the maintenance device transmits, based on an operation of designating a storage battery panel to be maintained by the maintenance person, a third signal to the superordinate relay panel of the storage battery panel to be maintained, and the relay panel masks and invalidates the first signal from the storage battery panel to be maintained or the second signal based on the first signal in accordance with the third signal.
A maintenance method of the power storage system according to one embodiment is a maintenance method including preventive maintenance of a power storage system which has one or more relay panels connected to one or more power control devices, a plurality of storage battery panels connected to the relay panel and equipped with one or more storage batteries, and one or more maintenance devices connected to the relay panel when performing maintenance works including preventative maintenance by a maintenance person, the maintenance method of the power storage system including: a first step of transmitting, based on an operation by the maintenance person, a masking start instructing signal from the maintenance device to the superordinate relay panel of a storage battery panel to be maintained and masking and invalidating, in accordance with the masking start instructing signal, a first signal transmitted from the storage battery panel to be maintained to the superordinate relay panel or a second signal transmitted from the relay panel to the superordinate power control device based on the first signal by the relay panel; a second step of performing, based on an operation by the maintenance person, maintenance works for the storage battery panel to be maintained in a state in which the storage battery panel to be maintained is electrically disconnected and electrically connecting the storage battery panel after the maintenance; and a third step of transmitting, based on an operation by the maintenance person, a masking cancel instructing signal from the maintenance device to the superordinate relay panel of the storage battery panel to be maintained and canceling the state of masking the first signal or the second signal and validating the first signal or the second signal in accordance with the masking cancel instructing signal by the relay panel.
A maintenance method of the power storage system according to one embodiment is a maintenance method including preventive maintenance of a power storage system which has one or more relay panels connected to one or more power control devices, a plurality of storage battery panels connected to the relay panel and equipped with one or more storage batteries, and one or more maintenance devices connected to the relay panel when performing maintenance works including preventive maintenance by a maintenance person, the maintenance method of the power storage system including: a first step of transmitting a first signal in which based on monitoring of a state of the storage battery, the state thereof is detected or determined to the superordinate relay panel by the storage battery panel; a second step of transmitting a second signal based on the first signal to the superordinate power control device by the relay panel; a third step of stopping an operation in units of a subordinate relay panel and the plurality of storage battery panels connected to the relay panel by the power control device based on the second signal; a fourth step of transmitting, based on an operation by the maintenance person, a masking start instructing signal from the maintenance device to the superordinate relay panel of the storage battery panel to be maintained and masking and invalidating, in accordance with the masking start instructing signal, a first signal transmitted from the storage battery panel to be maintained to the superordinate relay panel or a second signal transmitted from the relay panel to a superordinate power control device based on the first signal by the relay panel; a fifth step of resuming, based on an operation by the maintenance person, operation in units of the subordinate relay panel and the plurality of storage battery panels by the power control device in a state in which the storage battery panel to be maintained is electrically disconnected; a sixth step of performing, based on an operation by the maintenance person, maintenance works for the storage battery panel to be maintained and electrically connecting the storage battery panel after the maintenance; and a seventh step of transmitting, based on an operation by the maintenance person, a masking cancel instructing signal from the maintenance device to the superordinate relay panel of the storage battery panel to be maintained and canceling the state of masking the first signal or the second signal and validating the first signal or the second signal in accordance with the masking cancel instructing signal by the relay panel.
According to representative embodiments of the present invention, it is possible to reduce a stop time of operation in units of storage battery groups in performing maintenance works including preventive maintenance of storage battery facilities and enhance an operation rate of the entire system.
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.
In the description, maintenance includes preventive maintenance in a broad sense. That is, the maintenance methods according to the embodiments include preventive maintenance methods.
Problems and details of a prior-art power storage system and maintenance method as premises will be additionally described hereinafter. A prior-art power storage method transmits signals indicating the states such as an abnormal state or a warning state in performing maintenance works in a storage battery facility by a maintenance person, for example, when storage batteries are replaced due to a failure of a single storage battery, as a mechanism of monitoring storage batteries. Accordingly, the prior-art power storage system once stops operating the system, that is, charging/discharging functions in units of storage battery groups including the corresponding storage batteries. This is due to a mechanism of controlling power in units of storage battery groups. For ensuring soundness, it is necessary to maintain states of voltages or SOCs of the plurality of storage batteries to be identical as much as possible.
The maintenance person performs maintenance works in a state in which the storage battery groups are stopped. The maintenance person confirms a storage battery in a state with some malfunction such as a failure or degradation and performs diagnosis, examination or replacement of storage batteries or peripheral equipment as necessary. The cause of malfunction is eliminated by the maintenance works and after the normal state is confirmed, the power storage system resumes operation in units of storage battery groups. The stopped state of the storage battery groups continues until the cause of malfunction is eliminated. During the stop time, even though most storage batteries among the plurality of storage batteries are in a normal state, they cannot be utilized for charging/discharging.
When the stop time in units of storage battery groups becomes long, the user might feel inconvenient. For example, when it might take a long time to examine malfunctions of the storage batteries, the stop time becomes long. Moreover, particularly when the power storage system is applied to infrastructure directly linked to individual lives, it is preferable to shorten the stop time as much as possible and to utilize storage batteries in a normal state as much as possible. It is desirable to perform maintenance works in a state in which storage battery groups are operated as much as possible while ensuring safety in performing maintenance works by the maintenance person.
Note that the storage battery system of Patent Document 1 cannot cope with the problem of stop time when considering an application to a configuration of monitoring storage batteries. This system detects states such as an abnormal state or a warning state due to interruption of communication during monitoring of storage batteries when storage batteries using terminals for replacing are replaced. Accordingly, this system will stop operating the portion including the corresponding storage batteries to be replaced. That is, the stop time of the storage battery groups will become long in performing maintenance works.
The power storage system of the present embodiment shown in
In the present embodiment, objects of maintenance works are storage battery panels. In performing masking, a signal is transmitted from the maintenance device to a relay panel for instructing masking. Upon reception of the signal, the relay panel masks and invalidates the signal based on monitoring of storage batteries from a storage battery panel to be maintained. With this arrangement, a superordinate power control device can be operated in units of storage battery groups including the storage battery panel to be maintained. Then, the maintenance person performs electrical disconnection in units of storage battery panel to be maintained, so that the maintenance person can perform maintenance works in a state in which the storage battery group except for the storage battery panel to be maintained is operating. The power storage system of the present embodiment is characterized in that it not only enables the above operations but also enables disconnection of a stopped portion in the power storage system, irrespective of forms of superordinate power control devices.
Reference numeral 101 denotes a PCS unit in which one power control device 1, a plurality of relay panels 2 and a plurality of storage battery panels 3 connected thereto form a group, wherein there are N1 number thereof ranging from C1 to CN1. Reference numeral 102 denotes a relay panel unit in which one relay panel 2 and a plurality of storage battery panels 3 connected thereto form a group, wherein there are N2 number thereof corresponding to R1 to RN2. Reference numeral 103 denotes a storage battery panel unit in which a plurality of storage battery packs 4 (
The overall power storage system of
In a single PCS unit 101, one power control device 1 is connected to (N4=3) number of relay panels 2 through a main circuit wire 6. For example, reference characters R1 to R3 which are three relay panels 2 are connected to PCS1. In a single relay panel 2, (N5=10) number of storage battery panels 3 are connected in parallel. For example, reference characters L1 to L10 which are 10 storage battery panels 3 are connected to R1 in parallel. A single storage battery panel 3 is equipped with a plurality of storage battery packs 4 (
The power control device 1 is a PCS (power conditioning system) and performs control of the power storage system and has a function of controlling charge/discharge of the storage battery groups connected thereto through the relay panels 2. The PCS is connected to a power system, a load facility, a photovoltaic power generating system, and the like. The PCS charges the storage batteries with power from the power system, the photovoltaic power generating system, or the like and supplies power obtained by discharging from the storage batteries to the load of the load facility. When states of the storage batteries such as an abnormal state or a warning state are detected by a signal from a subordinate relay panel 2, the power control device 1 generates an alarm and stops operating the PCS unit 101 which is the subordinate system portion.
Specifically, the PCS includes a DC/DC converter, a DC/AC inverter, and the like as a function of converting direct current (DC) or alternating current (AC) power for stably adjusting and utilizing power of the storage batteries or photovoltaic generation.
Note that, in the power storage system of the present embodiment, the power control devices 1 do not need to be equipped with specific functions, and it is also possible to use hardware and software of conventional PCS. Stopping operations of storage batteries and the like in the present embodiment means stopping charging/discharging functions, and in the stopped state, charge of the storage batteries and discharge from the storage batteries do not work.
The maintenance device 5 is connected to the relay panels 2 by the maintenance person U when maintenance works are required. The maintenance device 5 is constituted in the form of a personal computer and the like. The maintenance device 5 may also be constituted by an exclusive device or circuit. Reference numeral 113 denotes L2 which is an example of storage battery panel 3 to be maintained. Reference numeral 112 denotes R1 which is an example of a relay panel 2 to be connected as a superordinate of the storage battery panel 3 to be maintained. For example, the maintenance device 5 is connected to R1 in performing maintenance works of, for example, L2, as an object to be maintained.
The connection of the maintenance device 5 and the relay panel 2 (R1) of
Also, in the power storage system of
In the power storage system of
The relay panel 2 includes the supervising BCU 21, the parallel connecting unit 22, and a connecting unit 23. The supervising BCU 21 includes a CPU, a memory, and the like and is a component of a storage battery control unit in a broad sense to be described later. The supervising BCU 21 is communicated and connected to the control unit 11 of the superordinate power control device 1 and BCUs 31 of the respective subordinate storage battery panels 3. The parallel connecting unit 22 is an interface unit for connecting a plurality of storage battery panels 3 (for example, L1 to L10) in parallel the relay panel 2. The parallel connecting unit 22 includes terminals for connecting main circuit wires of the respective storage battery panels 3. The connecting unit 23 is an interface unit for connecting the maintenance device 5 to the relay panel 2 and includes a terminal for connecting, for example, a cable. The relay panel 2 is provided with functions of connecting, monitoring, calculating SOCs, and the like of the plurality of storage battery panels 3.
The storage battery panel 3 is equipped with a plurality of BCUs 31, a plurality of storage battery monitoring units 32 and a storage battery block 40. The BCU 31 includes a CPU, a memory, and the like and is a component of the storage battery control unit in a broad sense to be described later. The storage battery block 40 includes a plurality of serially connected storage battery packs 4, disconnecting switches 41 on both ends, and a fuse 42 on one end. The storage battery panel 3 is provided with functions of connecting, monitoring, calculating SOCs, and the like of the storage battery packs 4.
The relay panel 2 and storage battery panel 3 include a storage battery control unit (BCU: battery control unit) in a broad sense. In the present embodiment, the storage battery control unit is comprised of the supervising BCU 21 provided in the relay panel 2 and one or more BCUs 31 provided in the storage battery panel 3. In other words, the BCUs 31 are subordinate BCUs, and the supervising BCU 21 is a superordinate BCU. The supervising BCU 21 communicates and connects a plurality of BCUs 31 to supervise and control the plurality of BCUs 31. The supervising BCU 21 comprehensively determines the state of the storage battery pack 4 groups using signals from the plurality of BCUs 31. The supervising BCU 21 and the BCUs 31 are provided with implementations corresponding to the masking function. The BCUs 31 and the BCU 21 are implemented by, for example, circuit boards.
The BCUs 31 each are of identical configuration, and representative one of the BCUs 31 is connected to the supervising BCU 21 of the superordinate relay panel 2, for example. The plurality of storage battery monitoring units 32 are connected to the BCU 31. The plurality of storage battery monitoring units 32 function as monitoring units of the storage battery block 40. One storage battery monitoring unit 32 monitors and detects states such as voltage, current, and temperature of one or more storage batteries pack 4 in the storage battery block 40. The storage battery monitoring units 32 each are of identical configuration. Note that it is also possible to employ a form in which the storage battery monitoring units 32 are integrated into the BCU 31. The BCU 31 use the plurality of storage battery monitoring units 32 to continuously monitor states of equipment and circuits such as the plurality of storage battery packs 4 in the storage battery block 40 in the storage battery panel 3 or the peripheral power sources thereof.
The maintenance device 5 includes a control unit 51, a communication unit 52, a connecting unit 53, and a screen unit 54. The control unit 51 performs control processes of the maintenance device 5. The communication unit 52 performs communicating processes with the relay panel 2 and the power control device 1 connected through the connecting unit 53. The connecting unit 53 is an interface unit for connection in the case in which the maintenance device 5 is connected to the relay panel 2 and the like. For example, the connecting unit 23 of the relay panel 2 and the connecting unit 53 of the maintenance device 5 are connected via a cable for performing communication. The screen unit 54 configures and provides a screen serving as a user interface when the maintenance person U performs maintenance works based on the control processes of the control unit 51.
The maintenance device 5 performs processes corresponding to support functions including the masking function in performing maintenance works and provides a screen corresponding to these functions and shown in
Reference character F1 denotes a flag signal which is transmitted from, for example, L1 or L2 which are storage battery panels 3 to, for example, reference character R1 which is a superordinate relay panel 2 based on monitoring. Reference character F2 denotes a flag signal which is transmitted from R1 which is the relay panel 2 to, for example, reference character PCS1 which is a superordinate power control device 1. When a mask signal M is received from the maintenance device 5, the relay panel 2 performs a process of masking the corresponding flag signal to exclude a storage battery panel 3 to be maintained and designated by the mask signal M from an object to be monitored. In the present embodiment, R1 which is a relay panel 2 transmits a flag signal F2 to the PCS1 which is a superordinate power control device 1 in a state in which it has been determined that the flag signal F1 from storage battery panel as an object to be masked is invalid. Accordingly, the superordinate power control device 1 is set to be a state in which operation of the PCS unit 101 including the object storage battery panel 3 is allowed to be resumed from a state in which operation thereof is not allowed to be stopped or is allowed to be stopped once.
Disconnecting switches 41 are provided on both ends of the storage battery blocks 40. One disconnecting switch 41 on one end of the storage battery blocks 40 is provided with the fuse 42. Based on control of the BCU 31, ON/OFF states of the disconnecting switches 41 are switched in accordance with functions of charge/discharge and storage battery protection. Also, the disconnecting switches 41 are switched ON/OFF based on control of the BCU 31 in attaching and detaching storage battery blocks 40. The fuse 42 is a protection circuit and is automatically cut off when the voltage difference between the plurality of storage battery packs 4 is large and there is an overload state, for example. Note that it is possible to omit the fuse 42 in some cases and the disconnecting switch 41 may have a function corresponding to that of the fuse 42.
In the storage battery blocks 40 in the plurality of storage battery panels 3 connected in parallel to the relay panel 2, when a failure occurs in one storage battery block 40, it is possible to perform operation in a degraded state using the remaining ones of the plurality of storage battery blocks 40 connected in parallel. When the storage battery pack 4 indicated by, for example, 310, which is one storage battery pack 4 in a storage battery block 40 fails and a replacement work in units of the storage battery block 40 is necessary, a flag signal F1 indicating an abnormal state or the like is transmitted to the superordinate relay panel 2 based on monitoring of this storage battery panel 3.
It is necessary that values of the voltage and SOC (state of charge: referred to as charged state or charging rate) of the storage battery packs 4 connected in parallel to the relay panel 2 and in the plurality of storage battery blocks 40 are uniform at predetermined values. That is, it is necessary that differences in potential and SOC fall within predetermined ranges. When they are not uniform, currents exceeding prescribed values might flow in replacing storage battery blocks 40 and the like, thereby not being safe.
In
In this case, in the prior-art, power storage system, a flag signal F1 indicating an abnormal state or the like due to the above failure is transmitted from the L2 which is the storage battery panel 3 to R1 which is a superordinate relay panel 2 by the function of monitoring the storage batteries, and a similar flag signal F2 is transmitted from R1 to PCS1 which is a superordinate power control device 1. Based on this flag signal F2, the PCS1 outputs an alarm and further stops operation in units of the PCS 101 of C1 including R1 which includes L2. In the stopped state of the PCS unit 101 of C1, all of the 30 storage battery panels 3, L1 to L30, become a state in which charge/discharge functions are prohibited. Until the malfunction of the storage battery panel 3 which is L2 including the faulty storage battery pack 4 is eliminated by maintenance works performed by a maintenance person, the stopped state of the PCS unit 101 of C1 continues.
According to the prior-art power storage system and the maintenance method thereof, the power control device can control operation and stop in units of PCSs but it cannot control charge/discharge in units of individual relay panels or in units of individual storage battery panels of storage battery groups in units of PCSs since they are connected in parallel. Supposing that in a storage battery group of a PCS unit, one storage battery panel is in a state in which charge/discharge is stopped while another storage battery panel is in a state in which charge/discharge is in operation, a difference in SOC occurs in the storage battery group due to the differences in charge/discharge. Accordingly, overcharge, overdischarge, or the like may occur, so that it is impossible to ensure soundness. Therefore, the prior-art power storage system controls operation and stop in units of PCSs for ensuring soundness. The prior-art power storage system stops operation in units of relay panels including these storage battery panels and in units of PCSs including these relay panels, even in a case in which a single storage battery panel fails.
In contrast, the power storage system of the present embodiment utilizes the masking function based on an operation from the maintenance device by a maintenance person in order to enable maintenance works in a state in which PCS units 101 of the storage battery pack 4 groups are operating. Accordingly, it is possible to instruct masking to temporally exclude a storage battery panel 3 to be maintained from an object to be monitored in the storage battery packs 4. In other words, it is possible to temporally mask and invalidate signals indicating states such as an abnormal state, a warning state, or the like which are transmitted from the storage battery panels 3 to the power control device 1 via the relay panels 2 by monitoring the storage battery packs 4.
Since the superordinate power control device 1 does not receive flag signals F2 indicating states such as an abnormal state, a warning state, or the like by executing the masking, storage battery pack 4 groups of PCS units 101 including storage battery panels 3 to be maintained will be in states in which they are not stopped, that is, in which they are operating. Masking allows the power control device 1 to see the subordinate relay panels 2 and the like being in a normal state. It is possible to perform maintenance works such as replacement of the storage battery blocks 40 by the maintenance person in a condition in which PCS units 101 are operating. When signals indicating states such as a warning state are being issued, it is possible to arbitrarily execute masking in accordance with judgments and confirmations of the states by the maintenance person.
The storage battery monitoring unit 32 includes a control unit 321, a calculating unit 322, a measuring unit 323 and a communication unit 324. The measuring unit 323 measures the voltage, current, temperature, and the like of the storage battery cells 7. The calculating unit 322 calculates SOC values and the like of the storage battery cells 7 using the measured values measured by the measuring unit 323. The communication unit 324 performs communication processes with the BCU 31. The control unit 321 refers to the measured values, makes determinations related to the states of the storage battery cells 7, and transmits a detection signal 401 indicating the states detected through the determination to the BCU1 through the communication unit 324. It is also possible to use detailed code signals to be described later as the detection signals 401.
The BCU 31 includes a control unit 311, a calculating unit 312, and a communication unit 313. The control unit 311 makes determinations related to the states of the storage battery cells 7 using the detection signals 401 from the storage battery monitoring unit 32 and transmits flag signals F1 indicating states such as a normal state, an abnormal state, a warning state obtained through the determination to the supervising BCU 21 of the superordinate relay panel 2 via the communication unit 313. The calculating unit 312 calculates SOC values and the like of the storage battery blocks 40 using the measured values transmitted from the storage battery monitoring unit 32. The communication unit 313 performs communication processes with the supervising BCU 21 and the storage battery monitoring unit 32.
States of the flag signals F1 and F2 are three types such as a normal state, a warning state, or an abnormal state in the present embodiment. Note that it is possible to use detailed code signals to be described later as the flag signals.
The supervising BCU 21 of the relay panel 2 receives a flag signal F1 from the subordinate storage battery panel 3. The control unit 211 determines the state of the subordinate storage battery panel 3 using the flag signal F1 and transmits a flag signal F2 based on the determination to the superordinate power control device 1 via the communication unit 213. The calculating unit 212 calculates SOC values and the like in units of storage battery pack 4 groups of the plurality of storage battery panels 3 using information from the storage battery panel 3 and the flag signal F1. Note that the supervising BCU 21 may also transmit the flag signal F1 as it is from the subordinate storage battery panel 3 to the superordinate power control device 1 as the flag signal F2.
In accordance with operations by the maintenance person, a masking signal M is transmitted from the maintenance device 5 to the supervising BCU 21 of the superordinate relay panel 2 to which the storage battery panel 3 to be maintained is connected. The supervising BCU 21 of the relay panel 2 receives the masking signal from the maintenance device 5. There are a masking start instructing signal M1 and a masking cancel instructing signal M2 as the masking signals M. The masking start instructing signal M1 is an instructing signal for starting masking and the masking cancel instructing signal M2 is an instructing signal for canceling masking. When the masking start instructing signal M1 is received, the supervising BCU 21 starts invalidation by the masking of the flag signal F2 based on the flag signal F1 so as to exclude the storage battery panel 3 to be designated by the signal M1 from an object to be monitored. When the masking cancel instructing signal M2 is received, the supervising BCU 21 cancels the masking state of the flag signal F2 and validates the flag signal.
In the present embodiment, invalidation by the masking is assumed that the flag signal F2 itself is not transmitted to the power control device 1 in a case in which the content of the original flag signal F2 indicates the state such as an abnormal state or a warning state. In another embodiment, invalidation by the masking may be assumed that the state such as an abnormal state or a warning state which is the content of the flag signal F2 is changed to a normal state to be transmitted to the power control device 1. In still another embodiment, invalidation by the masking may be assumed that the state such as an abnormal state or a warning state, which is the content of the flag signal F2, is changed to a state indicating that specific masking is being performed to be transmitted to the power control device 1. Note that, in such a case, the power control device 1 needs to be implemented with a different function than usual, so that it can recognize states of masking indicated by the flag signals F2.
Upon reception of the flag signal F2 from the supervising BCU 21 of the subordinate relay panel 2, the control unit 11 of the power control device 1 stops operations of charge/discharge functions of the PCS unit 101 including the subordinate relay panel 2 when the state indicated by the flag signal F2 is an abnormal state or a warning state. When flag signal F2 indicating an abnormal state or the like has not been received or when a flag signal F2 indicating a normal state has been received, the control unit 11 of the power control device 1 operates charge/discharge functions in the PCS unit 101 including the subordinate relay panel 2.
Upon reception of the masking start instructing signal M1, the supervising BCU 21 of the relay panel 2 (R1) masks and invalidates the flag signal F2 for the storage battery panel 3 (L2) to be maintained through preventive maintenance and designated by the signal. By starting the masking, the storage battery panel (L2) to be maintained through preventive maintenance becomes a state in which it is excluded from the object to be monitored when seen from the power control device 1, and an operating state of the relay panel unit including the storage battery panel 3 (L2) and the PCS unit are maintained.
The maintenance person confirms whether the total voltage or the relay panel unit is within a prescribed range, for example, within ±3.0 V. After confirming that the value is within this range, the maintenance person performs operations of connecting and restoring the storage battery panel 3 (L2) to be maintained to the main circuit wires 301, 302 of the relay panel 2 (R1) by switching ON the disconnecting switch 41 corresponding to the breaker. If the value is not within this range, the maintenance person performs charge/discharge using a known electronic load device and the like to adjust the voltage to fall within this range.
As another example of maintenance works, maintenance works for peripheral equipment and circuits such as the power source other than the storage battery packs 4 provided in the storage battery panels 3 as objects to be maintained can be similarly performed. Further, while the above is an example in which detection and determination is performed as the “abnormal” state due to a failure, the masking function is similarly applicable also to cases of other states. For example, when detecting and determining interruption of communication through monitoring of the storage battery packs 4 as a “warning” state, it is possible to perform masking of the flag signal F2 indicating warning thereby.
Note that, as a matter of course, in operation, top priority is given to ensuring safety when utilizing the masking function in performing maintenance works, and masking is executed upon confirmation and judgment of states by the maintenance person. For example, when it has been confirmed that effects of a storage battery panel 3 in an “abnormal” state are limited to be within the storage battery panel 3, the maintenance person can perform masking of this storage battery panel 3 to be maintained.
Note that, depending on power storage systems, it is also possible to stop the entire function of monitoring the storage batteries. However, in a case, since the entire power storage system is in a stopped state, it is not desirable. By recording detection signals 401 by monitoring and related information thereof, the power storage system can perform reference or examination at a later time.
On the screen of
By referring to the table 700, the maintenance person can confirm states of the plurality of storage battery panels 3 for each of the relay panels 2, and by turning on the check buttons on the item of the masking 704, it is possible to designate masking of storage battery panels 3 to be maintained.
The maintenance person can instruct start of masking corresponding to the state of the masking 704 in the table 700 by pressing a masking start button indicated by 711. Corresponding thereto, the above-described masking start instructing signal M1 is transmitted. Further, by pressing the masking cancel button indicated by 712, it is possible to instruct cancel of masking corresponding to the state of the masking in the table 700. Corresponding thereto, the above-described masking start instructing signal M2 is transmitted.
The screen of the masking function is not limited to the style of the table shown in
In the table of
Referring to some code examples, code “00” indicates a normal state, and no flags such as abnormal or warning are generated. Code “01” indicates “operational upper limit voltage” which is output when the voltage of storage batteries becomes 500 V or more, and the type is “warning.” Code “02” indicates “overcharge” which is output when the total voltage of a relay panel becomes 520 V or more, and the type is “abnormal.” Code “03” indicates “operational lower limit voltage” which is output when the voltage of storage batteries becomes 360 V or less, and the type is “warning.” Code “04” indicates “overdischarge” which is output when the total voltage of a relay panel becomes 300 V or less, and the type is “abnormal.”
Code “05” indicates “overcurrent” which is output when the voltage of storage batteries becomes 180 A or more, and the type is “warning.” Code “08” indicates “abnormal storage battery temperature” which is output when the temperature of a storage battery pack 4 becomes 60 degrees C. or more, and the type is “abnormal.” Code “09” indicates “communication interruption” which is output when communication between a BCU 31 and a supervising BCU 21 has been interrupted for two minutes or more, and the type is “abnormal.” Code “10” indicates “BCU failure” which is output when a BCU 31 fails, and the type is “abnormal.”
Codes indicating “abnormal” as the type, particularly “02,” “08,” and “10,” for example, are codes which require attention in that operation of these portions needs to be stopped immediately when these states are detected. In such a case, the maintenance person gives top priority to coping with these abnormalities, and utilization of the masking function should be judged carefully.
In cases of codes indicating “warning” as the type, for example, code “01,” when the warning state is detected, operation of the corresponding portion in accordance with judgments and confirmations of the state by the maintenance person may cause no problems in most cases, since the warning state is not so serious as the abnormal state. In this case, utilizing the above-described masking function to set the system in an operating state will reduce the stop time.
As explained so far, according to the power storage system and the maintenance method of the present embodiments, it is possible to reduce the time of stopping operation in units of storage battery groups in performing maintenance works of the storage battery facilities to thereby improve the operation rate of the entire system. Accordingly, convenience for users is improved. The present embodiments make it possible to perform maintenance works in a state in which storage battery groups other than storage batteries to be maintained are in operation by utilizing the masking function with respect to the time of stopping storage battery groups based on monitoring of the storage batteries. Specifically, it is possible to perform maintenance works in a state in which storage battery groups are in operation, in a large-sized power storage system which includes a large number of lithium ion rechargeable storage batteries and the function of monitoring thereof and is assumed to be used regularly. When a malfunction of the facility including storage batteries is generated, a maintenance person can utilize the masking function in accordance with a judgment of the state and degree of the malfunction. The maintenance person can easily utilize the masking function while confirming the state on a screen of the maintenance device.
In the foregoing, the invention made by the inventors of the present invention has been concretely described based on the embodiments. However, it is needless to say that the present invention is not limited to the foregoing embodiments and various modifications and alterations can be made within the scope of the present invention. Some modification examples of the present embodiment are as follows.
The present invention is applicable to a power storage system and preventive maintenance and a maintenance work thereof.
1 . . . Power control device, 2 . . . Relay panel, 3 . . . Storage battery panel, 4 . . . Storage battery pack, 5 . . . Maintenance device, 6 . . . Main circuit wire, 7 . . . Storage battery cell, 11 . . . Control unit, 12 . . . Communication unit, 13 . . . Power connecting unit, 21 . . . Supervising BCU, 22 . . . Parallel connecting unit, 23 . . . Connecting unit, 32 . . . Storage battery monitoring unit, 40 . . . Storage battery block, 41 . . . Disconnecting switch, 42 . . . Fuse, 51 . . . Control unit, 52 . . . Communication unit, 53 . . . Connecting unit, 54 . . . Screen unit, 101 . . . PCS unit, 102 . . . Relay panel unit, 103 . . . Storage battery panel unit, F1, F2 . . . Flag signal, M . . . Mask signal, M1 . . . Masking start instructing signal, M2 . . . Masking cancel instructing signal.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-196201 | Sep 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/074557 | 9/17/2014 | WO | 00 |
