Patent Application
20150188347
1. Field of the Invention
The invention relates to a battery management device and a power supplying system including the same.
2. Description of the Related Art
In applications of electric vehicles, multiple battery units are generally connected in series for providing a required high voltage. However, for preventing damage to the battery units due to performance differences, a battery management system is employed to manage and monitor charge-discharge operations of the battery units.
Referring to
The battery management system 12 is connected electrically to the sensors 112, the current sensor 15 and the primary switches 13, and performs real-time monitoring on the voltage, the temperature, and the current of each battery 111 during charge operation, so as to control the primary switches 13 to make or break electrical connection.
When the power supplying device 1 is abnormal or requires repair, the primary switches 13 have to be switched off while the series-connected battery units 11 may still output a high voltage, thereby resulting in safety concerns. In U.S. Pat. No. 7,990,105 B2, a safety plug is provided to isolate each of the battery units 11 during maintenance for ensuring safety of personnel. However, when the power supplying device 1 is used in an electric vehicle (e.g., a car or a boat), it may suffer from electricity leakage, being soaked in water, or impact. The safety plug cannot provide protection in such situations.
Therefore, an object of the present invention is to provide a battery management device that may perform real-time monitoring on batteries and that may reduce safety concerns arising from high voltage of the batteries.
According to one aspect of the present invention, a battery management device for controlling supply of electric power from a battery device to a load of an electric device is provided. The battery device includes a plurality of battery units that are electrically connected. Each of the battery units is independently controllable to switch between an output enabled state and an output disabled state. The battery management device comprises:
a device sensor configured to detect a present state of the electric device, and to output a detection signal corresponding to the present state of the electric device;
a control module to be electrically connected to each of the battery units, electrically connected to the determining module for receiving the device state signal, and configured to switch each of the battery units to the output disabled state and thereby stop supply of the electric power to the load when the device state signal indicates that the electric device is in the abnormal state.
Another object of the present invention is to provide a power supplying system that that may reduce safety concerns arising from high voltage of the batteries.
According to another aspect of the present invention, a power supplying system for an electric device is provided. The electric device includes a load. The power supplying system comprises:
a battery device including a plurality of battery units that are electrically connected for providing electric power to the load, each of the battery units being independently controllable to switch between an output enabled state and an output disabled state; and
a battery management device of the present invention.
According to yet another aspect of the present invention, an electric device comprises a load and a power supplying system of the present invention.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Referring to
The load 4 operates using a high direct current (DC) voltage. The power supplying system 8 is configured to provide the DC voltage to the load 4, and includes a battery device 5 and a battery management device 3.
In this embodiment, the battery device 5 includes a plurality of battery units 51 electrically connected in series and two primary switches 52. Each of the battery units 51 includes a battery 511, an isolation switch 512 connected electrically to the battery 511 in series, and a battery sensor 513. The battery 511 may be composed of several lithium Manganese battery cells, lithium iron battery cells, or other types of battery cells connected in series and/or in parallel. The battery sensor 513 is adapted to sense a state of the battery 511 (e.g., a voltage, a current, and/or a temperature of the battery 511), and to output, according to the state of the battery 511, a battery state signal that indicates whether the corresponding battery unit 51 is in a normal state or an abnormal state.
Although the battery units 51 are connected in series, there is no direct electrical connection among the batteries 511 of the battery units 51 since the batteries 511 are isolated from each other using the isolation switches 512. Each of the battery units 51 is independently controllable to switch between an output enabled state and an output disabled state via control of the isolation switch 512 thereof.
Each of the primary switches 52 is connected electrically between the series-connected battery units 51 and the load 4. In other embodiments, the battery device 5 may include only one primary switch 52.
The battery management device 3 includes a device sensor 33, a determining module 32, a control module 31 and an activation switch 6.
The device sensor 33 is adapted to detect a present state of the electric device, and to output a detection signal corresponding to the present state of the electric device. In detail, the device sensor 33 may include a voltage/current converter, an accelerometer, a hygrometer, etc., so as to detect: a voltage condition of the battery device 5; a temperature condition of the battery device 5; a discharge current condition of the battery device 5; a load condition of the electric device; whether the electric device suffers from a short circuit; whether the electric device suffers from electricity leakage; whether the electric device is subjected to an impact; a humidity condition of the electric device, and the like. In this embodiment, the detection signal outputted by the device sensor 33 has a detection value corresponding to the present state of the electric device.
The determining module 32 stores a predetermined threshold value, is coupled to the device sensor 33 for receiving the detection signal, compares the detection signal with the predetermined threshold value, and outputs a device state signal according to a comparison result between the detection signal and the predetermined threshold value. The device state signal indicates whether the electric device is in a normal state or an abnormal state. The abnormal state may include an overvoltage state, an undervoltage state, an overload state, a short-circuit state, an electricity leakage state, an impact state, a humid state, or a water soaked state, which may be determined by the determining module 32 using the detection signal.
The control module 31 is electrically connected to the determining module 32 for receiving the device state signal, and to the battery sensor 513 of each of the battery units 51 for receiving the battery state signal, and controls the primary switches 512 and the isolation switch 512 of each of the battery units 51 to make or break electrical connection according to the device state signal from the determining module 32, and the battery state signals from the battery sensors 513. In detail, the control module 31 controls the primary switches 52 to break electrical connection between the battery units 51 and the load 4, and controls the isolation switch 512 of each of the battery units 51 to break electrical connection (i.e., to switch each of the battery units 51 to the output disabled state), to thereby stop supply of the electric power to the load when the device state signal indicates that the electric device is in the abnormal state, and/or the battery state signal of one of the battery units 51 indicates that the corresponding battery 511 is in the abnormal state. In this condition, there is no electrical connection between any two of the battery units 51, so that high voltage is not provided in the electric device.
The activation switch 6 has a first terminal 61 to receive a bias voltage Vcc, a second terminal 62 electrically connected to the control module 31, and a control terminal 63 to receive an activation signal. The activation switch 6 is controlled by the activation signal to make or break electrical connection between the first terminal 61 and the second terminal 62 thereof to thereby control supply of the bias voltage Vcc to the control module 31.
Referring to
The logic unit 312 is configured to output an operating signal to the controller 311 when the logic unit 312 receives one of the enable signal and the bias voltage Vcc, and receives the device state signal indicative of the electric device being in the normal state. The controller 311 is responsive to the operating signal to control the primary switches 52 to make electrical connection and to control the isolation switch 512 of each of the battery units 51 to make electrical connection (i.e., to switch each of the battery units 51 to the output enabled state). Otherwise, the controller 311 controls the primary switches 52 to break electrical connection and to control the isolation switch 512 of each of the battery units 51 to break electrical connection (i.e., to switch each of the battery units 51 to the output disabled state).
When the electric device is turned on, the activation signal is provided to the activation switch 6, so that the bias voltage Vcc is transmitted to the logic unit 312. At this time, when the device state signal indicates that the electric device is in the normal state, the logic unit 312 outputs the operating signal to the controller 312, so that the controller 312 controls the primary switches 52 and the isolation switch 512 of each of the battery units 51 to make electrical connection, thereby enabling the battery device 5 to output electric power to the load 4 for normal operation of the electric device. After the battery device 5 is enabled to output electric power, the load driver 7 receives electric power from the battery device 5 to output the enable signal. It should be noted that the load driver 7 is used for driving functions of the load 4, and is not designed for battery management. Through such a design, the activation switch 6 is not required to be always closed after the electric device is turned on, and the battery device 5 can still provide electric power normally. At the same time, the controller 311 may transmit messages to the load driver 7 for monitoring purposes.
To sum up, when the electric device is in an abnormal state or requires repair, the battery management device 3 may operate to isolate the battery units 51 so as to prevent output of high voltage, thereby ensuring safety of personnel.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
