Battery equalization system and energy storage equipment

Abstract

The utility model discloses a battery equalization system and an energy storage device. The battery equalization system comprises a plurality of isolation diodes and a plurality of first bypass switches. Each isolation diode is reversely connected with the corresponding single battery through the corresponding first bypass switch, and the positive electrode of the first equalization voltage source is connected with the negative electrode of the first equalization voltage source through the corresponding first bypass switch. And the control circuit is used for controlling the first bypass switch to be switched off, so that the first equalization voltage source provides equalization voltage for the corresponding battery monomer through the corresponding isolation diode. When the first bypass switch is short-circuited, the first equalization voltage source does not supply power to the battery cells. The anodes of the single batteries are connected with the cathodes of the single batteries through the isolating diodes and the first bypass switches, the isolating diodes are reversely cut off, the anodes and the cathodes of the single batteries cannot be short-circuited, short circuit of the battery pack cannot be caused, and the risk of short circuit of the battery pack caused by short circuit of switches in the battery equalization circuit is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of battery packs, and more specifically, to a battery equalization system and energy storage equipment. Background Art

[0002] If the capacities of the battery cells in a battery pack vary greatly, when the battery pack is being charged, the battery cell with the largest capacity may be overcharged, and when the battery pack is being discharged, the battery cell with the smallest capacity may be over-discharged, which may damage the battery cells.

[0003] In the related art, a transformer and a matrix switch solution can be used to achieve voltage balancing of each battery cell. The balancing power supply provides a balancing voltage to the battery cell through a transformer, and the matrix switch is connected between the transformer and the battery cell. The battery cell to be balanced and the transformer can be connected by controlling the matrix switch, so that the transformer provides the balancing voltage to the battery cell to be balanced.

[0004] However, when the matrix switch is short-circuited, the positive and negative electrodes of the battery cells will be short-circuited, resulting in the risk of short-circuiting the battery pack. Utility Model Content

[0005] The utility model provides a battery equalization system and energy storage equipment.

[0006] The battery balancing system provided in the embodiment of the utility model is used for a battery pack, and the battery pack includes a plurality of battery cells. The battery balancing system includes a plurality of isolation diodes and a plurality of first bypass switches. Each of the isolation diodes is reversely connected to the corresponding battery cell through the corresponding first bypass switch, and the positive electrode of the first balancing voltage source is connected to the negative electrode of the first balancing voltage source through the corresponding first bypass switch.

[0007] The battery balancing system includes a control circuit, and the control circuit is used to control the first bypass switch to be disconnected, so that the first balancing voltage source provides a balancing voltage to the corresponding battery cell through the corresponding isolation diode.

[0008] The control circuit can control the first bypass switch to be disconnected. When the first bypass switch is disconnected, the first balancing voltage source can provide a balancing voltage to the corresponding battery cell through the corresponding isolation diode.

[0009] When the first bypass switch is closed or short-circuited, the first balancing voltage source is short-circuited by the first bypass switch, so the first balancing voltage source will not supply power to the battery cell. The positive electrode of the battery cell is connected to the negative electrode of the battery cell through the isolation diode and the first bypass switch. The isolation diode is reversely cut off, and the positive and negative electrodes of the battery cell will not be short-circuited, which will not cause a short circuit of the battery cell, and will not cause a short circuit of the battery pack, thereby avoiding the risk of a short circuit of the battery pack due to a short circuit of the switch in the battery balancing circuit.

[0010] In some embodiments, the positive electrode of each battery cell is connected to the cathode of the corresponding isolation diode, and the anode of each isolation diode is connected to the negative electrode of the corresponding battery cell through the corresponding first bypass switch. The positive electrode of the first balancing voltage source is connected to the positive electrode of the corresponding battery cell through each isolation diode, and the negative electrode of the first balancing voltage source is connected to the negative electrode of each battery cell.

[0011] In some embodiments, the battery balancing system includes a plurality of switch drive circuits. Each of the first bypass switches includes a control terminal, and the positive electrode of each battery cell is connected to the corresponding control terminal through the corresponding switch drive circuit, and each battery cell is used to provide a drive voltage to the corresponding control terminal to drive the corresponding first bypass switch to turn on or off.

[0012] The first bypass switch can be an electronic switch device such as a triode, a MOS tube, an IGBT, etc. The switch driving circuit can use the voltage of the battery cell as the driving voltage of the first bypass switch, which is conducive to simplifying the circuit design.

[0013] In some embodiments, the battery balancing system includes a rectifier and filter circuit. The first balancing voltage source is connected to each of the battery cells through the rectifier and filter circuit and each of the isolation diodes. The rectifier and filter circuit is used to rectify and filter the balancing voltage provided by the first balancing voltage source, and provide the rectified and filtered balancing voltage to each of the battery cells.

[0014] The voltage source provided by the first balancing voltage source may be an AC voltage source. The rectifying and filtering circuit may rectify and filter the balancing voltage provided by the first balancing voltage source, and provide the rectified and filtered balancing voltage to each battery cell.

[0015] In some embodiments, the battery balancing system includes a transformer, a primary side of the transformer is connected to a second balancing voltage source, and a secondary side of the transformer is connected to a corresponding battery cell through each isolation diode.

[0016] The transformer can change the value of the voltage provided by the second balancing voltage source, and provide the voltage after the value change to the battery cells that need to be balanced, so as to charge the battery cells that need to be balanced.

[0017] In some embodiments, the battery balancing system includes a plurality of transformers, each battery cell corresponds to a transformer, and a secondary side of each transformer is connected to a corresponding battery cell through a corresponding isolation diode.

[0018] Different battery cells may require different equalizing voltages. Each transformer may change the value of the voltage provided by the second equalizing voltage source, and provide the voltage after the change in value to a corresponding battery cell.

[0019] In some embodiments, the battery balancing system includes a voltage conversion circuit, wherein the primary sides of the plurality of transformers are connected in series, and a third balancing voltage source is connected to the primary sides of the plurality of transformers through the voltage conversion circuit, and the voltage conversion circuit is used to convert a DC voltage provided by the third balancing voltage source into an AC voltage.

[0020] In some embodiments, the battery balancing system includes an isolation capacitor, and the voltage conversion circuit is connected to the primary side of the transformer through the isolation capacitor.

[0021] The voltage conversion circuit, transformer and isolation capacitor can form a corresponding LLC converter, half-bridge converter or full-bridge converter, and can realize energy transmission between the primary and secondary sides. The transformer bypassed by the first bypass switch on the secondary side can be equivalent to an inductor, working as a resonant inductor in the LLC converter, or working as an additional leakage inductor in the full-bridge converter or converter. The isolation capacitor works as a resonant capacitor in the LLC converter and as a DC blocking capacitor in the full-bridge converter or half-bridge converter.

[0022] In some embodiments, the third balancing voltage source is a battery pack or an external power source.

[0023] In some embodiments, the battery balancing system includes a second bypass switch connected in parallel with the primary side of the transformer.

[0024] The primary side of the transformer is equipped with a bypass switch as needed, and a single bypass switch can cut off one or more transformers.

[0025] In some embodiments, the battery balancing system includes a plurality of parameter detection circuits and a current detection circuit. Each of the parameter detection circuits is connected to the corresponding battery cell, and each of the parameter detection circuits is used to detect the operating parameters of the corresponding battery cell, and the operating parameters of the battery cell include at least one of the voltage and temperature of the battery cell. The current detection circuit is connected to the primary side of the transformer, and the current detection circuit is used to detect the primary current of the transformer. The control circuit is respectively connected to the plurality of parameter detection circuits and the current detection circuit, and controls the conduction or disconnection of each of the first bypass switches and / or the conduction or disconnection of each of the second bypass switches according to the operating parameters of the plurality of battery cells and the primary current of the transformer.

[0026] An embodiment of the utility model provides an energy storage device, and the energy storage device includes a battery equalization system of any one of the above embodiments.

[0027] The utility model provides a battery balancing system and energy storage device. The battery balancing system is used for a battery pack, and the battery pack includes a plurality of battery cells. The battery balancing system includes a plurality of isolation diodes and a plurality of first bypass switches. Each isolation diode is reversely connected to the corresponding battery cell through the corresponding first bypass switch, and the positive electrode of the first balancing voltage source is connected to the negative electrode of the first balancing voltage source through the corresponding first bypass switch. The battery balancing system also includes a control circuit, and the control circuit is used to control the first bypass switch to be disconnected so that the first balancing voltage source provides a balancing voltage to the corresponding battery cell through the corresponding isolation diode. When the first bypass switch is closed or short-circuited, the first balancing voltage source is short-circuited by the first bypass switch, so the first balancing voltage source will not supply power to the battery cell. The positive electrode of the battery cell is connected to the negative electrode of the battery cell through the isolation diode and the first bypass switch, and the isolation diode is reversely cut off, so that the positive and negative electrodes of the battery cell will not be short-circuited, and the short circuit of the battery cell will not be caused, and the short circuit of the battery pack will not be caused, thereby avoiding the risk of short circuit of the battery pack due to short circuit of the switch in the battery balancing circuit.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0030] Figure 1 is a schematic diagram of a battery equalization system according to a first embodiment of the present utility model;

[0031] Figure 2is a schematic diagram of a battery equalization system according to a second embodiment of the present utility model;

[0032] Figure 3 It is a schematic diagram of the energy storage device of the utility model. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, and the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] If the capacities of the battery cells in a battery pack vary greatly, when the battery pack is being charged, the battery cell with the largest capacity may be overcharged, and when the battery pack is being discharged, the battery cell with the smallest capacity may be over-discharged, which may damage the battery cells.

[0035] In the related art, a transformer and a matrix switch solution can be used to achieve voltage balancing of each battery cell. The balancing power supply provides a balancing voltage to the battery cell through a transformer, and the matrix switch is connected between the transformer and the battery cell. The battery cell to be balanced and the transformer can be connected by controlling the matrix switch, so that the transformer provides the balancing voltage to the battery cell to be balanced.

[0036] However, when the matrix switch is short-circuited, the positive and negative electrodes of the battery cells will be short-circuited, resulting in the risk of short-circuiting the battery pack.

[0037] Reference Figure 1 The embodiment of the utility model provides a battery balancing system 1000, which is used for a battery pack, and the battery pack includes a plurality of battery cells 100. The battery balancing system 1000 includes a plurality of isolation diodes 10 and a plurality of first bypass switches 20. Each isolation diode 10 is reversely connected to a corresponding battery cell 100 through a corresponding first bypass switch 20, and a positive electrode of a first balancing voltage source 30 is connected to a negative electrode of the first balancing voltage source 30 through a corresponding first bypass switch 20.

[0038] The control circuit 200 can control the first bypass switch 20 to be turned off. When the first bypass switch 20 is turned off, the first balancing voltage source 30 can provide a balancing voltage to the corresponding battery cell 100 through the corresponding isolation diode 10 .

[0039] When the first bypass switch 20 is closed or short-circuited, the first balancing voltage source 30 is short-circuited by the first bypass switch 20, so the first balancing voltage source 30 will not supply power to the battery cell 100. The positive electrode of the battery cell 100 is connected to the negative electrode of the battery cell 100 through the isolation diode 10 and the first bypass switch 20. The isolation diode 10 is reversely cut off, and the positive and negative electrodes of the battery cell 100 are not short-circuited, which does not cause a short circuit of the battery cell 100, and also does not cause a short circuit of the battery pack, thereby avoiding the risk of a short circuit of the battery pack caused by a short circuit of a switch in the battery balancing circuit.

[0040] Specifically, the battery pack includes a plurality of battery cells 100, and the plurality of battery cells 100 may be connected in series or in parallel. The first balancing voltage source 30 may provide a balancing voltage to the battery cells 100 with a lower voltage, charge the battery cells 100 with a lower voltage, and thereby reduce or eliminate the voltage difference between the battery cells 100 with a higher voltage and the battery cells 100 with a lower voltage, so that the voltages of the battery cells 100 in the battery pack reach a balanced state.

[0041] Each battery cell 100 is provided with a corresponding isolation diode 10, and the first balancing voltage source 30 can provide a balancing voltage to a battery cell 100 through the corresponding isolation diode 10. The isolation diode 10 can prevent the first balancing voltage source 30 from being reversely connected to the battery cell 100.

[0042] Each of the isolation diodes is reversely connected to the corresponding battery cell through the corresponding first bypass switch. Further, the positive electrode of each battery cell 100 can be connected to the cathode of the corresponding isolation diode 10, and the anode of each isolation diode 10 is connected to the negative electrode of the corresponding battery cell 100 through the corresponding first bypass switch 20.

[0043] The positive electrode of each battery cell 100 may also be connected to the cathode of the corresponding isolation diode 10 through the corresponding first bypass switch 20 , and the anode of each isolation diode 10 is connected to the negative electrode of the corresponding battery cell 100 .

[0044] Each battery cell 100 is also provided with a corresponding first bypass switch 20. When the first bypass switch 20 is disconnected, the first balancing voltage source 30 can provide a balancing voltage to a battery cell 100 through the corresponding isolation diode 10. When the first bypass switch 20 is closed, the first balancing voltage source 30 is short-circuited by the first bypass switch 20, so the first balancing voltage source 30 will not supply power to the battery cell 100. The positive electrode of the battery cell 100 is connected to the negative electrode of the battery cell 100 through the isolation diode 10 and the first bypass switch 20, and the isolation diode 10 is reversely cut off, so the positive and negative electrodes of the battery cell 100 will not be short-circuited, and the battery cell 100 will not be short-circuited.

[0045] Therefore, the control circuit 200 can control the first bypass switch 20 corresponding to the battery cell 100 with a lower voltage to be disconnected, so that the first balancing voltage source 30 charges the battery cell 100 with a lower voltage, thereby reducing or eliminating the voltage difference between the battery cell 100 with a higher voltage and the battery cell 100 with a lower voltage, so that the voltage of each battery cell 100 in the battery pack reaches a balanced state.

[0046] When the first bypass switch 20 is short-circuited, the positive electrode of the battery cell 100 is connected to the negative electrode of the battery cell 100 through the isolation diode 10 and the first bypass switch 20. The isolation diode 10 is reversely cut off, and the positive and negative electrodes of the battery cell 100 will not be short-circuited, which will not cause a short circuit in the battery cell 100, and will not cause a short circuit in the battery pack.

[0047] For example, refer to Figure 1 The battery pack may include n battery cells 100, the n battery cells 100 may be BAT1-BATn, the n battery cells 100 are connected in series, the positive electrode connection terminal of the battery pack may be the B+ connection terminal, and the negative electrode connection terminal of the battery pack may be the B- connection terminal.

[0048] The isolation diode 10 corresponding to BAT1 may be a diode D1, and the first bypass switch 20 corresponding to BAT1 may be a switch SB1. The positive electrode of the first balancing voltage source 30 may be connected to the anode of the diode D1 through the connection terminal Va1+, the cathode of the diode D1 is connected to the positive electrode of BAT1, and the negative electrode of the first balancing voltage source 30 may be connected to the negative electrode of BAT1 through the connection terminal Va1-. When the switch SB1 is disconnected, the first balancing voltage source 30 provides a balancing voltage to BAT1 through the connection terminal Va1+ and the connection terminal Va1- to charge BAT1. The control circuit 200 may control the switch SB1 to be disconnected, so that the first balancing voltage source 30 charges BAT1.

[0049] The isolation diode 10 corresponding to BAT2 may be a diode D2, and the first bypass switch 20 corresponding to BAT2 may be a switch SB2. The positive electrode of the first balancing voltage source 30 may be connected to the anode of the diode D2 through the connection terminal Va2+, the cathode of the diode D2 may be connected to the positive electrode of BAT2, and the negative electrode of the first balancing voltage source 30 may be connected to the negative electrode of BAT2 through the connection terminal Va2-. When the switch SB2 is closed, the connection terminal Va2+ and the connection terminal Va2- are short-circuited, and the first balancing voltage source 30 does not provide a balancing voltage to BAT2. Since the diode D2 is reversely cut off, the positive electrode of BAT2 will not be short-circuited with the negative electrode of BAT2, so BAT2 will not be burned due to the short-circuit between the positive electrode and the negative electrode. The control circuit 200 may control the switch SB2 to be closed, so that the first balancing voltage source 30 does not charge BAT2.

[0050] Compared with the solution of using transformers and matrix switches to achieve balancing of each battery cell 100, the battery balancing system 1000 provided by the embodiment of the utility model avoids the risk of short circuit of the battery pack due to short circuit of the switch.

[0051] In some embodiments, the battery balancing system 1000 includes a plurality of switch driving circuits 40. Each first bypass switch 20 includes a control terminal, and the positive electrode of each battery cell 100 is connected to the corresponding control terminal through the corresponding switch driving circuit 40, and each battery cell 100 is used to provide a driving voltage to the corresponding control terminal to drive the corresponding first bypass switch 20 to be turned on or off.

[0052] The first bypass switch 20 can be an electronic switch device such as a triode, a MOS tube, an IGBT, etc. The switch driving circuit 40 can use the voltage of the battery cell 100 as the driving voltage of the first bypass switch 20, which is conducive to simplifying the circuit design.

[0053] Specifically, the driving voltage provided by the battery cell 100 can be used to drive the first bypass switch 20 to be turned on. For example, the first bypass switch 20 can be an NPN transistor. When the control circuit 200 controls the first bypass switch 20 to be turned on, the battery cell 100 provides the driving voltage to the base of the NPN transistor, so that the NPN transistor is turned on.

[0054] The driving voltage provided by the battery cell 100 can also be used to drive the first bypass switch 20 to be disconnected. For example, the first bypass switch 20 can be a PMOS tube. When the control circuit 200 controls the first bypass switch 20 to be disconnected, the battery cell 100 can provide the driving voltage to the gate of the PMOS tube to disconnect the PMOS tube.

[0055] Therefore, the switch driving circuit 40 can use the voltage of the battery cell 100 as the driving voltage of the first bypass switch 20, which is beneficial to simplify the circuit design.

[0056] In some embodiments, the battery balancing system 1000 includes a rectifier and filter circuit 50. The first balancing voltage source 30 is connected to each battery cell 100 through the rectifier and filter circuit 50 and each isolation diode 10. The rectifier and filter circuit 50 is used to rectify and filter the balancing voltage provided by the first balancing voltage source 30, and provide the rectified and filtered balancing voltage to each battery cell 100.

[0057] The voltage source provided by the first balancing voltage source 30 may be an AC voltage source. The rectifying and filtering circuit 50 may rectify and filter the balancing voltage provided by the first balancing voltage source 30 , and provide the rectified and filtered balancing voltage to each battery cell 100 .

[0058] Specifically, the first voltage source may be a voltage provided by a primary side of a transformer, and the voltage provided by the primary side of the transformer is an AC voltage.

[0059] The rectifier and filter circuit 50 can rectify the AC signal provided by the first balanced voltage source 30, and the function of the rectification is to convert the AC signal into a DC signal. After rectifying the AC signal provided by the first balanced voltage source 30, the rectifier and filter circuit 50 can also filter the rectified signal, and the function of the filtering is to filter out the high-frequency noise in the DC signal, thereby reducing the noise interference and fluctuation in the circuit, so that the balanced voltage provided by the first balanced voltage source 30 is more stable and reliable.

[0060] Further, refer to Figure 2 In some embodiments, the battery balancing system 1000 includes a transformer 300 , a primary side of the transformer 300 is connected to a second balancing voltage source 110 , and a secondary side of the transformer 300 is connected to a corresponding battery cell 100 through each isolation diode 10 .

[0061] The transformer 300 can change the value of the voltage provided by the second equalizing voltage source 110 , and provide the voltage after the value change to the battery cells 100 that need to be equalized, so as to charge the battery cells 100 that need to be equalized.

[0062] Specifically, the transformer 300 can boost the voltage provided by the second balancing voltage source 110, and provide the boosted voltage to the battery cell 100 that needs to be balanced. The transformer 300 can also step down the voltage provided by the second balancing voltage source 110, and provide the stepped-down voltage to the battery cell 100 that needs to be balanced. The balancing voltage required by the battery cell 100 in different time periods may be different, and the transformer 300 can change the value of the voltage provided by the second balancing voltage source 110 according to the needs of the battery cell 100.

[0063] The transformer 300 can also achieve electrical isolation between the second balancing voltage source 110 and the battery cells 100 , so as to prevent the second balancing voltage source 110 from affecting the battery cells 100 of the battery pack when a fault occurs.

[0064] Furthermore, in some embodiments, the battery balancing system 1000 includes a plurality of transformers 300 . Each battery cell 100 corresponds to a transformer 300 , and the secondary side of each transformer 300 is connected to a corresponding battery cell 100 through a corresponding isolation diode 10 .

[0065] Different battery cells 100 may require different equalizing voltages. Each transformer 300 may change the value of the voltage provided by the second equalizing voltage source 110 and provide the voltage after the change to a corresponding battery cell 100 .

[0066] Specifically, refer to Figure 2 The voltage provided by the second voltage source is connected to the primary sides of T1 and T2 through the connection terminal Vb1+ and the connection terminal Vb1-. The transformer 300 corresponding to BAT1 is T1, and BAT1 is connected to the secondary side of T1 through the diode D1 and the rectifier filter circuit 50. The transformer 300 corresponding to BAT2 is T2, and BAT2 is connected to the secondary side of T2 through the diode D2 and the rectifier filter circuit 50.

[0067] When the switch SB1 is disconnected, the primary voltage of T1 can charge BAT1. The primary voltage of T1 can be adjusted by adjusting the position of the center tap W3 on the primary side of T1, that is, the balanced voltage provided to BAT1 can be adjusted.

[0068] When the switch SB2 is disconnected, the primary voltage of T2 can charge BAT2. The primary voltage of T2 can be adjusted by adjusting the position of the center tap on the primary side of T2, that is, the balanced voltage provided to BAT2 can be adjusted.

[0069] In some embodiments, the battery balancing system 1000 includes a voltage conversion circuit 130. The third balancing voltage source 120 is connected to the primary side of the transformer 300 through the voltage conversion circuit 130, and the voltage conversion circuit 130 is used to convert the DC voltage provided by the third balancing voltage source 120 into an AC voltage.

[0070] Specifically, the third balanced voltage source 120 may be a DC voltage source, and the voltage conversion circuit 130 may convert the DC voltage provided by the third balanced voltage source 120 into an AC voltage. The voltage conversion circuit 130 may be a full-bridge circuit or a half-bridge circuit, and may convert the DC power provided by the DC voltage source into AC power, which is connected to both sides of the transformer 300.

[0071] Furthermore, in some embodiments, the battery balancing system 1000 includes an isolation capacitor 140 , and the voltage conversion circuit 130 is connected to the primary side of the transformer 300 via the isolation capacitor 140 .

[0072] Specifically, on the primary side of the transformer 300, the primary sides of the multiple transformers 300 are connected in series one by one and connected to the voltage conversion circuit 130 through the isolation capacitor 140. The DC voltage source provided by the third balanced voltage source 120 can be converted into an AC voltage source through the voltage conversion circuit 130, and the primary sides of the multiple transformers 300 are connected in series with the AC voltage source through the isolation capacitor 140, and the primary sides of the multiple transformers 300 can be equivalent to inductors.

[0073] On the secondary side of the transformer 300, when the first bypass switch 20 is turned on, the secondary side of the transformer 300 corresponding to the first bypass switch 20 can be equivalent to an inductor. When the first bypass switch 20 is turned off, the secondary side of the transformer 300 corresponding to the first bypass switch 20 can provide a balanced voltage to the corresponding battery cell 100.

[0074] The voltage conversion circuit 130, the transformer 300 and the isolation capacitor 140 can form a corresponding LLC converter, a half-bridge converter or a full-bridge converter, and can realize energy transmission between the primary and secondary sides. The transformer 300 bypassed by the first bypass switch 20 on the secondary side can be equivalent to an inductor, and works as a resonant inductor in the LLC converter, or works as an additional leakage inductor in the full-bridge converter or converter. The isolation capacitor 140 works as a resonant capacitor in the LLC converter and as a DC isolation capacitor in the full-bridge converter or half-bridge converter.

[0075] In some embodiments, the third balancing voltage source 120 is a battery pack or an external power source.

[0076] Specifically, refer to Figure 2 , the positive pole of the voltage input terminal of the voltage conversion circuit 130 may be the connection terminal Vc1+, and the negative pole of the voltage input terminal of the voltage conversion circuit 130 may be the connection terminal Vc1-. The positive pole of the battery pack may be connected to the connection terminal Vc1+ through the connection terminal B+, and the negative pole of the battery pack may be connected to the connection terminal Vc1- through the connection terminal B-, and the battery pack provides input voltage to the voltage conversion circuit 130. An external power source may also provide input voltage to the voltage conversion circuit 130 through the connection terminals Vc1+ and Vc1-.

[0077] In some embodiments, the battery balancing system 1000 includes a second bypass switch 150 , which is connected in parallel to the primary side of the transformer 300 .

[0078] The primary side of the transformer 300 may have a corresponding second bypass switch 150. When the second bypass switch 150 is closed, the primary side of the corresponding transformer 300 is short-circuited. The corresponding circuit operating parameter requirements can be achieved by controlling the second bypass switch 150 to be closed so that the primary side of the corresponding transformer 300 is short-circuited.

[0079] When the first bypass switch 20 is closed, the transformer 300 connected to the first bypass switch 20 is equivalent to an inductor. When the second bypass switch 150 is closed, the transformer 300 connected to the second bypass switch 150 is cut off.

[0080] Specifically, please refer to Figure 2 The switch SA1 and the switch SA2 are the second bypass switch 150. When the switch SA1 is closed, T1 and T2 are cut off. When the switch SA2 is closed, T3 and T4 are cut off.

[0081] In some embodiments, the battery balancing system 1000 includes a plurality of parameter detection circuits 60 and a current detection circuit 160. Each parameter detection circuit 60 is connected to a corresponding battery cell 100, and each parameter detection circuit 60 is used to detect an operating parameter of the corresponding battery cell 100, and the operating parameter of the battery cell 100 includes at least one of a voltage and a temperature of the battery cell 100. The current detection circuit 160 is connected to the primary side of the transformer 300, and the current detection circuit 160 is used to detect the primary current of the transformer 300. The control circuit 200 is respectively connected to the plurality of parameter detection circuits 60 and the current detection circuit 160, and controls the on or off of each first bypass switch 20 and / or the on or off of each second bypass switch 150 according to the operating parameters of the plurality of battery cells 100 and the primary current of the transformer 300.

[0082] Specifically, the primary side of the transformer 300 is provided with a corresponding current detection circuit 160, which can be used to detect the current magnitude of the primary side of the transformer 300. The multiple parameter detection circuits 60 may include multiple voltage acquisition circuits and multiple temperature acquisition circuits, and the multiple parameter detection circuits 60 can detect the temperature and voltage of multiple battery cells 100.

[0083] The control circuit 200 can obtain the voltage, temperature or other data of each battery cell 100, and control the first bypass switch 20 to be turned on or off and the second bypass switch 150 to be turned on or off according to the obtained data. The control circuit 200 communicates with the voltage conversion circuit 130, and the control circuit 200 can obtain the working state of the voltage conversion circuit 130 and can also control the operation of the voltage conversion circuit 130.

[0084] The control circuit 200 can also obtain the magnitude of the primary loop current of the transformer 300 and the voltage magnitude of the battery cell 100 currently being balanced, calculate the actual magnitude of the balancing current and the capacity of the completed balance, and control the first bypass switch 20 to be turned on or off according to the calculated balancing current magnitude and the capacity of the completed balance to control the balancing of the battery cell 100.

[0085] Reference Figure 3 An embodiment of the utility model provides an energy storage device 10000, and the energy storage device 10000 includes a battery balancing system 1000 of any one of the above embodiments.

[0086] The implementation of the battery balancing system 1000 may refer to the above implementation, and the beneficial effects of the energy storage device 10000 include all the beneficial effects of the battery balancing system 1000, which are not described one by one here.

[0087] The present invention provides a battery balancing system 1000 and an energy storage device 10000. The battery balancing system 1000 is used for a battery pack, and the battery pack includes a plurality of battery cells 100. The battery balancing system 1000 includes a plurality of isolation diodes 10 and a plurality of first bypass switches 20. Each isolation diode 10 is reversely connected to the corresponding battery cell 100 through the corresponding first bypass switch 20, and the positive electrode of the first balancing voltage source 30 is connected to the negative electrode of the first balancing voltage source 30 through the corresponding first bypass switch 20. The battery balancing system 1000 includes a control circuit 200, and the control circuit 200 is used to control the first bypass switch 20 to be disconnected, so that the first balancing voltage source 30 provides a balancing voltage to the corresponding battery cell 100 through the corresponding isolation diode 10. When the first bypass switch 20 is closed or short-circuited, the first balancing voltage source 30 is short-circuited by the first bypass switch 20, so the first balancing voltage source 30 does not supply power to the battery cell 100. The positive electrode of the battery cell 100 is connected to the negative electrode of the battery cell 100 through the isolation diode 10 and the first bypass switch 20. The isolation diode 10 is reversely cut off, and the positive and negative electrodes of the battery cell 100 will not be short-circuited, which will not cause a short circuit in the battery cell 100, and will not cause a short circuit in the battery pack, thereby avoiding the risk of a short circuit in the battery pack due to a short circuit in the switch in the battery balancing circuit.

[0088] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0089] In addition, the term "connection" should be understood in a broad sense, for example, it can include fixed connection, detachable connection, or integral connection; it can include direct connection, indirect connection through an intermediate medium, and internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0090] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0091] Any process or method description in the flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present invention includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present invention belong.

[0092] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A battery balancing system for a battery pack, wherein the battery pack comprises a plurality of battery cells, characterized in that: The battery balancing system includes a plurality of isolation diodes and a plurality of first bypass switches, each of the isolation diodes is reversely connected to the corresponding battery cell through the corresponding first bypass switch, and the positive electrode of the first balancing voltage source is connected to the negative electrode of the first balancing voltage source through the corresponding first bypass switch; The battery balancing system includes a control circuit, and the control circuit is used to control the first bypass switch to be disconnected, so that the first balancing voltage source provides a balancing voltage to the corresponding battery cell through the corresponding isolation diode.

2. The battery equalization system according to claim 1, characterized in that: The battery balancing system includes a plurality of switch driving circuits, each of the first bypass switches includes a control end, a positive electrode of each of the battery cells is connected to the corresponding control end through the corresponding switch driving circuit, and each of the battery cells is used to provide a driving voltage to the corresponding control end to drive the corresponding first bypass switch to be turned on or off.

3. The battery equalization system according to claim 1, characterized in that: The battery balancing system includes a rectifier and filter circuit, wherein the first balancing voltage source is connected to each of the battery cells through the rectifier and filter circuit and each of the isolation diodes, and the rectifier and filter circuit is used to rectify and filter the balancing voltage provided by the first balancing voltage source, and provide the rectified and filtered balancing voltage to each of the battery cells.

4. The battery equalization system according to claim 1, characterized in that: The battery balancing system includes a transformer, a primary side of the transformer is connected to a second balancing voltage source, and a secondary side of the transformer is connected to the corresponding battery cell through each isolation diode.

5. The battery equalization system according to claim 4, characterized in that: The battery balancing system includes a plurality of transformers, each battery cell corresponds to one transformer, and a secondary side of each transformer is connected to a corresponding battery cell through a corresponding isolation diode.

6. The battery equalization system according to claim 4, characterized in that: The battery balancing system includes a voltage conversion circuit, a plurality of primary sides of the transformers are connected in series, a third balancing voltage source is connected to the primary sides of the plurality of transformers through the voltage conversion circuit, and the voltage conversion circuit is used to convert a DC voltage provided by the third balancing voltage source into an AC voltage.

7. The battery equalization system according to claim 6, characterized in that: The battery balancing system includes an isolation capacitor, and the voltage conversion circuit is connected to the primary side of the transformer through the isolation capacitor.

8. The battery equalization system according to claim 6, characterized in that: The third balancing voltage source is a battery pack or an external power source.

9. The battery equalization system according to claim 4, characterized in that: The battery balancing system includes a second bypass switch, and the second bypass switch is connected in parallel with the primary side of the transformer.

10. The battery equalization system according to claim 9, characterized in that: The battery balancing system comprises: A plurality of parameter detection circuits, each of which is connected to a corresponding battery cell, and each of which is used to detect an operating parameter of a corresponding battery cell, wherein the operating parameter of the battery cell includes at least one of a voltage and a temperature of the battery cell; A current detection circuit, the current detection circuit is connected to the primary side of the transformer, and the current detection circuit is used to detect the primary side current of the transformer; The control circuit is connected to the multiple parameter detection circuits and the current detection circuit respectively, and controls the on or off of each first bypass switch and / or the on or off of each second bypass switch according to the operating parameters of the multiple battery cells and the primary current of the transformer.

11. An energy storage device, characterized in that: The energy storage device comprises the battery balancing system according to any one of claims 1-10.

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