Battery equalization circuit, battery management circuit, electronic equipment and method

Abstract

The embodiment of the invention discloses a battery equalization circuit, a battery management circuit, electronic equipment and a method. In the capacitor charging stage, the connection conversion module is controlled to switch the connection state among the plurality of capacitor modules into the parallel connection state, and the battery cells with relatively high voltage in the battery pack charge the plurality of capacitor modules which are connected in parallel; in a capacitor discharging stage, the connection conversion module is controlled to switch a connection state among the plurality of capacitor modules into a series connection state, and at the moment, the voltage provided by the plurality of capacitor modules connected in series is increased, so that a battery cell with relatively low voltage in the battery pack can be normally charged; and energy loss in the battery equalization process can be effectively reduced through energy transfer of the capacitor module, and the battery equalization effect is improved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to power management technology, and in particular to a battery equalization circuit, a battery management circuit, an electronic device and a method. BACKGROUND

[0002] With the development of batteries such as lithium batteries, the application of batteries in various industries is also becoming more and more widespread. With the long-term use of batteries, the voltage and capacity between the battery cells in the battery will differ due to the use time and production process, etc., resulting in a significant reduction in the use efficiency of the entire battery.

[0003] In order to ensure the use efficiency of the battery, active equalization management is often performed on the battery to balance the voltage and capacity between the battery cells. At present, the battery equalization is basically performed by using an isolation voltage transformer to charge the battery cells that need to be equalized with a small current, so that the voltage and capacity of each battery cell in the entire battery are consistent. However, the battery equalization method based on the isolation voltage transformer has a large energy loss when energy is exchanged, and the battery equalization effect is poor. SUMMARY

[0004] Embodiments of the present application provide a battery equalization circuit, a battery management circuit, an electronic device and a method to solve the technical problem that the battery equalization method based on the isolation voltage transformer has a large energy loss when energy is exchanged, and the battery equalization effect is poor, which can reduce the energy loss in the battery equalization process and improve the battery equalization effect.

[0005] In a first aspect, embodiments of the present application provide a battery equalization circuit, comprising an equalization voltage connection circuit, a plurality of capacitor modules and a connection conversion module, wherein: The positive terminals of the plurality of capacitor modules are connected with the equalization voltage connection circuit, and the negative terminals of the plurality of capacitor modules are connected with the negative terminal of the equalization circuit, and the equalization voltage connection circuit is used for connecting battery cells; The connection conversion module is connected with the plurality of capacitor modules, and the connection conversion module is used for switching the connection state between the plurality of capacitor modules, and the connection state includes a parallel state and a series state; The control end of the connection conversion module is used for connecting a control module, and in response to a first control signal sent by the control module in a capacitor charging phase, the connection conversion module switches the connection state between the plurality of capacitor modules to the parallel state, and in response to a second control signal sent by the control module in a capacitor discharging phase, the connection conversion module switches the connection state between the plurality of capacitor modules to the series state.

[0006] Further, the connection conversion module includes a plurality of parallel switch sub-modules and a plurality of series switch sub-modules, wherein: A plurality of the parallel switch sub-modules are connected in parallel loops of the plurality of the capacitor modules, for switching on or off parallel states of the plurality of the capacitor modules. A plurality of the series switch sub-modules are connected in series loops of the plurality of the capacitor modules, for switching on or off series states of the plurality of the capacitor modules.

[0007] Further, the parallel switch sub-module comprises a first switch element and a second switch element, a second connection end of the first switch element is connected with a first connection end of the second switch element, a control end of the first switch element and a control end of the second switch element are connected with the control module, the series switch sub-module comprises a third switch element and a fourth switch element, a second connection end of the third switch element is connected with a first connection end of the fourth switch element, a control end of the third switch element and a control end of the fourth switch element are connected with the control module.

[0008] Further, the connection conversion module further comprises a plurality of turn-off acceleration sub-modules, the turn-off acceleration sub-modules correspond to the parallel switch sub-modules and / or the series switch sub-modules, and are connected with the corresponding parallel switch sub-modules and / or the series switch sub-modules, the turn-off acceleration sub-modules are used for accelerating turn-off speeds of the parallel switch sub-modules and / or the series switch sub-modules.

[0009] Further, the turn-off acceleration sub-module comprises a fifth switch element, a first diode and a first resistor, wherein: a first connection end of the fifth switch element is connected with a control end of the corresponding first switch element, a control end of the corresponding second switch element and a cathode end of the diode, a second connection end of the fifth switch element is connected with a second connection end of the corresponding first switch element, an anode end of the diode is connected with a control end of the fifth switch element and the control module, a first connection end of the first resistor is connected with the control end of the fifth switch element, and a second connection end of the first resistor is connected with the second connection end of the fifth switch element; and / or a first connection end of the fifth switch element is connected with a control end of the corresponding third switch element, a control end of the corresponding fourth switch element and a cathode end of the diode, a second connection end of the fifth switch element is connected with a second connection end of the corresponding third switch element, an anode end of the diode is connected with a control end of the fifth switch element and the control module, a first connection end of the first resistor is connected with the control end of the fifth switch element, and a second connection end of the first resistor is connected with the second connection end of the fifth switch element.

[0010] Further, the capacitor module comprises a first capacitor and a second capacitor, the plurality of parallel switch sub-modules comprises a first parallel switch sub-module, a second parallel switch sub-module and a third parallel switch sub-module, and the plurality of series switch sub-modules comprises a first series switch sub-module and a second series switch sub-module, wherein: The first connection end of the first parallel switch sub-module is connected with the equalization voltage connection line, the second connection end of the first parallel switch sub-module is connected with the positive electrode end of the first capacitor, and the control end of the first parallel switch sub-module is connected with the control module. The first connection end of the second parallel switch sub-module is connected with the positive electrode end of the first capacitor, the second connection end of the second parallel switch sub-module is connected with the positive electrode end of the second capacitor, and the control end of the second parallel switch sub-module is connected with the control module. The first connection end of the third parallel switch sub-module is connected with the negative electrode end of the second capacitor, the second connection end of the third parallel switch sub-module is connected with the negative electrode end of the first capacitor, and the control end of the third parallel switch sub-module is connected with the control module. The first connection end of the first series switch sub-module is connected with the positive electrode end of the first capacitor, the second connection end of the first series switch sub-module is connected with the negative electrode end of the second capacitor, and the control end of the first series switch sub-module is connected with the control module. The first connection end of the second series switch sub-module is connected with the equalization voltage connection line, the second connection end of the second series switch sub-module is connected with the positive electrode end of the second capacitor, and the control end of the second series switch sub-module is connected with the control module.

[0011] Further, the capacitor module comprises a third capacitor, a fourth capacitor and a fifth capacitor, the plurality of parallel switch sub-modules comprises a fourth parallel switch sub-module, a fifth parallel switch sub-module, a sixth parallel switch sub-module, a seventh parallel switch sub-module and an eighth parallel switch sub-module, and the plurality of series switch sub-modules comprises a third series switch sub-module, a fourth series switch sub-module and a fifth series switch sub-module, wherein: The first connection end of the fourth parallel switch sub-module is connected with the equalization voltage connection line, the second connection end of the fourth parallel switch sub-module is connected with the positive electrode end of the third capacitor, and the control end of the fourth parallel switch sub-module is connected with the control module. The first connection end of the fifth parallel switch sub-module is connected with the positive electrode end of the third capacitor, the second connection end of the fifth parallel switch sub-module is connected with the positive electrode end of the fourth capacitor, and the control end of the fifth parallel switch sub-module is connected with the control module. The first connection end of the sixth parallel switch sub-module is connected with the negative pole end of the fourth capacitor, the second connection end of the sixth parallel switch sub-module is connected with the negative pole end of the third capacitor, and the control end of the sixth parallel switch sub-module is connected with the control module. The first connection end of the seventh parallel switch sub-module is connected with the positive pole end of the fourth capacitor, the second connection end of the seventh parallel switch sub-module is connected with the positive pole end of the fifth capacitor, and the control end of the seventh parallel switch sub-module is connected with the control module. The first connection end of the eighth parallel switch sub-module is connected with the negative pole end of the fifth capacitor, the second connection end of the eighth parallel switch sub-module is connected with the negative pole end of the fourth capacitor, and the control end of the eighth parallel switch sub-module is connected with the control module. The first connection end of the third series switch sub-module is connected with the positive pole end of the third capacitor, the second connection end of the third series switch sub-module is connected with the negative pole end of the fourth capacitor, and the control end of the third series switch sub-module is connected with the control module. The first connection end of the fourth series switch sub-module is connected with the positive pole end of the fourth capacitor, the second connection end of the fourth series switch sub-module is connected with the negative pole end of the fifth capacitor, and the control end of the fourth series switch sub-module is connected with the control module. The first connection end of the fifth series switch sub-module is connected with the equalization voltage connection line, the second connection end of the fifth series switch sub-module is connected with the positive pole end of the fifth capacitor, and the control end of the fifth series switch sub-module is connected with the control module.

[0012] In a second aspect, the embodiments of the present application provide a battery management circuit, comprising a control module and a battery equalization circuit according to any one of the first aspect, and the control module is connected with the control end of the connection conversion module in the battery equalization circuit.

[0013] In a third aspect, the embodiments of the present application provide an electronic device, comprising a battery management circuit according to the second aspect.

[0014] In a fourth aspect, the embodiments of the present application provide a battery management method, applied to the control module in the battery management circuit according to the second aspect or the control module in the electronic device according to the third aspect, and the method comprises the following steps. In the capacitor charging stage, a first control signal is sent to the connection conversion module to control the connection conversion module to switch the connection state between the plurality of capacitor modules to a parallel state. In the capacitor discharging stage, a second control signal is sent to the connection conversion module to control the connection conversion module to switch the connection state between the plurality of capacitor modules to a series state.

[0015] The embodiment of the application switches the connection state between the plurality of capacitor modules to the parallel state by controlling the connection conversion module in the capacitor charging phase, the battery cell with higher voltage in the battery pack charges the plurality of capacitor modules in parallel, and switches the connection state between the plurality of capacitor modules to the series state by controlling the connection conversion module in the capacitor discharging phase, at this time, the plurality of capacitor modules in series provide higher voltage to the outside, and the battery cell with lower voltage in the battery pack can be normally charged, and the energy transfer through the capacitor module can effectively reduce the energy loss in the battery equalization process, and improve the battery equalization effect. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a schematic diagram of a battery equalization circuit of the prior art; Figure 2 is a schematic diagram of a battery equalization circuit provided by the embodiment of the application; Figure 3 is a schematic diagram of a parallel switch sub-module circuit provided by the embodiment of the application; Figure 4 is a schematic diagram of a series switch sub-module circuit provided by the embodiment of the application; Figure 5 is a schematic diagram of a battery equalization circuit in the capacitor charging phase provided by the embodiment of the application; Figure 6 is a schematic diagram of a battery equalization circuit structure in the capacitor charging phase provided by the embodiment of the application; Figure 7 is a schematic diagram of a battery equalization circuit in the capacitor discharging phase provided by the embodiment of the application; Figure 8 is a schematic diagram of another battery equalization circuit in the capacitor charging phase provided by the embodiment of the application; Figure 9 is a schematic diagram of another battery equalization circuit in the capacitor discharging phase provided by the embodiment of the application; Figure 10 is a schematic diagram of a battery management circuit provided by the embodiment of the application.

[0017] The reference signs are as follows: 1, equalization voltage connection line; 2, capacitor module; 3, connection conversion module; 31, parallel switch sub-module; 311, first switch piece; 312, second switch piece; 32, series switch sub-module; 321, third switch piece; 322, fourth switch piece; 33, off acceleration sub-module; 331, fifth switch piece; 332, first diode; 4, control module. DETAILED DESCRIPTION

[0018] In order to make the purposes, technical solutions and advantages of the present application clearer, the specific embodiments of the present application are further described in detail below with reference to the drawings. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only parts related to the present application are shown in the drawings, but not all. Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowchart describes each operation (or step) as a sequential process, many of the operations can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The above process can be terminated when its operations are completed, but can also have additional steps not included in the drawings. The above process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0019] As Figure 1 An existing battery equalization circuit provided by the prior art is shown in the schematic diagram. In the existing battery equalization scheme based on an isolation voltage transformer, the battery voltage (INPUT in the figure) provided by the battery is converted into a 5V isolation voltage (BAL_5V) through a DC-DC conversion isolation output realized by a control chip U4 and a voltage transformer TI, and then the switching channel composed of MOS tubes is switched to supply power to the battery cell with the lowest voltage to increase the battery capacity and voltage, thereby realizing the active equalization of the battery pack. However, in the battery equalization scheme based on the isolation voltage transformer, the equalization current is small, and there is still a large energy loss in the conversion voltage process. If the equalization current is to be increased, the size and power of the transformer need to be increased, and the power of the peripheral elements also needs to be increased, in addition, the heat will be more serious, which will also increase the cost, and the requirements for the structure of the battery pack and the heat dissipation measures will be greater.

[0020] Figure 2 A principle schematic diagram of a battery equalization circuit provided by an embodiment of the present application is given, referring to Figure 2 The battery equalization circuit includes an equalization voltage connection end, a plurality of (two or more) capacitor modules 2 and a connection conversion module 3. The positive ends of the plurality of capacitor modules 2 are connected to the equalization voltage connection end, the negative ends of the plurality of capacitor modules 2 are connected to the negative end of the equalization circuit, and the equalization voltage connection end is used to connect the battery cell.

[0021] Further, the connection conversion module 3 provided by the present scheme is connected to the plurality of capacitor modules 2, and the connection conversion module 3 can be used to switch the connection state between the plurality of capacitor modules 2. The connection state between the plurality of capacitor modules 2 includes a parallel state and a series state.

[0022] The control end of the connection conversion module 3 is connected to the control module 4, and the connection conversion module 3 can be controlled to switch the connection state between the plurality of capacitor modules 2 to a parallel state in response to a first control signal sent by the control module 4 in a capacitor charging phase, and to switch the connection state between the plurality of capacitor modules 2 to a series state in response to a second control signal sent by the control module 4 in a capacitor discharging phase. The capacitor charging phase can be understood as a phase in which the capacitor module 2 is charged by the battery cell with the highest voltage in the battery pack, and the capacitor discharging phase can be understood as a phase in which the battery cell with the lowest voltage in the battery pack is charged by the capacitor module 2.

[0023] Optionally, the capacitor module 2 provided in the scheme can be a super capacitor. It needs to be explained that the working voltage range of the super capacitor is generally 0-2.7V, and it has the ability of large current charging and discharging. When the equalization between the battery cells needs to be performed, the energy of the battery cell with the highest voltage needs to be transferred to the battery cell with the lowest voltage. The application utilizes the capacitor module 2 as a carrier for energy transfer, and first connects the battery cell with the highest voltage (for example, the voltage of the battery cell is 3.65V) to the equalization voltage connection end to charge the plurality of capacitor modules 2 in a parallel state, so that the plurality of capacitor modules 2 are charged to 2.7V. At this time, the voltage of the capacitor module 2 is 2.7V, and the battery cell with the lowest voltage (assuming 3.1V) cannot be charged. At this time, the connection state between the plurality of capacitor modules 2 is switched to a series state in a capacitor discharging phase, and assuming that two capacitor modules 2 are configured, the voltage provided by the two capacitor modules 2 becomes 5.4V, which can charge the battery cell with the lowest voltage (3.1V). After a period of reciprocating cycle of the capacitor charging phase and the capacitor discharging phase, the equalization purpose of achieving the consistency of the plurality of battery cell voltages is finally achieved.

[0024] In one embodiment, the connection conversion module 3 provided in the application includes a plurality of parallel switch sub-modules 31 and a plurality of series switch sub-modules 32. The plurality of parallel switch sub-modules 31 are connected in a parallel loop of the plurality of capacitor modules 2, and are used to turn on or turn off the parallel state of the plurality of capacitor modules 2; the plurality of series switch sub-modules 32 are connected in a series loop of the plurality of capacitor modules 2, and are used to turn on or turn off the series state of the plurality of capacitor modules 2. The plurality of parallel switch sub-modules 31 and the plurality of series switch sub-modules 32 are respectively connected in the parallel loop and the series loop of the plurality of capacitor modules 2, so as to accurately realize the switching of the connection state between the plurality of capacitor modules 2.

[0025] In one embodiment, as Figure 3The parallel switch sub-module circuit schematic diagram provided by the application shows that the parallel switch sub-module 31 provided by the application comprises a first switch component 311 and a second switch component 312, the second connection end of the first switch component 311 is connected with the first connection end of the second switch component 312, and the control end of the first switch component 311 and the control end of the second switch component 312 are connected with the control module 4. In the figure, a1, a2 and a3 are respectively the first connection end, the second connection end and the control end of the parallel switch sub-module 31. When the first control signal (for example, a high-level signal) is sent to the control end of the parallel switch sub-module 31, the first switch component 311 and the second switch component 312 are turned on, and when the third control signal (for example, a low-level signal) is sent to the control end of the parallel switch sub-module 31, the first switch component 311 and the second switch component 312 are turned off. The application realizes the on-off function of the parallel switch sub-module 31 through the first switch component 311 and the second switch component 312, and can accurately realize the switching of the parallel state of the plurality of capacitor modules 2.

[0026] In one embodiment, as Figure 4 The series switch sub-module circuit schematic diagram provided by the application shows that the series switch sub-module 32 provided by the application comprises a third switch component 321 and a fourth switch component 322, the second connection end of the third switch component 321 is connected with the first connection end of the fourth switch component 322, and the control end of the third switch component 321 and the control end of the fourth switch component 322 are connected with the control module 4. In the figure, b1, b2 and b3 are respectively the first connection end, the second connection end and the control end of the series switch sub-module 32. When the second control signal (for example, a high-level signal) is sent to the control end of the series switch sub-module 32, the third switch component 321 and the fourth switch component 322 are turned on, and when the fourth control signal (for example, a low-level signal) is sent to the control end of the series switch sub-module 32, the third switch component 321 and the fourth switch component 322 are turned off. The application realizes the on-off function of the series switch sub-module 32 through the third switch component 321 and the fourth switch component 322, and can accurately realize the switching of the series state of the plurality of capacitor modules 2.

[0027] Optionally, the switch component (including the first switch component 311, the second switch component 312, the third switch component 321, the fourth switch component 322 and the fifth switch component 331) provided by the application can be a MOS tube (for example, an NMOS tube, a PMOS tube) and / or a transistor (for example, an NPN transistor, a PNP transistor), and in the figure, an NMOS tube is taken as the first switch component 311, the second switch component 312, the third switch component 321 and the fourth switch component 322, and a PNP transistor is taken as the fifth switch component 331, which is taken as an example for description, wherein the drain, the source and the gate of the NMOS tube are respectively taken as the first connection end, the second connection end and the control end of the switch component, and the emitter, the collector and the base of the PNP transistor are respectively taken as the first connection end, the second connection end and the control end of the switch component.

[0028] In one embodiment, the connection conversion module 3 provided by the present application further comprises a plurality of turn-off acceleration sub-modules 33, the turn-off acceleration sub-modules 33 correspond to the parallel switch sub-modules 31 and / or the series switch sub-modules 32 one by one and are connected with the corresponding parallel switch sub-modules 31 and / or the series switch sub-modules 32, the turn-off acceleration sub-modules 33 are used to accelerate the turn-off speed of the parallel switch sub-modules 31 and / or the series switch sub-modules 32, which can effectively reduce the damage of the high-frequency switch action of the parallel switch sub-modules 31 and / or the series switch sub-modules 32 and prolong the service life of the battery equalization circuit.

[0029] In one embodiment, the turn-off acceleration sub-module 33 provided by the present application comprises a fifth switch element 331, a first diode 332 and a first resistor. When the turn-off acceleration sub-module 33 is arranged in the parallel switch sub-module 31, as shown in FIG. 4, the first connection end of the fifth switch element 331 is connected with the control end of the corresponding first switch element 311, the control end of the corresponding second switch element 312 and the cathode end of the diode, the second connection end of the fifth switch element 331 is connected with the second connection end of the corresponding first switch element 311, the anode end of the diode is connected with the control end of the fifth switch element 331 and the control module 4, the first connection end of the first resistor is connected with the control end of the fifth switch element 331, and the second connection end of the first resistor is connected with the second connection end of the fifth switch element 331, the turn-off acceleration of the parallel switch sub-module 31 is realized by the fifth switch element, the first diode 332 and the first resistor, which can effectively reduce the damage of the high-frequency switch action of the parallel switch sub-module 31 and prolong the service life of the battery equalization circuit. Figure 3 In one embodiment, when the turn-off acceleration sub-module 33 is arranged in the series switch sub-module 32, as shown in FIG. 5, the first connection end of the fifth switch element 331 is connected with the control end of the corresponding third switch element 321, the control end of the corresponding fourth switch element 322 and the cathode end of the diode, the second connection end of the fifth switch element 331 is connected with the second connection end of the corresponding third switch element 321, the anode end of the diode is connected with the control end of the fifth switch element 331 and the control module 4, the first connection end of the first resistor is connected with the control end of the fifth switch element 331, and the second connection end of the first resistor is connected with the second connection end of the fifth switch element 331, the turn-off acceleration of the series switch sub-module 32 is realized by the fifth switch element, the first diode 332 and the first resistor, which can effectively reduce the damage of the high-frequency switch action of the series switch sub-module 32 and prolong the service life of the battery equalization circuit.

[0030] Figure 4

[0031] ​​Optionally, in one possible embodiment, the capacitor module 2 provided by the present application can be configured as 2, or 3 or more, through the combination of different numbers of capacitor modules 2, the flexibility of circuit design is improved, the number of capacitor modules 2 can be configured according to different circuit design requirements and battery cell specifications, and more flexible selection space can be provided for the capacitor module 2.

[0032] In one possible embodiment, as Figure 5 A battery equalization circuit principle diagram in the capacitor charging stage is provided, and Figure 6 As shown in a battery equalization circuit structure diagram in the capacitor charging stage provided by the present application, the capacitor module 2 provided by the present application includes a first capacitor (CE1 in the figure) and a second capacitor (CE2 in the figure), a plurality of parallel switch sub-modules 31 includes a first parallel switch sub-module (A1 in the figure), a second parallel switch sub-module (A2 in the figure) and a third parallel switch sub-module (A3 in the figure), a plurality of series switch sub-modules 32 includes a first series switch sub-module (B1 in the figure) and a second series switch sub-module (B2 in the figure). a1, a2 and a3 are respectively the first connection end, the second connection end and the control end of the parallel switch sub-module 31, b1, b2 and b3 are respectively the first connection end, the second connection end and the control end of the series switch sub-module 32. Figure 6 Q1 and Q2 correspond to the first parallel switch sub-module, Q3 and Q4 correspond to the second parallel switch sub-module, Q7 and Q8 correspond to the third parallel switch sub-module, Q5 and Q6 correspond to the first series switch sub-module, and Q9 and Q10 correspond to the second series switch sub-module. At this time, Figure 5 CELL is the battery cell with the highest voltage in the battery pack accessed through the switch channel composed of MOS tubes.

[0033] The first connection end of the first parallel switch sub-module is connected with the equalization voltage connection end, the second connection end of the first parallel switch sub-module is connected with the positive pole end of the first capacitor, and the control end of the first parallel switch sub-module is connected with the control module 4. The first connection end of the second parallel switch sub-module is connected with the positive pole end of the first capacitor, the second connection end of the second parallel switch sub-module is connected with the positive pole end of the second capacitor, and the control end of the second parallel switch sub-module is connected with the control module 4. The first connection end of the third parallel switch sub-module is connected with the negative pole end of the second capacitor, the second connection end of the third parallel switch sub-module is connected with the negative pole end of the first capacitor, and the control end of the third parallel switch sub-module is connected with the control module 4. The first connection end of the first series switch sub-module is connected with the positive pole end of the first capacitor, the second connection end of the first series switch sub-module is connected with the negative pole end of the second capacitor, and the control end of the first series switch sub-module is connected with the control module 4. The first connection end of the second series switch sub-module is connected with the equalization voltage connection end, the second connection end of the second series switch sub-module is connected with the positive pole end of the second capacitor, and the control end of the second series switch sub-module is connected with the control module 4. Through the first parallel switch sub-module, the second parallel switch sub-module and the third parallel switch sub-module, and the first series switch sub-module and the second series switch sub-module, the application realizes accurate switching of the first capacitor and the second capacitor between the parallel state and the series state, accurately and flexibly switches the battery for energy storage and charging, can effectively reduce the energy loss in the battery equalization process, and improves the battery equalization effect.

[0034] As shown in Figure 5 and Figure 6 the control module 4 sends a first control signal (for example, a high-level signal) to the control end of each parallel switch sub-module 31 and sends a fourth control signal (for example, a low-level signal) to the control end of each series switch sub-module 32 in the capacitor charging stage. At this time, the first connection end and the second connection end of each parallel switch sub-module 31 are turned on, the first connection end and the second connection end of each series switch sub-module 32 are turned off, the first capacitor and the second capacitor are in a parallel state, and the current flowing direction of the power supply of the battery cell to the first capacitor and the second capacitor in the battery equalization circuit is shown by the arrow direction in the figure.

[0035] As shown in Figure 7 a battery equalization circuit principle schematic diagram in the capacitor discharging stage is provided, at this time, Figure 7The middle CELL is the battery cell with the lowest voltage in the battery group accessed by the switch channel composed of MOS tubes. The control module 4 sends a third control signal (for example, a low-level signal) to the control end of each parallel switch sub-module 31 and a second control signal (for example, a high-level signal) to the control end of each series switch sub-module 32 in the capacitor discharge stage. At this time, the first connection end and the second connection end of each parallel switch sub-module 31 are off, the first connection end and the second connection end of each series switch sub-module 32 are on, the first capacitor and the second capacitor are in series, and the current flowing direction of the first capacitor and the second capacitor in the battery equalization circuit to the battery cell is shown by the arrow direction in the figure.

[0036] In one possible embodiment, as Figure 8 Another principle schematic diagram of the battery equalization circuit in the capacitor charging stage is provided. The capacitor module 2 provided by the application includes a third capacitor, a fourth capacitor and a fifth capacitor, a plurality of parallel switch sub-modules 31 include a fourth parallel switch sub-module, a fifth parallel switch sub-module, a sixth parallel switch sub-module, a seventh parallel switch sub-module and an eighth parallel switch sub-module, and a plurality of series switch sub-modules 32 include a third series switch sub-module, a fourth series switch sub-module and a fifth series switch sub-module. At this time, Figure 8 The middle CELL is the battery cell with the highest voltage in the battery group accessed by the switch channel composed of MOS tubes.

[0037] The first connection end of the fourth parallel switch sub-module is connected with the equalization voltage connection end, the second connection end of the fourth parallel switch sub-module is connected with the positive electrode end of the third capacitor, and the control end of the fourth parallel switch sub-module is connected with the control module 4. The first connection end of the fifth parallel switch sub-module is connected with the positive electrode end of the third capacitor, the second connection end of the fifth parallel switch sub-module is connected with the positive electrode end of the fourth capacitor, and the control end of the fifth parallel switch sub-module is connected with the control module 4. The first connection end of the sixth parallel switch sub-module is connected with the negative electrode end of the fourth capacitor, the second connection end of the sixth parallel switch sub-module is connected with the negative electrode end of the third capacitor, and the control end of the sixth parallel switch sub-module is connected with the control module 4. The first connection end of the seventh parallel switch sub-module is connected with the positive electrode end of the fourth capacitor, the second connection end of the seventh parallel switch sub-module is connected with the positive electrode end of the fifth capacitor, and the control end of the seventh parallel switch sub-module is connected with the control module 4. The first connection end of the eighth parallel switch sub-module is connected with the negative electrode end of the fifth capacitor, the second connection end of the eighth parallel switch sub-module is connected with the negative electrode end of the fourth capacitor, and the control end of the eighth parallel switch sub-module is connected with the control module 4.

[0038] Furthermore, the first connection terminal of the third series switch submodule is connected to the positive terminal of the third capacitor, the second connection terminal of the third series switch submodule is connected to the negative terminal of the fourth capacitor, and the control terminal of the third series switch submodule is connected to the control module 4. The first connection terminal of the fourth series switch submodule is connected to the positive terminal of the fourth capacitor, the second connection terminal of the fourth series switch submodule is connected to the negative terminal of the fifth capacitor, and the control terminal of the fourth series switch submodule is connected to the control module 4. The first connection terminal of the fifth series switch submodule is connected to the equalization voltage connection terminal, the second connection terminal of the fifth series switch submodule is connected to the positive terminal of the fifth capacitor, and the control terminal of the fifth series switch submodule is connected to the control module 4. This application, through the fourth, fifth, sixth, seventh, and eighth parallel switch submodules, as well as the third, fourth, and fifth series switch submodules, achieves accurate switching between parallel and series states for the third, fourth, and fifth capacitors, enabling precise and flexible switching between energy storage and charging of the battery, effectively reducing energy loss during battery equalization and improving battery equalization performance.

[0039] like Figure 8 As shown, during the capacitor charging stage, the control module 4 sends a first control signal (e.g., a high-level signal) to the control terminal of each parallel switch submodule 31 and a fourth control signal (e.g., a low-level signal) to the control terminal of each series switch submodule 32. At this time, the first and second connection terminals of each parallel switch submodule 31 are turned on, and the first and second connection terminals of each series switch submodule 32 are turned off. The third, fourth, and fifth capacitors are in a parallel state. The direction of current flow from the battery cell to the third, fourth, and fifth capacitors in the battery balancing circuit is shown by the arrow in the figure.

[0040] like Figure 9 Another schematic diagram of the battery balancing circuit during the capacitor discharge stage is provided. Figure 9 In the middle, CELL is the battery cell with the lowest voltage in the battery pack connected via a switching channel composed of MOSFETs. During the capacitor discharge stage, control module 4 sends a third control signal (e.g., a low-level signal) to the control terminals of each parallel switch submodule 31 and a second control signal (e.g., a high-level signal) to the control terminals of each series switch submodule 32. At this time, the first and second connection terminals of each parallel switch submodule 31 are turned off, and the first and second connection terminals of each series switch submodule 32 are turned on. The third, fourth, and fifth capacitors are in series. The direction of current flow from the third, fourth, and fifth capacitors to the battery cell in the battery balancing circuit is shown by the arrow in the figure.

[0041] The above, by controlling the connection state between the plurality of capacitor modules to be switched to the parallel state by the connection conversion module 3 in the capacitor charging stage, the battery cell with higher voltage in the battery pack charges the plurality of capacitor modules in parallel, and the connection state between the plurality of capacitor modules is switched to the series state by the connection conversion module 3 in the capacitor discharging stage, at this time, the voltage provided by the plurality of capacitor modules in series is increased, and the battery cell with lower voltage in the battery pack can be normally charged, and the energy transfer through the capacitor module can effectively reduce the energy loss in the battery balancing process, and improve the battery balancing effect.

[0042] Figure 10 A principle diagram of a battery management circuit provided by the embodiment is given, referring to Figure 10 The battery management circuit includes a control module and a battery balancing circuit provided by any of the above embodiments, wherein the control module is connected with the control end of the connection conversion module in the battery balancing circuit.

[0043] The above, by controlling the connection state between the plurality of capacitor modules to be switched to the parallel state by the connection conversion module 3 in the capacitor charging stage, the battery cell with higher voltage in the battery pack charges the plurality of capacitor modules in parallel, and the connection state between the plurality of capacitor modules is switched to the series state by the connection conversion module 3 in the capacitor discharging stage, at this time, the voltage provided by the plurality of capacitor modules in series is increased, and the battery cell with lower voltage in the battery pack can be normally charged, and the energy transfer through the capacitor module can effectively reduce the energy loss in the battery balancing process, and improve the battery balancing effect.

[0044] The embodiment also provides an electronic device including a battery management circuit provided by the above embodiment. The electronic device controls the connection state between the plurality of capacitor modules to be switched to the parallel state by the connection conversion module in the capacitor charging stage by the control module, the battery cell with higher voltage in the battery pack charges the plurality of capacitor modules in parallel, and the connection state between the plurality of capacitor modules is switched to the series state by the connection conversion module in the capacitor discharging stage, at this time, the voltage provided by the plurality of capacitor modules in series is increased, and the battery cell with lower voltage in the battery pack can be normally charged, and the energy transfer through the capacitor module can effectively reduce the energy loss in the battery balancing process, and improve the battery balancing effect.

[0045] The embodiment also provides a battery management method, applied to the control module in the battery management circuit or the control module in the electronic device, including: S11: in the capacitor charging stage, a first control signal is sent to the connection conversion module to control the connection conversion module to switch the connection state between the plurality of capacitor modules to the parallel state.

[0046] Exemplarily, the control module accesses the battery cell with the highest voltage in the battery pack through the switch channel composed of MOS tubes in the capacitor charging stage, and sends a first control signal to the control end of each parallel switch sub-module and a fourth control signal to the control end of each series switch sub-module, at this time, the first connection end and the second connection end of each parallel switch sub-module are turned on, the first connection end and the second connection end of each series switch sub-module are turned off, the plurality of capacitor modules are in parallel state, and the battery cell with the highest voltage in the battery pack charges the plurality of capacitor modules in parallel state.

[0047] S12 sends a second control signal to the connection conversion module to control the connection conversion module to switch the connection state between the plurality of capacitor modules to series state in the capacitor discharging stage.

[0048] Exemplarily, the control module accesses the battery cell with the lowest voltage in the battery pack through the switch channel composed of MOS tubes in the capacitor charging stage, and sends a third control signal to the control end of each parallel switch sub-module and a second control signal to the control end of each series switch sub-module, at this time, the first connection end and the second connection end of each parallel switch sub-module are turned off, the first connection end and the second connection end of each series switch sub-module are turned on, the plurality of capacitor modules are in series state, and the plurality of capacitor modules in series state charge the battery cell with the lowest voltage in the battery pack.

[0049] The above, by controlling the connection conversion module to switch the connection state between the plurality of capacitor modules to parallel state in the capacitor charging stage, the battery cell with higher voltage in the battery pack charges the plurality of capacitor modules in parallel, and by controlling the connection conversion module to switch the connection state between the plurality of capacitor modules to series state in the capacitor discharging stage, the plurality of capacitor modules in series provide higher voltage, which can normally charge the battery cell with lower voltage in the battery pack, and the energy transfer through the capacitor module can effectively reduce the energy loss in the battery equalization process and improve the battery equalization effect.

[0050] The above is only the preferred embodiment of the present application and the technical principle applied. The present application is not limited to the specific embodiments provided herein, and various obvious changes, re-adjustments and replacements made by those skilled in the art will not deviate from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without deviating from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. A battery equalization circuit, characterized by, The equalization voltage connection circuit, the plurality of capacitor modules, and the connection conversion module are connected, wherein: The positive terminals of the plurality of capacitor modules are connected with the equalization voltage connection circuit, and the negative terminals of the plurality of capacitor modules are connected with the negative terminal of the equalization circuit, and the equalization voltage connection circuit is used for connecting battery cells; The connection conversion module is connected with the plurality of capacitor modules, and the connection conversion module is used for switching the connection state between the plurality of capacitor modules, and the connection state includes a parallel state and a series state; The control terminal of the connection conversion module is used for connecting a control module, and in response to a first control signal sent by the control module in a capacitor charging stage, the connection conversion module is controlled to switch the connection state between the plurality of capacitor modules to the parallel state, and in response to a second control signal sent by the control module in a capacitor discharging stage, the connection conversion module is controlled to switch the connection state between the plurality of capacitor modules to the series state.

2. The battery equalization circuit of claim 1, wherein, The connection conversion module includes a plurality of parallel switch sub-modules and a plurality of series switch sub-modules, wherein: The plurality of parallel switch sub-modules are connected in a parallel loop of the plurality of capacitor modules, and are used for turning on or turning off the parallel state of the plurality of capacitor modules; The plurality of series switch sub-modules are connected in a series loop of the plurality of capacitor modules, and are used for turning on or turning off the series state of the plurality of capacitor modules.

3. A battery equalization circuit according to claim 2, characterized in that The parallel switch sub-module includes a first switch piece and a second switch piece, the second connection terminal of the first switch piece is connected with the first connection terminal of the second switch piece, the control terminal of the first switch piece and the control terminal of the second switch piece are connected with the control module, the series switch sub-module includes a third switch piece and a fourth switch piece, the second connection terminal of the third switch piece is connected with the first connection terminal of the fourth switch piece, and the control terminal of the third switch piece and the control terminal of the fourth switch piece are connected with the control module.

4. The battery equalization circuit of claim 2, wherein, The connection conversion module further includes a plurality of turn-off acceleration sub-modules, the turn-off acceleration sub-modules correspond to the parallel switch sub-modules and / or the series switch sub-modules, and are connected with the corresponding parallel switch sub-modules and / or series switch sub-modules, and the turn-off acceleration sub-modules are used for accelerating the turn-off speed of the parallel switch sub-modules and / or the series switch sub-modules.

5. A battery equalization circuit according to claim 4, characterized in that The turn-off acceleration sub-module includes a fifth switch piece, a first diode, and a first resistor, wherein: The first connection terminal of the fifth switch piece is connected with the control terminal of the corresponding first switch piece, the control terminal of the corresponding second switch piece, and the cathode terminal of the diode, the second connection terminal of the fifth switch piece is connected with the second connection terminal of the corresponding first switch piece, the anode terminal of the diode is connected with the control terminal of the fifth switch piece and the control module, the first connection terminal of the first resistor is connected with the control terminal of the fifth switch piece, and the second connection terminal of the first resistor is connected with the second connection terminal of the fifth switch piece; and / or The first connection end of the fifth switch element is connected with the control end of the corresponding third switch element, the control end of the corresponding fourth switch element and the cathode end of the diode, the second connection end of the fifth switch element is connected with the second connection end of the corresponding third switch element, the anode end of the diode is connected with the control end of the fifth switch element and the control module, the first connection end of the first resistor is connected with the control end of the fifth switch element, and the second connection end of the first resistor is connected with the second connection end of the fifth switch element.

6. The battery equalization circuit of claim 2, wherein, The capacitor module comprises a first capacitor and a second capacitor, a plurality of the parallel switch sub-modules comprises a first parallel switch sub-module, a second parallel switch sub-module and a third parallel switch sub-module, and a plurality of the series switch sub-modules comprises a first series switch sub-module and a second series switch sub-module, wherein: The first connection end of the first parallel switch sub-module is connected with the equalization voltage connection line, the second connection end of the first parallel switch sub-module is connected with the positive electrode end of the first capacitor, and the control end of the first parallel switch sub-module is connected with the control module. The first connection end of the second parallel switch sub-module is connected with the positive electrode end of the first capacitor, the second connection end of the second parallel switch sub-module is connected with the positive electrode end of the second capacitor, and the control end of the second parallel switch sub-module is connected with the control module. The first connection end of the third parallel switch sub-module is connected with the negative electrode end of the second capacitor, the second connection end of the third parallel switch sub-module is connected with the negative electrode end of the first capacitor, and the control end of the third parallel switch sub-module is connected with the control module. The first connection end of the first series switch sub-module is connected with the positive electrode end of the first capacitor, the second connection end of the first series switch sub-module is connected with the negative electrode end of the second capacitor, and the control end of the first series switch sub-module is connected with the control module. The first connection end of the second series switch sub-module is connected with the equalization voltage connection line, the second connection end of the second series switch sub-module is connected with the positive electrode end of the second capacitor, and the control end of the second series switch sub-module is connected with the control module.

7. The battery equalization circuit of claim 2, wherein, The capacitor module comprises a third capacitor, a fourth capacitor and a fifth capacitor, a plurality of the parallel switch sub-modules comprises a fourth parallel switch sub-module, a fifth parallel switch sub-module, a sixth parallel switch sub-module, a seventh parallel switch sub-module and an eighth parallel switch sub-module, and a plurality of the series switch sub-modules comprises a third series switch sub-module, a fourth series switch sub-module and a fifth series switch sub-module, wherein: The first connection end of the fourth parallel switch sub-module is connected with the equalization voltage connection line, the second connection end of the fourth parallel switch sub-module is connected with the positive electrode end of the third capacitor, and the control end of the fourth parallel switch sub-module is connected with the control module. The first connecting end of the fifth parallel switch sub-module is connected with the positive pole end of the third capacitor, the second connecting end of the fifth parallel switch sub-module is connected with the positive pole end of the fourth capacitor, and the control end of the fifth parallel switch sub-module is connected with the control module; The first connecting end of the sixth parallel switch sub-module is connected with the negative pole end of the fourth capacitor, the second connecting end of the sixth parallel switch sub-module is connected with the negative pole end of the third capacitor, and the control end of the sixth parallel switch sub-module is connected with the control module; The first connecting end of the seventh parallel switch sub-module is connected with the positive pole end of the fourth capacitor, the second connecting end of the seventh parallel switch sub-module is connected with the positive pole end of the fifth capacitor, and the control end of the seventh parallel switch sub-module is connected with the control module; The first connecting end of the eighth parallel switch sub-module is connected with the negative pole end of the fifth capacitor, the second connecting end of the eighth parallel switch sub-module is connected with the negative pole end of the fourth capacitor, and the control end of the eighth parallel switch sub-module is connected with the control module; The first connecting end of the third series switch sub-module is connected with the positive pole end of the third capacitor, the second connecting end of the third series switch sub-module is connected with the negative pole end of the fourth capacitor, and the control end of the third series switch sub-module is connected with the control module; The first connecting end of the fourth series switch sub-module is connected with the positive pole end of the fourth capacitor, the second connecting end of the fourth series switch sub-module is connected with the negative pole end of the fifth capacitor, and the control end of the fourth series switch sub-module is connected with the control module; The first connecting end of the fifth series switch sub-module is connected with the equalization voltage connection line, the second connecting end of the fifth series switch sub-module is connected with the positive pole end of the fifth capacitor, and the control end of the fifth series switch sub-module is connected with the control module.

8. A battery management circuit, characterized by, A battery management circuit comprising a control module and a battery equalization circuit according to any one of claims 1-7, wherein the control module is connected with the control end of the connection conversion module in the battery equalization circuit.

9. An electronic device, comprising: A battery management circuit according to claim 8.

10. A battery management method applied to the control module in the battery management circuit according to claim 8 or the control module in the electronic device according to claim 9, characterized in that, Comprising: In the capacitor charging phase, a first control signal is sent to the connection conversion module to control the connection conversion module to switch the connection state between the plurality of capacitor modules to a parallel state; In the capacitor discharging phase, a second control signal is sent to the connection conversion module to control the connection conversion module to switch the connection state between the plurality of capacitor modules to a series state.

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