Battery bidirectional equalization control method and control circuit

Abstract

The invention provides a battery bidirectional equalization control method and a control circuit. A bidirectional switching circuit receives a control signal, controls a switch and a rectifying device to be turned off according to the control signal, detects the winding voltage of a transformer, and controls the switch and the rectifying device to be turned on according to the control signal and the winding voltage. Or the voltage of the transformer winding does not need to be detected, and the switch and the rectifying device are controlled to be switched on after a period of time. According to the battery bidirectional equalization control method and the control circuit, when the control signal is at a high level, the switch and the rectification device are turned off, and when the control signal is at a low level, whether the switch and the rectification device are turned on or not is determined by detecting whether the voltage of the transformer winding jumps or not. Or after a period of time is delayed, the switch and the rectifying device are switched on. Two-way transmission can be achieved only through one signal isolation device, and the problem that in the prior art, switches and rectifying devices of the primary side and the secondary side are conducted at the same time is solved.

Description

Technical Field

[0001] The present invention relates to the field of battery bidirectional balancing control, and in particular to a battery bidirectional balancing control method and a control circuit. Background Art

[0002] The battery energy storage industry is currently developing rapidly and its applications are becoming more and more extensive. Due to battery materials and processes, the voltage of individual batteries in the battery pack will be different after charging or discharging. This will reduce the life of the battery pack and cause safety problems due to overcharging. The cost of batteries accounts for more than 80% of the total cost. Improving battery life is equivalent to significantly reducing costs. Battery balancing technology has now become a necessary means to improve battery life.

[0003] Bidirectional balancing technology, in simple terms, is to charge the low-voltage battery and discharge the high-voltage battery, so that the working conditions of each single battery can reach the same state. The general working power of the balancing module is 5W~15W. The existing technology is generally as follows Figure 1 As shown. The key point is to control some devices in the circuit to work or not work through the control signal CTL, forming two flyback circuits for forward work (charging) and reverse work (discharging). When working in the forward direction, the control signal CTL controls the PWM controller 1 to work, and the control signal CTL controls the synchronous rectification controller to work through the optocoupler, and the PWM controller 2 does not work; accordingly, the MOS tube TR1 is the main switch tube, the MOS tube TR2 is the synchronous rectifier tube, and the diode D1 does not participate in the work. When discharging in the reverse direction, the control signal CTL controls the PWM controller 1 not to work, and the control signal CTL controls the synchronous rectification controller not to work through the optocoupler, and the PWM controller 2 works; accordingly, the MOS tube TR2 is the main switch tube, the diode D1 is the freewheeling diode, and the MOS tube TR1 does not participate in the work.

[0004] Regardless of the control mode, the PWM controller will actively output a square wave signal to control the on and off of the MOS tube. Figure 1 In the flyback circuit composed of the transformer and MOS tubes TR1 and TR2, MOS tubes TR1 and TR2 are controlled by different PWM controllers respectively, and MOS tubes TR1 and TR2 may be turned on at the same time, which is equivalent to connecting the primary and secondary ends of the transformer to the input and output at the same time. At this time, the current flowing from the VIN+ end is IIN=(V IN+ N PS *V O ) / R 内阻 . R 内阻 It is the sum of the internal resistance of the MOS tube and the internal resistance of the circuit, which is usually less than 0.1Ω. Therefore, the current flowing through the MOS tube will be very large, causing damage to the device. Therefore, in practical applications, it is absolutely necessary to avoid the situation where the primary and secondary PWM controllers work at the same time.

[0005] The basic control principle of the synchronous rectification controller is to detect the negative voltage of the MOS tube body diode before controlling the MOS tube to turn on. Figure 1 In the main power circuit, if the MOS tubes TR1 and TR2 are connected to the synchronous rectification controller but not the PWM controller, even if the synchronous rectification controllers on the primary and secondary sides work at the same time, there will be no reliability problem of simultaneous conduction. This is because when the power is turned on, the synchronous rectification controller is waiting for the negative voltage of the MOS tube, but the MOS tube is in the off state when it is powered on, and there is no current, which causes the synchronous rectification controller to never output a square wave signal, the MOS tube is always in the off state, and the circuit does not work.

[0006] In industrial control applications, interference is often large. If the protection circuit is not handled properly, the control signal CTL may generate random jitters. The control signal CTL controls the operation of the two PWM controllers on the primary and secondary sides. There is a certain delay in the start and shutdown of the PWM controller. At this time, if the control signal CTL jitters, the two PWM controllers on the primary and secondary sides will work at the same time, and there is a probability that the MOS tube TR1 and the MOS tube TR2 will be turned on at the same time, which will eventually lead to damage. Therefore, it is necessary to improve the current control technology to solve the current reliability problem. Summary of the invention

[0007] The purpose of the present invention is to provide a battery bidirectional balancing control method and a control circuit, which can solve the problem of simultaneous conduction of two power MOS tubes on the primary and secondary sides in the prior art.

[0008] The objective of the present invention is achieved through the following technical solutions:

[0009] In one aspect, the present invention provides a battery bidirectional balancing control method, comprising the following steps:

[0010] S1, a first bidirectional switching circuit and a signal isolation device receive an external control signal;

[0011] S2. If the control signal is a positive working signal, the first bidirectional switching circuit detects the working voltage of the first winding of the transformer. When the working voltage of the first winding is a stable voltage, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned on through the first main controller; the signal isolation device flips the control signal and outputs it to the second bidirectional switching circuit, and then goes to S3; or

[0012] If the control signal is a forward working signal, the first bidirectional switching circuit delays for a period of time, and then controls the first switch and the rectifier device to be turned on through the first main controller; the signal isolation device flips the control signal and outputs it to the second bidirectional switching circuit, and then goes to S3;

[0013] If the control signal is a reverse working signal, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned off through the first main controller; the signal isolation device reverses the control signal and outputs it to the second bidirectional switching circuit, and then goes to S4;

[0014] S3, the second bidirectional switching circuit controls the second switch and the rectifier device to turn off through the second main controller, and returns to S1;

[0015] S4, the second bidirectional switching circuit detects the operating voltage of the second winding of the transformer. When the operating voltage of the second winding is a stable voltage, the second bidirectional switching circuit controls the second switch and the rectifier device to be turned on through the second main controller, and returns to S1; or

[0016] After a delay of a period of time, the second bidirectional switching circuit controls the second switch and the rectifying device to be turned on through the second main controller, and returns to S1.

[0017] On the other hand, the present invention provides a battery bidirectional balancing control circuit, comprising a transformer and a signal isolation device, and further comprising a first switch and a rectifier device, a first main controller and a first bidirectional switching circuit connected in sequence between a first winding of the transformer and one end of the signal isolation device, and a second switch and a rectifier device, a second main controller and a second bidirectional switching circuit connected in sequence between a second winding of the transformer and the other end of the signal isolation device;

[0018] A control signal is input to the input end of the first bidirectional switching circuit, and the first switch and the rectifying device are controlled to be turned off according to the control signal; a voltage signal of the first winding of the transformer is detected, and the first switch and the rectifying device are controlled to be turned on according to the control signal and the voltage signal of the first winding; or

[0019] The input end of the first bidirectional switching circuit inputs a control signal, controls the first switch and the rectifying device to be turned off according to the control signal, and controls the first switch and the rectifying device to be turned on after a delay of a period of time according to the control signal;

[0020] One end of the signal isolation device receives the control signal and outputs it to the second bidirectional switching circuit from the other end of the signal isolation device after transmission;

[0021] The input end of the second bidirectional switching circuit inputs a control signal transmitted by the signal isolation device, and controls the second switch and the rectifier device to be turned off according to the control signal transmitted by the signal isolation device; detects the voltage signal of the second winding of the transformer, and controls the second switch and the rectifier device to be turned on according to the control signal transmitted by the signal isolation device and the voltage signal of the second winding; or

[0022] The input end of the second bidirectional switching circuit inputs a control signal transmitted by the signal isolation device, and controls the second switch and the rectifier device to be turned off according to the control signal transmitted by the signal isolation device; and controls the second switch and the rectifier device to be turned on after a delay period according to the control signal.

[0023] Furthermore, the first main controller or the second main controller includes a PWM controller.

[0024] Further, the first switch and rectifying device includes a first MOS transistor TR1 and a first diode D1, and the second switch and rectifying device includes a second MOS transistor TR2 and a second diode D2; the anode of the first diode D1 is respectively connected to the source of the first MOS transistor TR1, the anode of the second diode D2 and the source of the second MOS transistor TR2; the cathode of the first diode D1 is respectively connected to the drain of the first MOS transistor TR1 and one end of the first winding; the cathode of the second diode D2 is respectively connected to the drain of the second MOS transistor TR2 and one end of the second winding; the gate of the first MOS transistor TR1 is connected to the PWM controller in the first main controller, and the gate of the second MOS transistor TR2 is connected to the PWM controller in the second main controller.

[0025] Furthermore, the first main controller or the second main controller includes a PWM controller and a synchronous rectification controller connected in parallel.

[0026] Further, the first switch and rectifying device is a first MOS transistor TR1, and the second switch and rectifying device is a second MOS transistor TR2; the source of the first MOS transistor TR1 is connected to the ground GND_P on one side of the first winding of the transformer, and the source of the second MOS transistor TR2 is connected to the ground GND_S on one side of the second winding of the transformer; the drain of the first MOS transistor TR1 is connected to one end of the first winding; the drain of the second MOS transistor TR2 is connected to one end of the second winding; the gate of the first MOS transistor TR1 is connected to the first main controller, and the gate of the second MOS transistor TR2 is connected to the second main controller.

[0027] Furthermore, the first bidirectional switching circuit or the second bidirectional switching circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first comparator COMP1, a second comparator COMP2, a third comparator COMP3, a first capacitor C1, a first RS trigger RS1, a first NOT gate NOT1 and a first AND gate AND1; the reverse input end of the second comparator COMP2 serves as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit; one end of the first resistor R1 is connected to one end of the first winding or one end of the second winding; the other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the reverse input end of the third comparator COMP3; the positive input end of the third comparator COMP3, the positive input end of the second comparator COMP2 and the positive input end of the first comparator COMP1 are respectively input with a reference voltage REF; the output of the third comparator COMP3 The first end of the second resistor R2 is connected to one end of the third resistor R3, and the other end of the third resistor is respectively connected to one end of the first capacitor C1, one end of the fourth resistor R4 and the inverting input end of the first comparator COMP1; the other end of the second resistor R2, the other end of the first capacitor C1 and the other end of the fourth resistor R4 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding; the output end of the first comparator COMP1 is connected to the S end of the first RS trigger RS1, and the output end of the second comparator COMP2 is respectively connected to an input end of the first AND gate AND1 and an input end of the first NOT gate NOT1; the output end of the first NOT gate NOT1 is connected to the R end of the first RS trigger RS1; the Q end of the first RS trigger RS1 is connected to the other input end of the first AND gate AND1; the output end of the first AND gate AND1 outputs the PWM control signal PWM_EN to the PWM controller of the first master controller or the PWM controller of the second master controller.

[0028] Furthermore, the first bidirectional switching circuit or the second bidirectional switching circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first comparator COMP1, a second comparator COMP2, a third comparator COMP3, a first capacitor C1, a first RS trigger RS1, a first NOT gate NOT1 and a first AND gate AND1; the reverse input end of the second comparator COMP2 serves as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit; one end of the first resistor R1 is connected to one end of the first winding or one end of the second winding; the other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the reverse input end of the third comparator COMP3; the positive input end of the third comparator COMP3, the positive input end of the second comparator COMP2 and the positive input end of the first comparator COMP1 are respectively input with a reference voltage REF; the output end of the third comparator COMP3 is connected to one end of the third resistor R3, and the other end of the third resistor is respectively connected to one end of the third resistor R3. One end of the first capacitor C1, one end of the fourth resistor R4 and the inverting input end of the first comparator COMP1 are connected; the other end of the second resistor R2, the other end of the first capacitor C1 and the other end of the fourth resistor R4 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding; the output end of the first comparator COMP1 is connected to the S end of the first RS trigger RS1, and the output end of the second comparator COMP2 is respectively connected to an input end of the first AND gate AND1 and an input end of the first NOT gate NOT1; the output end of the first NOT gate NOT1 is connected to the R end of the first RS trigger RS1, and outputs the synchronous rectification control signal SR_EN to the synchronous rectification controller of the first master controller or the synchronous rectification controller of the second master controller; the Q end of the first RS trigger RS1 is connected to the other input end of the first AND gate AND1; the output end of the first AND gate AND1 outputs the PWM control signal PWM_EN to the PWM controller of the first master controller or the PWM controller of the second master controller.

[0029] Further, the first bidirectional switching circuit or the second bidirectional switching circuit includes a first resistor R1, a second resistor R2, a counter, a second comparator COMP2, a first RS trigger RS1 and a first AND gate AND1; the reverse input end of the second comparator COMP2 is used as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit, and the positive input end of the second comparator COMP2 inputs the reference voltage REF; one end of the first resistor R1 is connected to one end of the first winding or one end of the second winding; the other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the reset input port RS of the counter; the other end of the second resistor R2 is connected to the ground G on one side of the first winding ND_P or the ground GND_S on one side of the second winding; the clock input port CT of the counter inputs a set number of square wave signals CLK; the output end OUT of the counter is connected to the S end of the first RS trigger RS1, and the output end of the second comparator COMP2 is respectively connected to an input end of the first AND gate AND1 and an input end of the first NOT gate NOT1; the output end of the first NOT gate NOT1 is connected to the R end of the first RS trigger RS1; the Q end of the first RS trigger RS1 is connected to the other input end of the first AND gate AND1; the output end of the first AND gate AND1 outputs the PWM control signal PWM_EN to the PWM controller of the first master controller or the PWM controller of the second master controller.

[0030] Further, the first bidirectional switching circuit or the second bidirectional switching circuit includes a first resistor R1, a second resistor R2, a counter, a second comparator COMP2, a first RS trigger RS1, a first NOT gate NOT1 and a first AND gate AND1; the reverse input end of the second comparator COMP2 serves as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit, and the reference voltage REF is input to the positive input end of the second comparator COMP2; one end of the first resistor R1 is connected to one end of the first winding or one end of the second winding; the other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the reset input port RS of the counter; the other end of the second resistor R2 is connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding; A set number of square wave signals CLK are input to the clock input port CT of the counter; the output end OUT of the counter is connected to the S end of the first RS trigger RS1, and the output end of the second comparator COMP2 is respectively connected to an input end of the first AND gate AND1 and an input end of the first NOT gate NOT1; the output end of the first NOT gate NOT1 is connected to the R end of the first RS trigger RS1, and outputs a synchronous rectification control signal SR_EN to the synchronous rectification controller of the first master controller or the synchronous rectification controller of the second master controller; the Q end of the first RS trigger RS1 is connected to the other input end of the first AND gate AND1; the output end of the first AND gate AND1 outputs a PWM control signal PWM_EN to the PWM controller of the first master controller or the PWM controller of the second master controller.

[0031] Further, the first bidirectional switching circuit or the second bidirectional switching circuit includes a fourth comparator COMP7, a fifth comparator COMP8, a fifth resistor R5, a first transistor Q1 and a second capacitor C2; the reverse input end of the fourth comparator COMP7 serves as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit, and the positive input end of the fourth comparator COMP7 and the reverse input end of the fifth comparator COMP8 input the reference voltage REF; the output end of the fourth comparator COMP7 is respectively connected to one end of the fifth resistor R5 and the base of the first transistor Q1; the other end of the fifth resistor R5 is respectively connected to the emitter of the first transistor Q1, one end of the second capacitor C2 and the positive input end of the fifth comparator COMP8; the collector of the first transistor Q1 and the other end of the second capacitor C2 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding; the output end of the fifth comparator COMP8 outputs a PWM control signal PWM_EN to the PWM controller of the first master controller or the PWM controller of the second master controller.

[0032] Furthermore, the first bidirectional switching circuit or the second bidirectional switching circuit includes a fourth comparator COMP7, a fifth comparator COMP8, a fifth resistor R5, a first transistor Q1, a second capacitor C2 and a second NOT gate NOT2; the reverse input end of the fourth comparator COMP7 serves as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit, and the reference voltage REF is input to the positive input end of the fourth comparator COMP7 and the reverse input end of the fifth comparator COMP8; the output end of the fourth comparator COMP7 is respectively connected to one end of the fifth resistor R5, the base of the first transistor Q1 and the input end of the second NOT gate NOT2; the output end of the second NOT gate NOT2 outputs a synchronous rectification control signal SR_EN to the synchronous rectification controller of the first master controller or the synchronous rectification controller of the second master controller; the collector of the first transistor Q1 and the other end of the second capacitor C2 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding; the output end of the fifth comparator COMP8 outputs a PWM control signal PWM_EN to the PWM controller of the first master controller or the PWM controller of the second master controller.

[0033] The present invention discloses a battery bidirectional balancing control method and control circuit. When the control signal is at a high level, the switch and the rectifier are turned off. When the control signal is at a low level, the switch and the rectifier are detected to determine whether to turn on the switch and the rectifier. Alternatively, the switch and the rectifier are turned on after a delay of a period of time. The present invention can realize bidirectional transmission with only one signal isolation device, solving the problem of simultaneous conduction of the switch and the rectifier on the primary and secondary sides in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a block diagram of a battery bidirectional balancing control circuit in the prior art;

[0035] Figure 2 The block diagram of the battery bidirectional balancing control circuit of the present invention;

[0036] Figure 3 A waveform timing diagram of a battery bidirectional balancing control circuit block diagram of the present invention;

[0037] Figure 4 This is a block diagram of a battery bidirectional balancing control circuit according to Embodiment 1 of the present invention;

[0038] Figure 5 One of the circuit principle diagrams of the bidirectional switching circuit of the present invention;

[0039] Figure 6 This is a waveform timing diagram of a battery bidirectional balancing control circuit according to the first embodiment of the present invention;

[0040] Figure 7 A schematic diagram of a synchronous rectification controller;

[0041] Figure 8 The second circuit schematic diagram of the bidirectional switching circuit of the present invention;

[0042] Fig. 9 This is a block diagram of a battery bidirectional balancing control circuit according to Embodiment 3 of the present invention;

[0043] Fig.10 This is a block diagram of a battery bidirectional balancing control circuit according to a fourth embodiment of the present invention;

[0044] Fig.11 The third circuit schematic diagram of the bidirectional switching circuit of the present invention;

[0045] Fig.12 The fourth circuit schematic diagram of the bidirectional switching circuit of the present invention;

[0046] Fig.13 This is a waveform timing diagram of a battery bidirectional balancing control circuit according to a fourth embodiment of the present invention;

[0047] Fig.14 A schematic diagram of a PWM controller. DETAILED DESCRIPTION

[0048] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0049] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present disclosure.

[0050] Embodiment 1

[0051] On the one hand, a battery bidirectional balancing control method of this embodiment includes the following steps:

[0052] S1, a first bidirectional switching circuit and a signal isolation device receive an external control signal;

[0053] S2. If the control signal is a positive working signal, the first bidirectional switching circuit detects the working voltage of the first winding of the transformer. When the working voltage of the first winding is a stable voltage, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned on through the first main controller; the signal isolation device flips the control signal and outputs it to the second bidirectional switching circuit, and then goes to S3.

[0054] If the control signal is a reverse working signal, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned off through the first main controller; the signal isolation device reverses the control signal and outputs it to the second bidirectional switching circuit, and then goes to S4;

[0055] S3, the second bidirectional switching circuit controls the second switch and the rectifier device to turn off through the second main controller, and returns to S1;

[0056] S4, the second bidirectional switching circuit detects the operating voltage of the second winding of the transformer. When the operating voltage of the second winding is a stable voltage, the second bidirectional switching circuit controls the second switch and the rectifier device to turn on through the second main controller, and returns to S1.

[0057] The first bidirectional switching circuit and the second bidirectional switching circuit will couple the transformer winding voltage. When it is detected that the transformer winding voltage is still in a high-low jump state (i.e., a square wave signal), this means that the switch and rectifier device on the opposite side are still working. It is necessary to wait until the transformer winding voltage is at a stable value (i.e., a high level) before the local PWM controller can be controlled to work. In the present invention, the first winding or the second winding can be a main power winding (primary winding or secondary winding) or an auxiliary winding.

[0058] The control signal CTL controls the battery bidirectional balancing control circuit to work forward or reverse. The control signal CTL can be a high level when the battery bidirectional balancing control circuit works forward, or a low level when the battery bidirectional balancing control circuit works forward. For the convenience of description, this embodiment takes the battery bidirectional balancing control circuit working forward when CTL is a low level as an example, but it does not mean that the protection scope of the present invention is limited to this.

[0059] Due to the characteristics of the device itself, the signal isolation device generally generates a transmission delay. After receiving the control signal CTL, it will delay for a period of time before outputting the flipped control signal. This is determined by the characteristics of the device itself. Of course, a signal isolation device without delay can also meet the requirements of the present invention.

[0060] When switching between forward and reverse operation, switch and rectifier device 1 and switch and rectifier device 2 cannot be in the switching mode at the same time, otherwise the left and right switches may be actively turned on. At this time, transformer T1 will be in a short-circuit state, causing device damage. When switch and rectifier device 1 and switch and rectifier device 2 are in the rectification mode at the same time, neither the primary side nor the secondary side will be actively turned on, and no problems will occur. This state is similar to a "dead zone interval". In actual work, due to the delay in signal transmission and signal switching, there is a delay in the mode switching of the switch and rectifier device, resulting in the risk of the circuit topology being in the switching mode at the same time. In order to ensure reliable forward and reverse switching, a certain dead zone interval must be left during the switching process, such as Figure 3 shown.

[0061] On the other hand, a battery bidirectional balancing control circuit of this embodiment is as follows Figure 2 and Figure 4 As shown, it includes a transformer T1 and a signal isolation device, and also includes a first switch and a rectifier device 1 connected between the first winding of the transformer T1 and one end of the signal isolation device, a first main controller 1 and a first bidirectional switching circuit 1, and a second switch and a rectifier device 2, a second main controller 2 and a second bidirectional switching circuit 2 connected between the second winding of the transformer T1 and the other end of the signal isolation device.

[0062] The input end of the first bidirectional switching circuit 1 inputs a control signal CTL, and controls the first switch and the rectifier device 1 to be turned off according to the control signal CTL; detects the voltage signal of the first winding of the transformer T1, and controls the first switch and the rectifier device 1 to be turned on according to the control signal CTL and the voltage signal of the first winding.

[0063] One end of the signal isolation device receives the control signal CTL and outputs it from the other end of the signal isolation device to the second bidirectional switching circuit 2 after transmission. The signal isolation device transmits the control signal CTL, which actually inverts the level of the control signal CTL.

[0064] The input end of the second bidirectional switching circuit 2 inputs the control signal transmitted by the signal isolation device, and controls the second switch and the rectifier device 2 to be turned off according to the control signal transmitted by the signal isolation device; detects the voltage signal of the second winding of the transformer T1, and controls the second switch and the rectifier device 2 to be turned on according to the flipped control signal and the voltage signal of the second winding.

[0065] In general applications, the two ends of the windings of transformer T1 are connected to batteries respectively, such as Figure 2 Battery 1 and Battery 2. When working in the forward direction, the battery bidirectional balancing control circuit discharges Battery 1 and charges Battery 2; when working in the reverse direction, the battery bidirectional balancing control circuit charges Battery 1 and discharges Battery 2.

[0066] The specific control process is as follows: when the control signal CTL is at a low level, the bidirectional switching circuit 1 controls the switch and the rectifier device 1 to work in the switching mode through the main controller 1; the control signal CTL is transmitted to the other end of the transformer through the signal isolator, and the bidirectional switching circuit 2 controls the switch and the rectifier device 2 to work in the rectification mode through the main controller 2. At this time, the main power circuit constitutes a forward-working flyback circuit, and the battery 1 is discharged as a power source, and the battery 2 is charged as a load. When CTL is at a high level, the main controller 1 controls the switch and the rectifier device 1 to work in the rectification mode; the control signal CTL is transmitted to the right side through the signal isolator, and the main controller 2 controls the switch rectifier device 2 to work in the switching mode. At this time, the main power circuit constitutes a reverse-working flyback circuit, and the battery 1 is charged as a load, and the battery 2 is discharged as a power source.

[0067] Furthermore, the first main controller 1 or the second main controller 2 includes a PWM controller and a synchronous rectification controller connected in parallel, such as Figure 4 When the above-mentioned operation is in the switching mode, the PWM controller is working and the synchronous rectification controller is not working; when the above-mentioned operation is in the rectification mode, the PWM controller is not working and the synchronous rectification controller is working.

[0068] Wherein: The PWM controller can adopt any control method of the existing technology, such as Fig.14 The voltage type control mode shown in the figure cuts off the conduction or shutdown of the GT port of the PWM controller through the PMW_EN signal, thereby controlling whether the module works. The synchronous rectification controller can adopt any control mode of the prior art, such as Figure 7 Typical discontinuous mode synchronous rectification control cuts off the connection with the GT port through the RS_EN signal to control whether the module works.

[0069] Further, the first switch and rectifier device 1 is a first MOS transistor TR1, and the second switch and rectifier device 2 is a second MOS transistor TR2. The source of the first MOS transistor TR1 is connected to the ground GND_P on one side of the first winding of the transformer, and the source of the second MOS transistor TR2 is connected to the ground GND_S on one side of the second winding of the transformer. The drain of the first MOS transistor TR1 is connected to one end of the first winding, and the drain of the second MOS transistor TR2 is connected to one end of the second winding. The gate of the first MOS transistor TR1 is connected to the first main controller 1, and the gate of the second MOS transistor TR2 is connected to the second main controller 2.

[0070] Furthermore, the first bidirectional switching circuit 1 or the second bidirectional switching circuit 2 is as follows Figure 5As shown, it includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first comparator COMP1, a second comparator COMP2, a third comparator COMP3, a first capacitor C1, a first RS trigger RS1, a first NOT gate NOT1 and a first AND gate AND1. The reverse input end of the second comparator COMP2 serves as the input end of the first bidirectional switching circuit 1 or the input end of the second bidirectional switching circuit 2. One end of the first resistor R1 is connected to one end of the first winding or one end of the second winding. The other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the reverse input end of the third comparator COMP3. The positive input end of the third comparator COMP3, the positive input end of the second comparator COMP2 and the positive input end of the first comparator COMP1 are respectively input with a reference voltage REF. The output end of the third comparator COMP3 is connected to one end of the third resistor R3, and the other end of the third resistor is respectively connected to one end of the first capacitor C1, one end of the fourth resistor R4 and the reverse input end of the first comparator COMP1. The other end of the second resistor R2, the other end of the first capacitor C1 and the other end of the fourth resistor R4 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding. The output end of the first comparator COMP1 is connected to the S end of the first RS trigger RS1, and the output end of the second comparator COMP2 is respectively connected to an input end of the first AND gate AND1 and an input end of the first NOT gate NOT1. The output end of the first NOT gate NOT1 is connected to the R end of the first RS trigger RS1, and outputs the synchronous rectification control signal SR_EN to the synchronous rectification controller in the first master controller or the second master controller. The Q end of the first RS trigger RS1 is connected to the other input end of the first AND gate AND1. The output end of the first AND gate AND1 outputs the PWM control signal PWM_EN to the PWM controller in the first master controller or the second master controller.

[0071] Combine the following Figures 4 to 6 The working principle of the present invention is described:

[0072] According to the description of the background technology, when the primary and secondary PWM controllers work at the same time, it will cause the reliability problem of the MOS tubes of the primary and secondary sides being turned on at the same time. In the present invention, in order to solve the problem of the MOS tubes of the primary and secondary sides being turned on at the same time, when the bidirectional switching circuit wants to control the local PWM controller to work, it is necessary to detect whether the PWM controller on the opposite side has stopped working. In this scheme, it is achieved in the following way. The bidirectional switching circuit couples the winding voltage of the transformer (it can be the main power winding or the auxiliary winding). When it is detected that the voltage of the transformer is still in a high-low jump state, this means that the MOS tube on the opposite side is still working. It is necessary to wait until the voltage of the transformer winding is at a stable value before the local PWM controller can be controlled to work. Because the circuits of the primary and secondary sides are completely symmetrical, in Figure 6In the key node waveform diagram, the prefix P_ is used to represent the device or signal on the primary side of the transformer, and the prefix S_ is used to represent the device or signal on the secondary side of the transformer.

[0073] When the control signal P_CTL of the primary side is 0, it is working in the forward direction. At this time, the control signal will control the PWM control signal P_PWM_EN=1 output by the bidirectional switching circuit of the primary side to control the PWM controller of the primary side to work; and control the synchronous rectification control signal P_SR_EN=0 output by the bidirectional switching circuit of the primary side to control the synchronous rectification controller of the primary side not to work. At the same time, the output signal S_CTL of the signal isolation device is 1. At this time, the S_CTL signal will control the PWM signal S_PWM_EN=0 output by the bidirectional switching circuit of the secondary side to control the PWM controller of the secondary side not to work; and control the synchronous rectification control signal S_SR_EN=1 output by the bidirectional switching circuit of the secondary side to control the synchronous rectification controller of the secondary side to work.

[0074] Combined with Figure 6 :

[0075] Before time t1, P_CTL=0, P_PWM_EN=1, the primary PWM controller is working, P_SR_EN=0, the primary synchronous rectification controller is not working; S_CTL=1, P_PWM_EN=0, the primary PWM controller is not working, S_SR_EN=1, and the secondary synchronous rectification controller is working.

[0076] At time t1, P_CTL changes from 0 to 1, at this time P_PWM_EN = 0, the primary PWM controller does not work, P_SR_EN = 1, the primary synchronous rectifier controller works. Due to the transmission delay of the signal isolation device, S_CTL is still maintained at 1, and the secondary synchronous rectifier controller works. As described in the background technology, when the primary and secondary synchronous rectifier controllers work at the same time, it is a dead time and does not cause reliability problems.

[0077] At time t2, S_CTL becomes 0. At this time, it is detected that the voltage VDS of the secondary winding of the transformer remains at a high voltage (i.e., the voltage across battery 2), proving that the primary PWM controller is no longer working. The comparator S_COMP3 outputs a low level, causing the voltage of the capacitor S_C1 to drop. When the voltage of S_C1 is lower than the reference voltage REF, the S input of the S_RS1 trigger receives a rising edge signal. At this time, the Q end of S_RS1 outputs a high level, and the output of the comparator S_COMP2 is also high, which eventually causes the AND gate S_AND1 to output a high level, controlling the secondary PWM controller to work. In the process of switching from forward operation to reverse operation, the PWM controllers on both the primary and secondary sides will not work at the same time.

[0078] At t3, P_CTL changes from 1 to 0, and P_SR_EN=1, the synchronous rectification controller on the primary side works, and the comparator P_COMP2 outputs a high level. However, due to the transmission delay of the signal isolation device at this time, the secondary side S_CTL signal has not yet changed to 1, so the secondary side PWM controller is still working, the voltage of P_VDS is a square wave signal, and the output of P_COMP3 is also a square wave signal, so that the average voltage of P_C1 is higher than the reference voltage REF, the output of the comparator P_COMP1 maintains a low level, P_RS1 also outputs a low level, and the output signal P_PWM_EN of the AND gate P_AND1 is also a low level, so the primary side PWM controller will not work. This prevents the primary and secondary side PWM controllers from working at the same time.

[0079] At t4, S_CTL becomes 1, the PWM controller on the secondary side does not work, and the synchronous rectification controller on the secondary side works. At this time, the MOS tubes TR1 and TR2 on both the primary and secondary sides are in the off state, the P_VDS signal is maintained at a high level, and the comparator P_COMP3 outputs a low level. At this time, the voltage of the capacitor C1 gradually decreases to below the threshold REF, the comparator P_COMP1 outputs a rising edge signal, and the Q end of P_RS1 outputs a high level. At t3, the comparator P_COMP2 has already output a high level, so the AND gate P_AND1 outputs a high level to control the PWM controller on the primary side to work. That is, when P_CTL=0 and P_VDS is at a high level (the secondary side PWM controller does not work), the primary side PWM controller works.

[0080] Embodiment 2

[0081] The difference from the first embodiment is that the first bidirectional switching circuit or the second bidirectional switching circuit of the first embodiment determines whether the MOS transistor on the opposite side is in a switching state by detecting the average voltage of the transformer winding. In the second embodiment, the edge signal of the transformer winding is detected to determine whether the MOS transistor on the opposite side is in a switching state. Therefore, the bidirectional switching circuit of the second embodiment is different from that of the first embodiment.

[0082] like Figure 8As shown, the first bidirectional switching circuit or the second bidirectional switching circuit of this embodiment includes a first resistor R1, a second resistor R2, a counter, a second comparator COMP2, a first RS trigger RS1, a first NOT gate NOT1 and a first AND gate AND1. The reverse input end of the second comparator COMP2 serves as the input end of the first bidirectional switching circuit 1 or the input end of the second bidirectional switching circuit 2, and the reference voltage REF is input to the positive input end of the second comparator COMP2. One end of the first resistor R1 is connected to one end of the first winding or one end of the second winding. The other end of the first resistor R1 is respectively connected to one end of the second resistor R2 and the reset input port RS of the counter. The other end of the second resistor R2 is connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding. The clock input port CT of the counter inputs a set number of square wave signals CLK. The output end OUT of the counter is connected to the S end of the first RS trigger RS1, and the output end of the second comparator COMP2 is respectively connected to one input end of the first AND gate AND1 and the input end of the first NOT gate NOT1. The output terminal of the first NOT gate NOT1 is connected to the R terminal of the first RS flip-flop RS1 and outputs the synchronous rectification control signal SR_EN. The Q terminal of the first RS flip-flop RS1 is connected to the other input terminal of the first AND gate AND1. The output terminal of the first AND gate AND1 outputs the PWM control signal PWM_EN.

[0083] The working principle of the bidirectional switching circuit of this embodiment is as follows: when the control signal CTL=0, COMP2 outputs a high level signal, the synchronous rectification control signal SR_EN=0, and the synchronous rectification controller is controlled not to work. When the MOS tube on the opposite side is still working, VDS outputs a square wave signal. The RS end of the counter is the reset input port. When a falling edge is received, the counter will be reset so that the output port OUT is always maintained at a low level. When the MOS tube on the opposite side is not working, VDS will maintain a high voltage. At this time, the RS port will not receive a reset signal. When the clock input port CT receives a set number of square wave signals, the output port OUT will be controlled to output a high level. At this time, the first trigger RS1 will output a high level, and the AND gate AND1 will output a high level to control the PWM control operation.

[0084] The circuit connection relationship and working principle of other circuits except the bidirectional switching circuit, and the battery bidirectional balancing control method of this embodiment are the same as those of the first embodiment, and are not described in detail here.

[0085] Embodiment 3

[0086] In the third embodiment, the synchronous rectification controller in the first and second embodiments is removed, and a diode D1 and a diode D2 are added between the drain and source of the power tube TR1 and the power tube TR2 as freewheeling diodes for reverse operation and forward operation, respectively. The bidirectional switching circuit can adopt the circuits of the first and second embodiments.

[0087] like Fig. 9 As shown, the first main controller 1 or the second main controller 2 includes a PWM controller, the first switch and rectifier device 1 includes a first MOS transistor TR1 and a first diode D1, and the second switch and rectifier device 2 includes a second MOS transistor TR2 and a second diode D2. The anode of the first diode D1 is connected to the source of the first MOS transistor TR1, and the cathode of the first diode D1 is connected to the drain of the first MOS transistor TR1. The anode of the second diode D2 is connected to the source of the second MOS transistor TR2, and the cathode of the second diode D2 is connected to the drain of the second MOS transistor TR2.

[0088] Its working principle is as follows: when working in the forward direction, MOS tube TR1 is turned on, diode D1 is not working, and MOS tube TR2 is not working. MOS tube TR1 is used as the main MOS tube, and diode D2 is used as a freewheeling diode to form a flyback circuit with primary input and secondary output. When working in the reverse direction, MOS tube TR2 is turned on, diode D2 is not working, and MOS tube TR1 is not working. MOS tube TR2 is used as the main MOS tube, and diode D1 is used as a freewheeling diode to form a flyback circuit with secondary input and primary output.

[0089] This embodiment removes the synchronous rectification controller, and the bidirectional switching circuit corresponds to the output of the synchronous rectification control signal SR_EN. The connection relationship and working principle of other components, the connection relationship of other circuit modules and the battery bidirectional balancing control method are the same as those of the first or second embodiment, which will not be described in detail here.

[0090] Embodiment 4

[0091] Different from the first to third embodiments, in the fourth embodiment, the bidirectional switching circuit ensures that the primary and secondary PWM controllers do not work simultaneously by delaying the operation of the PWM controller, rather than detecting the voltage of the transformer winding by the bidirectional switching circuit.

[0092] On the one hand, a battery bidirectional balancing control method of this embodiment includes the following steps:

[0093] S1, a first bidirectional switching circuit and a signal isolation device receive an external control signal;

[0094] S2, if the control signal is a forward working signal, the first bidirectional switching circuit delays for a period of time, and then controls the first switch and the rectifier device to be turned on through the first main controller; the signal isolation device flips the control signal and outputs it to the second bidirectional switching circuit, and then goes to S3;

[0095] If the control signal is a reverse working signal, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned off through the first main controller; the signal isolation device reverses the control signal and outputs it to the second bidirectional switching circuit, and then goes to S4;

[0096] S3, the second bidirectional switching circuit controls the second switch and the rectifier device to turn off through the second main controller, and returns to S1;

[0097] S4. After a delay of a period of time, the second bidirectional switching circuit controls the second switch and the rectifier device to be turned on through the second main controller, and returns to S1.

[0098] The control signal CTL controls the battery bidirectional balancing control circuit to work forward or reverse. The control signal CTL can be a high level when the battery bidirectional balancing control circuit works forward, or a low level when the battery bidirectional balancing control circuit works forward. For the convenience of description, this embodiment takes the battery bidirectional balancing control circuit working forward when CTL is a low level as an example, but it does not mean that the protection scope of the present invention is limited to this.

[0099] Due to the characteristics of the device itself, the signal isolation device generally generates a transmission delay. After receiving the control signal CTL, it will delay for a period of time before outputting the flipped control signal. This is determined by the characteristics of the device itself. Of course, a signal isolation device without delay can also meet the requirements of the present invention.

[0100] On the other hand, in the battery bidirectional balancing control circuit of this embodiment, since the bidirectional switching circuit does not need to detect the voltage of the transformer winding, the internal component connection relationship of the bidirectional switching circuit is different from that of the first to third embodiments.

[0101] In this embodiment, when the main controller includes a PWM controller, the first bidirectional switching circuit 1 or the second bidirectional switching circuit 2 is as follows: Fig.11As shown, it includes a fourth comparator COMP7, a fifth comparator COMP8, a fifth resistor R5, a first transistor Q1 and a second capacitor C2. The reverse input end of the fourth comparator COMP7 serves as the input end of the first bidirectional switching circuit 1 or the input end of the second bidirectional switching circuit 2, and the positive input end of the fourth comparator COMP7 and the reverse input end of the fifth comparator COMP8 input the reference voltage REF. The output end of the fourth comparator COMP7 is respectively connected to one end of the fifth resistor R5 and the base of the first transistor Q1. The other end of the fifth resistor R5 is respectively connected to the emitter of the first transistor Q1, one end of the second capacitor C2 and the positive input end of the fifth comparator COMP8. The collector of the first transistor Q1 and the other end of the second capacitor C2 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding. The output end of the fifth comparator COMP8 outputs the PWM control signal PWM_EN to the PWM controller.

[0102] In the case where the main controller includes a PWM controller and a synchronous rectification controller, the first bidirectional switching circuit 1 or the second bidirectional switching circuit 2 is as follows: Fig.12 As shown, it includes a fourth comparator COMP7, a fifth comparator COMP8, a fifth resistor R5, a first transistor Q1, a second capacitor C2 and a second NOT gate NOT2. The reverse input end of the fourth comparator COMP7 is used as the input end of the first bidirectional switching circuit 1 or the input end of the second bidirectional switching circuit 2, and the reference voltage REF is input to the positive input end of the fourth comparator COMP7 and the reverse input end of the fifth comparator COMP8. The output end of the fourth comparator COMP7 is respectively connected to one end of the fifth resistor R5, the base of the first transistor Q1 and the input end of the second NOT gate NOT2. The output end of the second NOT gate NOT2 outputs a synchronous rectification control signal SR_EN to the synchronous rectification controller. The collector of the first transistor Q1 and the other end of the second capacitor C2 are connected to the ground GND_P on one side of the first winding or the ground GND_S on one side of the second winding. The output end of the fifth comparator COMP8 outputs a PWM control signal PWM_EN to the PWM controller.

[0103] Combination Fig.13 The working principle of this embodiment when a synchronous rectification controller is included is described below:

[0104] Before time t1, P_CTL=0, P_PWM_EN=1, the primary side PWM controller is working, P_SR_EN=0, the primary side synchronous rectification controller is not working; S_CTL=1, P_PWM_EN=0, the secondary side PWM controller is not working, S_SR_EN=1, the secondary side synchronous rectification controller is working.

[0105] At time t1, P_CTL changes from 0 to 1, and the comparator P_COM7 outputs a low level. Due to the presence of the NPN transistor P_Q1, the voltage of the capacitor P_C2 will be quickly pulled to 0V. At this time, P_PWM_EN=0, the primary PWM controller does not work, and P_SR_EN=1 synchronous rectification controller works. Due to the transmission delay of the signal isolation device, S_CTL is still maintained at 1 at this time, and the secondary synchronous rectification controller works. As can be seen from the description of the background technology, when the synchronous rectification controllers of the primary and secondary sides work at the same time, it does not cause reliability problems.

[0106] At time t2, S_CTL becomes 0, S_COMP7 outputs a high level, and due to the presence of resistor S_R3, the S_C2 voltage will slowly rise, and will reach the reference voltage REF after a delay period, S_COMP8 outputs a high level, and S_PWM_EN=1 controls the PWM controller on the secondary side to work. The delay function of the bidirectional switching circuit of this embodiment is generated by the charging of capacitor C2. The time length of the voltage of capacitor C2 from 0 to the reference voltage REF is the delay of the bidirectional switching circuit. Therefore, adjusting the size of capacitor C2 can control the delay.

[0107] At t3, P_CTL changes from 1 to 0. At this time, P_COMP7 outputs a high level. Due to the existence of resistor P_R3, the voltage on capacitor P_C2 rises slowly but has not reached the threshold REF. The output of P_COMP8 is still low, and the primary PWM controller does not work. At the same time, NOT2 outputs a low level, P_SR_EN=0, and the synchronous rectification of the primary side is controlled not to work. Due to the transmission delay, the S_CTL signal still remains at 0, S_PWM_EN=1, and the secondary PWM controller is still working. Due to the delay effect of the P_C2 capacitor, the primary and secondary PWM controllers will not work at the same time. The delay of C2 must be greater than the delay of the signal isolation device.

[0108] At time t4, S_CTL becomes 1. Similarly, the capacitor voltage of S_C2 is quickly pulled to 0, the secondary side PWM controller does not work, and SR_EN=1 and the secondary side synchronous rectification works.

[0109] At time t5, the voltage of capacitor P_C2 reaches the threshold REF, and comparator P_COMP8 outputs a high level to control the primary PWM controller to work. In actual engineering applications, setting a sufficiently large delay can prevent the primary and secondary PWM controllers from working at the same time.

[0110] The above is only for explaining the implementation mode of the present invention and is not intended to limit the present invention. For those skilled in the art, any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention without creative work should be included in the protection scope of the present invention.

Claims

1. A battery bidirectional balancing control method, characterized in that: The following steps are involved: S1, a first bidirectional switching circuit and a signal isolation device receive an external control signal; S2. If the control signal is a positive working signal, the first bidirectional switching circuit detects the working voltage of the first winding of the transformer. When the working voltage of the first winding is a stable voltage, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned on through the first main controller; the signal isolation device flips the control signal and outputs it to the second bidirectional switching circuit, and then goes to S3; or If the control signal is a forward working signal, the first bidirectional switching circuit delays for a period of time, and then controls the first switch and the rectifier device to be turned on through the first main controller; the signal isolation device flips the control signal and outputs it to the second bidirectional switching circuit, and then goes to S3; If the control signal is a reverse working signal, the first bidirectional switching circuit controls the first switch and the rectifier device to be turned off through the first main controller; the signal isolation device reverses the control signal and outputs it to the second bidirectional switching circuit, and then goes to S4; S3, the second bidirectional switching circuit controls the second switch and the rectifier device to turn off through the second main controller, and returns to S1; S4, the second bidirectional switching circuit detects the operating voltage of the second winding of the transformer. When the operating voltage of the second winding is a stable voltage, the second bidirectional switching circuit controls the second switch and the rectifier device to be turned on through the second main controller, and returns to S1; or After a delay of a period of time, the second bidirectional switching circuit controls the second switch and the rectifier device to be turned on through the second main controller, and returns to S1.

2. A battery bidirectional balancing control circuit, comprising a transformer and a signal isolation device, characterized in that: It also includes a first switch and a rectifier device, a first main controller and a first bidirectional switching circuit connected in sequence between the first winding of the transformer and one end of the signal isolation device, and a second switch and a rectifier device, a second main controller and a second bidirectional switching circuit connected in sequence between the second winding of the transformer and the other end of the signal isolation device; A control signal is input to the input end of the first bidirectional switching circuit, and the first switch and the rectifying device are controlled to be turned off according to the control signal; a voltage signal of the first winding of the transformer is detected, and the first switch and the rectifying device are controlled to be turned on according to the control signal and the voltage signal of the first winding; or The input end of the first bidirectional switching circuit inputs a control signal, controls the first switch and the rectifying device to be turned off according to the control signal, and controls the first switch and the rectifying device to be turned on after a delay of a period of time according to the control signal; One end of the signal isolation device receives the control signal and outputs it from the other end of the signal isolation device to the second bidirectional switching circuit after transmission; The input end of the second bidirectional switching circuit inputs a control signal transmitted by the signal isolation device, and controls the second switch and the rectifier device to be turned off according to the control signal transmitted by the signal isolation device; detects the voltage signal of the second winding of the transformer, and controls the second switch and the rectifier device to be turned on according to the control signal transmitted by the signal isolation device and the voltage signal of the second winding; or The input end of the second bidirectional switching circuit inputs a control signal transmitted by the signal isolation device, and controls the second switch and the rectifier device to be turned off according to the control signal transmitted by the signal isolation device; and controls the second switch and the rectifier device to be turned on after a delay period according to the control signal.

3. The battery bidirectional balancing control circuit according to claim 2, characterized in that: The first master controller or the second master controller includes a PWM controller.

4. The battery bidirectional balancing control circuit according to claim 3, characterized in that: The first switch and rectifier device comprises a first MOS tube (TR1) and a first diode (D1), and the second switch and rectifier device comprises a second MOS tube (TR2) and a second diode (D2); the anode of the first diode (D1) is respectively connected to the source of the first MOS tube (TR1), the anode of the second diode (D2) and the source of the second MOS tube (TR2); the cathode of the first diode (D1) is respectively connected to the drain of the first MOS tube (TR1) and one end of the first winding; the cathode of the second diode (D2) is respectively connected to the drain of the second MOS tube (TR2) and one end of the second winding; the gate of the first MOS tube (TR1) is connected to a PWM controller in the first main controller, and the gate of the second MOS tube (TR2) is connected to the PWM controller in the second main controller.

5. The battery bidirectional balancing control circuit according to claim 2, characterized in that: The first master controller or the second master controller includes a PWM controller and a synchronous rectification controller connected in parallel.

6. The battery bidirectional balancing control circuit according to claim 5, characterized in that: The first switch and rectifying device is a first MOS tube (TR1), and the second switch and rectifying device is a second MOS tube (TR2); the source of the first MOS tube (TR1) is connected to the ground (GND_P) on one side of the first winding, and the source of the second MOS tube (TR2) is connected to the ground (GND_S) on one side of the second winding; the drain of the first MOS tube (TR1) is connected to one end of the first winding; the drain of the second MOS tube (TR2) is connected to one end of the second winding; the gate of the first MOS tube (TR1) is connected to the first main controller, and the gate of the second MOS tube (TR2) is connected to the second main controller.

7. The battery bidirectional balancing control circuit according to claim 3 or 4, characterized in that: The first bidirectional switching circuit or the second bidirectional switching circuit comprises a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a first comparator (COMP1), a second comparator (COMP2), a third comparator (COMP3), a first capacitor (C1), a first RS trigger (RS1), a first NOT gate (NOT1) and a first AND gate (AND1); the inverting input terminal of the second comparator (COMP2) serves as the input terminal of the first bidirectional switching circuit or the input terminal of the second bidirectional switching circuit; one end of the first resistor (R1) is connected to one end of the first winding or one end of the second winding; the other end of the first resistor (R1) is respectively connected to one end of the second resistor (R2) and the inverting input terminal of the third comparator (COMP3); the positive input terminal of the third comparator (COMP3), the positive input terminal of the second comparator (COMP2) and the positive input terminal of the first comparator (COMP1) are respectively input with a reference voltage (REF); the output terminal of the third comparator (COMP3) is connected to the positive input terminal of the first comparator (COMP2) and the positive input terminal of the second comparator (COMP1); One end of the third resistor (R3) is connected, and the other end of the third resistor is respectively connected to one end of the first capacitor (C1), one end of the fourth resistor (R4) and the reverse input end of the first comparator (COMP1); the other end of the second resistor (R2), the other end of the first capacitor (C1) and the other end of the fourth resistor (R4) are connected to the ground (GND_P) on one side of the first winding or the ground (GND_S) on one side of the second winding; the output end of the first comparator (COMP1) is connected to the S end of the first RS trigger (RS1), and the output end of the second comparator (COMP2) is respectively connected to an input end of the first AND gate (AND1) and an input end of the first NOT gate (NOT1); the output end of the first NOT gate (NOT1) is connected to the R end of the first RS trigger (RS1); the Q end of the first RS trigger (RS1) is connected to the other input end of the first AND gate (AND1); the output end of the first AND gate (AND1) outputs a PWM control signal (PWM_EN) to the PWM controller of the first master controller or the PWM controller of the second master controller.

8. The battery bidirectional balancing control circuit according to claim 5 or 6, characterized in that: The first bidirectional switching circuit or the second bidirectional switching circuit comprises a first resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a first comparator (COMP1), a second comparator (COMP2), a third comparator (COMP3), a first capacitor (C1), a first RS trigger (RS1), a first NOT gate (NOT1) and a first AND gate (AND1); the inverting input terminal of the second comparator (COMP2) serves as the input terminal of the first bidirectional switching circuit or the input terminal of the second bidirectional switching circuit ; one end of the first resistor (R1) is connected to one end of the first winding or one end of the second winding; the other end of the first resistor (R1) is respectively connected to one end of the second resistor (R2) and the inverting input end of the third comparator (COMP3); the positive input end of the third comparator (COMP3), the positive input end of the second comparator (COMP2) and the positive input end of the first comparator (COMP1) are respectively input with a reference voltage (REF); the output end of the third comparator (COMP3) is connected to one end of the third resistor (R3), and the other end of the third resistor is respectively connected to One end of the first capacitor (C1), one end of the fourth resistor (R4) and the inverting input end of the first comparator (COMP1) are connected; the other end of the second resistor (R2), the other end of the first capacitor (C1) and the other end of the fourth resistor (R4) are connected to the ground (GND_P) on one side of the first winding or the ground (GND_S) on one side of the second winding; the output end of the first comparator (COMP1) is connected to the S end of the first RS trigger (RS1), and the output end of the second comparator (COMP2) is respectively connected to an input end and an output end of the first AND gate (AND1) The input end of the first NOT gate (NOT1); the output end of the first NOT gate (NOT1) is connected to the R end of the first RS trigger (RS1), and outputs a synchronous rectification control signal (SR_EN) to the synchronous rectification controller of the first master controller or the synchronous rectification controller of the second master controller; the Q end of the first RS trigger (RS1) is connected to the other input end of the first AND gate (AND1); the output end of the first AND gate (AND1) outputs a PWM control signal (PWM_EN) to the PWM controller of the first master controller or the PWM controller of the second master controller.

9. The battery bidirectional balancing control circuit according to claim 3 or 4, characterized in that: The first bidirectional switching circuit or the second bidirectional switching circuit comprises a first resistor (R1), a second resistor (R2), a counter, a second comparator (COMP2), a first RS flip-flop (RS1) and a first AND gate (AND1); the inverting input terminal of the second comparator (COMP2) serves as the input terminal of the first bidirectional switching circuit or the input terminal of the second bidirectional switching circuit, and the positive input terminal of the second comparator (COMP2) inputs a reference voltage (REF); one end of the first resistor (R1) is connected to one end of the first winding or one end of the second winding; the other end of the first resistor (R1) is respectively connected to one end of the second resistor (R2) and a reset input port RS of the counter; the other end of the second resistor (R2) is connected to a ground (GND_ P) or the ground (GND_S) on one side of the second winding; the clock input port CT of the counter inputs a set number of square wave signals (CLK); the output end OUT of the counter is connected to the S end of the first RS trigger (RS1), and the output end of the second comparator (COMP2) is respectively connected to an input end of the first AND gate (AND1) and an input end of the first NOT gate (NOT1); the output end of the first NOT gate (NOT1) is connected to the R end of the first RS trigger (RS1); the Q end of the first RS trigger (RS1) is connected to the other input end of the first AND gate (AND1); the output end of the first AND gate (AND1) outputs a PWM control signal (PWM_EN) to the PWM controller of the first master controller or the PWM controller of the second master controller.

10. The battery bidirectional balancing control circuit according to claim 5 or 6, characterized in that: The first bidirectional switching circuit or the second bidirectional switching circuit comprises a first resistor (R1), a second resistor (R2), a counter, a second comparator (COMP2), a first RS flip-flop (RS1), a first NOT gate (NOT1) and a first AND gate (AND1); the inverting input end of the second comparator (COMP2) serves as the input end of the first bidirectional switching circuit or the input end of the second bidirectional switching circuit, and the reference voltage (REF) is input to the positive input end of the second comparator (COMP2); one end of the first resistor (R1) is connected to one end of the first winding or one end of the second winding; the other end of the first resistor (R1) is respectively connected to one end of the second resistor (R2) and a reset input port RS of the counter; the other end of the second resistor (R2) is connected to a ground (GND_P) on one side of the first winding or a ground (GND_S) on one side of the second winding. ; The clock input port CT of the counter inputs a set number of square wave signals (CLK); the output end OUT of the counter is connected to the S end of the first RS trigger (RS1), and the output end of the second comparator (COMP2) is respectively connected to an input end of the first AND gate (AND1) and an input end of the first NOT gate (NOT1); the output end of the first NOT gate (NOT1) is connected to the R end of the first RS trigger (RS1), and outputs a synchronous rectification control signal (SR_EN) to the synchronous rectification controller of the first master controller or the synchronous rectification controller of the second master controller; the Q end of the first RS trigger (RS1) is connected to the other input end of the first AND gate (AND1); the output end of the first AND gate (AND1) outputs a PWM control signal (PWM_EN) to the PWM controller of the first master controller or the PWM controller of the second master controller.

11. The battery bidirectional balancing control circuit according to claim 3 or 4, characterized in that: The first bidirectional switching circuit or the second bidirectional switching circuit comprises a fourth comparator (COMP7), a fifth comparator (COMP8), a fifth resistor (R5), a first transistor (Q1) and a second capacitor (C2); the inverting input terminal of the fourth comparator (COMP7) serves as the input terminal of the first bidirectional switching circuit or the input terminal of the second bidirectional switching circuit, and the reference voltage (REF) is input to the positive input terminal of the fourth comparator (COMP7) and the inverting input terminal of the fifth comparator (COMP8); the output terminals of the fourth comparator (COMP7) are respectively connected to the fifth resistor (R5) and the reverse input terminal of the fifth comparator (COMP8). and the base of the first transistor (Q1); the other end of the fifth resistor (R5) is respectively connected to the emitter of the first transistor (Q1), one end of the second capacitor (C2) and the positive input end of the fifth comparator (COMP8); the collector of the first transistor (Q1) and the other end of the second capacitor (C2) are connected to the ground (GND_P) on one side of the first winding or the ground (GND_S) on one side of the second winding; and the output end of the fifth comparator (COMP8) outputs a PWM control signal (PWM_EN) to the PWM controller of the first master controller or the PWM controller of the second master controller.

12. The battery bidirectional balancing control circuit according to claim 5 or 6, characterized in that: The first bidirectional switching circuit or the second bidirectional switching circuit comprises a fourth comparator (COMP7), a fifth comparator (COMP8), a fifth resistor (R5), a first transistor (Q1), a second capacitor (C2) and a second NOT gate (NOT2); the inverting input terminal of the fourth comparator (COMP7) serves as the input terminal of the first bidirectional switching circuit or the input terminal of the second bidirectional switching circuit, the positive input terminal of the fourth comparator (COMP7) and the inverting input terminal of the fifth comparator (COMP8) are input with a reference voltage (REF); the output terminal of the fourth comparator (COMP7) is respectively connected to the positive input terminal of the fifth resistor (R5); the output terminal of the fourth comparator (COMP7) is respectively connected to the positive input terminal of the fifth resistor (R5); the output terminal of the fifth comparator (COMP8) is respectively connected to the positive input terminal of the fifth comparator (R5); the output terminal of the fifth comparator (R5 ... one end, the base of the first transistor (Q1) and the input end of the second NOT gate (NOT2); the output end of the second NOT gate (NOT2) outputs a synchronous rectification control signal (SR_EN) to the synchronous rectification controller of the first master controller or the synchronous rectification controller of the second master controller; the collector of the first transistor (Q1) and the other end of the second capacitor (C2) are connected to the ground (GND_P) on one side of the first winding or the ground (GND_S) on one side of the second winding; the output end of the fifth comparator (COMP8) outputs a PWM control signal (PWM_EN) to the PWM controller of the first master controller or the PWM controller of the second master controller.

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