Battery bidirectional equalization control circuit based on magnetic isolation transmission

Abstract

The utility model provides a battery bidirectional equalization control circuit based on magnetic isolation transmission, which is characterized by comprising a first transformer and a magnetic isolator, and further comprising a first switch, a rectifying device and a first controller which are sequentially connected between a first winding of the first transformer and one end of the magnetic isolator, the second switch, the rectifying device and the second controller are sequentially connected between a second winding of the first transformer and the other end of the magnetic isolator; one end of the magnetic isolator and the input end of the first controller input control signals. According to the battery bidirectional equalization control circuit based on magnetic isolation transmission, the magnetic isolator is adopted to replace an optocoupler for isolation transmission, and the problems that the optocoupler isolation cost is high and the model selection is difficult are solved. In addition, the damage risk of the magnetic isolator is lower than that of an optocoupler, and the service life of the switching power supply can be prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery equalization control technical field, especially the battery bidirectional equalization control circuit based on magnetic isolation transmission. BACKGROUND

[0002] Battery energy storage industry is developing rapidly at present, and is applied more and more widely. Due to the reasons of battery material and process, etc., it will lead to the inconsistency of single battery voltage in battery pack after charging or discharging. This will lead to the safety problems of battery pack life reduction and overcharge discharge. The cost of battery accounts for more than 80% of the total cost, and improving battery life is equivalent to significantly reducing the cost. The battery equalization technology has become a necessary means to improve the battery life. With the continuous increase of total voltage of battery, the safety requirement is also increased, and the requirements of isolation withstand voltage and creepage distance are also increased. At present, in the 800V battery system, the isolation withstand voltage requirement is above 4200VAC, and the creepage distance requirement is above 16mm. With the development of the industry, the demand for battery capacity will also gradually increase, and the subsequent battery system may use 1200V system or even 1500V system, at which time the requirements of isolation withstand voltage and creepage distance will be further increased.

[0003] The existing battery bidirectional equalization control circuit adopts optocoupler to meet the requirements of isolation withstand voltage and creepage distance. With the continuous increase of isolation withstand voltage and creepage distance requirements, the cost of optocoupler will also increase exponentially. And the available optocoupler models are limited, and the risk of spare parts is also large. In addition, compared with semiconductor devices and magnetic core devices, the service life of optocoupler is shorter. Therefore, the optocoupler is also the weak link of the service life of switching power supply, which further affects the working life and maintenance cost of the entire energy storage system. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of battery bidirectional equalization control circuit based on magnetic isolation transmission, can solve the problems of high cost and short life caused by using optocoupler for isolation in prior art.

[0005] The utility model aims at realizing the following technical scheme:

[0006] The battery bidirectional equalization control circuit based on magnetic isolation transmission includes first transformer and magnetic isolator, and further includes first switch and rectifier device and first controller connected between the first winding of first transformer and one end of magnetic isolator in sequence, and second switch and rectifier device and second controller connected between the second winding of first transformer and the other end of magnetic isolator in sequence;The input end of magnetic isolator one end and first controller inputs control signal.

[0007] Further, the magnetic isolator comprises an excitation circuit, a second transformer and a rectifier circuit; the input end of the excitation circuit inputs a control signal, and the output end of the excitation circuit is connected with the primary winding of the second transformer; the two ends of the secondary winding of the second transformer are connected with the input end of the rectifier circuit, and the output end of the rectifier circuit is connected with the input end of the second PWM controller.

[0008] Further, the excitation circuit comprises a pulse generator and a third MOS tube TR3; the input end of the excitation circuit inputs a control signal, and the output end of the pulse generator is connected with the gate of the third MOS tube TR3; one end of the primary winding of the second transformer inputs a power supply voltage; the source of the third MOS tube TR3 is grounded, and the drain of the third MOS tube TR3 is connected with the other end of the primary winding of the second transformer.

[0009] Further, the excitation circuit comprises a pulse generator, a fourth MOS tube TR3-1 and a fifth MOS tube TR3-2; the pulse generator has two output ends; the gate of the fourth MOS tube TR3-1 is connected with the first output end of the pulse circuit, and the gate of the fifth MOS tube TR3-2 is connected with the second output end of the pulse circuit; the source of the fourth MOS tube TR3-1 and the source of the fifth MOS tube TR3-2 are connected with a primary ground; the drain of the fourth MOS tube TR3-1 is connected with one end of the primary winding of the second transformer, and the drain of the fifth MOS tube TR3-2 is connected with the other end of the primary winding of the second transformer; the center tap of the primary winding of the second transformer inputs a power supply voltage.

[0010] Further, the excitation circuit comprises a pulse generator, a fourth MOS tube TR3-1, a fifth MOS tube TR3-2, a sixth MOS tube TR3-3 and a seventh MOS tube TR3-4; the pulse generator has two output ends; the gate of the fourth MOS tube TR3-1 and the gate of the seventh MOS tube TR3-4 are connected with the first output end of the pulse circuit, and the gate of the fifth MOS tube TR3-2 and the gate of the sixth MOS tube TR3-3 are connected with the second output end of the pulse circuit; the drain of the fourth MOS tube TR3-1 and the drain of the fifth MOS tube TR3-2 input a power supply voltage; the source of the fifth MOS tube TR3-2 and the drain of the seventh MOS tube TR3-4 are connected with one end of the primary winding of the second transformer; the source of the fourth MOS tube TR3-1 and the drain of the sixth MOS tube TR3-3 are connected with the other end of the primary winding of the second transformer; the source of the sixth MOS tube TR3-3 and the source of the seventh MOS tube TR3-4 are connected with a primary ground.

[0011] Further, the rectifier circuit comprises a third diode D3 and a first capacitor C1; a positive electrode of the third diode D3 is connected to one end of the secondary winding of the second transformer, a negative electrode of the third diode D3 is connected to one end of the first capacitor C1 and serves as an output terminal of the rectifier circuit; the other end of the first capacitor C1 is connected to the other end of the secondary winding of the second transformer.

[0012] Further, the rectifier circuit comprises a fourth diode D3-1, a fifth diode D3-2 and a first capacitor C1; a positive electrode of the fourth diode D3-1 is connected to one end of the secondary winding of the second transformer, a positive electrode of the fifth diode D3-2 is connected to the other end of the secondary winding of the second transformer; a negative electrode of the fourth diode D3-1 and a negative electrode of the fifth diode D3-2 are connected to one end of the first capacitor C1 and serve as an output terminal of the rectifier circuit; the other end of the first capacitor C1 and a center tap of the secondary winding of the second transformer are connected to the secondary ground.

[0013] Further, the rectifier circuit comprises a fourth diode D3-1, a fifth diode D3-2, a sixth diode D3-3, a seventh diode D3-4 and a first capacitor C1; a positive electrode of the fourth diode D3-1 and a negative electrode of the sixth diode D3-3 are connected to one end of the secondary winding of the second transformer, a positive electrode of the fifth diode D3-2 and a negative electrode of the seventh diode D3-4 are connected to the other end of the secondary winding of the second transformer; a negative electrode of the fourth diode D3-1 and a negative electrode of the fifth diode D3-2 are connected to one end of the first capacitor C1 and serve as an output terminal of the rectifier circuit; the other end of the first capacitor C1, a positive electrode of the sixth diode D3-3 and a positive electrode of the seventh diode D3-4 are connected to the secondary ground.

[0014] Further, the first switch and rectifier device comprises a first MOS transistor TR1 and a first diode D1; a drain of the first MOS transistor TR1 and a negative electrode of the first diode D1 are connected to one end of the first winding; a source of the first MOS transistor TR1 and a positive electrode of the first diode D1 are connected to the primary ground; a gate of the first MOS transistor TR1 is connected to an output terminal of the first PWM controller.

[0015] Further, the second switch and rectifier device comprises a second MOS transistor TR2 and a second diode D2; a drain of the second MOS transistor TR2 and a negative electrode of the second diode D2 are connected to one end of the second winding; a source of the second MOS transistor TR2 and a positive electrode of the second diode D2 are connected to the secondary ground; a gate of the second MOS transistor TR2 is connected to an output terminal of the second PWM controller.

[0016] The battery bidirectional equalization control circuit based on magnetic isolation transmission of the utility model, adopt magnetic isolator to replace photoelectric coupler to carry out isolation transmission, solve the problem of high cost and difficult selection of photoelectric coupler isolation. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the battery bidirectional equalization control circuit based on magnetic isolation transmission of the utility model;

[0018] Figure 2 It is the internal block diagram of the magnetic isolator of the utility model;

[0019] Figure 3 It is the magnetic isolator circuit schematic diagram one of the utility model;

[0020] Figure 4 It is the magnetic isolator circuit schematic diagram two of the utility model;

[0021] Figure 5 It is the magnetic isolator circuit schematic diagram three of the utility model. DETAILED DESCRIPTION

[0022] The embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0023] The embodiments of the present disclosure will be described in detail below with reference to the drawings.

[0024] The embodiments of the present disclosure will be described in detail below with reference to the drawings. Figures 1 to 5

[0025] ​The first winding or the second winding can be a main power winding (a primary winding or a secondary winding) or an auxiliary winding.

[0026] In the utility model, the first controller and the second controller can be devices capable of outputting square wave signals to control the first switch and the rectifier to turn on or turn off in the prior art, and the utility model takes the first controller as the first PWM controller 1 and the second controller as the second PWM controller 2 as an example for description, but it does not mean that the first controller and the second controller of the utility model can only be realized by using the PWM controller.

[0027] In Figure 1 The general control logic of the battery bidirectional equalization control circuit is as follows:

[0028] When forward operation is needed, the control signal P_CTL output by the external control unit is a forward operation signal, the first PWM controller 1 outputs a square wave signal to control the first switch and the rectifier to turn on, the magnetic isolator outputs a low level to control the second PWM controller 2 to not work, and the second switch and the rectifier are turned off.

[0029] When reverse operation is needed, the control signal P_CTL output by the external control unit is a reverse operation signal, the first PWM controller 1 does not work, the first switch and the rectifier are turned off, the magnetic isolator outputs a high level to control the second PWM controller 2 to work, and the second PWM controller 2 outputs a square wave signal to control the second switch and the rectifier to turn on.

[0030] The forward operation signal can be a low level signal or a high level signal, and conversely, the reverse operation signal is a high level signal or a low level signal, for the convenience of description, the utility model takes the forward operation signal as a low level signal and the reverse operation signal as a high level signal for description.

[0031] Further, the magnetic isolator of the utility model is shown in Figure 2 The input end of the excitation circuit inputs the control signal P_CTL, and the output end is connected with the primary winding of the second transformer T2. The two ends of the secondary winding of the second transformer T2 are connected with the input end of the rectifier circuit, and the output end of the rectifier circuit is connected with the input end of the second PWM controller 2.

[0032] When forward operation is needed, the control signal P_CTL is a low level, the excitation circuit is not worked, at this time, the secondary winding of the second transformer T2 has no output, and the second PWM controller 2 does not work.

[0033] When the reverse work is needed, the control signal P_CTL is high level, at this time the PWM controller 1 does not work. The high level control signal P_CTL controls the excitation circuit to work, at this time the secondary side of the second transformer T2 outputs high level after the rectifier circuit, and controls the second PWM controller 2 to work.

[0034] Further, the excitation circuit is any one of the flyback circuit, the half-bridge circuit and the full-bridge circuit.

[0035] Further, the rectifier circuit is any one of the half-wave rectifier circuit, the full-wave rectifier circuit and the bridge rectifier circuit.

[0036] The excitation circuit and the rectifier circuit can be combined arbitrarily. Taking the excitation circuit as the flyback circuit and the rectifier circuit as the half-wave rectifier circuit as an example, as shown in the figure: Figure 3 The excitation circuit includes a pulse generator and a third MOS tube TR3. The input end of the excitation circuit inputs the control signal P_CTL. The output end of the pulse generator is connected to the gate of the third MOS tube TR3. One end of the primary winding of the second transformer inputs the power supply voltage VCC. The source of the third MOS tube TR3 is grounded, and the drain is connected to the other end of the primary winding of the second transformer.

[0037] The rectifier circuit includes a third diode D3 and a first capacitor C1. The anode of the third diode D3 is connected to one end of the secondary winding of the second transformer, and the cathode is connected to one end of the first capacitor C1 and serves as the output end of the rectifier circuit. The other end of the first capacitor C1 is connected to the other end of the secondary winding of the second transformer.

[0038] When the control signal P_CTL is high level, the pulse generator outputs a square wave signal, and the third MOS tube TR3 is turned on. At this time, the primary winding of the second transformer T2 is excited, and the secondary winding outputs a square wave signal, which is outputted as high level after being rectified by the third diode D3.

[0039] When the control signal P_CTL is low level, the pulse generator does not output a signal. At this time, the secondary winding of the second transformer T2 outputs low level.

[0040] Taking the excitation circuit as the half-bridge circuit and the rectifier circuit as the half-wave rectifier circuit as an example, as shown in the figure: Figure 4The excitation circuit includes a pulse generator, a fourth MOS transistor TR3-1 and a fifth MOS transistor TR3-2. The pulse generator has two output terminals. The gate of the fourth MOS transistor TR3-1 is connected to the first output terminal of the pulse circuit, and the gate of the fifth MOS transistor TR3-2 is connected to the second output terminal of the pulse circuit. The source of the fourth MOS transistor TR3-1 and the source of the fifth MOS transistor TR3-2 are connected to the primary side ground GND_P. The drain of the fourth MOS transistor TR3-1 is connected to one end of the primary side winding of the second transformer T2, and the drain of the fifth MOS transistor TR3-2 is connected to the other end of the primary side winding of the second transformer. The center tap of the primary side winding of the second transformer T2 inputs the power supply voltage VCC.

[0041] The rectifier circuit includes a fourth diode D3-1, a fifth diode D3-2 and a first capacitor C1. The anode of the fourth diode D3-1 is connected to one end of the secondary side winding of the second transformer T2, and the anode of the fifth diode D3-2 is connected to the other end of the secondary side winding of the second transformer T2. The cathode of the fourth diode D3-1 and the cathode of the fifth diode D3-2 are connected to one end of the first capacitor C1 and serve as the output terminal of the rectifier circuit. The other end of the first capacitor C1 and the center tap of the secondary side winding of the second transformer T2 are connected to the secondary side ground GND_S.

[0042] When the control signal P_CTL is high, the two output terminals of the pulse generator alternately output square wave signals. When the first output terminal outputs a square wave signal, the fourth MOS transistor TR3-1 is turned on, and at this time the second output terminal has no output, and the fifth MOS transistor TR3-2 is turned off. At this time, the primary side of the second transformer T2 forms a voltage with the upper negative and the lower positive, the primary side winding is excited, the secondary side outputs a square wave signal, and after being rectified by the fifth diode D3-2, a high level is output. When the second output terminal outputs a square wave signal, the fifth MOS transistor TR3-2 is turned on, and at this time the first output terminal has no output, and the fourth MOS transistor TR3-1 is turned off. At this time, the primary side of the second transformer T2 forms a voltage with the upper positive and the lower negative, the primary side winding is excited, the secondary side outputs a square wave signal, and after being rectified by the fourth diode D3-1, a high level is output.

[0043] When the control signal P_CTL is low, the two output terminals of the pulse generator do not output square wave signals, and the fourth MOS transistor TR3-1 and the fifth MOS transistor TR3-2 are simultaneously turned off at this time. At this time, the second transformer T2 is not excited, and the secondary side outputs a low level.

[0044] Again, take the excitation circuit as a full-bridge circuit and the rectifier circuit as a full-wave rectifier circuit as an example for description, as shown in FIG. 4. Figure 5The excitation circuit includes a pulse generator, a fourth MOS transistor TR3-1, a fifth MOS transistor TR3-2, a sixth MOS transistor TR3-3 and a seventh MOS transistor TR3-4. The pulse generator has two output terminals. The gate of the fourth MOS transistor TR3-1 and the gate of the seventh MOS transistor TR3-4 are connected to the first output terminal of the pulse circuit, and the gate of the fifth MOS transistor TR3-2 and the gate of the sixth MOS transistor TR3-3 are connected to the second output terminal of the pulse circuit. The drain of the fourth MOS transistor TR3-1 and the drain of the fifth MOS transistor TR3-2 are input with the supply voltage VCC. The source of the fifth MOS transistor TR3-2 and the drain of the seventh MOS transistor TR3-4 are connected to one end of the primary winding of the second transformer T2. The source of the fourth MOS transistor TR3-1 and the drain of the sixth MOS transistor TR3-3 are connected to the other end of the primary winding of the second transformer. The source of the sixth MOS transistor TR3-3 and the source of the seventh MOS transistor TR3-4 are connected to the primary ground GND_P.

[0045] The rectifier circuit includes a fourth diode D3-1, a fifth diode D3-2, a sixth diode D3-3, a seventh diode D3-4 and a first capacitor C1. The anode of the fourth diode D3-1 and the cathode of the sixth diode D3-3 are connected to one end of the secondary winding of the second transformer T2, and the anode of the fifth diode D3-2 and the cathode of the seventh diode D3-4 are connected to the other end of the secondary winding of the second transformer T2. The cathode of the fourth diode D3-1 and the cathode of the fifth diode D3-2 are connected to one end of the first capacitor C1 and serve as the output terminal of the rectifier circuit. The other end of the first capacitor C1, the anode of the sixth diode D3-3 and the anode of the seventh diode D3-4 are connected to the secondary ground GND_S.

[0046] When the control signal P_CTL is high, the two output terminals of the pulse generator alternately output square wave signals. When the first output terminal outputs a square wave signal, the fourth MOS transistor TR3-1 and the seventh MOS transistor TR3-4 are turned on, and at this time the second output terminal has no output, and the fifth MOS transistor TR3-2 and the sixth MOS transistor TR3-3 are turned off. At this time, the primary winding of the second transformer T2 forms a voltage with the upper negative and the lower positive, the primary winding is excited, the secondary winding outputs a square wave signal, and after rectification by the fifth diode D3-2, a high level is output. When the second output terminal outputs a square wave signal, the fifth MOS transistor TR3-2 and the sixth MOS transistor TR3-3 are turned on, and at this time the first output terminal has no output, and the fourth MOS transistor and the seventh MOS transistor TR3-4 TR3-1 are turned off. At this time, the primary winding of the second transformer T2 forms a voltage with the upper positive and the lower negative, the primary winding is excited, the secondary winding outputs a square wave signal, and after rectification by the fourth diode D3-1, a high level is output.

[0047] When the control signal P_CTL is low, neither of the two outputs of the pulse generator outputs a square wave signal, the fourth MOS transistor TR3-1, the fifth MOS transistor TR3-2, the sixth diode D3-3 and the seventh diode D3-4 are simultaneously in the off state, at this time the secondary side of the second transformer T2 is not excited and outputs a low level.

[0048] Similarly, when the excitation circuit is any one of a flyback circuit, a half-bridge circuit and a full-bridge circuit, any one of a half-wave rectifier circuit, a full-wave rectifier circuit and a bridge rectifier circuit can be matched, and the working principle is the same as above, only the matching mode is different, which will not be described here.

[0049] Further, the first switch and rectifier device comprises a first MOS transistor TR1 and a first diode D1, one end of the first winding is connected to the drain of the first MOS transistor TR1 and the negative electrode of the first diode D1, and the source of the first MOS transistor TR1 and the positive electrode of the first diode D1 are connected to the primary side ground. The gate of the first MOS transistor TR1 is connected to the output end of the first PWM controller 1. When the output end of the first PWM controller 1 outputs a square wave signal, the first MOS transistor TR1 is turned on. When the first PWM controller 1 does not work, the first MOS transistor TR1 is turned off.

[0050] Further, the second switch and rectifier device comprises a second MOS transistor TR2 and a second diode D2, one end of the second winding is connected to the drain of the second MOS transistor TR2 and the negative electrode of the second diode D2, and the source of the second MOS transistor TR2 and the positive electrode of the second diode D2 are connected to the secondary side ground. The gate of the second MOS transistor TR2 is connected to the output end of the second PWM controller 2. When the output end of the second PWM controller 2 outputs a square wave signal, the second MOS transistor TR2 is turned on. When the second PWM controller 2 does not work, the second MOS transistor TR2 is turned off.

[0051] The utility model discloses a magnetic isolator replaces the optical coupling as signal transmission device, solves the problem of high cost of optical coupling isolation, and the selection is difficult.In addition, the damage risk of magnetic isolator is lower than optical coupling, and the service life of switching power supply can be prolonged.

[0052] The above is only for illustrating the embodiment of the utility model, and is not used for limiting the utility model, for the person skilled in the art, any modification, equivalent replacement, improvement etc. that is made without creative labor within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A battery bidirectional equalization control circuit based on magnetic isolation transmission, characterized in that, The magnetic isolator comprises an excitation circuit, a second transformer and a rectifier circuit; the input end of the excitation circuit inputs a control signal, and the output end of the excitation circuit is connected with the primary winding of the second transformer; the two ends of the secondary winding of the second transformer are connected with the input end of the rectifier circuit, and the output end of the rectifier circuit is connected with the input end of the second PWM controller.

2. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 1, characterized in that, The excitation circuit comprises a pulse generator and a third MOS tube (TR3); the input end of the excitation circuit inputs a control signal, and the output end of the pulse generator is connected with the gate of the third MOS tube (TR3).

3. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 2, characterized in that, The input end of the primary winding of the second transformer inputs a power supply voltage; the source of the third MOS tube (TR3) is grounded, and the drain of the third MOS tube (TR3) is connected with the other end of the primary winding of the second transformer. The excitation circuit comprises a pulse generator, a fourth MOS tube (TR3-1) and a fifth MOS tube (TR3-2); the pulse generator has two output ends; the gate of the fourth MOS tube (TR3-1) is connected with the first output end of the pulse circuit, and the gate of the fifth MOS tube (TR3-2) is connected with the second output end of the pulse circuit; the source of the fourth MOS tube (TR3-1) and the source of the fifth MOS tube (TR3-2) are connected with the primary ground; the drain of the fourth MOS tube (TR3-1) is connected with one end of the primary winding of the second transformer, and the drain of the fifth MOS tube (TR3-2) is connected with the other end of the primary winding of the second transformer; the center tap of the primary winding of the second transformer inputs a power supply voltage.

4. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 2, characterized in that, The excitation circuit comprises a pulse generator, a fourth MOS tube (TR3-1), a fifth MOS tube (TR3-2), a sixth MOS tube (TR3-3) and a seventh MOS tube (TR3-4); the pulse generator has two output ends; the gate of the fourth MOS tube (TR3-1) and the gate of the seventh MOS tube (TR3-4) are connected with the first output end of the pulse circuit, and the gate of the fifth MOS tube (TR3-2) and the gate of the sixth MOS tube (TR3-3) are connected with the second output end of the pulse circuit; the drain of the fourth MOS tube (TR3-1) and the drain of the fifth MOS tube (TR3-2) input a power supply voltage; the source of the fifth MOS tube (TR3-2) and the drain of the seventh MOS tube (TR3-4) are connected with one end of the primary winding of the second transformer; the source of the fourth MOS tube (TR3-1) and the drain of the sixth MOS tube (TR3-3) are connected with the other end of the primary winding of the second transformer; the source of the sixth MOS tube (TR3-3) and the source of the seventh MOS tube (TR3-4) are connected with the primary ground.

5. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 2, characterized in that, ​ 6. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 2, characterized in that, The rectifier circuit comprises a third diode (D3) and a first capacitor (C1); a positive electrode of the third diode (D3) is connected to one end of a secondary winding of the second transformer, a negative electrode of the third diode (D3) is connected to one end of the first capacitor (C1) and serves as an output end of the rectifier circuit; the other end of the first capacitor (C1) is connected to the other end of the secondary winding of the second transformer.

7. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 2, characterized in that, The rectifier circuit comprises a fourth diode (D3-1), a fifth diode (D3-2) and a first capacitor (C1); a positive electrode of the fourth diode (D3-1) is connected to one end of a secondary winding of the second transformer, a positive electrode of the fifth diode (D3-2) is connected to the other end of the secondary winding of the second transformer; a negative electrode of the fourth diode (D3-1) and a negative electrode of the fifth diode (D3-2) are connected to one end of the first capacitor (C1) and serve as an output end of the rectifier circuit; the other end of the first capacitor (C1) and a center tap of the secondary winding of the second transformer are connected to a secondary ground.

8. The battery bidirectional equalization control circuit based on magnetic isolation transmission according to claim 2, characterized in that, The rectifier circuit comprises a fourth diode (D3-1), a fifth diode (D3-2), a sixth diode (D3-3), a seventh diode (D3-4) and a first capacitor (C1); a positive electrode of the fourth diode (D3-1) and a negative electrode of the sixth diode (D3-3) are connected to one end of a secondary winding of the second transformer, a positive electrode of the fifth diode (D3-2) and a negative electrode of the seventh diode (D3-4) are connected to the other end of the secondary winding of the second transformer; a negative electrode of the fourth diode (D3-1) and a negative electrode of the fifth diode (D3-2) are connected to one end of the first capacitor (C1) and serve as an output end of the rectifier circuit; the other end of the first capacitor (C1), a positive electrode of the sixth diode (D3-3) and a positive electrode of the seventh diode (D3-4) are connected to a secondary ground.

9. The battery bidirectional equalization control circuit based on magnetic isolation transmission of claim 1, wherein, The first switch and rectifier device comprises a first MOS tube (TR1) and a first diode (D1); a drain of the first MOS tube (TR1) and a negative electrode of the first diode (D1) are connected to one end of the first winding; a source of the first MOS tube (TR1) and a positive electrode of the first diode (D1) are connected to a primary ground; a gate of the first MOS tube (TR1) is connected to an output end of the first PWM controller.

10. The battery bidirectional equalization control circuit based on magnetic isolation transmission of claim 1, wherein, The second switch and rectifier device comprises a second MOS tube (TR2) and a second diode (D2); a drain of the second MOS tube (TR2) and a negative electrode of the second diode (D2) are connected to one end of the second winding; a source of the second MOS tube (TR2) and a positive electrode of the second diode (D2) are connected to a secondary ground; a gate of the second MOS tube (TR2) is connected to an output end of the second PWM controller.

Images