GaN-MOS bidirectional inverter circuit and electronic equipment

Abstract

The present application provides a GaN-MOS bidirectional inverter circuit and electronic equipment, which belongs to the field of power electronics technology. The circuit includes a full-bridge circuit, a full-bridge drive circuit, a GaN-Mos control drive circuit, a high-frequency transformer, four GaN-Mos switch tubes, a main control circuit, 4 capacitors, 2 inductors, 3 resistors and 1 current sensor. The main control circuit includes full-bridge phase shift, synchronization, control and other signals and sampling circuits, and the full-bridge drive circuit is used to drive the Mos-type full-bridge circuit. Under the control of the GaN-Mos control drive circuit, the GaN-MOS switch tube synthesizes the upper and lower half-cycle sine waves according to the control signal requirements of the main control circuit. The present application is a single-stage circuit topology, which effectively improves the power conversion efficiency. The gallium nitride power switch tube has low loss and less heat in this topology application, reduces the heat dissipation requirements, improves reliability, and the circuit is small in size and light in weight, which reduces product costs.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a GaN-MOS bidirectional inverter circuit and electronic equipment. Background Art

[0002] In the field of power electronics technology, it is often necessary to convert direct current into alternating current, or to convert alternating current into direct current. Such a circuit is called an inverter circuit.

[0003] Common inverter circuits include full-bridge circuits, full-bridge drive circuits, GaN-Mos control drive circuits, waveform synthesis circuits, main control circuits and isolation transformer circuits, etc.; wherein the isolation transformer circuit includes a first inductor and a high-frequency transformer; further, three capacitors are provided in the output part of the waveform synthesis circuit, which are recorded as the second capacitor, the third capacitor and the fourth capacitor to correspond to the present application, and the fourth capacitor is discharged through the second capacitor and the third capacitor, thereby realizing current inversion.

[0004] However, it can be seen from the above content that when the second capacitor and the third capacitor are charged by the transformer circuit, the fourth capacitor is directly discharged. Charging and discharging will generate a high-frequency and large-amplitude ripple current. This ripple current will cause the second capacitor and the third capacitor to heat up or even burn, and will also generate a higher radiation field strength. Summary of the invention

[0005] The purpose of the present application is to provide a GaN-MOS bidirectional inverter circuit and an electronic device to solve the problems described in the background technology.

[0006] To achieve the above objectives, this application provides the following solutions:

[0007] In a first aspect, the present application provides a GaN-Mos bidirectional inverter circuit, including: a full-bridge circuit, a full-bridge drive circuit, a GaN-Mos control drive circuit, a waveform synthesis circuit, a main control circuit and an isolation transformer circuit; wherein the isolation transformer circuit includes a first inductor L1 and a high-frequency transformer TR;

[0008] Wherein, the full-bridge circuit includes a MOS-type first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a first sampling resistor R1 and a first capacitor C1; the first pin of the high-frequency transformer TR is connected to the S pin of the first switch tube S1 of the full-bridge circuit, the D pin of the third switch tube S3, and the first pin of the first inductor L1; the second pin of the high-frequency transformer TR is connected to the S pin of the second switch tube S2 of the full-bridge circuit, the D pin of the fourth switch tube S4 and the second pin of the first inductor L1; the positive DC electrode of the full-bridge circuit is connected to the first pin of the first capacitor C1, the D pin of the first switch tube S1, and the D pin of the second switch tube S2, the negative DC electrode is connected to the second pin of the first sampling resistor R1, the first pin of the first sampling resistor R1 is connected to the S pin of the third switch tube S3 and the S pin of the fourth switch tube S4, and the positive DC electrode and the negative DC electrode are respectively connected to the positive and negative electrodes of the introduced working power supply;

[0009] The full-bridge driving circuit is used to drive the MOS-type first switch tube S1, the second switch tube S2, the third switch tube S3, and the fourth switch tube S4 constituting the full bridge to enable them to work normally;

[0010] Wherein, the waveform synthesis circuit is a sine wave synthesis circuit, including a GaN-Mos type fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7, an eighth switch tube S8, a second sampling resistor R2, a third sampling resistor R3, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a second inductor L2, an AC electrode A, an AC electrode B and a first current sensor IS1;

[0011] The third output terminal of the high-frequency transformer TR is connected to the D pin of the fifth switch tube S5, the fourth output terminal of the high-frequency transformer TR is connected to the 2nd pin of the second capacitor C2 and the 1st pin of the second inductor L2; the S pin of the fifth switch tube S5 is connected to the 1st pin of the second sampling resistor R2, the S pin of the sixth switch tube S6 is connected to the 2nd pin of the second sampling resistor R2, the D pin of the sixth switch tube S6 is connected to the 1st pin of the second capacitor C2, the 1st pin of the fourth capacitor C4 and the AC electrode A;

[0012] The 6th output terminal of the high-frequency transformer TR is connected to the D pin of the seventh switch tube S7, and the 5th output terminal of the high-frequency transformer TR is connected to the 2nd pin of the third capacitor C3 and the 2nd pin of the second inductor L2; the S pin of the seventh switch tube S7 is connected to the 1st pin of the third sampling resistor R3, the S pin of the eighth switch tube S8 is connected to the 2nd pin of the third sampling resistor R3, and the D pin of the eighth switch tube S8 is connected to the 1st pin of the third capacitor C3, the 2nd pin of the fourth capacitor C4 and the AC electrode B;

[0013] The GaN-Mos control drive circuit is connected to the G pin, S pin, and D pin of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 to collect the Vds voltage signal of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8; it is also connected to the second sampling resistor R2 and the third sampling resistor R3 to collect the current signal of the second sampling resistor R2 and the third sampling resistor R3; it is also connected to the AC electrode A and the AC electrode B to collect the AC voltage signal of the AC electrode A and the AC electrode B; it is also connected to the main control circuit to send and receive the control signal and the synchronization signal from the main control circuit to work in coordination and return the working status data to the main control circuit;

[0014] The main control circuit can send out a full-bridge phase shift signal to drive the full-bridge circuit to work normally, and send out a control signal and a synchronization signal at the same time to control and drive the GaN-Mos control drive circuit and the waveform synthesis circuit to work in coordination with the full-bridge circuit to complete the bidirectional inverter function of DC-AC and AC-DC.

[0015] Among them, the main control circuit is used to collect the DC voltage signal between the positive DC electrode and the negative DC electrode, and is also used to collect the current signal of the first sampling resistor R1, and is also used to collect the AC voltage signal between the AC electrode A and the AC electrode B, and is also used to collect the AC current signal of the first current sensor IS1; the main control circuit calculates the sampled AC voltage signal, DC voltage signal, AC current signal, and DC current signal to control the conversion power and efficiency of DC to AC or AC to DC.

[0016] Optionally, the primary side Np of the high-frequency transformer TR is connected in parallel with the first inductor L1; the secondary side pins 3 and 6 are like-name terminals, respectively connected to the D pins of the fifth switch tube S5 and the seventh switch tube S7; the secondary side pins 4 and 5 are different-name terminals, respectively connected to the second pin of the second capacitor C2 and the second pin of the third capacitor C3, and the second inductor L2 is connected in series between the second pin of the second capacitor C2 and the second pin of the third capacitor C3;

[0017] If the synthesized alternating current is in the first half cycle, the level of the alternating current electrode A is higher than the level of the alternating current electrode B. The synthesis process of the alternating current in the first half cycle is as follows:

[0018] When the high-frequency transformer TR drives the current to flow from the same-name end of the primary side Np to the opposite-name end of the primary side Np, the same-name end level of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the opposite-name end level. At this time, the GaN-Mos control driving circuit controls the seventh switch tube S7 to turn off, the eighth switch tube S8 to turn on, the fifth switch tube S5 to turn on, and the sixth switch tube S6 to turn on. The first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the first pin of the second capacitor C2 is higher than the level of the second pin of the second capacitor C2.

[0019] When the high-frequency transformer TR drives the current to flow from the opposite-name end of the 2nd pin of the primary side Np to the same-name end of the 1st pin, the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the level of the same-name end. At this time, the GaN-Mos control driving circuit controls the fifth switch tube S5 to be turned on, the sixth switch tube S6 to be turned off, the seventh switch tube S7 to be turned on, and the eighth switch tube S8 to be turned on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, and the level of the second pin of the third capacitor C3 is higher than the level of the first pin of the third capacitor C3.

[0020] At this time, the second capacitor C2, the third capacitor C3, the second inductor L2 and the fourth capacitor C4 form a closed loop, the second capacitor C2 and the third capacitor C3 have the same level direction, and the fourth capacitor C4 is charged through the second inductor L2, so that the level of the AC electrode A is higher than that of the AC electrode B, and the AC current is in the upper half cycle.

[0021] If the synthesized alternating current is in the second half cycle, the level of the alternating current electrode B is higher than the level of the alternating current electrode A. The synthesis process of the alternating current in the second half cycle is as follows:

[0022] When the high-frequency transformer TR drives the current to flow from the same-name end of the primary side Np to the opposite-name end of the primary side Np, the same-name end level of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the opposite-name end level. At this time, the GaN-Mos control driving circuit controls the fifth switch tube S5 to turn off, the sixth switch tube S6 to turn on, the seventh switch tube S7 to turn on, and the eighth switch tube S8 to turn on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, and the level of the first pin of the third capacitor C3 is higher than the level of the second pin of the third capacitor C3.

[0023] When the high-frequency transformer TR drives the current to flow from the opposite-name end of the 2nd pin of the primary side Np to the same-name end of the 1st pin, the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the level of the same-name end. At this time, the GaN-Mos control driving circuit controls the seventh switch tube S7 to turn on, the eighth switch tube S8 to turn off, the fifth switch tube S5 to turn on, and the sixth switch tube S6 to turn on. The first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the second pin of the second capacitor C2 is higher than the level of the first pin of the second capacitor C2.

[0024] At this time, the second capacitor C2, the third capacitor C3, the second inductor L2 and the fourth capacitor C4 form a closed loop, and the second capacitor C2 and the third capacitor C3 are in the same level direction to charge the fourth capacitor C4 through the second inductor L2, so that the level of the AC electrode B is higher than that of the AC electrode A, and shows the characteristics of the AC power being in the second half cycle.

[0025] Optionally, the secondary side of the high-frequency transformer TR has two outputs, a first secondary winding Ns1 and a second secondary winding Ns2, the third output pin of the first secondary winding Ns1 is connected to the D pin of the fifth switch tube S5, and the fourth output pin is connected to the second pin of the second capacitor C2 and the first pin of the second inductor L2; the sixth output pin of the second secondary winding Ns2 is connected to the D pin of the seventh switch tube S7, and the fifth output pin is connected to the second pin of the third capacitor C3 and the second pin of the second inductor L2; when the primary driving current alternates, the first secondary winding Ns1 and the second secondary winding Ns2 respectively bear the current in one direction and charge the second capacitor C2 and the third capacitor C3 through the switch tube, and the next moment the second capacitor C2 and the third capacitor C3 charge the fourth capacitor C4 through the second inductor L2;

[0026] Among them, if there is no second inductor L2, the second foot of the second capacitor C2 and the second foot of the third capacitor C3 are directly connected, and the second capacitor C2 and the third capacitor C3 are charged by the first secondary winding Ns1 and the second secondary winding Ns2, and the fourth capacitor C4 is directly discharged. At the same time, the charging and discharging will generate a high-frequency and large-amplitude ripple current, which will cause the second capacitor C2 and the third capacitor C3 to generate high heat or even burn, and will generate a higher radiation field strength; the addition of the second inductor L2 slows down the speed of charging the fourth capacitor C4 through the second inductor L2 when the second capacitor C2 and the third capacitor C3 are charged, effectively reducing the ripple current of the second capacitor C2 and the third capacitor C3 and the high-frequency ripple voltage of the fourth capacitor C4, so that the temperature rise of the second capacitor C2 and the third capacitor C3 is reduced and they can withstand a larger output power, and the radiation field strength is greatly reduced, making it easier for the circuit to meet EMI test requirements.

[0027] Optionally, the GaN-Mos switch tube has no body diode. When it is reverse-conducting, the voltage drop is relatively high and it cannot be used as a rectifier diode.

[0028] During the synthesis of the waveform in the first half cycle, based on the second sampling resistor R2, the GaN-MOS control driving circuit controls the conduction or shutdown of the sixth switch tube S6 by the following method:

[0029] When the voltage between the same-name end and the opposite-name end of the first secondary winding Ns1 is higher than the voltage between the first pin and the second pin of the second capacitor C2, the fifth switch tube S5 and the sixth switch tube S6 must be turned on synchronously to charge the second capacitor C2 to achieve the highest power transmission efficiency; at this time, the fifth switch tube S5 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the sixth switch tube S6. When the S pin level of the sixth switch tube S6 is higher than the D pin or the second sampling resistor R2 has a current flowing from pin 1 to pin 2, the sixth switch tube S6 is instantly turned on. When the TR primary side drive current changes, the current from pin 1 to pin 2 of the second sampling resistor R2 drops to 0, and the sixth switch tube S6 is turned off at this time; therefore, based on the second sampling resistor R2, the GaN-Mos control drive circuit can control the sixth switch tube S6 to operate in a zero voltage turn-on and zero current turn-off working state;

[0030] During the synthesis of the waveform of the first half cycle, based on the third sampling resistor R3, the GaN-Mos control driving circuit controls the conduction or closing of the seventh switch tube S7 by the following method: when the level of the opposite-name end of the second secondary winding Ns2 is higher than the second pin of the third capacitor C3, the seventh switch tube S7 and the eighth switch tube S8 must be turned on synchronously to charge the third capacitor C3 to achieve the highest power transmission efficiency; at this time, the eighth switch tube S8 is turned on, and the GaN-Mos control driving circuit compares the levels of the D pin and the S pin of the seventh switch tube S7. When the S pin level is higher than the D pin or the third sampling resistor R3 has a current flowing from the 2 pin to the 1 pin, the seventh switch tube S7 is turned on instantly. When the TR primary side driving current changes, the current of the third sampling resistor R3 drops from the 2 pin to the 1 pin to 0, so that the seventh switch tube S7 is turned off; therefore, based on the third sampling resistor R3, the GaN-Mos control driving circuit can control the seventh switch tube S7 to work in a zero voltage conduction and zero current off working state;

[0031] During the synthesis of the waveform in the second half cycle, based on the second sampling resistor R2, the GaN-MOS control driving circuit controls the conduction or shutdown of the fifth switch tube S5 by the following method:

[0032] When the voltage between the opposite-terminal and the same-terminal of the first secondary winding Ns1 is higher than the voltage between the second pin and the first pin of the second capacitor C2, the fifth switch tube S5 and the sixth switch tube S6 must be turned on synchronously to charge the second capacitor C2 to achieve the highest power transmission efficiency; at this time, the sixth switch tube S6 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the fifth switch tube S5. When the S pin level of the fifth switch tube S5 is higher than the D pin or the second sampling resistor R2 has a current flowing from the 2nd pin to the 1st pin, the fifth switch tube S5 is turned on instantly. When the TR primary side drive current changes, the current from the 2nd pin to the 1st pin of the second sampling resistor R2 drops to 0, so that the fifth switch tube S5 is turned off; therefore, based on the second sampling resistor R2, the GaN-Mos control drive circuit can control the fifth switch tube S5 to operate in a zero voltage turn-on and zero current turn-off working state;

[0033] During the synthesis of the waveform in the second half cycle, based on the third sampling resistor R3, the GaN-MOS control driving circuit controls the conduction or shutdown of the eighth switch tube S8 by the following method:

[0034] When the voltage between the same-name terminal level and the opposite-name terminal of the second secondary winding Ns2 is higher than the voltage between the second pin and the first pin of the third capacitor C3, the seventh switch tube S7 and the eighth switch tube S8 must be turned on synchronously to charge the third capacitor C3 to achieve the highest power transmission efficiency; at this time, the seventh switch tube S7 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the eighth switch tube S8. When the S pin level is higher than the D pin or the third sampling resistor R3 has a current flowing from pin 1 to pin 2, the eighth switch tube S8 is turned on instantly. When the TR primary side drive current changes, the current from pin 1 to pin 2 of the third sampling resistor R3 drops to 0, so that the eighth switch tube S8 is turned off; therefore, based on the third sampling resistor, the GaN-Mos control drive circuit can control the eighth switch tube S8 to operate in a zero voltage turn-on and zero current turn-off working state.

[0035] Optionally, when the first switch tube S1, the second switch tube S2, the third switch tube S3, and the fourth switch tube S4 are GaN-MOS switch tubes, the main control circuit turns off or turns on each switch tube in the full-bridge circuit by the following method:

[0036] Among them, the main control circuit compares the signal level of the L and R midpoints with the positive and negative levels of the DC power supply. When the Vds voltage of the switch tube changes from positive to negative, the Vds zero voltage conduction condition of the switch tube is established, and the main control circuit turns on the corresponding GaN-Mos switch tube through the full-bridge drive circuit;

[0037] Among them, in the AC-DC mode, when the current from the second pin to the first pin of the first sampling resistor R1 increases from 0, the corresponding GaN-Mos first switch tube, the third switch tube or the second switch tube, the fourth switch tube that is about to be turned on must be turned on instantly in pairs, so that the corresponding switch tubes work in a zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 becomes 0, the corresponding two turned-on switch tubes must be turned off at the same time, so that the corresponding GaN-Mos switch tube works in a zero current turn-off condition.

[0038] The second sampling resistor R2 and the third sampling resistor R3 are replaced by the second current sensor IS2 and the third current sensor IS3 respectively;

[0039] When the second current sensor IS2 is used to replace the second sampling resistor R2, the S pins of the fifth switch tube S5 and the sixth switch tube S6 of the GaN-Mos are connected, and the S pins of the seventh switch tube S7 and the eighth switch tube S8 are connected. The second current sensor IS2 detects the branch current of the fifth switch tube S5 and the sixth switch tube S6, and the third current sensor IS3 detects the branch current of the seventh switch tube S7 and the eighth switch tube S8. At this time, the voltage of the D pin of the fifth switch tube S5 and the D pin of the sixth switch tube S6 is sampled and the current size and direction of the second current sensor IS2 are determined. The method is used to identify whether the fifth switch tube S5 or the sixth switch tube S6 enters the Vds zero voltage and zero current working condition; at this time, the voltages of the D pin of the seventh switch tube S7 and the D pin of the eighth switch tube S8 are sampled and whether the seventh switch tube S7 or the eighth switch tube S8 enters the Vds zero voltage and zero current working condition is identified according to the current size and direction of the third current sensor IS3; the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 are controlled to operate in the Vds zero voltage conduction and Ids zero current off state, so as to achieve the minimum switching loss working condition.

[0040] Optionally, the DC-AC working mode of the bidirectional inverter circuit includes:

[0041] (1) The first switch tube S1 and the fourth switch tube S4 are turned on, and the current of the primary side Np of the high-frequency transformer TR flows from the same-name terminal to the opposite-name terminal. The level of the same-name terminal of the first secondary winding Ns1 and the second secondary winding Ns2 is high. In the first half cycle of the AC power, the level of the AC electrode A is higher than that of the AC electrode B. The fifth switch tube S5 and the sixth switch tube S6 are turned on, and the first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6. The level of the first pin of the second capacitor C2 is higher than that of the second pin, and the second capacitor C2 is charged through the third capacitor C3 and the sixth switch tube S6. The second inductor L2 charges the fourth capacitor C4, and the level of the first pin of the fourth capacitor C4 is higher than the level of the second pin; in the second half cycle of the AC power, the level of the AC electrode B is higher than the AC electrode A, the seventh switch tube S7 is turned on, the eighth switch tube S8 is turned on, the second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, the level of the first pin of the third capacitor C3 is higher than the level of the second pin, and the fourth capacitor C4 is charged through the second capacitor C2 and the second inductor L2, and the level of the second pin of the fourth capacitor C4 is higher than the level of the first pin;

[0042] (2) The first switch tube S1 is turned off, and the energy of the first inductor L1 is relayed through the body diode of the third switch tube S3, so that the third switch tube S3 reaches a zero voltage turn-on condition, and the third switch tube S3 is turned on; in the first half cycle of the AC power, the fifth switch tube S5 and the sixth switch tube S6 are in the on state, at this time, the current through the fifth switch tube S5 and the sixth switch tube S6 decreases rapidly, when the second sampling resistor R2 detects that the current from the first pin to the second pin drops to zero, the sixth switch tube S6 reaches a zero current turn-off condition, and the sixth switch tube S6 is turned off; in the second half cycle of the AC power, the seventh switch tube S7 and the eighth switch tube S8 are in the on state, at this time, the current through the seventh switch tube S7 and the eighth switch tube S8 decreases rapidly, when the third sampling resistor R3 detects that the current from the first pin to the second pin drops to zero, the eighth switch tube S8 reaches a zero current turn-off condition, and the eighth switch tube S8 is turned off;

[0043] (3) The fourth switch tube S4 is turned off, and the energy of the first inductor L1 is passed through the second switch tube S2 so that the second switch tube S2 reaches the zero voltage turn-on condition;

[0044] (4) The second switch tube S2 is turned on, the third switch tube S3 is turned on, the current of the primary side Np of the high-frequency transformer TR flows from the opposite-name end to the same-name end, and the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than that of the same-name end; in the first half cycle of the AC power, the level of the AC electrode A is higher than that of the AC electrode B. At this time, the seventh switch tube S7 is turned on, and the eighth switch tube S8 is turned on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8. The level of the second pin of the third capacitor C3 is higher than that of the first pin, and the third capacitor C3 is charged through the second switch tube S7 and the eighth switch tube S8. The first secondary winding Ns1 charges the second capacitor C2 and the second inductor L2, and the level of the first pin of the fourth capacitor C4 is higher than the level of the second pin; in the second half cycle of the alternating current, the level of the AC electrode B is higher than that of the AC electrode A, the fifth switch tube S5 is turned on, and the sixth switch tube S6 is turned on, the first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the second pin of the second capacitor C2 is higher than the level of the first pin, and charges the fourth capacitor C4 through the third capacitor C3 and the second inductor L2, and the level of the second pin of the fourth capacitor C4 is higher than the level of the first pin;

[0045] (5) The third switch tube S3 is turned off, and the energy of the first inductor L1 is passed through the body diode of the first switch tube S1 to make the first switch tube S1 reach the zero voltage turn-on condition, and the first switch tube S1 is turned on; in the first half cycle of the AC power, the seventh switch tube S7 and the eighth switch tube S8 are in the on state, at this time, the current through the seventh switch tube S7 and the eighth switch tube S8 decreases, when the third sampling resistor R3 detects that the current from the second pin to the first pin drops to zero, the seventh switch tube S7 reaches the zero current turn-off condition, and the seventh switch tube S7 is turned off; in the second half cycle of the AC power, the fifth switch tube S5 and the sixth switch tube S6 are in the on state, at this time, the current through the fifth switch tube S5 and the sixth switch tube S6 decreases rapidly, when the second sampling resistor R2 detects that the current from the second pin to the first pin drops to zero, the fifth switch tube S5 reaches the zero current turn-off condition, and the fifth switch tube S5 is turned off;

[0046] (6) The second switch tube S2 is turned off, and the energy of the first inductor L1 is passed through the body diode of the fourth switch tube S4 to make the fourth switch tube S4 reach the zero voltage turn-on condition;

[0047] The fourth switch tube S4 is turned on, the first switch tube S1 is turned on, and the working mode 1 is restored. The above working modes are repeatedly cycled, so that the AC electrode A and the AC electrode B realize the AC power output characteristics.

[0048] Optionally, the inverter circuit is of a bidirectional type, and in the AC-DC mode, the AC power inputted through the AC electrode A and the AC electrode B is converted into DC power, and outputted through the DC electrode positive and the DC electrode negative; when the AC power is inputted from the AC electrode A and the AC electrode B;

[0049] Among them, when the input AC power is in the positive half cycle, the level of AC electrode A is higher than that of AC electrode B, the level of the first pin of the fourth capacitor C4 is higher than that of the second pin, and the fourth capacitor C4 charges the second capacitor C2 and the third capacitor C3 through the second inductor L2; the level of the first pin of the second capacitor C2 is higher than that of the second pin, and the level of the second pin of the third capacitor C3 is higher than that of the first pin; the working mode is as follows:

[0050] (1) The fifth switch tube S5 and the eighth switch tube S8 are always on. At this time, the sixth switch tube S6 is turned on. The second capacitor C2 discharges to the first secondary winding Ns1 of the high-frequency transformer TR through the fifth switch tube S5 and the sixth switch tube S6. The current flows from the same-name end to the opposite-name end of the first secondary winding Ns1. The same-name end of the primary side Np and the same-name end of the second secondary winding Ns2 are both at high level.

[0051] (2) When the level at point L rises to the point where the body diode of the first switch tube S1 is turned on and reaches the zero voltage turn-on condition of the first switch tube S1, the first switch tube S1 is turned on; when the level at point R drops to the point where the body diode of the fourth switch tube S4 is turned on and the fourth switch tube S4 reaches the zero voltage turn-on condition, the fourth switch tube S4 is turned on; at this time, the same-name end of the primary side Np is at a high level and the opposite-name end is at a low level, so that the first capacitor C1 is charged through the first switch tube S1 and the fourth switch tube S4, and the first pin of the first capacitor C1 is at a high level and the second pin of the first capacitor C1 is at a low level;

[0052] (3) The sixth switch tube S6 is turned off, the current of the first secondary winding Ns1 is cut off, and the second secondary winding Ns2 is freewheeling through magnetic coupling. At this time, when the voltage level of the same-name end of the second secondary winding Ns2 is reduced to zero, the seventh switch tube S7 reaches the zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the first switch tube S1 and the fourth switch tube S4 are turned off; the first inductor L1 follows the second secondary winding Ns2 to freewheel, and the voltage level at point L is reduced and the voltage level at point R is increased;

[0053] (4) When the Vds of the seventh switch tube S7 enters the zero voltage condition, the seventh switch tube S7 is turned on, and the third capacitor C3 discharges the second secondary winding Ns2 through the seventh switch tube S7 and the eighth switch tube S8. The current flows from the opposite-name end to the same-name end of the second secondary winding Ns2 of the high-frequency transformer TR, and the opposite-name end of the primary side Np and the opposite-name end of the first secondary winding Ns1 are at a high level.

[0054] When the level at point L drops to the point where the body diode of the third switch tube S3 is turned on, the third switch tube S3 reaches the zero voltage turn-on condition, and the third switch tube S3 is turned on; when the level at point R rises to the point where the body diode of the second switch tube S2 is turned on, the switch tube reaches the zero voltage turn-on condition, and the second switch tube S2 is turned on; the opposite-name end of the primary side Np is at a high level, and the same-name end of the primary side Np is at a low level, and the first capacitor C1 is charged through the second switch tube S2 and the third switch tube S3, and the first pin of the first capacitor C1 is at a high level, and the second pin of the first capacitor C1 is at a low level;

[0055] (5) The seventh switch tube S7 is turned off, the current of the second secondary winding Ns2 of the secondary side is turned off, and the first secondary winding Ns1 is continued to flow through the magnetic coupling. At this time, when the voltage level of the same-name end of the first secondary winding Ns1 is reduced to zero, the sixth switch tube S6 reaches the zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the second switch tube S2 and the third switch tube S3 are turned off; the first inductor L1 continues to flow following the first secondary winding Ns1, the voltage level at point R is reduced and the voltage level at point L is increased, and the working mode 1 is restored to work in a cycle;

[0056] Since the level of the first pin of the first capacitor C1 is always higher than the level of the second pin, the conversion of the AC power in the first half cycle into DC power is completed, showing the characteristic that the positive level of the DC electrode is higher than the negative level of the DC electrode.

[0057] Optionally, when AC power is input from AC electrode A and AC electrode B;

[0058] Among them, when the input AC power is in the negative half cycle, the level of AC electrode B is higher than that of AC electrode A, the level of the second pin of the fourth capacitor C4 is higher than that of the first pin, and the fourth capacitor C4 charges the second capacitor C2 and the third capacitor C3 through the second inductor L2; the level of the second pin of the second capacitor C2 is higher than that of the first pin, and the level of the first pin of the third capacitor C3 is higher than that of the second pin; the working mode is as follows:

[0059] (1) The sixth switch tube S6 and the seventh switch tube S7 are always on. At this time, the eighth switch tube S8 is turned on. The third capacitor C3 discharges to the second secondary winding Ns2 of the secondary side of the high-frequency transformer TR through the seventh switch tube S7 and the eighth switch tube S8. The current flows from the same-name end to the opposite-name end of the second secondary winding Ns2. The same-name end of the primary side Np and the same-name end of the second secondary winding Ns2 are both at high level.

[0060] (2) The same-name end Np of the primary side of the high-frequency transformer TR is at a high level. When the level at point L rises to the point where the body diode of the first switch tube S1 is turned on and reaches the zero voltage turn-on condition of the first switch tube S1, the first switch tube S1 is turned on; when the level at point R decreases to the point where the body diode of the fourth switch tube S4 is turned on and reaches the zero voltage turn-on condition, the fourth switch tube S4 is turned on; at this time, the same-name end Np of the primary side is at a high level and the opposite-name end is at a low level, and the first capacitor C1 is charged through the first switch tube S1 and the fourth switch tube S4, and the first pin of the first capacitor C1 is at a high level, and the second pin of the first capacitor C1 is at a low level;

[0061] (3) The eighth switch tube S8 is turned off, the current of the second secondary winding Ns2 is cut off, and the current is continued through the magnetic coupling of the first secondary winding Ns1. At this time, when the voltage level of the same-name terminal of the first secondary winding Ns1 is reduced so that the Vds voltage of the fifth switch tube S5 is zero, the fifth switch tube S5 reaches the zero voltage turn-on condition; when it is detected that the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the first switch tube S1 and the fourth switch tube S4 are turned off;

[0062] (4) The fifth switch tube S5 is turned on under zero voltage condition, and the second capacitor C2 discharges the first secondary winding Ns1 through the fifth switch tube S5 and the sixth switch tube S6. The current flows from the opposite-name end to the same-name end of the first secondary winding Ns1 of the high-frequency transformer TR. The opposite-name end of the primary winding Np and the opposite-name end of the second secondary winding Ns2 are both at high level through magnetic coupling.

[0063] When the same-name end of the first secondary winding Ns1 is at a low level, the level at point L decreases to the point where the body diode of the third switch tube S3 is turned on, the third switch tube S3 reaches a zero voltage turn-on condition, and the third switch tube S3 is turned on; when the level at point R rises to the point where the body diode of the second switch tube S2 is turned on, the switch tube reaches a zero voltage turn-on condition, and the second switch tube S2 is turned on;

[0064] At this time, the opposite-name end of the primary side Np forms a loop through the second switch tube S2 and the third switch tube S3 to the same-name end, charging the first capacitor C1. The first pin of the first capacitor C1 is at a high level, and the second pin of the first capacitor C1 is at a low level. Since the level of the first pin of the first capacitor C1 is always higher than the level of the second pin, the power of the second half of the AC cycle is converted into DC power.

[0065] (5) The fifth switch tube S5 is turned off, the current of the first secondary winding Ns1 is cut off, and the second secondary winding Ns2 is freewheeling through magnetic coupling. At this time, when the voltage level of the same-name end of the second secondary winding Ns2 is reduced to zero, the eighth switch tube S8 reaches the zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the second switch tube S2 and the third switch tube S3 are turned off; following the freewheeling of the second secondary winding Ns2, the voltage level at point R decreases and the voltage level at point L increases, and the working mode 1 is restored to work in a cycle;

[0066] Since the level of the first pin of the first capacitor C1 is always higher than the level of the second pin, the conversion of the AC power in the second half cycle into DC power is completed.

[0067] Optionally, the descriptions of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 are all applicable to gallium nitride GaN-Mos tubes, but silicon carbide SiC-Mos and ordinary Si-Mos tubes can also be used; because GaN-Mos has no body diode and requires precise switch conduction control timing to ensure low loss; using SiC-Mos and ordinary Si-Mos tubes using this control method can also effectively reduce losses.

[0068] In a second aspect, the present application provides a sub-device, comprising the GaN-Mos bidirectional inverter circuit described in any one of the first aspects above.

[0069] Optionally, the seed device is an inverter.

[0070] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0071] In the GaN-Mos bidirectional inverter circuit provided in the embodiment of the present application, a second inductor L2 is arranged between the second capacitor C2 and the third capacitor C3. The addition of the second inductor L2 slows down the speed of charging the fourth capacitor C4 through the second inductor L2 when the second capacitor C2 and the third capacitor C3 are charged. However, the second inductor L2 is not provided in the prior art, and the second pin of the second capacitor C2 and the second pin of the third capacitor C3 are directly connected. The second capacitor C2 and the third capacitor C3 are charged by the first secondary winding Ns1 and the second secondary winding Ns2, and the fourth capacitor C4 is directly discharged at the same time. The charging and discharging will generate a high-frequency and large-amplitude ripple current, which will cause the second capacitor C2 and the third capacitor C3 to generate high heat or even burn, and will generate a higher radiation field strength. Therefore, compared with the prior art, the present application effectively reduces the ripple current of the second capacitor C2 and the third capacitor C3 and the high-frequency ripple of the voltage of the fourth capacitor C4, so that the temperature rise of the second capacitor C2 and the third capacitor C3 is reduced and they can withstand a larger output power and greatly reduce the radiation field strength, so that the circuit can more easily meet the EMI test requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0073] Figure 1A GaN-Mos bidirectional inverter circuit in an embodiment of the present application;

[0074] Figure 2 A GaN-Mos bidirectional inverter circuit provided in another embodiment of the present application;

[0075] Figure 3 A GaN-Mos bidirectional inverter circuit provided in yet another embodiment of the present application;

[0076] Figure 4 A GaN-Mos bidirectional inverter circuit is provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0077] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0078] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0079] See also Figure 1 , the embodiment of the present application provides a GaN-Mos bidirectional inverter circuit, including: a full-bridge circuit, a full-bridge drive circuit, a GaN-Mos control drive circuit, a waveform synthesis circuit, a main control circuit and an isolation transformer circuit; wherein the isolation transformer circuit includes a first inductor L1 and a high-frequency transformer TR;

[0080] Wherein, the full-bridge circuit includes a MOS-type first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a first sampling resistor R1 and a first capacitor C1; the first pin of the high-frequency transformer TR is connected to the S pin of the first switch tube S1 of the full-bridge circuit, the D pin of the third switch tube S3, and the first pin of the first inductor L1; the second pin of the high-frequency transformer TR is connected to the S pin of the second switch tube S2 of the full-bridge circuit, the D pin of the fourth switch tube S4 and the second pin of the first inductor L1; the positive DC electrode of the full-bridge circuit is connected to the first pin of the first capacitor C1, the D pin of the first switch tube S1, and the D pin of the second switch tube S2, the negative DC electrode is connected to the second pin of the first sampling resistor R1, the first pin of the first sampling resistor R1 is connected to the S pin of the third switch tube S3 and the S pin of the fourth switch tube S4, and the positive DC electrode and the negative DC electrode are respectively connected to the positive and negative electrodes of the introduced working power supply;

[0081] The full-bridge driving circuit is used to drive the MOS-type first switch tube S1, the second switch tube S2, the third switch tube S3, and the fourth switch tube S4 constituting the full bridge to enable them to work normally;

[0082] Wherein, the waveform synthesis circuit is a sine wave synthesis circuit, including a GaN-Mos type fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7, an eighth switch tube S8, a second sampling resistor R2, a third sampling resistor R3, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a second inductor L2, an AC electrode A, an AC electrode B and a first current sensor IS1;

[0083] The third output terminal of the high-frequency transformer TR is connected to the D pin of the fifth switch tube S5, the fourth output terminal of the high-frequency transformer TR is connected to the 2nd pin of the second capacitor C2 and the 1st pin of the second inductor L2; the S pin of the fifth switch tube S5 is connected to the 1st pin of the second sampling resistor R2, the S pin of the sixth switch tube S6 is connected to the 2nd pin of the second sampling resistor R2, the D pin of the sixth switch tube S6 is connected to the 1st pin of the second capacitor C2, the 1st pin of the fourth capacitor C4 and the AC electrode A;

[0084] The 6th output terminal of the high-frequency transformer TR is connected to the D pin of the seventh switch tube S7, and the 5th output terminal of the high-frequency transformer TR is connected to the 2nd pin of the third capacitor C3 and the 2nd pin of the second inductor L2; the S pin of the seventh switch tube S7 is connected to the 1st pin of the third sampling resistor R3, the S pin of the eighth switch tube S8 is connected to the 2nd pin of the third sampling resistor R3, and the D pin of the eighth switch tube S8 is connected to the 1st pin of the third capacitor C3, the 2nd pin of the fourth capacitor C4 and the AC electrode B;

[0085] The GaN-Mos control drive circuit is connected to the G pin, S pin, and D pin of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 to collect the Vds voltage signal of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8; it is also connected to the second sampling resistor R2 and the third sampling resistor R3 to collect the current signal of the second sampling resistor R2 and the third sampling resistor R3; it is also connected to the AC electrode A and the AC electrode B to collect the AC voltage signal of the AC electrode A and the AC electrode B; it is also connected to the main control circuit to send and receive the control signal and the synchronization signal from the main control circuit to work in coordination and return the working status data to the main control circuit;

[0086] The main control circuit can send out a full-bridge phase shift signal to drive the full-bridge circuit to work normally, and send out a control signal and a synchronization signal at the same time to control and drive the GaN-Mos control drive circuit and the waveform synthesis circuit to work in coordination with the full-bridge circuit to complete the bidirectional inverter function of DC-AC and AC-DC.

[0087] Among them, the main control circuit is used to collect the DC voltage signal between the positive DC electrode and the negative DC electrode, and is also used to collect the current signal of the first sampling resistor R1, and is also used to collect the AC voltage signal between the AC electrode A and the AC electrode B, and is also used to collect the AC current signal of the first current sensor IS1; the main control circuit calculates the sampled AC voltage signal, DC voltage signal, AC current signal, and DC current signal to control the conversion power and efficiency of DC to AC or AC to DC.

[0088] Among them, the high-frequency transformer is a power transformer whose operating frequency exceeds the medium frequency (10kHz).

[0089] Wherein, Vds is the voltage between the D pin and the S pin of the switch tube.

[0090] The full-bridge driving circuit is used to drive the full-bridge circuit so that the full-bridge circuit works normally, and the two output ends of the full-bridge circuit are connected to the primary side Np of the high-frequency transformer TR;

[0091] Optionally, the primary side Np of the high-frequency transformer TR is connected in parallel with the first inductor L1; the secondary side pins 3 and 6 are like-name terminals, respectively connected to the D pins of the fifth switch tube S5 and the seventh switch tube S7; the secondary side pins 4 and 5 are different-name terminals, respectively connected to the second pin of the second capacitor C2 and the second pin of the third capacitor C3, and the second inductor L2 is connected in series between the second pin of the second capacitor C2 and the second pin of the third capacitor C3;

[0092] If the synthesized alternating current is in the first half cycle, the level of the alternating current electrode A is higher than the level of the alternating current electrode B. The synthesis process of the alternating current in the first half cycle is as follows:

[0093] When the high-frequency transformer TR drives the current to flow from the same-name end of the primary side Np to the opposite-name end of the primary side Np, the same-name end level of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the opposite-name end level. At this time, the GaN-Mos control driving circuit controls the seventh switch tube S7 to turn off, the eighth switch tube S8 to turn on, the fifth switch tube S5 to turn on, and the sixth switch tube S6 to turn on. The first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the first pin of the second capacitor C2 is higher than the level of the second pin of the second capacitor C2.

[0094] When the high-frequency transformer TR drives the current to flow from the opposite-name end of the 2nd pin of the primary side Np to the same-name end of the 1st pin, the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the level of the same-name end. At this time, the GaN-Mos control driving circuit controls the fifth switch tube S5 to be turned on, the sixth switch tube S6 to be turned off, the seventh switch tube S7 to be turned on, and the eighth switch tube S8 to be turned on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, and the level of the second pin of the third capacitor C3 is higher than the level of the first pin of the third capacitor C3.

[0095] At this time, the second capacitor C2, the third capacitor C3, the second inductor L2 and the fourth capacitor C4 form a closed loop, the second capacitor C2 and the third capacitor C3 have the same level direction, and the fourth capacitor C4 is charged through the second inductor L2, so that the level of the AC electrode A is higher than that of the AC electrode B, and the AC current is in the upper half cycle.

[0096] If the synthesized alternating current is in the second half cycle, the level of the alternating current electrode B is higher than the level of the alternating current electrode A. The synthesis process of the alternating current in the second half cycle is as follows:

[0097] When the high-frequency transformer TR drives the current to flow from the same-name end of the primary side Np to the opposite-name end of the primary side Np, the same-name end level of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the opposite-name end level. At this time, the GaN-Mos control driving circuit controls the fifth switch tube S5 to turn off, the sixth switch tube S6 to turn on, the seventh switch tube S7 to turn on, and the eighth switch tube S8 to turn on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, and the level of the first pin of the third capacitor C3 is higher than the level of the second pin of the third capacitor C3.

[0098] When the high-frequency transformer TR drives the current to flow from the opposite-name end of the 2nd pin of the primary side Np to the same-name end of the 1st pin, the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the level of the same-name end. At this time, the GaN-Mos control driving circuit controls the seventh switch tube S7 to turn on, the eighth switch tube S8 to turn off, the fifth switch tube S5 to turn on, and the sixth switch tube S6 to turn on. The first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the second pin of the second capacitor C2 is higher than the level of the first pin of the second capacitor C2.

[0099] At this time, the second capacitor C2, the third capacitor C3, the second inductor L2 and the fourth capacitor C4 form a closed loop, and the second capacitor C2 and the third capacitor C3 are in the same level direction to charge the fourth capacitor C4 through the second inductor L2, so that the level of the AC electrode B is higher than that of the AC electrode A, and shows the characteristics of the AC power being in the second half cycle.

[0100] It should be noted here that the flow direction of the high-frequency transformer TR driving current on the primary side Np is determined by the output of the full-bridge drive circuit.

[0101] Optionally, the secondary side of the high-frequency transformer TR has two outputs, a first secondary winding Ns1 and a second secondary winding Ns2, the third output pin of the first secondary winding Ns1 is connected to the D pin of the fifth switch tube S5, and the fourth output pin is connected to the second pin of the second capacitor C2 and the first pin of the second inductor L2; the sixth output pin of the second secondary winding Ns2 is connected to the D pin of the seventh switch tube S7, and the fifth output pin is connected to the second pin of the third capacitor C3 and the second pin of the second inductor L2; when the primary driving current alternates, the first secondary winding Ns1 and the second secondary winding Ns2 respectively bear the current in one direction and charge the second capacitor C2 and the third capacitor C3 through the switch tube, and the next moment the second capacitor C2 and the third capacitor C3 charge the fourth capacitor C4 through the second inductor L2;

[0102] Among them, if there is no second inductor L2, the second foot of the second capacitor C2 and the second foot of the third capacitor C3 are directly connected, and the second capacitor C2 and the third capacitor C3 are charged by the first secondary winding Ns1 and the second secondary winding Ns2, and the fourth capacitor C4 is directly discharged. At the same time, the charging and discharging will generate a high-frequency and large-amplitude ripple current, which will cause the second capacitor C2 and the third capacitor C3 to generate high heat or even burn, and will generate a higher radiation field strength; the addition of the second inductor L2 slows down the speed of charging the fourth capacitor C4 through the second inductor L2 when the second capacitor C2 and the third capacitor C3 are charged, effectively reducing the ripple current of the second capacitor C2 and the third capacitor C3 and the high-frequency ripple voltage of the fourth capacitor C4, so that the temperature rise of the second capacitor C2 and the third capacitor C3 is reduced and they can withstand a larger output power, and the radiation field strength is greatly reduced, making it easier for the circuit to meet EMI test requirements.

[0103] Optionally, the GaN-Mos switch tube has no body diode. When it is reverse-conducting, the voltage drop is relatively high and it cannot be used as a rectifier diode.

[0104] During the synthesis of the waveform in the first half cycle, based on the second sampling resistor R2, the GaN-MOS control driving circuit controls the conduction or shutdown of the sixth switch tube S6 by the following method:

[0105] When the voltage between the same-name end and the opposite-name end of the first secondary winding Ns1 is higher than the voltage between the first pin and the second pin of the second capacitor C2, the fifth switch tube S5 and the sixth switch tube S6 must be turned on synchronously to charge the second capacitor C2 to achieve the highest power transmission efficiency; at this time, the fifth switch tube S5 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the sixth switch tube S6. When the S pin level of the sixth switch tube S6 is higher than the D pin or the second sampling resistor R2 has a current flowing from pin 1 to pin 2, the sixth switch tube S6 is instantly turned on. When the TR primary side drive current changes, the current from pin 1 to pin 2 of the second sampling resistor R2 drops to 0, and the sixth switch tube S6 is turned off at this time; therefore, based on the second sampling resistor R2, the GaN-Mos control drive circuit can control the sixth switch tube S6 to operate in a zero voltage turn-on and zero current turn-off working state;

[0106] During the synthesis of the waveform of the first half cycle, based on the third sampling resistor R3, the GaN-Mos control driving circuit controls the conduction or closing of the seventh switch tube S7 by the following method: when the level of the opposite-name end of the second secondary winding Ns2 is higher than the second pin of the third capacitor C3, the seventh switch tube S7 and the eighth switch tube S8 must be turned on synchronously to charge the third capacitor C3 to achieve the highest power transmission efficiency; at this time, the eighth switch tube S8 is turned on, and the GaN-Mos control driving circuit compares the levels of the D pin and the S pin of the seventh switch tube S7. When the S pin level is higher than the D pin or the third sampling resistor R3 has a current flowing from the 2 pin to the 1 pin, the seventh switch tube S7 is turned on instantly. When the TR primary side driving current changes, the current of the third sampling resistor R3 drops from the 2 pin to the 1 pin to 0, so that the seventh switch tube S7 is turned off; therefore, based on the third sampling resistor R3, the GaN-Mos control driving circuit can control the seventh switch tube S7 to work in a zero voltage conduction and zero current off working state;

[0107] During the synthesis of the waveform in the second half cycle, based on the second sampling resistor R2, the GaN-MOS control driving circuit controls the conduction or shutdown of the fifth switch tube S5 by the following method:

[0108] When the voltage between the opposite-terminal and the same-terminal of the first secondary winding Ns1 is higher than the voltage between the second pin and the first pin of the second capacitor C2, the fifth switch tube S5 and the sixth switch tube S6 must be turned on synchronously to charge the second capacitor C2 to achieve the highest power transmission efficiency; at this time, the sixth switch tube S6 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the fifth switch tube S5. When the S pin level of the fifth switch tube S5 is higher than the D pin or the second sampling resistor R2 has a current flowing from the 2nd pin to the 1st pin, the fifth switch tube S5 is turned on instantly. When the TR primary side drive current changes, the current from the 2nd pin to the 1st pin of the second sampling resistor R2 drops to 0, so that the fifth switch tube S5 is turned off; therefore, based on the second sampling resistor R2, the GaN-Mos control drive circuit can control the fifth switch tube S5 to operate in a zero voltage turn-on and zero current turn-off working state;

[0109] During the synthesis of the waveform in the second half cycle, based on the third sampling resistor R3, the GaN-MOS control driving circuit controls the conduction or shutdown of the eighth switch tube S8 by the following method:

[0110] When the voltage between the same-name terminal level and the opposite-name terminal of the second secondary winding Ns2 is higher than the voltage between the second pin and the first pin of the third capacitor C3, the seventh switch tube S7 and the eighth switch tube S8 must be turned on synchronously to charge the third capacitor C3 to achieve the highest power transmission efficiency; at this time, the seventh switch tube S7 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the eighth switch tube S8. When the S pin level is higher than the D pin or the third sampling resistor R3 has a current flowing from pin 1 to pin 2, the eighth switch tube S8 is turned on instantly. When the TR primary side drive current changes, the current from pin 1 to pin 2 of the third sampling resistor R3 drops to 0, so that the eighth switch tube S8 is turned off; therefore, based on the third sampling resistor, the GaN-Mos control drive circuit can control the eighth switch tube S8 to operate in a zero voltage turn-on and zero current turn-off working state.

[0111] Therefore, during the waveform synthesis process, the second sampling resistor R2 and the third sampling resistor R3 can play a role in reducing loss.

[0112] Alternatively, see Figure 2 When the first switch tube S1, the second switch tube S2, the third switch tube S3, and the fourth switch tube S4 are GaN-Mos switch tubes, the main control circuit turns off or turns on each switch tube in the full-bridge circuit by the following method:

[0113] Among them, the main control circuit compares the signal level of the L and R midpoints with the positive and negative levels of the DC power supply. When the Vds voltage of the switch tube changes from positive to negative, the Vds zero voltage conduction condition of the switch tube is established, and the main control circuit turns on the corresponding GaN-Mos switch tube through the full-bridge drive circuit;

[0114] Among them, in the AC-DC mode, when the current from the second pin to the first pin of the first sampling resistor R1 increases from 0, the corresponding GaN-Mos first switch tube, the third switch tube or the second switch tube, the fourth switch tube that is about to be turned on must be turned on instantly in pairs, so that the corresponding switch tubes work in a zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 becomes 0, the corresponding two turned-on switch tubes must be turned off at the same time, so that the corresponding GaN-Mos switch tube works in a zero current turn-off condition.

[0115] Alternatively, see Figure 4 , the second sampling resistor R2 and the third sampling resistor R3 are replaced by the second current sensor IS2 and the third current sensor IS3 respectively;

[0116] When the second current sensor IS2 is used to replace the second sampling resistor R2, the S pins of the fifth switch tube S5 and the sixth switch tube S6 of the GaN-Mos are connected, and the S pins of the seventh switch tube S7 and the eighth switch tube S8 are connected. The second current sensor IS2 detects the branch current of the fifth switch tube S5 and the sixth switch tube S6, and the third current sensor IS3 detects the branch current of the seventh switch tube S7 and the eighth switch tube S8. At this time, the voltage of the D pin of the fifth switch tube S5 and the D pin of the sixth switch tube S6 is sampled and the current size and direction of the second current sensor IS2 are determined. The method is used to identify whether the fifth switch tube S5 or the sixth switch tube S6 enters the Vds zero voltage and zero current working condition; at this time, the voltages of the D pin of the seventh switch tube S7 and the D pin of the eighth switch tube S8 are sampled and whether the seventh switch tube S7 or the eighth switch tube S8 enters the Vds zero voltage and zero current working condition is identified according to the current size and direction of the third current sensor IS3; the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 are controlled to operate in the Vds zero voltage conduction and Ids zero current off state, so as to achieve the minimum switching loss working condition.

[0117] Optionally, the DC-AC working mode of the bidirectional inverter circuit includes:

[0118] (1) The first switch tube S1 and the fourth switch tube S4 are turned on, and the current of the primary side Np of the high-frequency transformer TR flows from the same-name terminal to the opposite-name terminal. The level of the same-name terminal of the first secondary winding Ns1 and the second secondary winding Ns2 is high. In the first half cycle of the AC power, the level of the AC electrode A is higher than that of the AC electrode B. The fifth switch tube S5 and the sixth switch tube S6 are turned on, and the first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6. The level of the first pin of the second capacitor C2 is higher than that of the second pin, and the second capacitor C2 is charged through the third capacitor C3 and the sixth switch tube S6. The second inductor L2 charges the fourth capacitor C4, and the level of the first pin of the fourth capacitor C4 is higher than the level of the second pin; in the second half cycle of the AC power, the level of the AC electrode B is higher than the AC electrode A, the seventh switch tube S7 is turned on, the eighth switch tube S8 is turned on, the second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, the level of the first pin of the third capacitor C3 is higher than the level of the second pin, and the fourth capacitor C4 is charged through the second capacitor C2 and the second inductor L2, and the level of the second pin of the fourth capacitor C4 is higher than the level of the first pin;

[0119] (2) The first switch tube S1 is turned off, and the energy of the first inductor L1 is relayed through the body diode of the third switch tube S3, so that the third switch tube S3 reaches a zero voltage turn-on condition, and the third switch tube S3 is turned on; in the first half cycle of the AC power, the fifth switch tube S5 and the sixth switch tube S6 are in the on state, at this time, the current through the fifth switch tube S5 and the sixth switch tube S6 decreases rapidly, when the second sampling resistor R2 detects that the current from the first pin to the second pin drops to zero, the sixth switch tube S6 reaches a zero current turn-off condition, and the sixth switch tube S6 is turned off; in the second half cycle of the AC power, the seventh switch tube S7 and the eighth switch tube S8 are in the on state, at this time, the current through the seventh switch tube S7 and the eighth switch tube S8 decreases rapidly, when the third sampling resistor R3 detects that the current from the first pin to the second pin drops to zero, the eighth switch tube S8 reaches a zero current turn-off condition, and the eighth switch tube S8 is turned off;

[0120] (3) The fourth switch tube S4 is turned off, and the energy of the first inductor L1 is passed through the second switch tube S2 so that the second switch tube S2 reaches the zero voltage turn-on condition;

[0121] (4) The second switch tube S2 is turned on, the third switch tube S3 is turned on, the current of the primary side Np of the high-frequency transformer TR flows from the opposite-name end to the same-name end, and the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than that of the same-name end; in the first half cycle of the AC power, the level of the AC electrode A is higher than that of the AC electrode B. At this time, the seventh switch tube S7 is turned on, and the eighth switch tube S8 is turned on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8. The level of the second pin of the third capacitor C3 is higher than that of the first pin, and the third capacitor C3 is charged through the second switch tube S7 and the eighth switch tube S8. The first secondary winding Ns1 charges the second capacitor C2 and the second inductor L2, and the level of the first pin of the fourth capacitor C4 is higher than the level of the second pin; in the second half cycle of the alternating current, the level of the AC electrode B is higher than that of the AC electrode A, the fifth switch tube S5 is turned on, and the sixth switch tube S6 is turned on, the first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the second pin of the second capacitor C2 is higher than the level of the first pin, and charges the fourth capacitor C4 through the third capacitor C3 and the second inductor L2, and the level of the second pin of the fourth capacitor C4 is higher than the level of the first pin;

[0122] (5) The third switch tube S3 is turned off, and the energy of the first inductor L1 is passed through the body diode of the first switch tube S1 to make the first switch tube S1 reach the zero voltage turn-on condition, and the first switch tube S1 is turned on; in the first half cycle of the AC power, the seventh switch tube S7 and the eighth switch tube S8 are in the on state, at this time, the current through the seventh switch tube S7 and the eighth switch tube S8 decreases, when the third sampling resistor R3 detects that the current from the second pin to the first pin drops to zero, the seventh switch tube S7 reaches the zero current turn-off condition, and the seventh switch tube S7 is turned off; in the second half cycle of the AC power, the fifth switch tube S5 and the sixth switch tube S6 are in the on state, at this time, the current through the fifth switch tube S5 and the sixth switch tube S6 decreases rapidly, when the second sampling resistor R2 detects that the current from the second pin to the first pin drops to zero, the fifth switch tube S5 reaches the zero current turn-off condition, and the fifth switch tube S5 is turned off;

[0123] (6) The second switch tube S2 is turned off, and the energy of the first inductor L1 is passed through the body diode of the fourth switch tube S4 to make the fourth switch tube S4 reach the zero voltage turn-on condition;

[0124] The fourth switch tube S4 is turned on, the first switch tube S1 is turned on, and the working mode 1 is restored. The above working modes are repeatedly cycled, so that the AC electrode A and the AC electrode B realize the AC power output characteristics.

[0125] Optionally, the inverter circuit is of a bidirectional type, and in the AC-DC mode, the AC power inputted through the AC electrode A and the AC electrode B is converted into DC power, and outputted through the DC electrode positive and the DC electrode negative; when the AC power is inputted from the AC electrode A and the AC electrode B;

[0126] Among them, when the input AC power is in the positive half cycle, the level of AC electrode A is higher than that of AC electrode B, the level of the first pin of the fourth capacitor C4 is higher than that of the second pin, and the fourth capacitor C4 charges the second capacitor C2 and the third capacitor C3 through the second inductor L2; the level of the first pin of the second capacitor C2 is higher than that of the second pin, and the level of the second pin of the third capacitor C3 is higher than that of the first pin; the working mode is as follows:

[0127] (1) The fifth switch tube S5 and the eighth switch tube S8 are always on. At this time, the sixth switch tube S6 is turned on. The second capacitor C2 discharges to the first secondary winding Ns1 of the high-frequency transformer TR through the fifth switch tube S5 and the sixth switch tube S6. The current flows from the same-name end to the opposite-name end of the first secondary winding Ns1. The same-name end of the primary side Np and the same-name end of the second secondary winding Ns2 are both at high level.

[0128] (2) When the level at point L rises to the point where the body diode of the first switch tube S1 is turned on and reaches the zero voltage turn-on condition of the first switch tube S1, the first switch tube S1 is turned on; when the level at point R drops to the point where the body diode of the fourth switch tube S4 is turned on and the fourth switch tube S4 reaches the zero voltage turn-on condition, the fourth switch tube S4 is turned on; at this time, the same-name end of the primary side Np is at a high level and the opposite-name end is at a low level, so that the first capacitor C1 is charged through the first switch tube S1 and the fourth switch tube S4, and the first pin of the first capacitor C1 is at a high level and the second pin of the first capacitor C1 is at a low level;

[0129] (3) The sixth switch tube S6 is turned off, the current of the first secondary winding Ns1 is cut off, and the second secondary winding Ns2 is freewheeling through magnetic coupling. At this time, when the voltage level of the same-name end of the second secondary winding Ns2 is reduced to zero, the seventh switch tube S7 reaches the zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the first switch tube S1 and the fourth switch tube S4 are turned off; the first inductor L1 follows the second secondary winding Ns2 to freewheel, and the voltage level at point L is reduced and the voltage level at point R is increased;

[0130] (4) When the Vds of the seventh switch tube S7 enters the zero voltage condition, the seventh switch tube S7 is turned on, and the third capacitor C3 discharges the second secondary winding Ns2 through the seventh switch tube S7 and the eighth switch tube S8. The current flows from the opposite-name end to the same-name end of the second secondary winding Ns2 of the high-frequency transformer TR, and the opposite-name end of the primary side Np and the opposite-name end of the first secondary winding Ns1 are at a high level.

[0131] When the level at point L drops to the point where the body diode of the third switch tube S3 is turned on, the third switch tube S3 reaches the zero voltage turn-on condition, and the third switch tube S3 is turned on; when the level at point R rises to the point where the body diode of the second switch tube S2 is turned on, the switch tube reaches the zero voltage turn-on condition, and the second switch tube S2 is turned on; the opposite-name end of the primary side Np is at a high level, and the same-name end of the primary side Np is at a low level, and the first capacitor C1 is charged through the second switch tube S2 and the third switch tube S3, and the first pin of the first capacitor C1 is at a high level, and the second pin of the first capacitor C1 is at a low level;

[0132] (5) The seventh switch tube S7 is turned off, the current of the second secondary winding Ns2 of the secondary side is turned off, and the first secondary winding Ns1 is continued to flow through the magnetic coupling. At this time, when the voltage level of the same-name end of the first secondary winding Ns1 is reduced to zero, the sixth switch tube S6 reaches the zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the second switch tube S2 and the third switch tube S3 are turned off; the first inductor L1 continues to flow following the first secondary winding Ns1, the voltage level at point R is reduced and the voltage level at point L is increased, and the working mode 1 is restored to work in a cycle;

[0133] Since the level of the first pin of the first capacitor C1 is always higher than the level of the second pin, the conversion of the AC power in the first half cycle into DC power is completed, showing the characteristic that the positive level of the DC electrode is higher than the negative level of the DC electrode.

[0134] Optionally, when AC power is input from AC electrode A and AC electrode B;

[0135] Among them, when the input AC power is in the negative half cycle, the level of AC electrode B is higher than that of AC electrode A, the level of the second pin of the fourth capacitor C4 is higher than that of the first pin, and the fourth capacitor C4 charges the second capacitor C2 and the third capacitor C3 through the second inductor L2; the level of the second pin of the second capacitor C2 is higher than that of the first pin, and the level of the first pin of the third capacitor C3 is higher than that of the second pin; the working mode is as follows:

[0136] (1) The sixth switch tube S6 and the seventh switch tube S7 are always on. At this time, the eighth switch tube S8 is turned on. The third capacitor C3 discharges to the second secondary winding Ns2 of the secondary side of the high-frequency transformer TR through the seventh switch tube S7 and the eighth switch tube S8. The current flows from the same-name end to the opposite-name end of the second secondary winding Ns2. The same-name end of the primary side Np and the same-name end of the second secondary winding Ns2 are both at high level.

[0137] (2) The same-name end Np of the primary side of the high-frequency transformer TR is at a high level. When the level at point L rises to the point where the body diode of the first switch tube S1 is turned on and reaches the zero voltage turn-on condition of the first switch tube S1, the first switch tube S1 is turned on; when the level at point R drops to the point where the body diode of the fourth switch tube S4 is turned on and reaches the zero voltage turn-on condition, the fourth switch tube S4 is turned on; at this time, the same-name end Np of the primary side is at a high level and the opposite-name end is at a low level, and the first capacitor C1 is charged through the first switch tube S1 and the fourth switch tube S4, and the first pin of the first capacitor C1 is at a high level, and the second pin of the first capacitor C1 is at a low level;

[0138] (3) The eighth switch tube S8 is turned off, the current of the second secondary winding Ns2 is cut off, and the current is continued through the magnetic coupling of the first secondary winding Ns1. At this time, when the voltage level of the same-name terminal of the first secondary winding Ns1 is reduced so that the Vds voltage of the fifth switch tube S5 is zero, the fifth switch tube S5 reaches the zero voltage turn-on condition; when it is detected that the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the first switch tube S1 and the fourth switch tube S4 are turned off;

[0139] (4) The fifth switch tube S5 is turned on under zero voltage condition, and the second capacitor C2 discharges the first secondary winding Ns1 through the fifth switch tube S5 and the sixth switch tube S6. The current flows from the opposite-name end to the same-name end of the first secondary winding Ns1 of the high-frequency transformer TR. The opposite-name end of the primary winding Np and the opposite-name end of the second secondary winding Ns2 are both at high level through magnetic coupling.

[0140] When the same-name end of the first secondary winding Ns1 is at a low level, the level at point L decreases to the point where the body diode of the third switch tube S3 is turned on, the third switch tube S3 reaches a zero voltage turn-on condition, and the third switch tube S3 is turned on; when the level at point R rises to the point where the body diode of the second switch tube S2 is turned on, the switch tube reaches a zero voltage turn-on condition, and the second switch tube S2 is turned on;

[0141] At this time, the opposite-name end of the primary side Np forms a loop through the second switch tube S2 and the third switch tube S3 to the same-name end, charging the first capacitor C1. The first pin of the first capacitor C1 is at a high level, and the second pin of the first capacitor C1 is at a low level. Since the level of the first pin of the first capacitor C1 is always higher than the level of the second pin, the power of the second half of the AC cycle is converted into DC power.

[0142] (5) The fifth switch tube S5 is turned off, the current of the first secondary winding Ns1 is cut off, and the second secondary winding Ns2 is freewheeling through magnetic coupling. At this time, when the voltage level of the same-name end of the second secondary winding Ns2 is reduced to zero, the eighth switch tube S8 reaches the zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 is reduced to 0, the second switch tube S2 and the third switch tube S3 are turned off; following the freewheeling of the second secondary winding Ns2, the voltage level at point R decreases and the voltage level at point L increases, and the working mode 1 is restored to work in a cycle;

[0143] Since the level of the first pin of the first capacitor C1 is always higher than the level of the second pin, the conversion of the AC power in the second half cycle into DC power is completed.

[0144] Alternatively, see Figure 3 The descriptions of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 are all applicable to gallium nitride GaN-Mos tubes, but silicon carbide SiC-Mos and ordinary Si-Mos tubes can also be used; because GaN-Mos has no body diode and requires precise switch conduction control timing to ensure low loss; using SiC-Mos and ordinary Si-Mos tubes using this control method can also effectively reduce losses.

[0145] In the GaN-Mos bidirectional inverter circuit provided in the embodiment of the present application, a second inductor L2 is arranged between the second capacitor C2 and the third capacitor C3. The addition of the second inductor L2 slows down the speed of charging the fourth capacitor C4 through the second inductor L2 when the second capacitor C2 and the third capacitor C3 are charged. However, the second inductor L2 is not provided in the prior art, and the second pin of the second capacitor C2 and the second pin of the third capacitor C3 are directly connected. The second capacitor C2 and the third capacitor C3 are charged by the first secondary winding Ns1 and the second secondary winding Ns2, and the fourth capacitor C4 is directly discharged at the same time. The charging and discharging will generate a high-frequency and large-amplitude ripple current, which will cause the second capacitor C2 and the third capacitor C3 to generate high heat or even burn, and will generate a higher radiation field strength. Therefore, compared with the prior art, the present application effectively reduces the ripple current of the second capacitor C2 and the third capacitor C3 and the high-frequency ripple of the voltage of the fourth capacitor C4, so that the temperature rise of the second capacitor C2 and the third capacitor C3 is reduced and they can withstand a larger output power and greatly reduce the radiation field strength, so that the circuit can more easily meet the EMI test requirements.

[0146] An embodiment of the present application also provides an electronic device, comprising any one of the GaN-Mos bidirectional inverter circuits described in the above embodiments.

[0147] Optionally, the electronic device is an inverter.

[0148] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0149] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A GaN-Mos bidirectional inverter circuit, characterized in that: include: Full-bridge circuit, full-bridge drive circuit, GaN-Mos control drive circuit, waveform synthesis circuit, main control circuit and high-frequency transformer TR; The full-bridge driving circuit is used to drive the full-bridge circuit so that the full-bridge circuit works normally, and the two output terminals L and R of the full-bridge circuit are connected to the primary side Np of the high-frequency transformer TR; The waveform synthesis circuit includes a GaN-Mos type fifth switch tube S5, a sixth switch tube S6, a seventh switch tube S7, an eighth switch tube S8, a second sampling resistor R2, a third sampling resistor R3, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a second inductor L2, an AC electrode A, an AC electrode B and a first current sensor IS1; The third output terminal of the high-frequency transformer TR is connected to the D pin of the fifth switch tube S5, and the fourth output terminal of the high-frequency transformer TR is connected to the 2nd pin of the second capacitor C2 and the 1st pin of the second inductor L2; the S pin of the fifth switch tube S5 is connected to the 1st pin of the second sampling resistor R2, the S pin of the sixth switch tube S6 is connected to the 2nd pin of the second sampling resistor R2, and the D pin of the sixth switch tube S6 is connected to the 1st pin of the second capacitor C2, the 1st pin of the fourth capacitor C4 and the AC electrode A; the sixth output terminal of the high-frequency transformer TR is connected to the D pin of the seventh switch tube S7, and the fifth output terminal of the high-frequency transformer TR is connected to the 2nd pin of the third capacitor C3 and the 2nd pin of the second inductor L2; the S pin of the seventh switch tube S7 is connected to the 1st pin of the third sampling resistor R3, the S pin of the eighth switch tube S8 is connected to the 2nd pin of the third sampling resistor R3, and the D pin of the eighth switch tube S8 is connected to the 1st pin of the third capacitor C3, the 2nd pin of the fourth capacitor C4 and the AC electrode B; The GaN-Mos control drive circuit is connected to the G pin, S pin, and D pin of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8 to collect the Vds voltage signal of the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7, and the eighth switch tube S8; it is also connected to the second sampling resistor R2 and the third sampling resistor R3 to collect the current signal of the second sampling resistor R2 and the third sampling resistor R3; it is also connected to the AC electrode A and the AC electrode B to collect the AC voltage signal of the AC electrode A and the AC electrode B; it is also connected to the main control circuit to send and receive the control signal and the synchronization signal from the main control circuit to work in coordination and return the working status data to the main control circuit; The main control circuit is used to send out a full-bridge phase shift signal to drive the full-bridge circuit to work normally, and at the same time send out a control signal and a synchronization signal to control and drive the GaN-Mos control drive circuit and the waveform synthesis circuit to work in coordination with the full-bridge circuit to complete the bidirectional inverter function of DC-AC and AC-DC.

2. The GaN-MOS bidirectional inverter circuit according to claim 1, characterized in that: The full-bridge circuit includes a MOS-type first switch tube S1, a second switch tube S2, a third switch tube S3, a fourth switch tube S4, a first sampling resistor R1 and a first capacitor C1; the first pin of the high-frequency transformer TR is connected to the S pin of the first switch tube S1, the D pin of the third switch tube S3 and the first pin of the first inductor L1 of the full-bridge circuit; the second pin of the high-frequency transformer TR is connected to the S pin of the second switch tube S2, the D pin of the fourth switch tube S4 and the second pin of the first inductor L1 of the full-bridge circuit; the positive DC electrode of the full-bridge circuit is connected to the first pin of the first capacitor C1, the D pin of the first switch tube S1 and the D pin of the second switch tube S2, the negative DC electrode is connected to the second pin of the first sampling resistor R1, the first pin of the first sampling resistor R1 is connected to the S pin of the third switch tube S3 and the S pin of the fourth switch tube S4, and the positive DC electrode and the negative DC electrode are respectively connected to the positive and negative electrodes of the introduced working power supply; The full-bridge driving circuit is used to drive the MOS-type first switch tube S1, the second switch tube S2, the third switch tube S3, and the fourth switch tube S4 constituting the full bridge to enable them to work normally.

3. The GaN-MOS bidirectional inverter circuit according to claim 2, characterized in that: The main control circuit is used to collect the DC voltage signal between the positive DC electrode and the negative DC electrode, and is also used to collect the current signal of the first sampling resistor R1, and is also used to collect the AC voltage signal between the AC electrode A and the AC electrode B, and is also used to collect the AC current signal of the first current sensor IS1; the main control circuit calculates the sampled AC voltage signal, DC voltage signal, AC current signal, and DC current signal to control the conversion power and efficiency of DC to AC or AC to DC.

4. The GaN-MOS bidirectional inverter circuit according to claim 1, characterized in that: The primary side Np of the high-frequency transformer TR is connected in parallel with the first inductor L1; the secondary side pins 3 and 6 are like-name terminals, connected to the D pins of the fifth switch tube S5 and the seventh switch tube S7 respectively; the secondary side pins 4 and 5 are different-name terminals, connected to the second pin of the second capacitor C2 and the second pin of the third capacitor C3 respectively, and the second inductor L2 is connected in series between the second pin of the second capacitor C2 and the second pin of the third capacitor C3; If the synthesized alternating current is in the first half cycle, the level of the alternating current electrode A is higher than the level of the alternating current electrode B. The synthesis process of the alternating current in the first half cycle is as follows: When the high-frequency transformer TR drives the current to flow from the same-name end of the primary side Np to the opposite-name end of the primary side Np, the same-name end level of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the opposite-name end level. At this time, the GaN-Mos control driving circuit controls the seventh switch tube S7 to turn off, the eighth switch tube S8 to turn on, the fifth switch tube S5 to turn on, and the sixth switch tube S6 to turn on. The first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the first pin of the second capacitor C2 is higher than the level of the second pin of the second capacitor C2. When the high-frequency transformer TR drives the current to flow from the opposite-name end of the 2nd pin of the primary side Np to the same-name end of the 1st pin, the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the level of the same-name end. At this time, the GaN-Mos control driving circuit controls the fifth switch tube S5 to be turned on, the sixth switch tube S6 to be turned off, the seventh switch tube S7 to be turned on, and the eighth switch tube S8 to be turned on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, and the level of the second pin of the third capacitor C3 is higher than the level of the first pin of the third capacitor C3. At this time, the second capacitor C2, the third capacitor C3, the second inductor L2 and the fourth capacitor C4 form a closed loop, the second capacitor C2 and the third capacitor C3 have the same level direction, and the fourth capacitor C4 is charged through the second inductor L2, so that the level of the AC electrode A is higher than that of the AC electrode B, and the AC current is in the upper half cycle. If the synthesized alternating current is in the second half cycle, the level of the alternating current electrode B is higher than the level of the alternating current electrode A. The synthesis process of the alternating current in the second half cycle is as follows: When the high-frequency transformer TR drives the current to flow from the same-name end of the primary side Np to the opposite-name end of the primary side Np, the same-name end level of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the opposite-name end level. At this time, the GaN-Mos control driving circuit controls the fifth switch tube S5 to turn off, the sixth switch tube S6 to turn on, the seventh switch tube S7 to turn on, and the eighth switch tube S8 to turn on. The second secondary winding Ns2 charges the third capacitor C3 through the seventh switch tube S7 and the eighth switch tube S8, and the level of the first pin of the third capacitor C3 is higher than the level of the second pin of the third capacitor C3. When the high-frequency transformer TR drives the current to flow from the opposite-name end of the 2nd pin of the primary side Np to the same-name end of the 1st pin, the level of the opposite-name end of the first secondary winding Ns1 and the second secondary winding Ns2 is higher than the level of the same-name end. At this time, the GaN-Mos control driving circuit controls the seventh switch tube S7 to turn on, the eighth switch tube S8 to turn off, the fifth switch tube S5 to turn on, and the sixth switch tube S6 to turn on. The first secondary winding Ns1 charges the second capacitor C2 through the fifth switch tube S5 and the sixth switch tube S6, and the level of the second pin of the second capacitor C2 is higher than the level of the first pin of the second capacitor C2. At this time, the second capacitor C2, the third capacitor C3, the second inductor L2 and the fourth capacitor C4 form a closed loop, and the second capacitor C2 and the third capacitor C3 are in the same level direction to charge the fourth capacitor C4 through the second inductor L2, so that the level of the AC electrode B is higher than that of the AC electrode A, and shows the characteristics of the AC power being in the second half cycle.

5. The GaN-MOS bidirectional inverter circuit according to claim 1, characterized in that: The secondary side of the high-frequency transformer TR includes two output windings, namely a first secondary winding Ns1 and a second secondary winding Ns2; the third output pin of the first secondary winding Ns1 is connected to the D pin of the fifth switch tube S5, and the fourth output pin is connected to the second pin of the second capacitor C2 and the first pin of the second inductor L2; the sixth output pin of the second secondary winding Ns2 is connected to the D pin of the seventh switch tube S7, and the fifth output pin is connected to the second pin of the third capacitor C3 and the second pin of the second inductor L2; when the driving current on the primary side Np alternates, the first secondary winding Ns1 and the second secondary winding Ns2 windings respectively bear the current in one direction and charge the second capacitor C2 and the third capacitor C3 through the switch tube, and the second capacitor C2 and the third capacitor C3 charge the fourth capacitor C4 through the second inductor L2.

6. The GaN-MOS bidirectional inverter circuit according to claim 1, characterized in that: During the synthesis of the waveform in the first half cycle, based on the second sampling resistor R2, the GaN-MOS control driving circuit controls the conduction or shutdown of the sixth switch tube S6 by the following method: When the voltage between the same-name end and the opposite-name end of the first secondary winding Ns1 is higher than the voltage between the first pin and the second pin of the second capacitor C2; at this time, the fifth switch tube S5 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the sixth switch tube S6. When the S pin level of the sixth switch tube S6 is higher than the D pin or the second sampling resistor R2 has a current flowing from pin 1 to pin 2, the sixth switch tube S6 is instantly turned on. When the TR primary side drive current drops to 0, the current from pin 1 to pin 2 of the second sampling resistor R2 drops to 0, and the sixth switch tube S6 is turned off; therefore, based on the second sampling resistor R2, the GaN-Mos control drive circuit can control the sixth switch tube S6 to operate in a zero voltage turn-on and zero current turn-off working state; During the synthesis of the waveform in the first half cycle, based on the third sampling resistor R3, the GaN-MOS control driving circuit controls the conduction or shutdown of the seventh switch tube S7 by the following method: When the level of the opposite-name end of the second secondary winding Ns2 is higher than the second pin of the third capacitor C3, the eighth switch tube S8 is turned on, and the GaN-Mos control driving circuit compares the levels of the D pin and the S pin of the seventh switch tube S7. When the S pin level is higher than the D pin or the third sampling resistor R3 has a current flowing from the 2 pin to the 1 pin, the seventh switch tube S7 is turned on instantly. When the TR primary driving current drops to 0, the current of the third sampling resistor R3 drops to 0 from the 2 pin to the 1 pin, so that the seventh switch tube S7 is turned off; Therefore, based on the third sampling resistor R3, the GaN-Mos control driving circuit can control the seventh switch tube S7 to operate in a zero voltage turn-on and zero current turn-off operating state; During the synthesis of the waveform in the second half cycle, based on the second sampling resistor R2, the GaN-MOS control driving circuit controls the conduction or shutdown of the fifth switch tube S5 by the following method: When the voltage between the opposite-terminal and the same-terminal of the first secondary winding Ns1 is higher than the voltage between the second pin and the first pin of the second capacitor C2; at this time, the sixth switch tube S6 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the fifth switch tube S5. When the S pin level of the fifth switch tube S5 is higher than the D pin or the second sampling resistor R2 has a current flowing from the 2nd pin to the 1st pin, the fifth switch tube S5 is turned on instantly. When the TR primary side drive current drops to 0, the current from the 2nd pin to the 1st pin of the second sampling resistor R2 drops to 0, so that the fifth switch tube S5 is turned off; therefore, based on the second sampling resistor R2, the GaN-Mos control drive circuit can control the fifth switch tube S5 to work in a zero voltage turn-on and zero current turn-off working state; During the synthesis of the waveform in the second half cycle, based on the third sampling resistor R3, the GaN-MOS control driving circuit controls the conduction or shutdown of the eighth switch tube S8 by the following method: When the voltage between the same-name terminal level and the opposite-name terminal level of the second secondary winding Ns2 is higher than the voltage between the second pin and the first pin of the third capacitor C3; at this time, the seventh switch tube S7 is turned on, and the GaN-Mos control drive circuit compares the D pin and S pin levels of the eighth switch tube S8. When the S pin level is higher than the D pin or the third sampling resistor R3 has a current flowing from pin 1 to pin 2, the eighth switch tube S8 is turned on instantly. When the TR primary side drive current drops to 0, the current from pin 1 to pin 2 of the third sampling resistor R3 drops to 0, so that the eighth switch tube S8 is turned off; therefore, based on the third sampling resistor, the GaN-Mos control drive circuit can control the eighth switch tube S8 to operate in a zero voltage turn-on and zero current turn-off working state.

7. The GaN-MOS bidirectional inverter circuit according to claim 1, characterized in that: The first switch tube S1, the second switch tube S2, the third switch tube S3, and the fourth switch tube S4 are GaN-MOS switch tubes. The main control circuit turns off or turns on each switch tube in the full-bridge circuit by the following method: The main control circuit compares the level of the S pin of the first switch tube S1 and the level of the S pin of the second switch tube S2 with the positive level of the DC electrode respectively; the level of the S pin of the first switch tube S1 and the level of the S pin of the second switch tube S2 are compared with the negative level of the DC electrode respectively. When the Vds voltage of the switch tube changes from positive to negative, the Vds zero voltage conduction condition of the switch tube is established, and the main control circuit turns on the corresponding GaN-Mos switch tube through the full-bridge drive circuit. The Vds voltage is the voltage between the D pin and the S pin of the switch tube. Among them, in the AC-DC mode, when the current from the second pin to the first pin of the first sampling resistor R1 increases from 0, the first switch tube S1, the third switch tube S3 or the second switch tube S2, the fourth switch tube S4 are turned on in pairs at the same time, so that the corresponding switch tubes work in a zero voltage turn-on condition; when the current from the second pin to the first pin of the first sampling resistor R1 becomes 0, the corresponding two turned-on switch tubes are correspondingly turned off at the same time, so that the corresponding GaN-Mos switch tube works in a zero current turn-off condition.

8. An electronic device, characterized in that: A GaN-Mos bidirectional inverter circuit comprising any one of claims 1 to 7.

9. The electronic device according to claim 8, characterized in that: The electronic device is an inverter.

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