An isolated high-frequency dual active bridge converter based on GaN devices

Abstract

The present invention discloses an isolated high-frequency dual-active bridge converter based on gallium nitride devices, including: a high-voltage three-phase full-bridge circuit module, a low-voltage three-phase full-bridge circuit module, a three-phase energy transfer inductor, a three-phase high-frequency coaxial transformer and a DSP module; the isolated high-frequency dual-active bridge converter proposed by the present invention has a simple and symmetrical structure, wherein the power electronic switch adopts gallium nitride power devices, so that the switching frequency of the dual-active bridge converter can be increased to the range of 100kHz-1MHz, and the three-phase high-frequency coaxial transformer adopts a coaxial structure, which reduces the volume and weight of passive components, reduces electromagnetic interference, improves the power density of the converter, can transmit electric energy bidirectionally and can quickly switch the transmission direction. The embodiment of the present invention can provide high-frequency switching frequency and high power density in applications with strict restrictions on volume and weight, and solve the technical problems of relatively low switching frequency and large volume and weight of traditional dual-active bridge converters in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of power electronic conversion circuits, and in particular to an isolated high-frequency dual active bridge converter based on a gallium nitride device. Background Art

[0002] The dual-active-bridge (DAB) DC-DC bidirectional converter consists of a transformer connected to two H-bridge full-bridge circuits. The full-bridge circuit converts the DC voltage into a bipolar AC rectangular wave. The two AC voltages are applied to the transformer and the inductor, and the size and direction of energy transmission are controlled by phase shift control. The dual-active-bridge DC converter has a symmetrical and simple structure, and can achieve electrical isolation between two levels, bidirectional energy flow and zero voltage switching of devices. It is suitable for applications such as new energy power generation systems, aviation power systems, DC uninterruptible power systems, electric vehicle energy management systems, multi-port hybrid power supply systems, data centers, power electronic transformers, etc.

[0003] The transformer in the dual active bridge DC-DC bidirectional converter not only provides the necessary electrical isolation, but also mainly determines the volume and weight of the converter. The higher the operating frequency of the switching device in this topology, the smaller and lighter the transformer required. However, most of the traditional dual active bridge converters are built with silicon devices, with relatively low switching frequencies, generally below 20kHz, and the transformer connecting the two H-bridge circuits is large in size and weight.

[0004] In summary, the conventional dual active bridge converter in the prior art is constructed using silicon devices, which has the technical problems of relatively low switching frequency and large size and weight. Summary of the invention

[0005] The present invention provides an isolated high-frequency dual active bridge converter based on gallium nitride devices, which is used to solve the technical problems in the prior art that the traditional dual active bridge converter is built with silicon devices, has a relatively low switching frequency, and is large in size and weight.

[0006] The present invention provides an isolated high-frequency dual-active bridge converter based on gallium nitride devices, comprising: a high-voltage three-phase full-bridge circuit module, a low-voltage three-phase full-bridge circuit module, a three-phase energy transfer inductor, a three-phase high-frequency coaxial transformer and a DSP module; the high-voltage three-phase full-bridge circuit module includes a first three-phase full-bridge circuit composed of gallium nitride high-voltage switching devices, and the low-voltage three-phase full-bridge circuit module includes a second three-phase full-bridge circuit composed of gallium nitride low-voltage switching devices;

[0007] The AC end of the first three-phase full-bridge circuit is connected to the first port of the three-phase energy transfer inductor, the second port of the three-phase energy transfer inductor is connected to the primary winding of the three-phase high-frequency coaxial transformer, the secondary winding of the three-phase high-frequency coaxial transformer is connected to the AC end of the second three-phase full-bridge circuit, and the second port of the first three-phase full-bridge circuit and the second port of the second three-phase full-bridge circuit are both connected to the DSP module.

[0008] Preferably, the high-voltage three-phase full-bridge circuit module includes a first power circuit board and a first control circuit board connected through a signal column, the first power circuit board is provided with a first three-phase full-bridge circuit and a first gate drive circuit, and the first control circuit board is provided with a first logic control circuit and a first isolator;

[0009] The first port of the first gate drive circuit is connected to the first port of the first logic control circuit through the signal column and the first isolator, the second port of the first gate drive circuit is connected to the gate of the gallium nitride high-voltage switch device in the first three-phase full-bridge circuit, and the second port of the first logic control circuit is connected to the DSP module;

[0010] The low-voltage three-phase full-bridge circuit module includes a second power circuit board and a second control circuit board connected through a signal column, the second power circuit board is provided with a second three-phase full-bridge circuit and a second gate drive circuit, and the second control circuit board is provided with a second logic control circuit and a second isolator;

[0011] The first port of the second gate drive circuit is connected to the first port of the second logic control circuit through a signal column and a second isolator, the second port of the second gate drive circuit is connected to the gate of the gallium nitride low-voltage switching device in the second three-phase full-bridge circuit, and the second port of the second logic control circuit is connected to the DSP module.

[0012] Preferably, the first power circuit board also includes a first overcurrent and voltage measurement circuit, a first temperature measurement circuit and a first emergency protection circuit; the first port of the first overcurrent and voltage measurement circuit, the first port of the first temperature measurement circuit and the first port of the first emergency protection circuit are all connected to the AC port and the DC port on the bridge arm of the first three-phase full-bridge circuit; the second port of the first overcurrent and voltage measurement circuit and the second port of the first temperature measurement circuit are both connected to the DSP module, and the second port of the first emergency protection circuit is connected to the first gate drive circuit;

[0013] The second power circuit board also includes a second overcurrent voltage measurement circuit, a second temperature measurement circuit and a second emergency protection circuit; the first port of the second overcurrent voltage measurement circuit, the first port of the second temperature measurement circuit and the first port of the second emergency protection circuit are all connected to the AC port and the DC port on the bridge arm of the second three-phase full-bridge circuit; the second port of the second overcurrent voltage measurement circuit and the second port of the second temperature measurement circuit are both connected to the DSP module; the second port of the second emergency protection circuit is connected to the second gate drive circuit.

[0014] Preferably, the first overcurrent voltage measurement circuit comprises a first bridge arm current sensor, a first comparison circuit and a first OR gate logic circuit; the output end of the first bridge arm current sensor is connected to the input end of the first comparison circuit, the output end of the first comparison circuit is connected to the input end of the first OR gate logic circuit, and the output end of the first OR gate logic circuit is connected to the input end of the first gate drive circuit;

[0015] The second overcurrent voltage flow measurement circuit includes a second bridge arm current sensor, a second comparison circuit and a second OR gate logic circuit; the output end of the second bridge arm current sensor is connected to the input end of the second comparison circuit, the output end of the second comparison circuit is connected to the input end of the second OR gate logic circuit, and the output end of the second OR gate logic circuit is connected to the input end of the second gate drive circuit.

[0016] Preferably, the first overcurrent voltage measurement circuit further includes a first DC voltage sensor, a first voltage precision operational amplifier circuit and a first DC current sensor, the output end of the first DC voltage sensor is connected to the input end of the first voltage precision operational amplifier circuit, and the output end of the first voltage precision operational amplifier circuit and the output end of the first DC current sensor are both connected to the DSP module;

[0017] The second overcurrent voltage measurement circuit also includes a second DC voltage sensor, a second voltage precision operational amplifier circuit and a second DC current sensor. The output end of the second DC voltage sensor is connected to the input end of the second voltage precision operational amplifier circuit, and the output end of the second voltage precision operational amplifier circuit and the output end of the second DC current sensor are both connected to the DSP module.

[0018] Preferably, the first temperature measurement circuit comprises a first temperature sensor, a first temperature comparison circuit and a third OR gate logic circuit; the output end of the first temperature sensor is connected to the input end of the first temperature comparison circuit, the output end of the first temperature comparison circuit is connected to the input end of the third OR gate logic circuit, and the output end of the third OR gate logic circuit is connected to the input end of the first gate drive circuit;

[0019] The second temperature measurement circuit includes a second temperature sensor, a second temperature comparison circuit and a fourth OR gate logic circuit; the output end of the second temperature sensor is connected to the input end of the second temperature comparison circuit, the output end of the second temperature comparison circuit is connected to the input end of the fourth OR gate logic circuit, and the output end of the fourth OR gate logic circuit is connected to the input end of the second gate drive circuit.

[0020] Preferably, the first control circuit board also includes a first dead zone circuit, a first optical fiber transceiver circuit, a third temperature measurement circuit and a third auxiliary power supply circuit; the first port of the first dead zone circuit, the first port of the first optical fiber transceiver circuit, the first port of the third temperature measurement circuit and the first port of the third auxiliary power supply circuit are all connected to the first logic control circuit; the second port of the first dead zone circuit, the second port of the first optical fiber transceiver circuit, the second port of the third temperature measurement circuit and the second port of the third auxiliary power supply circuit are all connected to the DSP module;

[0021] The second control circuit board also includes a second dead zone circuit, a second optical fiber transceiver circuit, a fourth temperature measurement circuit and a fourth auxiliary power supply circuit; the first port of the second dead zone circuit, the first port of the second optical fiber transceiver circuit, the first port of the fourth temperature measurement circuit and the first port of the fourth auxiliary power supply circuit are all connected to the second logic control circuit; the second port of the second dead zone circuit, the second port of the second optical fiber transceiver circuit, the second port of the fourth temperature measurement circuit and the second port of the fourth auxiliary power supply circuit are all connected to the DSP module.

[0022] Preferably, the first three-phase full-bridge circuit includes a first driving power supply for supplying power to the gallium nitride high-voltage switch device, a first port of the first driving power supply is connected to the gallium nitride high-voltage switch device, and a second port of the first driving power supply is connected to a first port of the first logic control circuit through a signal column;

[0023] The second three-phase full-bridge circuit includes a second driving power supply for powering the gallium nitride low-voltage switching device, a first port of the second driving power supply is connected to the gallium nitride high-voltage switching device, and a second port of the second driving power supply is connected to the first port of the second logic control circuit through a signal column.

[0024] Preferably, the first driving power supply includes a first isolated power chip and a second isolated power chip connected in series, the first isolated power chip is used to output a positive voltage of 5.5V, and the second isolated power chip is used to output a negative voltage of 3.3V.

[0025] Preferably, the second driving power supply includes a third isolated power supply chip, a fourth isolated power supply chip and a low voltage difference linear stabilizer connected in series, the third isolated power supply chip is used to output a positive voltage of 5.5V, the fourth isolated power supply chip is used for a negative voltage of 3.3V, and the low voltage difference linear stabilizer is used to adjust the voltage output by the fourth isolated power supply chip and output a negative voltage of 1.5V.

[0026] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:

[0027] The isolated high-frequency dual active bridge converter proposed in the embodiment of the present invention has a symmetrical and simple structure, wherein the power electronic switch adopts gallium nitride power devices, so that the switching frequency of the dual active bridge converter can be increased to the range of 100kHz-1MHz, and the three-phase high-frequency coaxial transformer adopts a coaxial structure, which reduces the volume and weight of passive components, reduces electromagnetic interference, and improves the power density of the converter. It can transmit electric energy in both directions and can quickly switch the transmission direction. The embodiment of the present invention can provide high-frequency switching frequency and high power density in application occasions with strict restrictions on volume and weight, and solve the technical problems of relatively low switching frequency and large volume and weight of traditional dual active bridge converters in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 A topological structure block diagram of an isolated high-frequency dual active bridge converter based on a gallium nitride device provided in an embodiment of the present invention.

[0030] Figure 2 A layout diagram of parallel devices in a high-voltage full-bridge power circuit board of an isolated high-frequency dual active bridge converter based on a gallium nitride device provided in an embodiment of the present invention.

[0031] Figure 3 A layout diagram of parallel devices in a low-voltage full-bridge power circuit board of an isolated high-frequency dual active bridge converter based on a gallium nitride device provided in an embodiment of the present invention.

[0032] Figure 4 A schematic diagram of the stacked arrangement of the drive circuit design of a power circuit board and a control circuit board bidirectional switch module of an isolated high-frequency dual active bridge converter based on gallium nitride devices provided in an embodiment of the present invention.

[0033] Figure 5 A schematic diagram of a protection circuit flow of an isolated high-frequency dual active bridge converter based on a gallium nitride device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The embodiment of the present invention provides an isolated high-frequency dual active bridge converter based on gallium nitride devices, which is used to solve the technical problems in the prior art that the traditional dual active bridge converter is built with silicon devices, has a relatively low switching frequency, and is large in size and weight.

[0035] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1 , Figure 1 A topological structure block diagram of an isolated high-frequency dual active bridge converter based on a gallium nitride device provided in an embodiment of the present invention.

[0037] The present invention provides an isolated high-frequency dual-active bridge converter based on gallium nitride devices, comprising: a high-voltage three-phase full-bridge circuit module 1, a low-voltage three-phase full-bridge circuit module 2, a three-phase energy transfer inductor 3, a three-phase high-frequency coaxial transformer 4 and a DSP module 5; the high-voltage three-phase full-bridge circuit module 1 includes a first three-phase full-bridge circuit composed of a gallium nitride high-voltage switch device GaN1, and the low-voltage three-phase full-bridge circuit module 2 includes a second three-phase full-bridge circuit composed of a gallium nitride low-voltage switch device GaN2;

[0038] The AC end of the first three-phase full-bridge circuit is connected to the first port of the three-phase energy transmission inductor 3, the second port of the three-phase energy transmission inductor 3 is connected to the primary winding of the three-phase high-frequency coaxial transformer 4, the secondary winding of the three-phase high-frequency coaxial transformer 4 is connected to the AC end of the second three-phase full-bridge circuit, and the second port of the first three-phase full-bridge circuit and the second port of the second three-phase full-bridge circuit are both connected to the DSP module 5.

[0039] It should be further explained that the DC side of the first three-phase full-bridge circuit is connected to the 400V high-voltage bus, the DC side of the second three-phase full-bridge circuit is connected to the 48V low-voltage bus, and the AC sides of the two three-phase full-bridge circuits are connected together through the three-phase energy transfer inductor 3 and the three-phase high-frequency coaxial transformer 4. The DSP module 5 executes the protection logic and communicates with the host computer or adjacent devices. The DSP module 5 outputs a switch PWM signal to control the conduction and shutdown of the gallium nitride high-voltage switch device GaN1 / gallium nitride low-voltage switch device GaN2, thereby controlling the bidirectional transmission of energy between the high and low voltage electrical buses.

[0040] It should be further explained that the inductance value of the three-phase energy transmission inductor 3 is determined according to the maximum inductance required for transmission. Usually, the leakage inductance of the three-phase high-frequency coaxial transformer 4 can be directly used and ignored. The three-phase high-frequency coaxial transformer 4 adopts a coaxial transformer structure, which has the characteristics of small size, light weight, good waterproof and temperature resistance, extremely high coupling coefficient, and extremely low loss. At the same time, the winding of the coaxial transformer is in the transformer annular shell, which can play a shielding role and has almost no electromagnetic interference to the outside world. The DSP module 5 can use a sampling measurement and control board adapted to the Texas Instruments DSP control card TMDSCNCD28379D.

[0041] As a preferred embodiment, the high-voltage three-phase full-bridge circuit module 1 includes a first power circuit board and a first control circuit board connected through a signal column, the first power circuit board is provided with a first three-phase full-bridge circuit and a first gate drive circuit, and the first control circuit board is provided with a first logic control circuit and a first isolator;

[0042] The first port of the first gate drive circuit is connected to the first port of the first logic control circuit through the signal column and the first isolator, the second port of the first gate drive circuit is connected to the gate of the gallium nitride high-voltage switch device GaN1 in the first three-phase full-bridge circuit, and the second port of the first logic control circuit is connected to the DSP module 5;

[0043] The low-voltage three-phase full-bridge circuit module 2 includes a second power circuit board and a second control circuit board connected via a signal column, the second power circuit board is provided with a second three-phase full-bridge circuit and a second gate drive circuit, and the second control circuit board is provided with a second logic control circuit and a second isolator;

[0044] The first port of the second gate drive circuit is connected to the first port of the second logic control circuit through a signal column and a second isolator, the second port of the second gate drive circuit is connected to the gate of the gallium nitride low-voltage switching device GaN2 in the second three-phase full-bridge circuit, and the second port of the second logic control circuit is connected to the DSP module 5.

[0045] It should be further explained that the DSP module 5 outputs a switch PWM signal to the first / second logic control circuit, and the first / second logic control circuit controls the output gate drive signal of the first / second gate drive circuit, controls the on and off of the gallium nitride high-voltage switch device GaN1 / gallium nitride low-voltage switch device GaN2, thereby controlling the bidirectional transmission of energy between the high and low voltage electrical buses.

[0046] Both the high-voltage three-phase full-bridge circuit module 1 and the low-voltage three-phase full-bridge circuit module 2 adopt a two-circuit board stacking structure, namely a power circuit board and a control circuit board. The power circuit board has a gallium nitride switch device, a three-phase full-bridge circuit and a gate drive circuit; the logic circuit board has a logic control circuit. Figure 4 As shown, when wiring and copper coating the circuit board, a floating ground is isolated on the control circuit board, and the gate drive circuit on the power circuit board is connected to the control circuit board through the signal column (i.e., the pin socket). The other parts on the control circuit board are electrically isolated from the isolated floating ground through the isolated power chip and the isolator. The gallium nitride switch device is also provided with a heat sink for heat dissipation, and the control circuit board is also provided with an isolated power supply V DD and isolated power supply V EE .

[0047] It should be further explained that the gallium nitride high-voltage switching device GaN1 on the bridge arm of the first three-phase full-bridge circuit adopts the top-cooled gallium nitride high-voltage switching device GaN1GS66508T, and the gallium nitride low-voltage switching device GaN2 on the bridge arm of the second three-phase full-bridge circuit adopts the top-cooled gallium nitride low-voltage switching device GaN2EPC2020, and the first gate drive circuit and the second gate drive circuit both adopt the driver UCC27511.

[0048] The top-cooled GaN high-voltage switch device GaN1GS66508T uses two GaN switch devices in parallel for each switch, with the two devices arranged at a 45-degree angle. Figure 2 As shown in the figure, it is driven by a high current and high slew rate driver UCC27511. The gallium nitride high voltage switch device GaN1 is placed on the top layer of the PCB circuit board. The driver UCC27511 is placed on the back side corresponding to the adjacent gate attachments of the two gallium nitride high voltage switch devices GaN1. Its P_OUT pin output first passes through a main on-resistance, then connects to the N_OUT pin and passes through a distributed on-resistance to reach the gate of the gallium nitride high voltage switch device GaN1, that is, the corresponding Figure 2 The G2 pin of QA1_1 and the G1 pin of QA1_2. Figure 2S is the source of the GaN1 high-voltage switch device, and D is the drain of the GaN1 high-voltage switch device. The two GaN1 high-voltage switch devices are placed at a 45-degree angle, which can minimize the loop length and loop difference of the two GaN1 high-voltage switch devices from the driver output to the gate of the GaN1 high-voltage switch device to the driving ground level. At the same time, the device spacing is expanded to enhance the heat dissipation capability and uniformize the heat distribution among the three bridge arms. Since this GaN1 high-voltage switch device does not have a Kelvin source, it is necessary to create one on the PCB and connect it to the floating ground of the first logic control circuit through another distributed conduction. The main on-resistance and the distributed on-resistance are both 0.2W power resistors, using SMD 0402 packages, and are arranged as closely as possible to ensure that the distance from the driver UCC27511 output pin to the gate of the GaN1 high-voltage switch device is as short as possible and equal, and the distance from the GaN1 source to the floating ground should also be equal and as short as possible.

[0049] Among them, each switch of the top-cooled GaN low-voltage switch device GaN2EPC2020 uses six GaN switch devices working in parallel. The six parallel devices are divided into two groups, with three devices arranged at a 90-degree angle each, and are driven by a high-current and high-slew rate driver UCC27511. Figure 3 As shown, GaN2Q1_1, Q1_2, Q1_3 and driver UCC27511 are used for GaN2 low-voltage switch devices. GaN2EPC2020 is placed on the top layer of the PCB circuit board, and driver UCC27511 is placed on the back side corresponding to the adjacent gate attachments of the three GaN2 low-voltage switch devices. Its P_OUT pin output first passes through an on-resistance, then connects to the N_OUT pin and passes through a distributed resistor to reach the gate of the GaN2 low-voltage switch device, that is, the corresponding Figure 3 The pad pins of Q1_1, Q1_2, and Q1_3 in the middle are ①. The main on-resistance and the distributed on-resistance are both 0.2W power resistors, using SMD 0402 packages and arranged as closely as possible to ensure that the distance from the driver UCC27511 output pin to the gate of the GaN2 low-voltage switch device is as short as possible and equal in length. The pad pin SS of this GaN2 low-voltage switch device GaN2EPC2020 is used as the Kelvin source, which is distinguished from other source pins in the wiring and connected to the floating ground of the driver circuit through another distributed conduction. The distance from the source of the GaN2 low-voltage switch device to the floating ground should also be equal and as short as possible. The three GaN2 low-voltage switch devices are placed at a 90-degree angle to minimize the loop length and loop difference of the three devices from the driver output to the gate of the GaN2 low-voltage switch device GaN2 back to the driving ground level, while expanding the device spacing to enhance the heat dissipation capability and even the heat distribution between the three bridge arms.

[0050] As a preferred embodiment, the first power circuit board also includes a first overcurrent and voltage measurement circuit, a first temperature measurement circuit and a first emergency protection circuit; the first port of the first overcurrent and voltage measurement circuit, the first port of the first temperature measurement circuit and the first port of the first emergency protection circuit are all connected to the AC port and the DC port on the bridge arm of the first three-phase full-bridge circuit; the second port of the first overcurrent and voltage measurement circuit and the second port of the first temperature measurement circuit are both connected to the DSP module 5, and the second port of the first emergency protection circuit is connected to the first gate drive circuit;

[0051] The second power circuit board also includes a second overcurrent and voltage measurement circuit, a second temperature measurement circuit and a second emergency protection circuit; the first port of the second overcurrent and voltage measurement circuit, the first port of the second temperature measurement circuit and the first port of the second emergency protection circuit are all connected to the AC port and the DC port on the bridge arm of the second three-phase full-bridge circuit; the second port of the second overcurrent and voltage measurement circuit and the second port of the second temperature measurement circuit are both connected to the DSP module 5; the second port of the second emergency protection circuit is connected to the second gate drive circuit.

[0052] It should be further explained that the DSP module 5 receives the voltage and current information of the three-phase full-bridge circuit and the hardware temperature information transmitted by the current and voltage measurement circuit and the temperature measurement circuit, and determines whether it is necessary to send a switch PWM signal to control the gallium nitride switch device to close according to the voltage and current information and the hardware temperature information of the three-phase full-bridge circuit.

[0053] As a preferred embodiment, the first overcurrent voltage measurement circuit includes a first bridge arm current sensor, a first comparison circuit and a first OR gate logic circuit; the output end of the first bridge arm current sensor is connected to the input end of the first comparison circuit, the output end of the first comparison circuit is connected to the input end of the first OR gate logic circuit, and the output end of the first OR gate logic circuit is connected to the input end of the first gate drive circuit;

[0054] The second overcurrent voltage flow measurement circuit includes a second bridge arm current sensor, a second comparison circuit and a second OR gate logic circuit; the output end of the second bridge arm current sensor is connected to the input end of the second comparison circuit, the output end of the second comparison circuit is connected to the input end of the second OR gate logic circuit, and the output end of the second OR gate logic circuit is connected to the input end of the second gate drive circuit.

[0055] It should be further explained that the first bridge arm current sensor adopts a 1.5MHz high-bandwidth on-board current sensor MCA1101-50-3, and the current input and output terminals of the sensor are connected in parallel with a 0.1 milliohm shunt resistor WSLP5931L1000FEA; the second bridge arm current sensor adopts a 1.5MHz high-bandwidth on-board current sensor MCA1101-50-3, and the current sensor MCA1101-50 performs high-frequency detection on the bridge arm AC current of the second three-phase full-bridge circuit. The bridge arm AC current is compared with the current limit value in the second comparison circuit, and then passes through the second OR gate logic circuit to generate a protection signal, which is output to the enable input pin of the primary side of the isolator to quickly shut down the gate-level drive signal of the second gate drive circuit when overcurrent occurs. The protection signal is also fed back to the DSP module 5 to perform further protection actions, such as Figure 5 shown.

[0056] As a preferred embodiment, the first overcurrent voltage measurement circuit further includes a first DC voltage sensor, a first voltage precision operational amplifier circuit and a first DC current sensor, the output end of the first DC voltage sensor is connected to the input end of the first voltage precision operational amplifier circuit, and the output end of the first voltage precision operational amplifier circuit and the output end of the first DC current sensor are both connected to the DSP module 5;

[0057] The second overcurrent voltage measurement circuit also includes a second DC voltage sensor, a second voltage precision operational amplifier circuit and a second DC current sensor. The output end of the second DC voltage sensor is connected to the input end of the second voltage precision operational amplifier circuit, and the output end of the second voltage precision operational amplifier circuit and the output end of the second DC current sensor are both connected to the DSP module 5.

[0058] It should be further explained that the DC voltage sensor uses the ACPL-C79B chip of BROADCOM, with a bandwidth of up to 200kHz, and its output is a differential signal, which can be measured by the high-slew rate precision op amp circuit TSB7191AILT of STMicroelectronics to obtain the voltage result; the second DC current sensor uses the ACS773KCB-150B-PFF-T chip of Allegro MicroSystems LLC, and the first DC current sensor uses the ACS725KMATR-20AB-T chip of Allegro MicroSystems LLC. ACS773KCB-150B-PFF-T, ACS725KMATR-20AB-T, ACPL-C79B and precision op amp circuit TSB7191AILT are all powered by 3.3V voltage, and their output results can be directly connected to DSP module 5 without going through the voltage and current mirror conversion circuit.

[0059] As a preferred embodiment, the first temperature measurement circuit includes a first temperature sensor, a first temperature comparison circuit and a third OR gate logic circuit; the output end of the first temperature sensor is connected to the input end of the first temperature comparison circuit, the output end of the first temperature comparison circuit is connected to the input end of the third OR gate logic circuit, and the output end of the third OR gate logic circuit is connected to the input end of the first gate drive circuit;

[0060] The second temperature measurement circuit includes a second temperature sensor, a second temperature comparison circuit and a fourth OR gate logic circuit; the output end of the second temperature sensor is connected to the input end of the second temperature comparison circuit, the output end of the second temperature comparison circuit is connected to the input end of the fourth OR gate logic circuit, and the output end of the fourth OR gate logic circuit is connected to the input end of the second gate drive circuit.

[0061] It should be further explained that the temperature sensor adopts Pt1000 SMD 0805FD in 0805 resistor package, wherein the height of the thermistor Pt1000 SMD 0805 FD does not exceed 0.55mm, which is lower than the selected gallium nitride switch device, and is therefore placed on the surface of the PCB circuit board close to the gallium nitride switch device. The temperature sensor adopts a bridge circuit including a thermistor, and the temperature comparison circuit includes a comparator and a voltage and current mirror conversion circuit. The output of the bridge circuit and the preset temperature limit value are converted through the comparator and the voltage and current mirror conversion circuit to generate a protection signal, which is output to the inverting input terminal of the driver UCC27511 to quickly shut down the gate-level drive signal when the temperature is too high and the current is too high. At the same time, the temperature measurement output is output to the DSP module 55 after the voltage and current mirror conversion circuit to perform further protection actions.

[0062] As a preferred embodiment, the first control circuit board also includes a first dead zone circuit, a first optical fiber transceiver circuit, a third temperature measurement circuit and a third auxiliary power supply circuit; the first port of the first dead zone circuit, the first port of the first optical fiber transceiver circuit, the first port of the third temperature measurement circuit and the first port of the third auxiliary power supply circuit are all connected to the first logic control circuit; the second port of the first dead zone circuit, the second port of the first optical fiber transceiver circuit, the second port of the third temperature measurement circuit and the second port of the third auxiliary power supply circuit are all connected to the DSP module 5;

[0063] The second control circuit board also includes a second dead zone circuit, a second optical fiber transceiver circuit, a fourth temperature measurement circuit and a fourth auxiliary power supply circuit; the first port of the second dead zone circuit, the first port of the second optical fiber transceiver circuit, the first port of the fourth temperature measurement circuit and the first port of the fourth auxiliary power supply circuit are all connected to the second logic control circuit; the second port of the second dead zone circuit, the second port of the second optical fiber transceiver circuit, the second port of the fourth temperature measurement circuit and the second port of the fourth auxiliary power supply circuit are all connected to the DSP module 5.

[0064] It should be further explained that the output of the bridge arm current sensor MCA1101-50 is compared in the comparison circuit, and then passes through the OR gate logic circuit to generate a protection signal. The protection signal is ORed with the output of the dead zone protection circuit to determine whether to enable the PWM switch signal. Figure 5 shown.

[0065] As a preferred embodiment, the first three-phase full-bridge circuit includes a first driving power supply for supplying power to the gallium nitride high-voltage switch device GaN1, a first port of the first driving power supply is connected to the gallium nitride high-voltage switch device GaN1, and a second port of the first driving power supply is connected to a first port of the first logic control circuit through a signal column;

[0066] The second three-phase full-bridge circuit includes a second driving power supply for powering the gallium nitride low-voltage switching device GaN2, a first port of the second driving power supply is connected to the gallium nitride high-voltage switching device GaN1, and a second port of the second driving power supply is connected to the first port of the second logic control circuit through a signal column.

[0067] As a preferred embodiment, the first driving power supply includes a first isolated power chip and a second isolated power chip connected in series, the first isolated power chip is used to output a positive voltage of 5.5V, and the second isolated power chip is used to output a negative voltage of 3.3V. It should be further explained that the first isolated power chip adopts a DC / DC module power supply F0505XT-2WR2, and the second isolated power chip adopts a DC / DC module power supply F0503XT-2WR2, and the two power supplies are connected in series to generate a supply voltage of a 5V positive voltage VDD and a -3.3V negative voltage VEE.

[0068] As a preferred embodiment, the second driving power supply includes a third isolated power chip, a fourth isolated power chip and a low voltage difference linear stabilizer connected in series, the third isolated power chip is used to output a positive voltage of 5.5V, the fourth isolated power chip is used for a negative voltage of 3.3V, and the low voltage difference linear stabilizer is used to adjust the voltage output by the fourth isolated power chip and output a negative voltage of 1.5V. Further, the output of the fourth isolated power chip is connected to a low voltage difference linear regulator LDO chip to adjust and generate a voltage of 1.5V, the ground of the third isolated power chip is connected to the positive output of the LDO with a 1.5V output, and the two are connected in series to form a power supply of a 5V positive voltage VDD and a -1.5V negative voltage VEE.

[0069] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0070] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0071] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0072] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An isolated high-frequency dual active bridge converter based on gallium nitride devices, characterized in that: include: A high-voltage three-phase full-bridge circuit module, a low-voltage three-phase full-bridge circuit module, a three-phase energy transfer inductor, a three-phase high-frequency coaxial transformer and a DSP module; the high-voltage three-phase full-bridge circuit module includes a first three-phase full-bridge circuit formed by a gallium nitride high-voltage switch device, and the low-voltage three-phase full-bridge circuit module includes a second three-phase full-bridge circuit formed by a gallium nitride low-voltage switch device; The AC end of the first three-phase full-bridge circuit is connected to the first port of the three-phase energy transfer inductor, the second port of the three-phase energy transfer inductor is connected to the primary winding of the three-phase high-frequency coaxial transformer, the secondary winding of the three-phase high-frequency coaxial transformer is connected to the AC end of the second three-phase full-bridge circuit, and the second port of the first three-phase full-bridge circuit and the second port of the second three-phase full-bridge circuit are both connected to the DSP module; The high-voltage three-phase full-bridge circuit module includes a first power circuit board and a first control circuit board connected through a signal column, the first power circuit board is provided with a first three-phase full-bridge circuit and a first gate drive circuit, and the first control circuit board is provided with a first logic control circuit and a first isolator; The first port of the first gate drive circuit is connected to the first port of the first logic control circuit through the signal column and the first isolator, the second port of the first gate drive circuit is connected to the gate of the gallium nitride high-voltage switch device in the first three-phase full-bridge circuit, and the second port of the first logic control circuit is connected to the DSP module; The low-voltage three-phase full-bridge circuit module includes a second power circuit board and a second control circuit board connected through a signal column, the second power circuit board is provided with a second three-phase full-bridge circuit and a second gate drive circuit, and the second control circuit board is provided with a second logic control circuit and a second isolator; The first port of the second gate drive circuit is connected to the first port of the second logic control circuit through the signal column and the second isolator, the second port of the second gate drive circuit is connected to the gate of the gallium nitride low-voltage switch device in the second three-phase full-bridge circuit, and the second port of the second logic control circuit is connected to the DSP module; The gallium nitride high-voltage switch device on the bridge arm of the first three-phase full-bridge circuit adopts a top-cooling gallium nitride high-voltage switch device, and the gallium nitride low-voltage switch device on the bridge arm of the second three-phase full-bridge circuit adopts a top-cooling gallium nitride low-voltage switch device; Each switch of the top-cooled gallium nitride high-voltage switch device uses two gallium nitride switch devices working in parallel, and the two devices are arranged at a 45-degree angle; each switch of the top-cooled gallium nitride low-voltage switch device uses six gallium nitride switch devices working in parallel, and the six parallel devices are divided into two groups, with each three devices arranged at a 90-degree angle.

2. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 1, characterized in that: The first power circuit board also includes a first overcurrent and voltage measurement circuit, a first temperature measurement circuit and a first emergency protection circuit; the first port of the first overcurrent and voltage measurement circuit, the first port of the first temperature measurement circuit and the first port of the first emergency protection circuit are all connected to the AC port and the DC port on the bridge arm of the first three-phase full-bridge circuit; the second port of the first overcurrent and voltage measurement circuit and the second port of the first temperature measurement circuit are both connected to the DSP module, and the second port of the first emergency protection circuit is connected to the first gate drive circuit; The second power circuit board also includes a second overcurrent voltage measurement circuit, a second temperature measurement circuit and a second emergency protection circuit; the first port of the second overcurrent voltage measurement circuit, the first port of the second temperature measurement circuit and the first port of the second emergency protection circuit are all connected to the AC port and the DC port on the bridge arm of the second three-phase full-bridge circuit; the second port of the second overcurrent voltage measurement circuit and the second port of the second temperature measurement circuit are both connected to the DSP module; the second port of the second emergency protection circuit is connected to the second gate drive circuit.

3. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 2, characterized in that: The first overcurrent voltage measurement circuit includes a first bridge arm current sensor, a first comparison circuit and a first OR gate logic circuit; the output end of the first bridge arm current sensor is connected to the input end of the first comparison circuit, the output end of the first comparison circuit is connected to the input end of the first OR gate logic circuit, and the output end of the first OR gate logic circuit is connected to the input end of the first gate drive circuit; The second overcurrent voltage flow measurement circuit includes a second bridge arm current sensor, a second comparison circuit and a second OR gate logic circuit; the output end of the second bridge arm current sensor is connected to the input end of the second comparison circuit, the output end of the second comparison circuit is connected to the input end of the second OR gate logic circuit, and the output end of the second OR gate logic circuit is connected to the input end of the second gate drive circuit.

4. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 3, characterized in that: The first overcurrent voltage measurement circuit also includes a first DC voltage sensor, a first voltage precision operational amplifier circuit and a first DC current sensor, the output end of the first DC voltage sensor is connected to the input end of the first voltage precision operational amplifier circuit, and the output end of the first voltage precision operational amplifier circuit and the output end of the first DC current sensor are both connected to the DSP module; The second overcurrent voltage measurement circuit also includes a second DC voltage sensor, a second voltage precision operational amplifier circuit and a second DC current sensor. The output end of the second DC voltage sensor is connected to the input end of the second voltage precision operational amplifier circuit, and the output end of the second voltage precision operational amplifier circuit and the output end of the second DC current sensor are both connected to the DSP module.

5. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 2, characterized in that: The first temperature measurement circuit includes a first temperature sensor, a first temperature comparison circuit and a third OR gate logic circuit; the output end of the first temperature sensor is connected to the input end of the first temperature comparison circuit, the output end of the first temperature comparison circuit is connected to the input end of the third OR gate logic circuit, and the output end of the third OR gate logic circuit is connected to the input end of the first gate drive circuit; The second temperature measurement circuit includes a second temperature sensor, a second temperature comparison circuit and a fourth OR gate logic circuit; the output end of the second temperature sensor is connected to the input end of the second temperature comparison circuit, the output end of the second temperature comparison circuit is connected to the input end of the fourth OR gate logic circuit, and the output end of the fourth OR gate logic circuit is connected to the input end of the second gate drive circuit.

6. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 1, characterized in that: The first control circuit board also includes a first dead zone circuit, a first optical fiber transceiver circuit, a third temperature measurement circuit and a third auxiliary power supply circuit; the first port of the first dead zone circuit, the first port of the first optical fiber transceiver circuit, the first port of the third temperature measurement circuit and the first port of the third auxiliary power supply circuit are all connected to the first logic control circuit; the second port of the first dead zone circuit, the second port of the first optical fiber transceiver circuit, the second port of the third temperature measurement circuit and the second port of the third auxiliary power supply circuit are all connected to the DSP module; The second control circuit board also includes a second dead zone circuit, a second optical fiber transceiver circuit, a fourth temperature measurement circuit and a fourth auxiliary power supply circuit; the first port of the second dead zone circuit, the first port of the second optical fiber transceiver circuit, the first port of the fourth temperature measurement circuit and the first port of the fourth auxiliary power supply circuit are all connected to the second logic control circuit; the second port of the second dead zone circuit, the second port of the second optical fiber transceiver circuit, the second port of the fourth temperature measurement circuit and the second port of the fourth auxiliary power supply circuit are all connected to the DSP module.

7. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 1, characterized in that: The first three-phase full-bridge circuit includes a first driving power supply for supplying power to the gallium nitride high-voltage switch device, a first port of the first driving power supply is connected to the gallium nitride high-voltage switch device, and a second port of the first driving power supply is connected to a first port of the first logic control circuit through a signal column; The second three-phase full-bridge circuit includes a second driving power supply for powering the gallium nitride low-voltage switching device, a first port of the second driving power supply is connected to the gallium nitride high-voltage switching device, and a second port of the second driving power supply is connected to the first port of the second logic control circuit through a signal column.

8. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 7, characterized in that: The first driving power supply includes a first isolated power chip and a second isolated power chip connected in series, the first isolated power chip is used to output a positive voltage of 5.5V, and the second isolated power chip is used to output a negative voltage of 3.3V.

9. The isolated high-frequency dual active bridge converter based on gallium nitride devices according to claim 7, characterized in that: The second driving power supply includes a third isolated power supply chip, a fourth isolated power supply chip and a low voltage difference linear stabilizer connected in series. The third isolated power supply chip is used to output a positive voltage of 5.5V, the fourth isolated power supply chip is used to output a negative voltage of 3.3V, and the low voltage difference linear stabilizer is used to adjust the voltage output by the fourth isolated power supply chip and output a negative voltage of 1.5V.

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