Ultrahigh-frequency bidirectional energy transfer DC / DC converter

Abstract

The invention provides an ultrahigh-frequency bidirectional energy transfer DC / DC converter. The ultrahigh-frequency bidirectional energy transfer DC / DC converter comprises a full-bridge primary main circuit, a high-frequency transformer and a full-bridge secondary main circuit, the full-bridge primary main circuit comprises a bus end and a SiC full-bridge primary module; the bus end is connected with the SiC full-bridge primary module, and the SiC full-bridge primary module is connected with the primary of the high-frequency transformer; the full-bridge secondary main circuit comprises a SiC full-bridge secondary module and a battery module; the secondary of the high-frequency transformer is connected with the SiC full-bridge secondary module, and the SiC full-bridge secondary module is connected with the battery module; and the SiC full-bridge primary module and the SiC full-bridge secondary module respectively adopt a full-bridge topological structure formed by SiC MOSFETs. According to the invention, a primary and secondary full-bridge topological structure mode is adopted, and a SiC power device is adopted as a main power device for energy transfer, so that ultrahigh frequency is realized in a bidirectional energy transfer process, and comprehensive performance such as dynamic characteristics, energy efficiency and power density can be further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conversion equipment, and more specifically, to an ultra-high frequency bidirectional energy transfer DC / DC converter. Background Art

[0002] As a power converter and stabilizer, DC / DC modules are widely used in the field of power electronics. For example, in a fully digital welding power supply, a DC / DC module can accurately provide operating voltage for each control system. In a train traction converter, a DC / DC module is responsible for further converting the inverted DC power into a voltage suitable for the operation of various systems at all levels of the train, ensuring that the train can run smoothly and efficiently.

[0003] In addition, DC / DC modules are also widely used in aerospace, medical equipment, security monitoring and other fields. In the aerospace field, due to the extreme environment and extremely high requirements for power quality, DC / DC modules can ensure that various airborne equipment can work stably in complex and changeable flight environments. In medical equipment, DC / DC modules provide stable power for various precision instruments to ensure the accuracy and safety of medical processes. In security monitoring systems, DC / DC modules are responsible for providing reliable power support for cameras, alarms and other equipment to ensure the stable operation of the monitoring system around the clock.

[0004] The DC / DC modules that are widely used at present generally tend to adopt the BUCK-BOOST topology composed of two power switch tubes, which has a high energy conversion efficiency. However, although the DC / DC modules with the BUCK-BOOST topology perform well in the field of small and medium power, their limitations gradually emerge when facing high-power application scenarios. Due to the limited output adjustment range of the Buck-Boost circuit, the output voltage and frequency adjustment range are limited, and the adaptability to grid fluctuations is poor. When higher output power or a wider input voltage range is required, it is often necessary to replace the DC / DC converter of the Buck-Boost circuit with different power specifications. This, to a certain extent, limits its wide application and adaptability in the context of the rapid development of energy storage battery technology and the continuous increase in capacity, and it is difficult to meet the market's urgent demand for efficient, reliable and compact energy storage solutions.

[0005] At the same time, almost all existing DC / DC modules use Si-based power devices, and their switching performance is close to the theoretical limit determined by their material properties, which restricts several key indicators that affect the efficiency of power conversion, such as inverter frequency, temperature rise, and loss. Summary of the invention

[0006] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide an ultra-high frequency bidirectional energy transfer DC / DC converter; the DC / DC converter adopts a full-bridge topology structure for both the primary and secondary, and uses SiC power devices as the main power devices for energy transfer, and achieves ultra-high frequency in the process of bidirectional energy transfer, which can further improve the comprehensive performance such as dynamic characteristics, energy efficiency, and power density.

[0007] In order to achieve the above object, the present invention is implemented by the following technical scheme: an ultra-high frequency bidirectional energy transfer DC / DC converter, characterized in that it includes a full-bridge primary main circuit, a high-frequency transformer T101 and a full-bridge secondary main circuit; The full-bridge primary main circuit includes a bus terminal and a SiC full-bridge primary module; wherein the bus terminal is connected to the SiC full-bridge primary module, and the SiC full-bridge primary module is connected to the primary of the high-frequency transformer T101; The full-bridge secondary main circuit includes a SiC full-bridge secondary module and a battery module; wherein the secondary of the high-frequency transformer T101 is connected to the SiC full-bridge secondary module, and the SiC full-bridge secondary module is connected to the battery module; The SiC full-bridge primary module and the SiC full-bridge secondary module are driven by SiC driving circuits respectively; the SiC full-bridge primary module and the SiC full-bridge secondary module are full-bridge topology structures formed by SiC MOSFETs respectively.

[0008] In the present invention, energy transfer can be from the bus terminal to the battery module or from the battery module to the bus terminal, and the energy transfer direction is determined according to the actual working requirements. The SiC power device is quickly turned on and off according to the preset timing to achieve the conversion of DC-high frequency AC-DC; the SiC power device of the SiC full-bridge primary module and the SiC power device of the SiC full-bridge secondary module are independently controlled by the driving signals.

[0009] Preferably, the SiC full-bridge primary module includes SiC MOSFETs M101 to M104 and a capacitor C100; After SiC MOSFET M101 and SiC MOSFET M103 are connected in series, they are connected in parallel to the bus terminal together with a circuit formed by SiC MOSFET M102 and SiC MOSFET M104 in series; the connection point of SiC MOSFET M101 and SiC MOSFET M103 is connected to the primary first input terminal of the high-frequency transformer T101 through capacitor C100; the connection point of SiC MOSFET M102 and SiC MOSFET M104 is connected to the primary second input terminal of the high-frequency transformer T101.

[0010] Preferably, the SiC full-bridge primary module further includes capacitors C101 to C104 and resistors R101 to R104; Capacitor C101 and resistor R101 are connected in series and then connected in parallel to SiC MOSFET M101; capacitor C102 and resistor R102 are connected in series and then connected in parallel to SiC MOSFET M102; capacitor C103 and resistor R103 are connected in series and then connected in parallel to SiC MOSFET M103; capacitor C104 and resistor R104 are connected in series and then connected in parallel to SiC MOSFET M104.

[0011] Preferably, the SiC full-bridge secondary module includes SiC MOSFETs M105 to M108 and a capacitor C109; After SiC MOSFET M105 and SiC MOSFET M107 are connected in series, they are connected in parallel to the battery module together with a circuit formed by SiC MOSFET M106 and SiC MOSFET M108 in series; the connection between SiC MOSFET M105 and SiC MOSFET M107 is connected to the secondary first output terminal of the high-frequency transformer T101 through capacitor C109; the connection between SiC MOSFET M106 and SiC MOSFET M108 is connected to the secondary second output terminal of the high-frequency transformer T101.

[0012] Preferably, the SiC full-bridge secondary module further includes capacitors C105-C108 and resistors R105-R108; Capacitor C105 and resistor R105 are connected in series and then connected in parallel to SiC MOSFET M105; capacitor C106 and resistor R106 are connected in series and then connected in parallel to SiC MOSFET M106; capacitor C107 and resistor R107 are connected in series and then connected in parallel to SiC MOSFET M107; capacitor C108 and resistor R108 are connected in series and then connected in parallel to SiC MOSFET M108.

[0013] Preferably, the working mode includes a forward energy transfer mode and a reverse energy transfer mode; When the energy is transferred in the forward direction, the SiC full-bridge primary module is used as an inverter circuit, and the SiC full-bridge secondary module is used as a rectifier circuit; when the energy is transferred in the reverse direction, the SiC full-bridge secondary module is used as an inverter circuit, and the SiC full-bridge primary module is used as a rectifier circuit. For the inverter circuit, the SiC drive circuit outputs two complementary PWM signals with dead zones to control the two SiC MOSFETs at the diagonal of the inverter circuit to turn on or off at high frequency at the same time, converting DC power into high-frequency AC power. For the rectifier circuit, the SiC drive circuit turns off all SiC MOSFETs; the high-frequency AC is rectified through the rectifier circuit formed by the body diode of the SiC MOSFET.

[0014] Preferably, when the energy forward transfer mode is adopted, the bus terminal is the input side and the battery module is the output side; when the energy reverse transfer mode is adopted, the battery module is the input side and the bus terminal is the output side; The measured current value and the measured voltage value on the output side are collected; the difference operation is performed with the preset current setting value and voltage setting value of the output side respectively, and the average difference is performed with PID operation for several times to obtain the current fluctuation value and the voltage fluctuation value; according to the current fluctuation value and the voltage fluctuation value, the on-time and off-time of the SiC MOSFET of the inverter circuit are changed to realize the duty cycle adjustment, so that the current value and the voltage value on the output side are close to the current setting value and the voltage setting value respectively.

[0015] Preferably, the SiC driving circuit comprises a power supply circuit, a PWM output circuit, a Miller clamp circuit and a short-circuit protection circuit.

[0016] Preferably, the power supply circuit is composed of a switching voltage X1 regulator and a power supply peripheral circuit; The PWM output circuit includes a logic device IC1, a logic device IC2, a pulse transformer T1, a pulse transformer T2 and a PWM peripheral circuit; the input ends of the logic device IC1 and the logic device IC2 are respectively connected to the MCU chip, and the output ends are respectively connected to the input ends of the pulse transformer T1 and the pulse transformer T2; The short-circuit protection circuit includes a logic device IC3, a push-pull MOS Q3, a push-pull MOS Q4, a discharge MOS Q5 and a protection peripheral circuit; the input end of the logic device IC3 is connected to the output end of the pulse transformer T1, the output end is connected to the push-pull MOS Q3, the push-pull MOS Q4, and the discharge MOS Q5, and the push-pull MOS Q3, the push-pull MOS Q4, and the discharge MOS Q5 are connected to the SiC MOSFET; The Miller clamp circuit includes a logic IC4, a clamp MOS Q7 and a clamp peripheral circuit; the input end of the logic IC4 is connected to the output end of the pulse transformer T2, the output end is connected to the clamp MOS Q7, and the clamp MOS Q7 is connected to the SiC MOSFET.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. Compared with the existing DC / DC converter using a Buck-Boost circuit topology structure composed of two power switch tubes, the present invention adopts a full-bridge topology structure in both the primary and secondary, and uses wide-bandgap SiC power devices with faster switching speed, lower switching loss and better heat resistance for upgrading. In the process of bidirectional energy transfer, ultra-high frequency is achieved, which can further improve the comprehensive performance such as dynamic characteristics, energy efficiency, and power density; 2. The power switch devices of the present invention all use new generation power electronic devices SiC power devices, with a switching frequency of up to 200kHz, and have good dynamic response speed and power density; 3. The present invention reduces the loss of magnetic components in the circuit and improves the efficiency of power conversion because SiC MOSFET has low conduction loss and realizes ultra-high frequency switching state operation. In addition, the ultra-high frequency bidirectional energy transfer DC / DC converter developed using SiC MOSFET has a very high inverter frequency, which greatly reduces the volume and mass of the high-frequency transformer, making it much smaller than the traditional specifications. This advantage directly facilitates the seamless integration of key components such as high-frequency transformers on the main circuit board without occupying additional valuable internal space of the chassis, and its layout is not restricted by the design of the main circuit board PCB, and has a high degree of flexibility and integration. It is conducive to making the DC / DC converter into a full-board card module structure, which not only significantly reduces the cost and volume, but also improves electromagnetic compatibility and reliability. 4. The present invention, due to the increase of the inverter frequency and the reduction of the loop time, can realize the high-speed and precise regulation of the output current and voltage, and improve the control effect of the voltage and current of the battery module during the charging and discharging process; 5. The energy conversion efficiency of the present invention is high, and the bidirectional energy transfer efficiency can reach up to 98.25%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a circuit diagram of the overall topological structure of the ultra-high frequency bidirectional energy transfer DC / DC converter of the present invention; FIG. 2 (a) to FIG. 2 (d) are schematic circuit diagrams of a bidirectional energy transfer working timing mode of an ultra-high frequency bidirectional energy transfer DC / DC converter of the present invention; Figure 3 It is a circuit schematic diagram of the SiC drive circuit of the ultra-high frequency bidirectional energy transfer DC / DC converter of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0020] Example like Figure 1As shown, this embodiment is an ultra-high frequency bidirectional energy transfer DC / DC converter, including a full-bridge primary main circuit, a high-frequency transformer T101 and a full-bridge secondary main circuit.

[0021] The full-bridge primary main circuit includes a bus terminal and a SiC full-bridge primary module; wherein the bus terminal is connected to the SiC full-bridge primary module, and the SiC full-bridge primary module is connected to the primary of the high-frequency transformer T101.

[0022] The full-bridge secondary main circuit includes a SiC full-bridge secondary module and a battery module; wherein the secondary of the high-frequency transformer T101 is connected to the SiC full-bridge secondary module, and the SiC full-bridge secondary module is connected to the battery module. The SiC full-bridge primary module and the SiC full-bridge secondary module are driven by SiC drive circuits respectively.

[0023] Specifically, the SiC full-bridge primary module includes SiC MOSFETs M101 to M104, capacitors C100 to C104, and resistors R101 to R104; After SiC MOSFET M101 and SiC MOSFET M103 are connected in series, they are connected in parallel to the bus terminal together with the circuit formed by SiC MOSFET M102 and SiC MOSFET M104 in series; capacitor C101 and resistor R101 are connected in series and connected in parallel to SiC MOSFET M101; capacitor C102 and resistor R102 are connected in series and connected in parallel to SiC MOSFET M102; capacitor C103 and resistor R103 are connected in series and connected in parallel to SiC MOSFET M103; capacitor C104 and resistor R104 are connected in series and connected in parallel to SiC MOSFET M104; the connection point of SiC MOSFET M101 and SiC MOSFET M103 is connected to the primary first input terminal of high-frequency transformer T101 through capacitor C100; the connection point of SiC MOSFET M102 and SiC MOSFET M104 is connected to the primary second input terminal of high-frequency transformer T101.

[0024] The SiC full-bridge secondary module includes SiC MOSFETs M105 to M108, capacitors C105 to C109, and resistors R105 to R108; After SiC MOSFET M105 and SiC MOSFET M107 are connected in series, they are connected in parallel to the battery module together with the circuit formed by SiC MOSFET M106 and SiC MOSFET M108 in series; capacitor C105 and resistor R105 are connected in series and connected in parallel to SiC MOSFET M105; capacitor C106 and resistor R106 are connected in series and connected in parallel to SiC MOSFET M106; capacitor C107 and resistor R107 are connected in series and connected in parallel to SiC MOSFET M107; capacitor C108 and resistor R108 are connected in series and connected in parallel to SiC MOSFET M108; the connection point of SiC MOSFET M105 and SiC MOSFET M107 is connected to the secondary first output terminal of high-frequency transformer T101 through capacitor C109; the connection point of SiC MOSFET M106 and SiC MOSFET M108 is connected to the secondary second output terminal of high-frequency transformer T101.

[0025] The working modes include forward energy transfer and reverse energy transfer: When the energy forward transfer mode is adopted, as shown in Figure 2 (a) and Figure 2 (b), the DC power output from the bus terminal is inverted through the inverter circuit composed of SiC MOSFETs M101 to M104 in the SiC full-bridge primary module; the SiC drive circuit outputs two complementary PWM signals with dead zones to control the two SiC MOSFETs at the diagonal of the inverter circuit to turn on or off at high frequency at the same time, converting the DC power into high-frequency AC power; then, it is electrically isolated, transformed and the power is transferred to the full-bridge secondary main circuit through the high-frequency transformer T101; The SiC drive circuit controls all SiC MOSFETs M105 to M108 in the SiC full-bridge secondary module to be turned off; the high-frequency AC power is rectified by the rectifier circuit composed of the body diode D105 of SiC MOSFET M105, the body diode D106 of SiC MOSFET M106, the body diode D107 of SiC MOSFET M107, and the body diode D108 of SiC MOSFET M108 in the SiC full-bridge secondary module, and the high-frequency AC power is converted into low-voltage smooth DC power and output to the battery module; When the energy reverse transfer mode is adopted, as shown in Figure 2 (c) and Figure 2 (d), the smooth DC power output by the battery module is inverted through the inverter circuit composed of SiC MOSFET M105~M108 in the SiC full-bridge secondary module; the SiC drive circuit outputs two complementary PWM signals with dead zones to control the two SiC MOSFETs at the diagonal of the inverter circuit to turn on or off at high frequency at the same time, converting the DC power into high-frequency AC power; then it is electrically isolated, transformed and the power is transferred to the primary main circuit of the full-bridge through the high-frequency transformer T101; The SiC drive circuit controls all SiC MOSFETs M101 to M104 in the SiC full-bridge primary module to be turned off; the high-frequency AC power is rectified by the rectifier circuit composed of the body diode D101 of SiC MOSFET M101, the body diode D102 of SiC MOSFET M102, the body diode D103 of SiC MOSFET M103 and the body diode D104 of SiC MOSFET M104 in the SiC full-bridge secondary module, and the high-frequency AC power is converted into low-voltage smooth DC power and output to the bus terminal.

[0026] When the energy is transmitted in the forward direction, the bus terminal is the input side and the battery module is the output side; when the energy is transmitted in the reverse direction, the battery module is the input side and the bus terminal is the output side. The measured current value and the measured voltage value on the output side are collected; the difference operation is performed with the preset current setting value and voltage setting value of the output side respectively, and the average difference is performed with PID operation for several times to obtain the current fluctuation value and the voltage fluctuation value; according to the current fluctuation value and the voltage fluctuation value, the on-time and off-time of the SiC MOSFET of the inverter circuit are changed to realize the duty cycle adjustment, so that the current value and the voltage value on the output side are close to the current setting value and the voltage setting value respectively.

[0027] The SiC driving circuits all include a power supply circuit, a PWM output circuit, a Miller clamp circuit and a short-circuit protection circuit.

[0028] like Figure 3 As shown, the power supply circuit is composed of a switching voltage X1 regulator and a power supply peripheral circuit; The PWM output circuit includes a logic device IC1, a logic device IC2, a pulse transformer T1, a pulse transformer T2 and a PWM peripheral circuit; the input ends of the logic device IC1 and the logic device IC2 are respectively connected to the MCU chip, and the output ends are respectively connected to the input ends of the pulse transformer T1 and the pulse transformer T2; The short-circuit protection circuit includes a logic device IC3, a push-pull MOS Q3, a push-pull MOS Q4, a discharge MOS Q5 and a protection peripheral circuit; the input end of the logic device IC3 is connected to the output end of the pulse transformer T1, the output end is connected to the push-pull MOS Q3, the push-pull MOS Q4, and the discharge MOS Q5, and the push-pull MOS Q3, the push-pull MOS Q4, and the discharge MOS Q5 are connected to the SiC MOSFET; The Miller clamp circuit includes a logic IC4, a clamp MOS Q7 and a clamp peripheral circuit; the input end of the logic IC4 is connected to the output end of the pulse transformer T2, the output end is connected to the clamp MOS Q7, and the clamp MOS Q7 is connected to the SiC MOSFET.

[0029] The working principle of the SiC drive circuit is as follows: the secondary side voltage in the power supply circuit is provided by the integrated DC / DC isolated from the primary side power supply to provide the driving voltage for the PWM signal; the PWM signal output by the MCU chip is amplified and magnetically isolated through the PWM output circuit, and then output to the Miller clamp circuit and the short-circuit protection circuit, and finally output to the SiC MOSFET; the CLAMP pin in the Miller clamp circuit inputs the SiC MOSFET gate voltage into the logic IC3 after comparison by the operational amplifier F1 and discharges the crosstalk charge; in the short-circuit protection circuit, the SiC MOSFET drain is connected to the operational amplifier F2 through the fast recovery diode D2 to detect the drain voltage, and when overcurrent occurs, the gate outputs a negative voltage through the logic IC4 to softly shut down the SiC MOSFET to prevent device damage; in addition, the fault signal in the PWM output circuit can be output to the MCU chip through pull-up to realize software monitoring, and the protection state can be reset and exited by controlling the Reset pin level.

[0030] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An ultra-high frequency bidirectional energy transfer DC / DC converter, characterized in that: It includes a full-bridge primary main circuit, a high-frequency transformer T101 and a full-bridge secondary main circuit; The full-bridge primary main circuit includes a bus terminal and a SiC full-bridge primary module; wherein the bus terminal is connected to the SiC full-bridge primary module, and the SiC full-bridge primary module is connected to the primary of the high-frequency transformer T101; The full-bridge secondary main circuit includes a SiC full-bridge secondary module and a battery module; wherein the secondary of the high-frequency transformer T101 is connected to the SiC full-bridge secondary module, and the SiC full-bridge secondary module is connected to the battery module; The SiC full-bridge primary module and the SiC full-bridge secondary module are driven by SiC driving circuits respectively; the SiC full-bridge primary module and the SiC full-bridge secondary module are full-bridge topology structures formed by SiC MOSFETs respectively.

2. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 1, characterized in that: The SiC full-bridge primary module includes SiC MOSFETs M101 to M104 and capacitor C100; After SiC MOSFET M101 and SiC MOSFET M103 are connected in series, they are connected in parallel to the bus terminal together with a circuit formed by SiC MOSFET M102 and SiC MOSFET M104 in series; the connection point of SiC MOSFET M101 and SiC MOSFET M103 is connected to the primary first input terminal of the high-frequency transformer T101 through the capacitor C100; the connection point of SiC MOSFET M102 and SiC MOSFET M104 is connected to the primary second input terminal of the high-frequency transformer T101.

3. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 2, characterized in that: The SiC full-bridge primary module also includes capacitors C101-C104 and resistors R101-R104; Capacitor C101 and resistor R101 are connected in series and then connected in parallel to SiC MOSFET M101; capacitor C102 and resistor R102 are connected in series and then connected in parallel to SiC MOSFET M102; capacitor C103 and resistor R103 are connected in series and then connected in parallel to SiC MOSFET M103; capacitor C104 and resistor R104 are connected in series and then connected in parallel to SiC MOSFET M104.

4. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 2, characterized in that: The SiC full-bridge secondary module includes SiC MOSFETs M105 to M108 and a capacitor C109; After SiC MOSFET M105 and SiC MOSFET M107 are connected in series, they are connected in parallel to the battery module together with a circuit formed by SiC MOSFET M106 and SiC MOSFET M108 in series; the connection between SiC MOSFET M105 and SiC MOSFET M107 is connected to the secondary first output terminal of the high-frequency transformer T101 through capacitor C109; the connection between SiC MOSFET M106 and SiC MOSFET M108 is connected to the secondary second output terminal of the high-frequency transformer T101.

5. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 4, characterized in that: The SiC full-bridge secondary module also includes capacitors C105-C108 and resistors R105-R108; Capacitor C105 and resistor R105 are connected in series and then connected in parallel to SiC MOSFET M105; capacitor C106 and resistor R106 are connected in series and then connected in parallel to SiC MOSFET M106; capacitor C107 and resistor R107 are connected in series and then connected in parallel to SiC MOSFET M107; capacitor C108 and resistor R108 are connected in series and then connected in parallel to SiC MOSFET M108.

6. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 1, characterized in that: The working modes include forward energy transfer mode and reverse energy transfer mode; When the energy is transferred in the forward direction, the SiC full-bridge primary module is used as an inverter circuit, and the SiC full-bridge secondary module is used as a rectifier circuit; when the energy is transferred in the reverse direction, the SiC full-bridge secondary module is used as an inverter circuit, and the SiC full-bridge primary module is used as a rectifier circuit. For the inverter circuit, the SiC drive circuit outputs two complementary PWM signals with dead zones to control the two SiC MOSFETs at the diagonal of the inverter circuit to turn on or off at high frequency at the same time, converting DC power into high-frequency AC power. For the rectifier circuit, the SiC drive circuit turns off all SiC MOSFETs; the high-frequency AC is rectified through the rectifier circuit formed by the body diode of the SiC MOSFET.

7. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 6, characterized in that: When the energy is transmitted in the forward direction, the bus terminal is the input side and the battery module is the output side; when the energy is transmitted in the reverse direction, the battery module is the input side and the bus terminal is the output side. Collect the measured current value and measured voltage value on the output side; The difference operation is performed with the preset current setting value and voltage setting value of the output side respectively, and the average difference is subjected to PID operation for several times to obtain the current fluctuation value and the voltage fluctuation value; according to the current fluctuation value and the voltage fluctuation value, the on-time and off-time of the SiC MOSFET of the inverter circuit are changed to realize the duty cycle adjustment, so that the current value and the voltage value of the output side are close to the current setting value and the voltage setting value respectively.

8. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 1, characterized in that: The SiC driving circuit includes a power supply circuit, a PWM output circuit, a Miller clamp circuit and a short-circuit protection circuit.

9. The ultra-high frequency bidirectional energy transfer DC / DC converter according to claim 8, characterized in that: The power supply circuit is composed of a switching voltage X1 regulator and a power supply peripheral circuit; The PWM output circuit includes a logic device IC1, a logic device IC2, a pulse transformer T1, a pulse transformer T2 and a PWM peripheral circuit; the input ends of the logic device IC1 and the logic device IC2 are respectively connected to the MCU chip, and the output ends are respectively connected to the input ends of the pulse transformer T1 and the pulse transformer T2; The short circuit protection circuit includes a logic IC3, a push-pull MOS Q3, a push-pull MOS Q4, a discharge MOS Q5 and a protection peripheral circuit; The input end of the logic IC3 is connected to the output end of the pulse transformer T1, the output end is connected to the push-pull MOS Q3, the push-pull MOS Q4, and the discharge MOS Q5, and the push-pull MOS Q3, the push-pull MOS Q4, and the discharge MOS Q5 are connected to the SiC MOSFET; The Miller clamp circuit includes a logic IC4, a clamp MOS Q7 and a clamp peripheral circuit; The input end of the logic IC4 is connected to the output end of the pulse transformer T2, the output end is connected to the clamp MOS Q7, and the clamp MOS Q7 is connected to the SiC MOSFET.

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