Vehicle-to-vehicle charging device and control method

Abstract

The application provides a vehicle-to-vehicle charging device and a control method, and relates to the technical field of power electronic energy conversion.The main circuit adopts an isolated high-gain DC-DC converter as the main circuit topology of the vehicle-to-vehicle charging device, so that energy transmission between electric vehicles can be realized, electrical isolation between two vehicles is realized, and the reliability of the vehicle charging device is improved.In addition, a new model predictive control method is adopted, so that the current stress of the charging device is reduced, the dynamic characteristics are improved, the circuit parameters are not sensitive, the reliability and safety of the vehicle-to-vehicle charging device are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronic power conversion technology, and particularly relates to a vehicle-to-vehicle charging device and a control method. BACKGROUND

[0002] In recent years, fossil energy crisis and environmental pollution problems such as haze have been widely concerned by the government and society, and the rapidly increasing number of vehicles has led to increasing energy consumption and environmental pollution. New energy vehicles represented by electric vehicles are one of the effective ways to solve environmental pollution and fossil energy consumption. However, the laying speed of electric vehicle charging stations in China cannot match the increasing growth rate of the number of electric vehicles, especially in remote areas. Once the electric vehicle has a battery range problem of insufficient power, the owner can only call for help and wait for rescue, which greatly reduces the enthusiasm of consumers to buy electric vehicles, so there is an urgent need for a vehicle charging device with high reliability and safety to solve the problem of lack of charging stations around when the electric vehicle is out of power.

[0003] At present, the mainstream DC / DC boost converter includes a boost converter, a BUCK-BOOST converter with a boost function, a bidirectional BUCK-BOOST converter, a DAB converter, etc. When performing unidirectional energy transmission, the traditional DAB converter and the bidirectional BUCK-BOOST converter are not suitable. However, the boost gain range of the BOOST converter and the BUCK-BOOST converter is small, and the safety is not as good as the converter topology with electrical isolation. The traditional DAB has electrical isolation and meets the safety requirements, but due to the switching loss problem, the switching frequency cannot be too high, resulting in a relatively large transformer volume and failing to meet the practical requirements of the portability of the vehicle charging device. SUMMARY

[0004] The technical problem to be solved by the present application is to solve the above-mentioned deficiencies of the prior art, and to provide a vehicle-to-vehicle charging device and a control method. The main circuit adopts an isolated high-gain DC-DC converter as the main circuit topology of the vehicle-to-vehicle charging device, which can realize energy transmission between electric vehicles and realize electrical isolation between the two vehicles, thereby improving the reliability of the vehicle charging device. In addition, the present application adopts a new model predictive control method to reduce the current stress of the charging device, improve the dynamic characteristics, and realize the insensitivity to circuit parameters, thereby improving the reliability and safety of the vehicle-to-vehicle charging device.

[0005] To solve the above technical problems, the technical solution adopted by the present application is:

[0006] In one aspect, the application provides a vehicle-to-vehicle charging device, comprising an LC series resonant DC-DC converter topology and an LC series resonant DC-DC converter control circuit; the LC series resonant DC-DC converter is used to realize power conversion between low-voltage direct current and high-voltage direct current, achieving the purpose of voltage boosting; the topology provides a charge-discharge port for each of two vehicles, realizing energy transfer from the discharging vehicle to the charging vehicle; the control circuit is used to realize an LC series resonant DC-DC converter control strategy, which adopts a single-sided double-phase-shift minimum current stress model predictive control strategy; the control circuit detects the output voltage and calculates the inner and outer phase shift angles according to the detected output voltage; a PWM control signal with a frequency greater than 200 kHz is generated according to the calculated phase shift angle data; finally, a PWM control signal meeting the driving voltage requirement is output, realizing control over the output voltage and further controlling vehicle-to-vehicle charging.

[0007] Further, the LC series resonant DC-DC converter comprises a high-frequency inverter module, a high-frequency transformer module and a rectifier output module; the input end of the high-frequency inverter module is connected to the electric vehicle discharging gun, the output end of the high-frequency inverter module is connected to the input end of the high-frequency transformer module; the output end of the high-frequency transformer module is connected to the input end of the rectifier output module; and the output end of the rectifier output module is connected to the electric vehicle charging gun.

[0008] The high-frequency inverter module is used to realize conversion between low-voltage direct current and low-voltage alternating current, and inversely convert low-voltage direct current into low-voltage alternating current.

[0009] The high-frequency transformer module is used to realize conversion between low-voltage alternating current and high-voltage alternating current, and convert low-voltage alternating current into high-voltage alternating current.

[0010] The rectifier output module is used to realize conversion between high-voltage alternating current and high-voltage direct current, and convert high-voltage alternating current into high-voltage direct current.

[0011] Further, the main topology of the device is an LC series resonant DC-DC converter, and the main circuit thereof comprises two H bridges, an LC series resonant circuit and a high-frequency transformer; the primary side H bridge comprises four power field effect transistors, the secondary side H bridge comprises four power field effect transistors, and each power field effect transistor has its corresponding anti-parallel diode and parasitic capacitor.

[0012] The high-frequency inverter module comprises four power field effect transistors S1, S2, S3 and S4 on the primary side and a voltage stabilizing capacitor C in on the input side; the high-frequency transformer module comprises L s and C sLC series resonant circuit and high frequency transformer; the rectification output module includes four power field effect transistors S5, S6, S7 and S8 on the secondary side and a voltage stabilizing capacitor C on the output side o .

[0013] Further, the control circuit of the LC series resonant DC-DC converter includes a DSP, a driving module, a power supply module and a data sampling module;

[0014] The DSP is configured to generate a PWM control signal of the power field effect transistor of the LC series resonant DC-DC converter, so as to realize an LC series resonant DC-DC converter control strategy.

[0015] The driving module is configured to amplify the PWM signal generated by the DSP, so as to control the power field effect transistor of the converter to be turned on or turned off.

[0016] The power supply module is configured to provide electric energy for the DSP, the data sampling module and the driving module.

[0017] The data sampling module is configured to collect a voltage signal V in on the input side of the high frequency inverter module, a voltage signal V o on the output side of the rectification output module and a current signal I o and transmit them to the DSP.

[0018] Further, the LC series resonant DC-DC converter control strategy in the DSP includes a transmission power calculation module, a minimum current stress optimization module, a virtual power module and a model prediction module.

[0019] The transmission power calculation module is configured to calculate a real-time charging power of the charging device, a maximum transmission power P max and a unit value of the transmission power as shown in the following formula.

[0020]

[0021]

[0022] wherein, P o is an average transmission power of the LC series resonant DC-DC converter in one period; M is a voltage gain, M≤1, V in , V o are input voltage and output voltage respectively, n is a high frequency transformer module transformation ratio; L s , C s are resonant capacitance and resonant inductance respectively; f n is a unitized switching frequency, fr is the series resonant frequency, ω r is the series resonant angular frequency, f s is the switching frequency, f s = ω s / 2π, f s > 200 kHz, ω s is the switching angular frequency; are the inner and outer phase-shift angles, respectively;

[0023] The minimum current stress optimization module is configured to calculate the inner phase-shift angle and the outer phase-shift angle of the LC series resonant DC-DC converter under single-sided double phase-shift control, so that the current stress of the converter is minimized; the inner phase-shift angle obtained by the minimum current stress optimization module is defined as the outer phase-shift angle is defined as as shown in the following formula;

[0024] When ,

[0025] When ,

[0026] The virtual power module directly generates a virtual power P Δ in the input PI link, instead of v and I o ;

[0027]

[0028]

[0029] wherein, the virtual output voltage of the desired transmission power, is the voltage reference value on the output side of the rectifier output module, V o is the voltage sampling actual value on the output side of the rectifier output module, I o is the current sampling actual on the output side of the rectifier output module, P v is the virtual power;

[0030] The model prediction module is configured to calculate the inner phase-shift angle and the outer phase-shift angle The calculation formula is shown as follows:

[0031]

[0032]

[0033] ​In another aspect, the application also provides a control method for vehicle-to-vehicle charging, which is realized by the vehicle-to-vehicle charging device. After the LC series resonant DC-DC converter is initialized, the control circuit collects voltage signals, and according to the detected output voltage, the inner and outer phase shift angles calculated by the built-in algorithm, the PWM control signals with a frequency greater than 200 kHz are generated according to the calculated inner and outer phase shift angle data, and finally the PWM control signals meeting the driving voltage requirements are output to realize the control of the output voltage and further control the vehicle charging.

[0034] Further, the control method specifically comprises the following steps:

[0035] Step 1: The LC series resonant DC-DC converter is initialized, and the data sampling module of the control circuit collects the voltage signals V in , the voltage signals V o and the current signals I o of the input side of the high-frequency inverter module and the output side of the rectifier output module, and transmits them to the DSP.

[0036] Step 2: The transmission power calculation module calculates the maximum transmission power P max of the single-sided double-shift time-varying converter and the transmission power unit value

[0037]

[0038]

[0039] wherein, P o is the average transmission power of the LC series resonant DC-DC converter in a cycle; M is the voltage gain, M≤1, V in , V o are the input voltage and the output voltage respectively, n is the high-frequency transformer module ratio; L s , C s are the resonant capacitance and the resonant inductance respectively; f n is the normalized switching frequency, f r is the series resonant frequency, ω r is the series resonant angular frequency, f s is the switching frequency, f s = ω s / 2π, f s >200kHz, ω s is the switching angular frequency; are the inner and outer phase shift angles respectively;

[0040] Step 3: The minimum current stress optimization module uses the power information obtained in Step 2 to obtain the inner phase shift angle of the converter in single-sided double phase shift control and the outer phase shift angle is as shown in the following formula;

[0041] When ,

[0042] When ,

[0043] Step 4: The virtual power module uses the error V Δ of the output voltage to input into the PI compensation link to generate virtual power P v ;

[0044]

[0045]

[0046] wherein, the virtual output voltage representing the desired transmission power, V o is the voltage reference value on the output side of the rectifier output module, o I v is the current sampling actual value on the output side of the rectifier output module, and P v is the virtual power;

[0047] Step 5: The model prediction module uses the inner phase shift angle and the outer phase shift angle obtained in Step 3 and the virtual power P v obtained in Step 4 to obtain the final inner phase shift angle and the outer phase shift angle

[0048]

[0049]

[0050] Step 6: According to the final inner phase shift angle and the outer phase shift angle of the converter obtained in Step 5, the DSP sends a control signal to the driving module, and after receiving the signal, the driving module opens or closes all power field effect transistors in the single-sided double phase shift control converter to realize the control of vehicle-to-vehicle charging.

[0051] The beneficial effects produced by the above technical solutions are that the vehicle-to-vehicle charging device and the control method provided by the application can realize energy transmission between electric vehicles, and the device realizes energy transmission through power electronic conversion technology, compared with the traditional vehicle-to-vehicle charging device without a transformer, the presence of the high-frequency transformer in the application makes there be electrical isolation between the two electric vehicles during charging, and the reliability of the operation of the vehicle-to-vehicle charging device is improved. The LC series resonant DC-DC converter proposed in the device of the application is different from the traditional transformer, and works in the high-frequency part above 200 KHZ, so that the volume and weight of the transformer in the circuit are greatly reduced, and the portability of the vehicle-to-vehicle charging device is improved.

[0052] The control method proposed by the application is different from the traditional double-phase-shift control, and adopts a single-sided double-phase-shift minimum current stress model predictive control strategy, which improves the dynamic characteristics of the charging device, reduces the current stress of the converter, and improves the safety of the vehicle-to-vehicle charging device; the control method proposed in the application is different from the traditional model predictive control, and it can be seen from the two phase-shift angle formulas calculated by the model prediction module that the model predictive model based on virtual power does not need the circuit parameters of the converter, so that the control method of the application is not sensitive to the circuit parameters, and the reliability of the vehicle-to-vehicle charging device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 The LC series resonant DC-DC converter structure diagram provided for the embodiment of the application;

[0054] Figure 2 The control strategy diagram provided for the embodiment of the application;

[0055] Figure 3 The converter working waveform diagram under the single-sided double-phase-shift control provided for the embodiment of the application. DETAILED DESCRIPTION

[0056] The specific embodiments of the application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the application, but are not used to limit the scope of the application.

[0057] A vehicle-to-vehicle charging device includes an LC series resonant DC-DC converter topology and an LC series resonant DC-DC converter control circuit thereof; the LC series resonant DC-DC converter is used to realize power conversion between low-voltage direct current and high-voltage direct current to achieve the purpose of voltage boosting; the topology provides a charging and discharging port for each of two vehicles to realize energy transfer from a discharging vehicle to a charging vehicle; the control circuit is used to realize an LC series resonant DC-DC converter control strategy, which adopts a single-sided double-phase-shift minimum current stress model predictive control strategy; the control circuit detects the output voltage and calculates the inner and outer phase shift angles according to the detected output voltage; the control circuit generates a PWM control signal with a frequency greater than 200 kHz according to the calculated phase shift angle data; finally, the control circuit outputs a PWM control signal meeting the driving voltage requirement to control the output voltage and further control the vehicle charging.

[0058] When the electric vehicle is low in power and there is no available charging pile or battery swap station around, the vehicle owner can use the vehicle-to-vehicle charging device to charge the vehicle with another electric vehicle with sufficient power.

[0059] The main topology of the device is an LC series resonant DC-DC converter, as shown in Figure 1 , which includes two H-bridges, an LC series resonant circuit, and a high-frequency transformer; the primary side H-bridge includes four power field effect transistors, the secondary side H-bridge includes four power field effect transistors, and each power field effect transistor has its corresponding anti-parallel diode and parasitic capacitor.

[0060] The LC series resonant DC-DC converter includes a high-frequency inverter module, a high-frequency transformer module, and a rectifier output module.

[0061] The input end of the high-frequency inverter module is connected to the electric vehicle discharging gun, and the output end of the high-frequency inverter module is connected to the input end of the high-frequency transformer module for connecting the discharging vehicle; in this embodiment, the input end voltage of the high-frequency inverter module is 72V. The high-frequency inverter module is used to realize the conversion between low-voltage direct current and low-voltage alternating current, and to invert low-voltage direct current into low-voltage alternating current. The high-frequency inverter module includes four power field effect transistors S1, S2, S3, and S4 on the primary side and an input side voltage stabilizing capacitor C in .

[0062] The output end of the high-frequency transformer module is connected to the input end of the rectifier output module to realize the conversion between low-voltage alternating current and high-voltage alternating current, and to boost low-voltage alternating current to high-voltage alternating current. The high-frequency transformer module includes an LC series resonant circuit composed of L s and C s and a high-frequency transformer.

[0063] The output end of the rectification output module is connected with an electric vehicle charging gun for connecting a charging vehicle, and the output end voltage of the rectification output module is 600V in the embodiment. The rectification output module is used for converting high-voltage alternating current into high-voltage direct current. The rectification output module comprises four power field effect transistors S5, S6, S7 and S8 on the secondary side and a voltage stabilizing capacitor C on the output side o .

[0064] The control circuit of the LC series resonance DC-DC converter comprises a DSP, a driving module, a power supply module and a data sampling module.

[0065] The DSP is configured to generate a PWM control signal of a power field effect transistor of the LC series resonance DC-DC converter, and realize an LC series resonance DC-DC converter control strategy.

[0066] The driving module is configured to amplify the PWM signal generated by the DSP, and control the power field effect transistor of the converter to be turned on or turned off.

[0067] The power supply module is configured to provide electric energy for the DSP, the data sampling module and the driving module.

[0068] The data sampling module is configured to collect a high-frequency inverter module input side voltage signal V in , a rectification output module output side voltage signal V o and a current signal I o , and transmit them to the DSP.

[0069] The LC series resonance DC-DC converter control strategy in the DSP comprises a transmission power calculation module, a minimum current stress optimization module, a virtual power module and a model prediction module, as shown in Figure 2 .

[0070] The transmission power calculation module is configured to calculate a real-time charging power of the charging device, a maximum transmission power P max and a transmission power unit value , as shown in the following formula;

[0071]

[0072]

[0073] wherein, P o is an average transmission power of the LC series resonance DC-DC converter in one period; M is a voltage gain, M≤1, V in , V o are input voltage and output voltage respectively, and n is a high-frequency transformer module transformation ratio; Ls , C s are resonance capacitance and resonance inductance respectively; f n is the normalized switching frequency, f r is the series resonance frequency, ω r is the series resonance angular frequency, f s is the switching frequency, f s = ω s / 2π, in order to reduce the volume of the device, the switching frequency f s >200kHz, ω s is the switching angular frequency; are inner and outer phase shift angles respectively.

[0074] The minimum current stress optimization module is configured to calculate the inner phase shift angle and the outer phase shift angle of the LC series resonance DC-DC converter under single-sided double phase shift control, so that the current stress of the converter is minimized; the inner phase shift angle obtained by the minimum current stress optimization module is defined as the outer phase shift angle is defined as as shown in the following formula;

[0075] when ,

[0076] when ,

[0077] The virtual power module directly generates a virtual power P Δ in the PI link with an output voltage error V v , instead of and I o , thereby increasing the flexibility of the control system.

[0078]

[0079]

[0080] wherein, represents a virtual output voltage of the expected transmission power, is a voltage reference value on the output side of the rectifier output module, V o is a voltage sampling actual value on the output side of the rectifier output module, I o is a current sampling actual on the output side of the rectifier output module, P v is a virtual power, P * is a virtual transmission power.

[0081] The model prediction module is configured to calculate the inner phase shift angle and the outer phase shift angle The model prediction makes the transformer dynamic performance and transmission efficiency improved, and the calculation formula is as follows:

[0082]

[0083]

[0084] Different from the traditional single-shift control, the single-sided double-shift control adds an inner phase shift angle in the H-bridge of the primary side or the secondary side, and adds an inner phase shift angle control variable to the outer phase shift angle variable of the SPS control. Figure 3 The single-sided double-shift control under the transformer working waveform in the single-sided double-shift control is taken as an example to illustrate the transformer mode as follows:

[0085] Mode a(t0~t1): Before t0, S2 and S3 of the primary side are turned on, and at this time the resonant current is negative. At t0, S2 is turned off and S1 is turned on, and the resonant current passes through S3 and D1; the secondary side current passes through D6 and D7, and the current gradually decreases.

[0086] Mode b(t1~t1'): At t1, S3 is turned off and S4 is turned on, at this time the resonant current passes through diodes D1 and D4, and the resonant current value is still negative; the secondary side current still passes through diodes D6 and D7 until t1' when it decreases to 0.

[0087] Mode c(t1'~t2): At t1', the resonant current changes from reverse to forward, and the current value changes from negative to positive, and S1 and S4 of the primary side are turned on; S6 and S7 of the secondary side are turned on, and the resonant circuit voltage is V in +nV o , and the resonant current gradually increases.

[0088] Mode d(t2~t3): At t2, the resonant current passes through S1 and S4 of the primary side; S6 and S7 of the secondary side are turned off, S5 and S8 are turned on, the secondary side current passes through D5 and D8, and the resonant circuit voltage is |V in -nV o |, and the resonant current increases to the maximum value.

[0089] Mode e(t3~t4): At t3, S1 is turned off, the resonant current passes through diode D2 and switch S4, and the current value is positive; the secondary side current passes through D5 and D8, and the resonant circuit voltage is -nV o , and the resonant current begins to decrease.

[0090] Mode f(t4~t4'): At t4, S4 is turned off and S3 is turned on, and the resonant current passes through D2 and D3 of the primary side; the secondary side current passes through D5 and D8. The resonant circuit voltage is -Vin -nV o , the resonant current continues to decrease until the moment t4' when it decreases to 0.

[0091] Mode g (t4' ~ t5): at the moment t4', the resonant current reverses, the current value becomes negative, the primary side S2 and S3 are turned on, and the secondary side S5 and S8 are turned on. The voltage across the resonant circuit is -V in -nV o , the resonant current begins to reverse and increase.

[0092] Mode h (t5 ~ t6): at the moment t5, the resonant current passes through S2 and S3, and the current value is negative; the secondary side S5 and S8 are turned off, S6 and S7 are turned on, and the secondary side current passes through D6 and D7. The voltage across the resonant circuit is |-V in +nV o |, the resonant current continues to reverse and increase. At this time, the series resonant converter works in the S-DPS control mode for one period, and then starts the next period, and so on.

[0093] A control method of vehicle-to-vehicle charging is realized by the above vehicle-to-vehicle charging device, specifically comprising the following steps:

[0094] Step 1: the LC series resonant DC-DC converter is initialized, and the data sampling module collects the voltage signal V in , the voltage signal V o and the current signal I o of the rectifier output module output side, and transmits them to the DSP;

[0095] Step 2: the transmission power calculation module calculates the maximum transmission power P max and the transmission power unit value

[0096]

[0097]

[0098] Step 3: the minimum current stress optimization module uses the power information obtained in step 2 to calculate the inner phase shift angle and the outer phase shift angle

[0099] When ,

[0100] When ,

[0101] Step 4: The virtual power module uses the error V Δ of the output voltage to generate a virtual power P v ;

[0102]

[0103]

[0104] Step 5: The model prediction module uses the internal phase shift angle and the external phase shift angle obtained in Step 3 and the virtual power P v obtained in Step 4 to obtain the final internal phase shift angle and the final external phase shift angle

[0105]

[0106]

[0107] Step 6: According to the final internal phase shift angle and the final external phase shift angle of the converter obtained in Step 5, the DSP sends a control signal to the driving module, and the driving module, after receiving the signal, opens or closes all power field effect transistors in the single-sided double phase shift control converter to realize the control of the vehicle-to-vehicle charging.

[0108] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope defined by the claims of the present application.

Claims

1. A vehicle-to-vehicle charging device, characterized by: LC series resonance DC-DC converter topology and LC series resonance DC-DC converter control circuit are disclosed. The LC series resonance DC-DC converter is used to realize power conversion between low-voltage direct current and high-voltage direct current, so as to achieve the purpose of voltage increase. The LC series resonance DC-DC converter comprises a high-frequency inverter module, a high-frequency transformer module and a rectifier output module. The high-frequency inverter module is used to realize conversion between low-voltage direct current and low-voltage alternating current, and inversely convert low-voltage direct current into low-voltage alternating current. The high-frequency transformer module is used to realize conversion between low-voltage alternating current and high-voltage alternating current, and convert low-voltage alternating current into high-voltage alternating current. The rectifier output module is used to realize conversion between high-voltage alternating current and high-voltage direct current, and convert high-voltage alternating current into high-voltage direct current. The main topology of the device is an LC series resonance DC-DC converter, and the main circuit thereof comprises two H-bridges, an LC series resonance circuit and a high-frequency transformer. The high-frequency inverter module includes four power field effect transistors on the primary side , , , and a voltage stabilizing capacitor on the input side ; The high-frequency transformer module comprises and LC series resonance circuit composed of a high-frequency transformer; the rectifier output module comprises four power field effect transistors 、 、 、 and an output-side voltage stabilizing capacitor ; The control circuit is used to realize an LC series resonance DC-DC converter control strategy, which adopts a single-sided double-phase-shift minimum current stress model predictive control strategy. The control circuit detects an output voltage and generates a PWM control signal with a frequency greater than 200 kHz according to the calculated inner and outer phase shift angles, and finally outputs a PWM control signal meeting the driving voltage requirements to realize control over the output voltage and further control over vehicle-to-vehicle charging. The control circuit of the LC series resonance DC-DC converter comprises a DSP, a driving module, a power module and a data sampling module. The DSP is used to generate a PWM control signal of a power field effect transistor of the LC series resonance DC-DC converter, and realize an LC series resonance DC-DC converter control strategy. The driving module is used to amplify the PWM signal generated by the DSP to control the opening or closing of the power field effect transistor of the converter. The data sampling module is used for collecting high-frequency inverter module input side voltage signal , rectifier output module output side voltage signal and current signal and transmitting to DSP.

2. The vehicle-to-vehicle charging apparatus according to claim 1, characterized by: The power module is used to provide electric energy for the DSP, the data sampling module and the driving module. The LC series resonance DC-DC converter control strategy in the DSP comprises a transmission power calculation module, a minimum current stress optimization module, a virtual power module and a model prediction module. The transmission power calculation module is configured to calculate a real-time charging power of the charging device and a maximum value of the transmission power and a unit value of the transmission power as shown in the following formula; ； ； wherein, is the average transferred power of the LC series resonant DC-DC converter in one period; M is the voltage gain, , , , are the input voltage and the output voltage, respectively; n is the high frequency transformer module turns ratio; , are the resonant capacitance and the resonant inductance, respectively; is the normalized switching frequency, , is the series resonant frequency, , is the series resonant angular frequency, is the switching frequency, , , is the switching angular frequency; , are the inner and outer phase shift angles, respectively; The minimum current stress optimization module is configured to calculate inner phase-shifting angles and outer phase-shifting angles of the LC series resonant DC-DC converter under single-sided double phase-shifting control, so that the current stress of the converter is minimized; the inner phase-shifting angles obtained by the minimum current stress optimization module are defined as and the outer phase-shifting angles are defined as as shown in the following formula. When Time, ; When Time, ; The virtual power module, which will output voltage error Directly generating virtual power in input PI link , instead of and ; ； ； wherein, a virtual output voltage representing the desired transmission power, a voltage reference value for the output side of the rectifier output module, a voltage sample actual value for the output side of the rectifier output module, a current sample actual for the output side of the rectifier output module, a virtual power; The model prediction module is used to calculate the inner phase shift angle. and outward phase angle The calculation formula is as follows: ； 。 3. A control method of vehicle-to-vehicle charging, implemented by the vehicle-to-vehicle charging device according to claim 1, characterized in that: After the LC series resonant DC-DC converter is initialized, the control circuit collects the voltage signal, and according to the detected output voltage, the inner and outer phase shift angles calculated by the built-in algorithm, the PWM control signal with a frequency greater than 200 kHz is generated according to the calculated inner and outer phase shift angle data, and finally the PWM control signal meeting the driving voltage requirement is output, realizing the control of the output voltage, and further controlling the vehicle charging.

4. The control method of vehicle-to-vehicle charging according to claim 3, characterized by: The method specifically comprises the following steps: Step 1: LC series resonant DC-DC converter is initialized, the data sampling module of the control circuit collects the voltage signal of the input side of the high-frequency inverter module , the voltage signal of the output side of the rectifier output module , and the current signal , and transmits them to the DSP; Step 2: The transmission power calculation module calculates the maximum transmission power of the single-sided double-shift time-varying converter using the sampling data obtained in step 1 and the transmission power unit ​ ； ； wherein, is the average transferred power of the LC series resonant DC-DC converter in one period; M is the voltage gain, , , , are the input voltage and the output voltage, respectively; n is the high frequency transformer module turns ratio; , are the resonant capacitance and the resonant inductance, respectively; is the normalized switching frequency, , is the series resonant frequency, , is the series resonant angular frequency, is the switching frequency, , , is the switching angular frequency; , are the inner and outer phase shift angles, respectively; Step 3: The minimum current stress optimization module uses the power information from Step 2 to find the inner phase angle of the converter under single-sided dual phase-shift control and the outer phase angle is as shown in the following equation; When Time, ; When time, ; Step 4: Virtual power module utilizes error in output voltage Input to PI compensation block to produce virtual power ; ； ； wherein, a virtual output voltage representing the desired transmission power, is a voltage reference value on the output side of the rectifier output module, is a voltage sample actual value on the output side of the rectifier output module, is a current sample actual on the output side of the rectifier output module, is a virtual power; Step 5: The model prediction module uses the internal shift phase angle from Step 3 and the external shift phase angle from Step 3 and the virtual power from Step 4 to determine the final internal shift phase angle and the external shift phase angle for the transformer ； ； Step 6: The inner phase shift angle of the transformer is finally solved according to step 5 And the outer phase shift angle The DSP sends a control signal to the driving module, and the driving module opens or closes all power field effect transistors in the unilateral double phase shift control transformer according to the signal received, thereby realizing the control of vehicle-to-vehicle charging.

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