A control method and device of a wireless bidirectional charging and discharging system

Abstract

The application relates to a control method and device of a wireless bidirectional charging and discharging system, the wireless bidirectional charging and discharging system comprising a bidirectional PFC circuit, a primary-side bidirectional full-bridge conversion circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network and a secondary-side bidirectional full-bridge conversion circuit, the bidirectional PFC circuit, the primary-side bidirectional full-bridge conversion circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network and the secondary-side bidirectional full-bridge conversion circuit being sequentially connected; wherein the bidirectional PFC circuit stabilizes the bus voltage through a DC bus voltage outer ring and an active current inner ring, a double-loop tracking control mode is adopted to control the primary-side bidirectional full-bridge conversion circuit and the secondary-side bidirectional full-bridge conversion circuit, and the power transmission direction of the wireless bidirectional charging and discharging system is adjusted by adjusting the outward moving phase angle alpha. Thus, the orderly action of bidirectional charging and discharging is realized, and the friendly interaction of the power grid and the electric vehicle energy is further realized.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a control method and apparatus for a wireless bidirectional charging and discharging system. Background Technology

[0002] Existing technologies typically employ wireless charging implementation methods such as... Figure 1 As shown, the system includes a rectifier circuit and a power factor correction circuit, a high-frequency inverter, a loosely coupled transformer and a supplementary circuit, and an EV-side rectifier and filter circuit. The rectifier circuit and power factor correction circuit are connected to the AC grid to provide a stable input DC bus voltage through active rectification. The primary-side high-frequency inverter adjusts the excitation voltage of the resonant circuit by adjusting the phase shift angle. Energy is transferred to the secondary-side rectifier through the loosely coupled transformer and the compensation circuit, and then outputs a stable DC charging power through the filter circuit. Summary of the Invention

[0003] Based on the above-mentioned situation of the prior art, the purpose of the present invention is to provide a control method and device for a wireless bidirectional charging and discharging system, which realizes bidirectional control of the wireless bidirectional charging and discharging system and ZVS control of the primary and secondary power conversion circuits by controlling the outward phase angle.

[0004] To achieve the above objectives, according to one aspect of the present invention, a control method for a wireless bidirectional charging and discharging system is provided. The wireless bidirectional charging and discharging system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit. The bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected sequentially. The control method includes:

[0005] Control the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit;

[0006] A dual-loop tracking control method is used to control both the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit.

[0007] The power transmission direction of the wireless bidirectional charging and discharging system is adjusted by adjusting the external phase shift angle α.

[0008] Furthermore, controlling the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit includes:

[0009] The error value between the DC bus voltage and the DC bus voltage reference value is processed by a PI controller to obtain the reference value of active power.

[0010] The phase-locked angle is obtained by passing the AC terminal voltage amplitude through Fourier phase-locking, and the actual value of active power is calculated accordingly.

[0011] The error value obtained by comparing the actual value of the active power with the reference value is passed through a PI controller to obtain the SPWM drive signal for controlling the bidirectional PFC circuit.

[0012] Furthermore, the dual-loop tracking control method for controlling the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit includes:

[0013] The error values ​​of the DC terminal voltage and the DC voltage reference value, and the DC terminal current and the DC current reference value of the secondary-side bidirectional full-bridge converter circuit are respectively input into the PI controller.

[0014] The output values ​​of the two PI controllers are passed through a dual-loop follower controller to output the first phase shift angle β. p Second phase shift angle β s ;

[0015] Using the first phase shift angle β p The primary-side bidirectional full-bridge converter circuit is controlled using the second phase shift angle β. s The secondary-side bidirectional full-bridge converter circuit is controlled.

[0016] Furthermore, adjusting the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the outward phase shift angle α includes:

[0017] The external phase shift angle α of the secondary-side bidirectional full-bridge converter circuit is compared with the external phase shift angle reference value α. ref The compared error value is then processed by a PI controller;

[0018] The output of the PI controller is passed through a PQ phase-locked pulse and a quadrature multiplier to obtain the external phase shift angle α.

[0019] The initial value of the outward phase angle is α = π.

[0020] Furthermore, adjusting the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the outward phase shift angle α includes:

[0021] During positive energy transfer, α = π - β s / 2;

[0022] During reverse energy transfer, α = π + β s / 2;

[0023] Where, β p and β s The initial value is β p =β s=0.

[0024] According to a second aspect of the present invention, a control device for a wireless bidirectional charging and discharging system is provided. The wireless bidirectional charging and discharging system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit. The bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected sequentially. The control device includes:

[0025] A DC bus voltage control module is used to control the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit.

[0026] The dual-loop tracking module is used to control the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit using a dual-loop tracking control method.

[0027] The power transmission control module is used to adjust the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the external phase shift angle α.

[0028] Furthermore, the DC bus voltage control module controls the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit, including:

[0029] The error value between the DC bus voltage and the DC bus voltage reference value is processed by a PI controller to obtain the reference value of active power.

[0030] The phase-locked angle is obtained by passing the AC terminal voltage amplitude through Fourier phase-locking, and the actual value of active power is calculated accordingly.

[0031] The error value obtained by comparing the actual value of the active power with the reference value is passed through a PI controller to obtain the SPWM drive signal for controlling the bidirectional PFC circuit.

[0032] Furthermore, the dual-loop tracking module employs a dual-loop tracking control method to control the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit, including:

[0033] The error values ​​of the DC terminal voltage and the DC voltage reference value, and the DC terminal current and the DC current reference value of the secondary-side bidirectional full-bridge converter circuit are respectively input into the PI controller.

[0034] The output values ​​of the two PI controllers are passed through a dual-loop follower controller to output the first phase shift angle β. p Second phase shift angle β s ;

[0035] Using the first phase shift angle β p The primary-side bidirectional full-bridge converter circuit is controlled using the second phase shift angle β. s The secondary-side bidirectional full-bridge converter circuit is controlled.

[0036] Furthermore, the power transmission control module adjusts the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the outward phase shift angle α, including:

[0037] The external phase shift angle α of the secondary-side bidirectional full-bridge converter circuit is compared with the external phase shift angle reference value α. ref The compared error value is then processed by a PI controller;

[0038] The output of the PI controller is passed through a PQ phase-locked pulse and a quadrature multiplier to obtain the external phase shift angle α.

[0039] The initial value of the outward phase angle is α = π.

[0040] According to a third aspect of the present invention, a wireless bidirectional charging and discharging system is provided, the system comprising a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit; wherein,

[0041] The bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected in sequence.

[0042] The wireless bidirectional charging and discharging system is controlled using the control method described in the first aspect of the present invention.

[0043] In summary, this invention provides a control method and apparatus for a wireless bidirectional charging and discharging system. The system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit, all connected sequentially. The bidirectional PFC circuit stabilizes the bus voltage through an outer loop of DC bus voltage and an inner loop of active current. A dual-loop tracking control method is used to control both the primary and secondary bidirectional full-bridge converter circuits. The power transmission direction of the wireless bidirectional charging and discharging system is adjusted by regulating the outer phase shift angle α. This enables orderly bidirectional charging and discharging, further facilitating the energy interaction between the power grid and the electric vehicle. Attached Figure Description

[0044] Figure 1This is a schematic diagram of the circuit structure for existing wireless charging technology;

[0045] Figure 2 This is a schematic diagram of the topology of a wireless bidirectional charging system;

[0046] Figure 3 This is a schematic diagram of the circuit structure of the wireless bidirectional charging and discharging system according to an embodiment of the present invention;

[0047] Figure 4 This is a simplified schematic diagram of the interleaved parallel bidirectional PFC circuit topology;

[0048] Figure 5 This is a schematic diagram of a typical BIPT system with a bidirectional LCC compensation network;

[0049] Figure 6 This is a simplified diagram of the BIPT circuit structure;

[0050] Figure 7 It is a simplified circuit of the BIPT system based on the harmonic time-domain system model;

[0051] Figure 8 This is the operating waveform of the bilateral LCC resonant network;

[0052] Figure 9 This is a schematic diagram of ZVS analysis during full-bridge charging on the secondary side;

[0053] Figure 10 This is a schematic diagram of ZVS analysis during secondary-side full-bridge discharge. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0055] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings. According to one embodiment of the present invention, a control method for a wireless bidirectional charging and discharging system is provided. The wireless bidirectional charging and discharging system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit, wherein the bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected sequentially. Figure 2 The diagram shows a schematic of the topology of a wireless bidirectional charging system. Figure 3The diagram shows a schematic of the circuit structure of a wireless bidirectional charging and discharging system according to an embodiment of the present invention. The system consists of two parts: a PFC capable of bidirectional AC-DC conversion and a bidirectional wireless charging circuit based on a dual active rectifier bridge and a bilateral LCC resonant circuit. The PFC is a totem-pole interleaved parallel PFC, which stabilizes the intermediate bus voltage U by controlling the magnitude and direction of the active current. dc0 The wireless charging system uses a triple phase-shift control algorithm to control the output voltage and current of the vehicle's DC port. This control method includes:

[0056] Controlling the active current at the AC terminal of the bidirectional PFC circuit stabilizes the DC bus voltage of the bidirectional PFC circuit. Combined with... Figure 3 As shown, the error value obtained by comparing the DC bus voltage with the DC bus voltage reference value is processed by a PI controller to obtain the reference value of active power; the AC terminal voltage amplitude is processed by Fourier phase-locked loop to obtain the phase-locked angle, and the actual value of active power is calculated accordingly; the error value obtained by comparing the actual value of active power with the reference value is processed by a PI controller to obtain the SPWM drive signal for controlling the bidirectional PFC circuit. The control of the bidirectional PFC circuit is analyzed as follows:

[0057] In this embodiment of the invention, for example, a totem-pole interleaved parallel bidirectional PFC circuit structure can be adopted. To simplify the circuit, the following assumptions are made: (1) parasitic parameters of each device in the converter are ignored, and there is no delay in the switching process; (2) the inductance values ​​of each path are identical and are ideal inductors; (3) the equivalent internal resistance (ESR) of the filter capacitor is ignored, and it is an ideal capacitor; (4) a purely resistive load is used. The simplified circuit topology is as follows: Figure 4 As shown. Based on the small-signal analysis model, the transfer functions of each part can be obtained:

[0058]

[0059]

[0060] It can be deduced that:

[0061]

[0062]

[0063] A dual-loop tracking control method is used to control both the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit. Combined with... Figure 3 As shown, the error values ​​of the DC terminal voltage and the DC voltage reference value, and the DC terminal current and the DC current reference value of the secondary-side bidirectional full-bridge converter circuit are respectively input to the PI controller; the output values ​​of the two PI controllers are then passed through a dual-loop follower controller to output the first phase shift angle β. p Second phase shift angle βs Using the first phase shift angle β p The primary-side bidirectional full-bridge converter circuit is controlled using the second phase shift angle β. s The secondary-side bidirectional full-bridge converter circuit is controlled.

[0064] The power transmission direction of the wireless bidirectional charging and discharging system is adjusted by adjusting the external phase shift angle α. Combined with... Figure 3 As shown, the external phase shift angle α of the secondary-side bidirectional full-bridge converter circuit is compared with the external phase shift reference value α. ref The compared error value is processed by a PI controller; the output of the PI controller is then processed by a PQ phase-locked pulse and a quadrature multiplier to obtain an external phase shift angle α; the initial value of the external phase shift angle is α = π. During forward energy transfer, α = π - β. s / 2; During reverse energy transfer, α=π+β s / 2; where β p and β s The initial value is β p =β s =0. α is the external phase shift angle of the vehicle-end full-bridge converter. Charging and discharging are achieved by adjusting the external phase shift angle. In the initial state, the resonant network is purely reactive, with no active power transmission. With the action of the voltage loop and current loop, the duty cycle of the primary and secondary sides gradually increases. During charging, the external phase shift angle tends to 90°, the vehicle-end voltage and current are in opposite phases, and power is transmitted in the forward direction. During discharging, the external phase shift angle gradually tends to 270°, the vehicle-end voltage and current are in phase, and power is transmitted in the reverse direction.

[0065] The following is a mathematical model analysis of the bilateral LCC resonant circuit:

[0066] A typical BIPT system with a bidirectional LCC compensation network, such as Figure 5 As shown. S 11 -S 14 and S 21 -S 24 These are the power switches for the primary and secondary sides of the full-bridge circuit, respectively. L P and L s It is the self-inductance of the primary and secondary coils. L rp C p and C ps It is the compensation component of the primary coil; L rs C s and C ss This is the compensation component of the secondary coil. M is the mutual inductance between the primary and secondary coils. V dp This is the DC bus voltage of the primary-side full-bridge converter, typically provided by the preceding power factor correction (PFC) converter, and has a constant value. V dsThis is the secondary DC bus voltage. Since the secondary DC bus is typically connected to the battery via an inductor, V... ds It is a variable. U p and Us These are the output voltages of the primary and secondary full-bridge circuits, respectively. Considering that both the primary and secondary sides can be symmetrically used as power supplies or loads, the system parameters are typically designed symmetrically. Due to the characteristics of resonant circuits, the fundamental frequency component is the primary component involved in power transfer in BIPT systems, while higher harmonics contribute very little. To simplify the analysis, the fundamental frequency approximation (FHA) method is used to simplify the circuit structure as follows: Figure 6 As shown. Let U p and U s U is the fundamental component of the output voltage of the full-bridge rectifier circuit. ps and U sp These are the induced voltages generated by the mutual inductance between the front and rear stage coils.

[0067]

[0068]

[0069]

[0070]

[0071]

[0072] In equation (7), M is the mutual inductance of the primary and secondary coils, and k is the coupling coefficient of the primary and secondary coils.

[0073] Assuming the system parameters are symmetric and the system frequency is w, then:

[0074]

[0075] The ratio of the inductance of the primary and secondary coils to their respective compensation inductances is defined as:

[0076]

[0077] To satisfy the resonance condition, we have:

[0078]

[0079]

[0080] Ignoring system impedance, the active and reactive power transmitted by the system are as follows:

[0081]

[0082]

[0083] δ represents the fundamental voltage at the bridge port and the compensation inductance (L). rp L rs The phase difference between the currents, as shown in equations (13) and (14), indicates that the power transmission direction is determined by δ. When δ is within the range of (π / 2, π), the power is in the forward charging direction; when δ is within the range of (π, 3π / 2), the power is in the reverse discharging direction. The amplitude of the fundamental voltage can be adjusted by the phase shift angles βp and βs of the preceding and following stages.

[0084] The following analysis examines the methods for implementing soft switching in a BIPT system. The BIPT system operates at a switching frequency of 85 kHz. Implementing soft switching significantly reduces switching losses and increases system efficiency. The ZVS implementation of the BIPT system is analyzed below using a harmonic-based time-domain system model. The high order of the circuit model makes it difficult to obtain analytical expressions. Due to L... rp C p L rs and C s The filtering function of the coil current results in very few high-order harmonics. Therefore, the FHA model can be used to calculate the coil current without the need for a precise model to simplify the calculation. The steady-state waveform of the coil current calculated by the FHA method is as follows:

[0085]

[0086]

[0087] U Cp The time-domain expression is:

[0088]

[0089] U Cs The time-domain expression is:

[0090]

[0091] Because of C p and C s The voltage is sinusoidal. Therefore, a sinusoidal voltage source can be implemented to further simplify the circuit, such as... Figure 7 As shown. The circuit model can be described by the following differential equation:

[0092]

[0093]

[0094] By integrating equations (19) and (20), the time-domain expressions for the current of the front and rear full-bridge circuits can be obtained. Figure 8 The diagram shows the operating waveforms of the bilateral LCC resonant network. Based on the periodic symmetry of the current, it can be concluded that:

[0095] I Lrp (t3=π / ω)=-I Lrp (t0) (21)

[0096] The output current of the front-end bridge port at time t1 is:

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] To achieve ZVS in the front-end active rectifier bridge, the following constraints must be met:

[0103]

[0104] Based on the symmetry of the current waveform, we can know that:

[0105] I Lrp (t1)+I Lrp (t2)>0 (28)

[0106] From equations (27) and (28), it can be seen that the necessary condition for realizing the ZVS of the front-stage active rectifier bridge is:

[0107] I Lrp (t1)<0 (29)

[0108] Similarly, the necessary condition for the subsequent stage to satisfy ZVS is:

[0109] I Lrs (t8)<0 (30)

[0110] Let I Lrp(t1) =0; I Lrs(t1) =0 can be used to calculate:

[0111]

[0112]

[0113] The optimal compensation phase angle for ZVS is:

[0114] Δδ opt =max(Δδ1,Δδ2,0) (33)

[0115] The following analysis uses waveforms to illustrate the full-bridge phase-shifting soft switching implementation. Figure 9The diagram shows a schematic of ZVS analysis during full-bridge charging on the secondary side. Figure 10 The diagram shows a schematic of ZVS analysis during secondary-side full-bridge discharge. (From...) Figure 9 It is known that all switching transistors can achieve zero-voltage turn-on, and all turn-off is hard turn-off. During charging, the leading arm turns off with a small current, and the lagging arm turns off with a large current. During discharging, the leading arm turns off with a large current, and the lagging arm turns off with a small current. Due to the symmetry of the system, during primary-side charging, the leading arm turns off with a large current, and the lagging arm turns off with a small current; during discharging, the leading arm turns off with a small current, and the lagging arm turns off with a large current. This will cause uneven heating between the leading and lagging arms, and the issue of uneven heating must be considered in engineering applications.

[0116] According to a second embodiment of the present invention, a control device for a wireless bidirectional charging and discharging system is provided. The wireless bidirectional charging and discharging system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit. The bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected sequentially. The control device includes:

[0117] A DC bus voltage control module is used to control the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit.

[0118] The dual-loop tracking module is used to control the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit using a dual-loop tracking control method.

[0119] The power transmission control module is used to adjust the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the external phase shift angle α.

[0120] The steps by which the control device of the wireless bidirectional charging and discharging system in this embodiment of the present invention implements the functions of its various modules are the same as those of the control method provided in the first embodiment of the present invention, and will not be repeated here.

[0121] According to a third embodiment of the present invention, a wireless bidirectional charging and discharging system is provided. This system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit; wherein,

[0122] The bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected in sequence.

[0123] The wireless bidirectional charging and discharging system is controlled using the control method described in the first embodiment of the present invention.

[0124] In summary, this invention provides a control method and apparatus for a wireless bidirectional charging and discharging system. The system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit, all connected sequentially. The bidirectional PFC circuit stabilizes the bus voltage through an outer loop of DC bus voltage and an inner loop of active current. A dual-loop tracking control method is used to control both the primary and secondary bidirectional full-bridge converter circuits. The power transmission direction of the wireless bidirectional charging and discharging system is adjusted by regulating the outer phase shift angle α. This enables orderly bidirectional charging and discharging, further facilitating the energy interaction between the power grid and the electric vehicle.

[0125] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A control method for a wireless bidirectional charging and discharging system, the wireless bidirectional charging and discharging system comprising a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit, wherein the bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected sequentially, characterized in that... The control method includes: Control the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit; A dual-loop tracking control method is used to control both the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit. Adjusting the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the external phase shift angle α includes: adjusting the external phase shift angle α of the secondary-side bidirectional full-bridge converter circuit relative to the external phase shift angle reference value α. ref The error value after comparison is passed through a PI controller; the output of the PI controller is passed through a PQ phase-locked pulse and a quadrature multiplier to obtain an external phase shift angle α; wherein, the initial value of the external phase shift angle is α = π.

2. The control method according to claim 1, characterized in that, The method of controlling the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit includes: The error value between the DC bus voltage and the DC bus voltage reference value is processed by a PI controller to obtain the reference value of active power. The phase-locked angle is obtained by passing the AC terminal voltage amplitude through Fourier phase-locking, and the actual value of active power is calculated accordingly. The error value obtained by comparing the actual value of the active power with the reference value is passed through a PI controller to obtain the SPWM drive signal for controlling the bidirectional PFC circuit.

3. The control method according to claim 1, characterized in that, The method of using dual-loop tracking control to control the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit includes: The error values ​​of the DC terminal voltage and the DC voltage reference value, and the DC terminal current and the DC current reference value of the secondary-side bidirectional full-bridge converter circuit are respectively input into the PI controller. The output values ​​of the two PI controllers are passed through a dual-loop follower controller to output the first phase shift angle β. p Second phase shift angle β s ; Using the first phase shift angle β p The primary-side bidirectional full-bridge converter circuit is controlled using the second phase shift angle β. s The secondary-side bidirectional full-bridge converter circuit is controlled.

4. The control method according to claim 3, characterized in that, The adjustment of the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the outer phase shift angle α includes: During positive energy transfer, α = π - β s / 2; During reverse energy transfer, α = π + β s / 2; Where, β p and β s The initial value is β p =β s =0.

5. A control device for a wireless bidirectional charging and discharging system, the wireless bidirectional charging and discharging system comprising a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit, wherein the bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected sequentially, characterized in that... The control device includes: A DC bus voltage control module is used to control the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit. The dual-loop tracking module is used to control the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit using a dual-loop tracking control method. The power transmission control module is used to adjust the power transmission direction of the wireless bidirectional charging and discharging system by adjusting the external phase shift angle α, including: adjusting the external phase shift angle α of the secondary-side bidirectional full-bridge converter circuit relative to the external phase shift angle reference value α. ref The error value after comparison is passed through a PI controller; the output of the PI controller is passed through a PQ phase-locked pulse and a quadrature multiplier to obtain an external phase shift angle α; wherein, the initial value of the external phase shift angle is α = π.

6. The control device according to claim 5, characterized in that, The DC bus voltage control module controls the active current at the AC terminal of the bidirectional PFC circuit to stabilize the DC bus voltage of the bidirectional PFC circuit, including: The error value between the DC bus voltage and the DC bus voltage reference value is processed by a PI controller to obtain the reference value of active power. The phase-locked angle is obtained by passing the AC terminal voltage amplitude through Fourier phase-locking, and the actual value of active power is calculated accordingly. The error value obtained by comparing the actual value of the active power with the reference value is passed through a PI controller to obtain the SPWM drive signal for controlling the bidirectional PFC circuit.

7. The control device according to claim 6, characterized in that, The dual-loop tracking module uses a dual-loop tracking control method to control the primary-side bidirectional full-bridge converter circuit and the secondary-side bidirectional full-bridge converter circuit, including: The error values ​​of the DC terminal voltage and the DC voltage reference value, and the DC terminal current and the DC current reference value of the secondary-side bidirectional full-bridge converter circuit are respectively input into the PI controller. The output values ​​of the two PI controllers are passed through a dual-loop follower controller to output the first phase shift angle β. p Second phase shift angle β s ; Using the first phase shift angle β p The primary-side bidirectional full-bridge converter circuit is controlled using the second phase shift angle β. s The secondary-side bidirectional full-bridge converter circuit is controlled.

8. A wireless bidirectional charging and discharging system, characterized in that, The system includes a bidirectional PFC circuit, a primary-side bidirectional full-bridge converter circuit, a primary-side LCC compensation network, a coupling mechanism, a secondary-side LCC compensation network, and a secondary-side bidirectional full-bridge converter circuit; among which, The bidirectional PFC circuit, the primary-side bidirectional full-bridge converter circuit, the primary-side LCC compensation network, the coupling mechanism, the secondary-side LCC compensation network, and the secondary-side bidirectional full-bridge converter circuit are connected in sequence. The wireless bidirectional charging and discharging system is controlled using the control method described in any one of claims 1-4.

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