Bidirectional resonant conversion circuit, control method and application

Abstract

The invention discloses a bidirectional resonant conversion circuit, a control method and application. The bidirectional resonant conversion circuit comprises a primary side inversion rectification multiplexing unit, a resonant unit and a secondary side inversion rectification multiplexing unit, the primary side inversion rectification multiplexing unit is used for converting direct-current electric energy into high-frequency alternating-current electric energy or converting the high-frequency alternating-current electric energy into direct-current electric energy; the secondary side inversion rectification multiplexing unit is used for converting direct-current electric energy into high-frequency alternating-current electric energy or converting the high-frequency alternating-current electric energy into direct-current electric energy; the resonance unit is used for coupling alternating current electric energy of the primary side inversion rectification multiplexing unit and the secondary side inversion rectification multiplexing unit through a high-frequency transformer, and realizing two-way energy transmission based on resonance characteristics; the bidirectional resonant conversion circuit does not comprise half-bridge and full-bridge switch units, so that a switch control signal does not need to be provided with a dead zone, and the circuit is not influenced by a dead zone effect, is safer and more efficient, and is more suitable for high-frequency development requirements; and bidirectional electric energy transmission can be simply realized.

Description

Technical Field

[0001] The present invention relates to the technical field of direct current power conversion, and more specifically, to a bidirectional resonant conversion circuit, a control method and applications. Background Art

[0002] Compared to energy transmission via metal wires, wireless power transmission offers advantages such as convenience, durability, and safety. Therefore, it has been widely used in charging systems for mobile terminals, electric vehicles, drones, and various robots. Existing wireless power transmission technologies are mostly based on various resonant conversion circuit designs, and existing resonant conversion circuits are generally based on half-bridge or full-bridge structures, such as series resonant circuits, parallel resonant circuits, series-parallel resonant circuits, and LLC resonant circuits. To prevent the upper and lower bridge arm switches in a half-bridge or full-bridge resonant circuit from being turned on simultaneously, a dead time must be added to the control signals of the upper and lower bridge arm switches. For wireless power transmission systems with very high switching frequencies, a dead time that is too long will seriously affect the converter's conversion performance, while a dead time that is too short will risk the upper and lower switches being turned on directly. This makes existing wireless power transmission technology severely affected by the switch dead time setting in the resonant circuit, making it difficult to meet the needs of high-frequency development.

[0003] Therefore, how to design a resonant conversion circuit that does not require a dead zone setting to meet the high-frequency development of wireless power transmission remains a problem to be solved. Summary of the Invention

[0004] In order to overcome the defect of the prior art that the proportion of dead time increases significantly in high-frequency scenarios, the present invention provides a bidirectional resonant conversion circuit, a control method and an application.

[0005] In order to solve the above technical problems, the technical solutions of the present invention are as follows:

[0006] The present invention provides a bidirectional resonant conversion circuit, comprising a primary-side inverting and rectifying multiplexing unit, a resonant unit, and a secondary-side inverting and rectifying multiplexing unit;

[0007] The first end of the primary-side inverting and rectifying multiplexing unit is connected to the primary-side first end of the resonant unit, and the second end of the primary-side inverting and rectifying multiplexing unit is connected to the primary-side second end of the resonant unit;

[0008] The first end of the secondary side of the resonant unit is connected to the first end of the secondary side inverter and rectifier multiplexing unit, and the second end of the secondary side of the resonant unit is connected to the second end of the secondary side inverter and rectifier multiplexing unit.

[0009] Preferably, the primary side inverter rectifier multiplexing unit includes a first inductor L1, a second inductor L2, a first switch tube S1, a second switch tube S2 and a primary side DC power supply V p ,in:

[0010] The first end of the first inductor L1 is connected to the first end of the second inductor L2 and serves as the primary DC positive terminal;

[0011] The second end of the first inductor L1 is connected to the first end of the first switch tube S1 and serves as the primary first AC end;

[0012] The second end of the second inductor L2 is connected to the first end of the second switch tube S2 and serves as the primary side second AC end;

[0013] The second end of the first switch tube S1 and the second end of the second switch tube S2 are connected and serve as the primary DC negative terminal;

[0014] The primary DC positive terminal and the primary DC negative terminal of the primary side inverter rectifier multiplexing unit are connected to the primary DC power supply V p The positive and negative poles are connected accordingly;

[0015] The first switch S1 and the second switch S2 are controlled in a complementary manner to output a high-frequency AC signal to the resonant unit.

[0016] Preferably, the secondary side inverter rectifier multiplexing unit includes a third inductor L3, a fourth inductor L4, a third switch tube S3, a fourth switch tube S4 and a secondary side DC power supply L s ,in:

[0017] The first end of the third inductor L3 is connected to the first end of the fourth inductor L4 and serves as the secondary DC positive terminal;

[0018] The second end of the third inductor S3 is connected to the first end of the third switch tube S3 and serves as the first AC end of the secondary side;

[0019] The second end of the fourth inductor L4 is connected to the first end of the fourth switch tube S4 and serves as the second AC end of the secondary side;

[0020] The second end of the third switch tube S3 and the second end of the fourth switch tube S4 are connected and serve as the secondary DC negative terminal;

[0021] The secondary side DC positive terminal and the secondary side DC negative terminal of the secondary side inverter rectifier multiplexing unit are connected to the secondary side DC power supply V s The positive and negative poles are connected accordingly;

[0022] The third switch tube S3 and the fourth switch tube S4 are controlled in a complementary manner to output or receive a high-frequency AC signal.

[0023] Preferably, the resonance unit includes a primary resonance capacitor C p , secondary side resonant capacitor C s , primary resonant inductor L p , secondary side resonant inductor Ls and a high-frequency transformer, wherein:

[0024] Primary resonant capacitor C p and the primary resonant inductor L p The primary resonant circuit is formed in series, and the primary winding n of the high frequency transformer is connected p connected to the primary first AC terminal and the primary second AC terminal;

[0025] Secondary side resonant capacitor C s and the secondary side resonant inductor L s The secondary resonant circuit is formed in series, and the secondary winding n of the high frequency transformer is connected s connected to the first AC terminal of the secondary side and the second AC terminal of the secondary side;

[0026] The high-frequency transformer couples the resonant circuit of the primary-side inverter-rectifier multiplexing unit and the secondary-side inverter-rectifier multiplexing unit to achieve energy transmission.

[0027] Preferably, the first switch tube S1, the second switch tube S2, the third switch tube S3 and the fourth switch tube S4 of the primary side inverter and rectifier multiplexing unit and the secondary side inverter and rectifier multiplexing unit are all N-channel MOSFETs, their control signals are complementary square wave signals, and there is no need to set dead time.

[0028] Preferably, the resonant frequencies of the primary resonant circuit and the secondary resonant circuit of the resonant unit match the frequency of the switch tube control signal.

[0029] Preferably, dynamic control of the direction and power of power transmission is achieved by adjusting the frequencies of control signals of the first switch S1 , the second switch S2 , the third switch S3 and the fourth switch S4 .

[0030] Preferably, the structures of the primary-side inverting and rectifying multiplexing unit and the secondary-side inverting and rectifying multiplexing unit are symmetrical, and the direction of power transmission is reversed by switching the input direction of the control signal.

[0031] The present invention also provides a control method based on the above-mentioned bidirectional resonant conversion circuit, the method comprising:

[0032] When the energy conversion direction is from the primary-side inverter-rectifier multiplexing unit to the secondary-side inverter-rectifier multiplexing unit, a forward energy transmission control step is performed;

[0033] When the energy conversion direction is from the secondary side inverter and rectifier multiplexing unit to the primary side inverter and rectifier multiplexing unit, a reverse energy transmission control step is performed;

[0034] The forward energy transmission control step includes:

[0035] Applying complementary square wave control signals with a preset duty cycle to the first switch tube S1 and the second switch tube S2 of the primary-side inverter-rectifier multiplexing unit to make them alternately conductive, thereby generating a high-frequency AC current on the AC side of the primary-side inverter-rectifier multiplexing unit;

[0036] The high-frequency AC current is transmitted to the AC side of the secondary-side inverter-rectifier multiplexing unit through the resonance unit;

[0037] The high-frequency AC current is converted into DC current through the parallel diode or synchronous rectification action of the third switch tube S3 and the fourth switch tube S4 of the secondary side inverter rectifier multiplexing unit and input into the secondary side DC power supply V s ;

[0038] Adjust the frequency of the square wave control signal to control the secondary DC power supply V s Input current or power;

[0039] The reverse energy transmission control step includes:

[0040] Applying complementary square wave control signals with a preset duty cycle to the third switch tube S3 and the fourth switch tube S4 of the secondary-side inverter-rectifier multiplexing unit to make them alternately conductive, thereby generating a high-frequency AC current on the AC side of the secondary-side inverter-rectifier multiplexing unit;

[0041] The high-frequency AC current is transmitted to the AC side of the primary-side inverter-rectifier multiplexing unit through the resonance unit;

[0042] The high-frequency AC current is converted into DC current through the parallel diode or synchronous rectification action of the first switch tube S1 and the second switch tube S2 of the primary side inverter rectifier multiplexing unit and input into the primary DC power supply V p ;

[0043] Adjust the frequency of the square wave control signal to control the primary DC power supply V p The input current or power.

[0044] The present invention also provides a wireless power transmission device, which includes the above-mentioned bidirectional resonant conversion circuit.

[0045] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0046] The present invention proposes a bidirectional resonant conversion circuit, control method and application. Since the bidirectional resonant conversion circuit does not contain half-bridge and full-bridge switching units, the switch control signal does not need to set a dead zone, and the circuit is not affected by the dead zone effect. It is safer and more efficient and more suitable for high-frequency development needs; it can simply realize bidirectional power transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1Schematic diagram of the structure of the bidirectional resonant conversion circuit described in Example 1;

[0048] Figure 2 Schematic diagram of the structure of the bidirectional resonant conversion circuit described in Example 1;

[0049] Figure 3 This is a circuit diagram of the state of the bidirectional resonant conversion circuit described in Example 2 when transmitting electric energy in the forward direction;

[0050] Figure 4 This is the state circuit of the bidirectional resonant conversion circuit described in Example 2 when transmitting electric energy in reverse;

[0051] Figure 5 Schematic diagram of the structure of the simulation model of the bidirectional resonant conversion circuit in Example 2 when transmitting energy in the forward direction;

[0052] Figure 6 Schematic diagram of the simulation waveform when the switching control signal frequency is 3 MHz in Example 2;

[0053] Figure 7 Schematic diagram of simulation results when the switch control signal frequency is 3.2 MHz in Example 2;

[0054] Figure 8 Schematic diagram of the simulation results when the switch control signal frequency is 3 MHz in Example 2;

[0055] Figure 9 Schematic diagram of simulation results when the switch control signal frequency is 2.5 MHz in Example 2;

[0056] Figure 10 This is a schematic structural diagram of the wireless power transmission device described in Example 3. DETAILED DESCRIPTION

[0057] The accompanying drawings are for illustrative purposes only and are not to be construed as limiting this patent;

[0058] In order to better illustrate this embodiment, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product size;

[0059] It is understandable to those skilled in the art that some well-known structures and descriptions thereof may be omitted in the drawings.

[0060] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0061] Example 1

[0062] This embodiment provides a bidirectional resonant conversion circuit, such as Figure 1As shown, it includes a primary side inverter and rectifier multiplexing unit, a resonant unit and a secondary side inverter and rectifier multiplexing unit;

[0063] The first end of the primary-side inverting and rectifying multiplexing unit is connected to the primary-side first end of the resonant unit, and the second end of the primary-side inverting and rectifying multiplexing unit is connected to the primary-side second end of the resonant unit;

[0064] The first end of the secondary side of the resonant unit is connected to the first end of the secondary side inverter and rectifier multiplexing unit, and the second end of the secondary side of the resonant unit is connected to the second end of the secondary side inverter and rectifier multiplexing unit.

[0065] like Figure 2 As shown, the primary side inverter rectifier multiplexing unit includes a first inductor L1, a second inductor L2, a first switch tube S1, a second switch tube S2 and a primary side DC power supply V p ,in:

[0066] The first end of the first inductor L1 is connected to the first end of the second inductor L2 and serves as the primary DC positive terminal;

[0067] The second end of the first inductor L1 is connected to the first end of the first switch tube S1 and serves as the primary first AC end;

[0068] The second end of the second inductor L2 is connected to the first end of the second switch tube S2 and serves as the primary side second AC end;

[0069] The second end of the first switch tube S1 and the second end of the second switch tube S2 are connected and serve as the primary DC negative terminal;

[0070] The primary DC positive terminal and the primary DC negative terminal of the primary side inverter rectifier multiplexing unit are connected to the primary DC power supply V p The positive and negative poles are connected accordingly;

[0071] The first switch S1 and the second switch S2 are controlled in a complementary manner to output a high-frequency AC signal to the resonant unit.

[0072] The secondary side inverter and rectifier multiplexing unit includes a third inductor L3, a fourth inductor L4, a third switch tube S3, a fourth switch tube S4 and a secondary side DC power supply V s ,in:

[0073] The first end of the third inductor L3 is connected to the first end of the fourth inductor L4 and serves as the secondary DC positive terminal;

[0074] The second end of the third inductor L3 is connected to the first end of the third switch tube S3 and serves as the first AC end of the secondary side;

[0075] The second end of the fourth inductor L4 is connected to the first end of the fourth switch tube S4 and serves as the second AC end of the secondary side;

[0076] The second end of the third switch tube S3 and the second end of the fourth switch tube S4 are connected and serve as the secondary DC negative terminal;

[0077] The secondary side DC positive terminal and the secondary side DC negative terminal of the secondary side inverter rectifier multiplexing unit are connected to the secondary side DC power supply V s The positive and negative poles are connected accordingly;

[0078] The third switch tube S3 and the fourth switch tube S4 are controlled in a complementary manner to output or receive a high-frequency AC signal.

[0079] The resonance unit includes a primary resonance capacitor C p , secondary side resonant capacitor C s , primary resonant inductor L p , secondary side resonant inductor L s and a high-frequency transformer, wherein:

[0080] Primary resonant capacitor C p and the primary resonant inductor L p The primary resonant circuit is formed in series, and the primary winding n of the high frequency transformer is connected p connected to the primary first AC terminal and the primary second AC terminal;

[0081] Secondary side resonant capacitor C s and the secondary side resonant inductor L s The secondary resonant circuit is formed in series, and the secondary winding n of the high frequency transformer is connected s connected to the first AC terminal of the secondary side and the second AC terminal of the secondary side;

[0082] The high-frequency transformer couples the resonant circuit of the primary-side inverter-rectifier multiplexing unit and the secondary-side inverter-rectifier multiplexing unit to achieve energy transmission;

[0083] The high-frequency transformer couples the resonant circuit of the primary-side inverter-rectifier multiplexing unit and the secondary-side inverter-rectifier multiplexing unit to achieve energy transmission.

[0084] The first switch tube S1, the second switch tube S2, the third switch tube S3 and the fourth switch tube S4 of the primary side inverter and rectifier multiplexing unit and the secondary side inverter and rectifier multiplexing unit are all N-channel MOSFETs, their control signals are complementary square wave signals, and no dead time is required.

[0085] The resonant frequencies of the primary resonant circuit and the secondary resonant circuit of the resonant unit match the frequency of the switch tube control signal.

[0086] By adjusting the control signal frequencies of the first switch tube S1 , the second switch tube S2 , the third switch tube S3 and the fourth switch tube S4 , dynamic control of the power transmission direction and power is achieved.

[0087] The structures of the primary-side inverting and rectifying multiplexing unit and the secondary-side inverting and rectifying multiplexing unit are symmetrical, and the direction of power transmission is reversed by switching the input direction of the control signal.

[0088] In a specific embodiment, the circuit is composed of a primary-side inverter-rectifier multiplexing unit, a secondary-side inverter-rectifier multiplexing unit, and a resonant unit. It is used to convert electrical energy between the primary side and the secondary side;

[0089] The primary-side inverter-rectifier multiplexing unit is composed of a first inductor L1, a second inductor L2, a first switch S1, and a second switch S2. The first end of the first inductor L1 is connected to the first end of the second inductor L2 and serves as the DC positive terminal of the primary-side inverter-rectifier multiplexing unit; the second end of the first inductor L1 is connected to the first end of the first switch S1 and serves as the first AC terminal of the primary-side inverter-rectifier multiplexing unit; the second end of the second inductor L2 is connected to the first end of the second switch S2 and serves as the second AC terminal of the primary-side inverter-rectifier multiplexing unit; the second end of the first switch S1 and the second end of the second switch S2 are connected and serve as the DC negative terminal of the primary-side inverter-rectifier multiplexing unit. The DC positive terminal and DC negative terminal of the primary-side inverter-rectifier multiplexing unit are connected to the positive and negative terminals of the primary DC power supply Vp, respectively.

[0090] The secondary-side inverter-rectifier multiplexing unit is composed of a third inductor L3, a fourth inductor L4, a third switch S3, and a fourth switch S4. The first end of the third inductor L3 is connected to the first end of the fourth inductor L4 and serves as the DC positive terminal of the secondary-side inverter-rectifier multiplexing unit; the second end of the third inductor L3 is connected to the first end of the third switch S3 and serves as the first AC terminal of the secondary-side inverter-rectifier multiplexing unit; the second end of the fourth inductor L4 is connected to the first end of the fourth switch S4 and serves as the second AC terminal of the secondary-side inverter-rectifier multiplexing unit; and the second end of the third switch S3 and the second end of the fourth switch S4 are connected to serve as the DC negative terminal of the secondary-side inverter-rectifier multiplexing unit. The DC positive terminal and DC negative terminal of the secondary-side inverter-rectifier multiplexing unit are connected to the positive and negative terminals of the secondary-side DC power supply Vs, respectively.

[0091] The resonant unit is composed of a primary resonant capacitor Cp, a secondary resonant capacitor Cs, a primary resonant inductor Lp, a secondary resonant inductor Ls, and a high-frequency transformer having a primary winding np and a secondary winding ns. The first end of the primary resonant capacitor Cp is connected to the first end of the primary resonant inductor Lp and serves as the primary first AC terminal of the resonant unit; the second end of the primary resonant inductor Lp is connected to the first end of the primary winding np; the second end of the primary winding np is connected to the second end of the primary resonant capacitor Cp and serves as the primary second AC terminal of the resonant unit; the first end of the secondary resonant capacitor Cs is connected to the first end of the secondary resonant inductor Ls and serves as the secondary first AC terminal of the resonant unit; the second end of the secondary resonant inductor Ls is connected to the first end of the secondary winding ns; the second end of the secondary winding ns is connected to the second end of the secondary resonant capacitor Cs and serves as the secondary second AC terminal of the resonant unit.

[0092] The first and second AC ends of the primary side of the resonant unit are respectively connected to the first and second AC ends of the primary side inverter and rectifier multiplexing unit; the first and second AC ends of the secondary side of the resonant unit are respectively connected to the first and second AC ends of the secondary side inverter and rectifier multiplexing unit.

[0093] Example 2

[0094] This embodiment provides a control method based on the bidirectional resonant conversion circuit described in Embodiment 1, the method comprising:

[0095] When the energy conversion direction is from the primary-side inverter-rectifier multiplexing unit to the secondary-side inverter-rectifier multiplexing unit, a forward energy transmission control step is performed;

[0096] When the energy conversion direction is from the secondary side inverter and rectifier multiplexing unit to the primary side inverter and rectifier multiplexing unit, a reverse energy transmission control step is performed;

[0097] The forward energy transmission control step includes:

[0098] Applying complementary square wave control signals with a preset duty cycle to the first switch tube S1 and the second switch tube S2 of the primary-side inverter-rectifier multiplexing unit to make them alternately conductive, thereby generating a high-frequency AC current on the AC side of the primary-side inverter-rectifier multiplexing unit;

[0099] The high-frequency AC current is transmitted to the AC side of the secondary-side inverter-rectifier multiplexing unit through the resonance unit;

[0100] The high-frequency AC current is converted into DC current through the parallel diode or synchronous rectification action of the third switch tube S3 and the fourth switch tube S4 of the secondary side inverter rectifier multiplexing unit and input into the secondary side DC power supply V s ;

[0101] Adjust the frequency of the square wave control signal to control the secondary DC power supply V s Input current or power;

[0102] The reverse energy transmission control step includes:

[0103] Applying complementary square wave control signals with a preset duty cycle to the third switch tube S3 and the fourth switch tube S4 of the secondary-side inverter-rectifier multiplexing unit to make them alternately conductive, thereby generating a high-frequency AC current on the AC side of the secondary-side inverter-rectifier multiplexing unit;

[0104] The high-frequency AC current is transmitted to the AC side of the primary-side inverter-rectifier multiplexing unit through the resonance unit;

[0105] The high-frequency AC current is converted into DC current through the parallel diode or synchronous rectification action of the first switch tube S1 and the second switch tube S2 of the primary side inverter rectifier multiplexing unit and input into the primary DC power supply V p ;

[0106] Adjust the frequency of the square wave control signal to control the primary DC power supply V p The input current or power.

[0107] like Figure 3 As shown, when the proposed bidirectional power transmission circuit transmits energy in the forward direction, switches S1 and S2 are controlled by a square wave signal, causing them to alternately conduct at a duty cycle of 0.5, thereby causing the AC side of the primary-side inverter-rectifier multiplexing unit to output a high-frequency AC current, which is transmitted to the AC side of the secondary-side inverter-rectifier multiplexing unit through the resonant unit. The current is then rectified by the secondary-side inverter-rectifier multiplexing unit (using the parallel diodes of S3 and S4) or synchronously rectified (using S3 and S4) into a DC current that flows into the secondary-side DC power supply Vs. By changing the frequency of the square wave control signal of switches S1 and S2, the current flowing into the secondary-side DC power supply Vs can be adjusted, thereby achieving control of the forward transmission current or power.

[0108] like Figure 4 As shown, when the proposed bidirectional power transmission circuit transmits energy in the reverse direction, switches S3 and S4 are controlled by a square wave signal, causing them to alternately conduct at a duty cycle of 0.5, thereby causing the AC side of the secondary inverter-rectifier multiplexing unit to output a high-frequency AC current. This current is transmitted to the AC side of the primary inverter-rectifier multiplexing unit via the resonant unit. The current is then rectified by the primary inverter-rectifier multiplexing unit (using the parallel diodes S1 and S2) or synchronously rectified (using S1 and S2) into a DC current that flows into the primary DC power supply Vp. By changing the frequency of the square wave control signal of switches S3 and S4, the current flowing into the secondary DC power supply Vp can be adjusted, thereby achieving control of the reverse transmission current or power.

[0109] like Figure 5 Figure 2 shows a simulation model of the bidirectional resonant circuit of the present invention during forward energy transfer, constructed in the simulation software PSIM. Switches S1 through S4 are N-channel MOSFETs, and other device parameters are shown in the figure. The control signals for S3 and S4 are grounded. Switches S1 and S2 are controlled by square wave signals, with S2 directly controlled by the square wave source and S1 controlled by the inverted square wave source. No dead zone is required between them.

[0110] like Figure 6 Figure 2 shows the simulated waveforms for a 3MHz square wave control signal frequency for switches S1 and S2 in the simulation model. These results effectively demonstrate the feasibility of the proposed converter circuit for forward energy transfer. Because the primary and secondary sides of the circuit are completely symmetrical, reverse energy transfer requires only grounding the control signals for switches S1 and S2, while S3 and S4 are controlled by a square wave signal.

[0111] like Figure 7 、 Figure 8 and Figure 9 Figure 2 shows the simulation waveforms at different switching frequencies. The simulation results effectively verify that the output current can be adjusted by changing the frequency of the square wave control signal, thereby achieving effective control of the transmission current and power.

[0112] Example 3

[0113] This embodiment also provides a wireless power transmission device, such as Figure 10 As shown, it includes the bidirectional resonant conversion circuit described in embodiment 1, wherein:

[0114] The primary resonant inductor L p The primary winding of the high-frequency transformer n p Integrated to form the primary side wireless charging coil;

[0115] Secondary side resonant inductor L s and the secondary winding n of the high frequency transformer s Integrated to form the secondary side wireless charging coil;

[0116] The primary wireless charging coil is connected to a primary DC power supply;

[0117] The secondary side wireless charging coil is connected to the secondary side DC power supply;

[0118] Electric energy is bidirectionally transmitted between the primary wireless charging coil and the secondary wireless charging coil through the resonance unit.

[0119] The device is applied to wireless charging scenarios of electric vehicles, drones or mobile terminals, and supports bidirectional interaction of energy between the primary side wireless charging coil and the secondary side wireless charging coil.

[0120] In the proposed bidirectional power transmission circuit, the primary resonant inductor L of the resonant unit is p and the primary winding n of the high-frequency transformer p Can be integrated into a wireless charging coil, namely the primary coil; the secondary resonant inductor L s and the secondary winding n of the high-frequency transformer s It can be integrated into another wireless charging coil, namely the secondary coil; thereby making the proposed bidirectional power transmission circuit a bidirectional wireless power transmission system.

[0121] The same or similar reference numerals correspond to the same or similar components;

[0122] The terms used in the drawings to describe positional relationships are for illustrative purposes only and should not be construed as limiting this patent;

[0123] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A bidirectional resonant conversion circuit, characterized in that: It includes a primary side inverter and rectifier multiplexing unit, a resonance unit and a secondary side inverter and rectifier multiplexing unit; The first end of the primary-side inverting and rectifying multiplexing unit is connected to the primary-side first end of the resonant unit, and the second end of the primary-side inverting and rectifying multiplexing unit is connected to the primary-side second end of the resonant unit; The first end of the secondary side of the resonant unit is connected to the first end of the secondary side inverter and rectifier multiplexing unit, and the second end of the secondary side of the resonant unit is connected to the second end of the secondary side inverter and rectifier multiplexing unit.

2. The bidirectional resonant converter circuit according to claim 1, wherein: The primary side inverter rectifier multiplexing unit includes a first inductor L1, a second inductor L2, a first switch tube S1, a second switch tube S2 and a primary side DC power supply V p ,in: The first end of the first inductor L1 is connected to the first end of the second inductor L2 and serves as the primary DC positive terminal; The second end of the first inductor L1 is connected to the first end of the first switch tube S1 and serves as the primary first AC end; The second end of the second inductor L2 is connected to the first end of the second switch tube S2 and serves as the primary side second AC end; The second end of the first switch tube S1 and the second end of the second switch tube S2 are connected and serve as the primary DC negative terminal; The primary DC positive terminal and the primary DC negative terminal of the primary side inverter rectifier multiplexing unit are connected to the primary DC power supply V p The positive and negative poles are connected accordingly; The first switch S1 and the second switch S2 are controlled in a complementary manner to output a high-frequency AC signal to the resonant unit.

3. The bidirectional resonant converter circuit according to claim 1, wherein: The secondary side inverter and rectifier multiplexing unit includes a third inductor L3, a fourth inductor L4, a third switch tube S3, a fourth switch tube S4 and a secondary side DC power supply V s ,in: The first end of the third inductor L3 is connected to the first end of the fourth inductor L4 and serves as the secondary DC positive terminal; The second end of the third inductor L3 is connected to the first end of the third switch tube S3 and serves as the first AC end of the secondary side; The second end of the fourth inductor L4 is connected to the first end of the fourth switch tube S4 and serves as the second AC end of the secondary side; The second end of the third switch tube S3 and the second end of the fourth switch tube S4 are connected and serve as the secondary DC negative terminal; The secondary side DC positive terminal and the secondary side DC negative terminal of the secondary side inverter rectifier multiplexing unit are connected to the secondary side DC power supply V s The positive and negative poles are connected accordingly; The third switch tube S3 and the fourth switch tube S4 are controlled in a complementary manner to output or receive a high-frequency AC signal.

4. The bidirectional resonant converter circuit according to claim 1, wherein: The resonance unit includes a primary resonance capacitor C p , secondary side resonant capacitor C s , primary resonant inductor L p , secondary side resonant inductor L s and a high-frequency transformer, wherein: Primary resonant capacitor C p and the primary resonant inductor L p The primary resonant circuit is formed in series, and the primary winding n of the high frequency transformer is connected p connected to the primary first AC terminal and the primary second AC terminal; Secondary side resonant capacitor C s and the secondary side resonant inductor L s The secondary resonant circuit is formed in series, and the secondary winding n of the high frequency transformer is connected s Connected to the first AC terminal of the secondary side and the second AC terminal of the secondary side.

5. The bidirectional resonant converter circuit according to claim 1, wherein: The first switch tube S1, the second switch tube S2, the third switch tube S3 and the fourth switch tube S4 of the primary side inverter and rectifier multiplexing unit and the secondary side inverter and rectifier multiplexing unit are all N-channel MOSFETs, their control signals are complementary square wave signals, and no dead time is required.

6. The bidirectional resonant converter circuit according to claim 4, wherein: The resonant frequencies of the primary resonant circuit and the secondary resonant circuit of the resonant unit match the frequency of the switch tube control signal.

7. The bidirectional resonant converter circuit according to claim 1, wherein: By adjusting the control signal frequencies of the first switch tube S1 , the second switch tube S2 , the third switch tube S3 and the fourth switch tube S4 , dynamic control of the power transmission direction and power is achieved.

8. The bidirectional resonant converter circuit according to claim 1, wherein: The structures of the primary-side inverting and rectifying multiplexing unit and the secondary-side inverting and rectifying multiplexing unit are symmetrical, and the direction of power transmission is reversed by switching the input direction of the control signal.

9. A control method based on the bidirectional resonant conversion circuit according to any one of claims 1 to 8, characterized in that: The method comprises: When the energy conversion direction is from the primary-side inverter-rectifier multiplexing unit to the secondary-side inverter-rectifier multiplexing unit, a forward energy transmission control step is performed; When the energy conversion direction is from the secondary side inverter and rectifier multiplexing unit to the primary side inverter and rectifier multiplexing unit, a reverse energy transmission control step is performed; The forward energy transmission control step includes: Applying complementary square wave control signals with a preset duty cycle to the first switch tube S1 and the second switch tube S2 of the primary-side inverter-rectifier multiplexing unit to make them alternately conductive, thereby generating a high-frequency AC current on the AC side of the primary-side inverter-rectifier multiplexing unit; The high-frequency AC current is transmitted to the AC side of the secondary-side inverter-rectifier multiplexing unit through the resonance unit; The high-frequency AC current is converted into DC current through the parallel diode or synchronous rectification action of the third switch tube S3 and the fourth switch tube S4 of the secondary side inverter rectifier multiplexing unit and input into the secondary side DC power supply V s ; Adjust the frequency of the square wave control signal to control the secondary DC power supply V s Input current or power; The reverse energy transmission control step includes: Applying complementary square wave control signals with a preset duty cycle to the third switch tube S3 and the fourth switch tube S4 of the secondary-side inverter-rectifier multiplexing unit to make them alternately conductive, thereby generating a high-frequency AC current on the AC side of the secondary-side inverter-rectifier multiplexing unit; The high-frequency AC current is transmitted to the AC side of the primary-side inverter-rectifier multiplexing unit through the resonance unit; The high-frequency AC current is converted into DC current through the parallel diode or synchronous rectification action of the first switch tube S1 and the second switch tube S2 of the primary side inverter rectifier multiplexing unit and input into the primary DC power supply V p ; Adjust the frequency of the square wave control signal to control the primary DC power supply V p The input current or power.

10. A wireless power transmission device, characterized in that: The wireless power transmission device includes the bidirectional resonant conversion circuit according to any one of claims 1 to 8.

Images