An electric vehicle wireless charging system
The wireless charging system, which utilizes ground-based and on-board charging terminals and employs filtering, rectification, inversion, and resonant technologies, solves the problems of low charging efficiency and high cost for electric vehicles, achieving efficient and low-cost wireless charging and meeting diverse user charging needs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 亿创智联(浙江)电子科技有限公司
- Filing Date
- 2022-10-31
- Publication Date
- 2026-07-10
AI Technical Summary
Existing electric vehicle charging is inefficient, slow, and costly, especially the problem of unattended charging after autonomous vehicles run out of power has not been effectively solved.
The wireless charging system employs ground-based and vehicle-mounted charging terminals, including a filtering unit, a SWISS rectifier unit, a flow-controlled inverter unit, and a vehicle-mounted resonant unit. It achieves efficient energy transfer through filtering, rectification, inversion, and resonance processes, and supports both single-phase and three-phase compatible charging.
It achieves efficient and low-cost wireless charging, meeting users' needs for fast and slow charging in different scenarios, reducing the number of charging devices, saving space and costs, and improving charging efficiency and power factor.
Smart Images
Figure CN115593248B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of wireless charging technology, and more particularly to a wireless charging system for electric vehicles. Background Technology
[0002] With global warming, especially after the long and hot summer of 2022, excessive carbon emissions have had a profound impact on people's work and lives. The country is vigorously promoting energy conservation, emission reduction, and pollution reduction targets, and new energy vehicles are gradually becoming the first choice for consumers' travel.
[0003] However, the low charging efficiency, slow charging speed, and high cost of new energy vehicles, especially the unattended charging of driverless vehicles after they run out of power, have become challenges in the development of electric vehicles. Summary of the Invention
[0004] To address the problems existing in the prior art, the present invention provides a wireless charging system for electric vehicles, comprising:
[0005] Ground charging terminal, the ground charging terminal includes:
[0006] A filtering unit is provided, the input of which is connected to an external AC input power supply, and the output of which is connected to the input of a SWISS rectifier unit. The SWISS rectifier unit is used to convert the AC power output from the AC input power supply after being filtered by the filtering unit into DC power.
[0007] A flow-controlled inverter unit, the input of which is connected to the output of the SWISS rectifier unit, is used to convert the DC power into a high-frequency pulse signal;
[0008] A ground-side isolation resonant unit, the input of which is connected to the output of the flow-controlled inverter unit, is used to convert the high-frequency pulse signal into a resonant signal and output it.
[0009] The vehicle-mounted charging terminal is wirelessly connected to the ground-based charging terminal, and the vehicle-mounted charging terminal includes:
[0010] The vehicle-mounted resonant unit has its output connected to the input of a vehicle-mounted rectifier unit, and the output of the vehicle-mounted rectifier unit is connected to the vehicle battery. The vehicle-mounted resonant unit is used to receive the resonant signal and convert it into a corresponding pulse signal. The vehicle-mounted rectifier unit is used to rectify the pulse signal and charge the vehicle battery.
[0011] Preferably, the filtering unit includes:
[0012] A first filter inductor, one end of which is connected to the AC input power supply, and the other end of which is grounded through a first filter capacitor;
[0013] The second filter inductor has one end connected to the AC input power supply and the other end grounded through the second filter capacitor.
[0014] The third filter inductor has one end connected to the AC input power supply and the other end grounded through the third filter capacitor.
[0015] The other ends of the first filter inductor, the second filter inductor, and the third filter inductor are also connected to the input terminal of the SWISS rectifier unit.
[0016] Preferably, the AC input power supply is a three-phase AC power supply, with phase A of the three-phase AC power supply connected to one end of the first filter inductor, phase B of the three-phase AC power supply connected to one end of the second filter inductor, and phase C of the three-phase AC power supply connected to one end of the third filter inductor.
[0017] Preferably, the ground charging terminal further includes a ground control unit connected to the SWISS rectifier unit, the SWISS rectifier unit comprising:
[0018] The anode of the first rectifier diode is connected to the cathode of the second rectifier diode and the other end of the first filter inductor, respectively.
[0019] The anode of the third rectifier diode is connected to the cathode of the fourth rectifier diode and the other end of the second filter inductor, respectively.
[0020] The fifth rectifier diode, the anode of which is connected to the cathode of the sixth rectifier diode and the other end of the first filter inductor;
[0021] The first transistor and the second transistor share a common source, and the drain of the first transistor is connected to the anode of the first rectifier diode and the cathode of the second rectifier diode, respectively.
[0022] The third transistor shares a common source with the fourth transistor, and the drain of the third transistor is connected to the anode of the third rectifier diode and the cathode of the fourth rectifier diode, respectively.
[0023] The fifth transistor shares a common source with the sixth transistor, and the drain of the fifth transistor is connected to the anode of the fifth rectifier diode and the cathode of the sixth rectifier diode, respectively.
[0024] The first power transistor has its drain connected to the cathodes of the first rectifier diode, the third rectifier diode, and the fifth rectifier diode, respectively, and its source connected to the cathode of the first freewheeling diode.
[0025] The second power transistor has its source connected to the anodes of the second rectifier diode, the fourth rectifier diode, and the sixth rectifier diode, respectively, and its drain connected to the anode of the second freewheeling diode.
[0026] The gates of the first power transistor, the second power transistor, the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, and the sixth transistor are respectively connected to the ground control unit;
[0027] The first step-down energy storage inductor has one end connected to the cathode of the first freewheeling diode and the other end connected to the positive terminal of the fourth filter capacitor.
[0028] The second step-down energy storage inductor has one end connected to the anode of the second freewheeling diode and the other end connected to the cathode of the fifth filter capacitor.
[0029] The positive terminal of the fifth filter capacitor is connected to the negative terminal of the fourth filter capacitor, the anode of the first freewheeling diode, the cathode of the second freewheeling diode, the drain of the second transistor, the drain of the fourth transistor, and the drain of the sixth transistor, respectively.
[0030] The other ends of the first step-down energy storage inductor and the second step-down energy storage inductor are also connected to the input terminal of the flow-controlled inverter unit.
[0031] Preferably, the ground charging terminal further includes a ground control unit connected to the SWISS rectifier unit, the SWISS rectifier unit comprising:
[0032] The anode of the first rectifier diode is connected to the cathode of the second rectifier diode and the other end of the first filter inductor, respectively.
[0033] The anode of the third rectifier diode is connected to the cathode of the fourth rectifier diode and the other end of the second filter inductor, respectively.
[0034] The fifth rectifier diode, the anode of which is connected to the cathode of the sixth rectifier diode and the other end of the first filter inductor;
[0035] The first transistor and the second transistor share a common source, and the drain of the first transistor is connected to the anode of the first rectifier diode and the cathode of the second rectifier diode, respectively.
[0036] The third transistor shares a common source with the fourth transistor, and the drain of the third transistor is connected to the anode of the third rectifier diode and the cathode of the fourth rectifier diode, respectively.
[0037] The fifth transistor shares a common source with the sixth transistor, and the drain of the fifth transistor is connected to the anode of the fifth rectifier diode and the cathode of the sixth rectifier diode, respectively.
[0038] The gates of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, and the sixth transistor are respectively connected to the ground control unit;
[0039] The first step-down energy storage inductor has one end connected to the positive terminal of the fourth filter capacitor;
[0040] The second step-down energy storage inductor has one end connected to the negative terminal of the fifth filter capacitor;
[0041] The positive terminal of the fifth filter capacitor is connected to the negative terminal of the fourth filter capacitor, the drain of the second transistor, the drain of the fourth transistor, and the drain of the sixth transistor, respectively.
[0042] The other ends of the first step-down energy storage inductor and the second step-down energy storage inductor are also connected to the input terminal of the flow-controlled inverter unit.
[0043] Preferably, the AC input power supply is a single-phase AC power supply, with the live wire of the single-phase AC power supply connected to one end of the first filter inductor, the second filter inductor, and the third filter inductor, respectively, and the neutral wire of the single-phase AC power supply connected to the drain of the second transistor, the fourth transistor, the sixth transistor, the negative terminal of the fourth filter capacitor, and the positive terminal of the fifth filter capacitor, respectively.
[0044] Preferably, the flow-controlled inverter unit includes:
[0045] The seventh transistor has its drain connected to one output terminal of the SWISS rectifier unit and its source connected to one end of the primary winding of the first high-frequency isolation transformer.
[0046] The eighth transistor has its drain connected to one end of the primary winding of the first high-frequency isolation transformer and its source connected to the other output terminal of the SWISS rectifier unit.
[0047] The ninth transistor has its drain connected to one output terminal of the SWISS rectifier unit, and its source connected to the other end of the primary winding of the first high-frequency isolation transformer via a first DC blocking capacitor.
[0048] The tenth transistor has its drain connected to the other end of the primary winding of the first high-frequency isolation transformer via the first DC blocking capacitor, and its source connected to the other output terminal of the SWISS rectifier unit.
[0049] The eleventh transistor has its drain connected to one output terminal of the SWISS rectifier unit and its source connected to one end of the primary winding of the second high-frequency isolation transformer.
[0050] The twelfth transistor has its drain connected to one end of the primary winding of the first high-frequency isolation transformer, and its source connected to the other output terminal of the SWISS rectifier unit.
[0051] The thirteenth transistor has its drain connected to one output terminal of the SWISS rectifier unit, and its source connected to the other end of the primary winding of the second high-frequency isolation transformer via a second DC blocking capacitor.
[0052] The fourteenth transistor, the drain of which is connected to the other end of the primary winding of the second high-frequency isolation transformer through the second DC blocking capacitor, and the source of which is connected to the other output terminal of the SWISS rectifier unit;
[0053] The ground control unit is connected to the gates of the seventh transistor, the eighth transistor, the ninth transistor, the tenth transistor, the eleventh transistor, the twelfth transistor, the thirteenth transistor, and the fourteenth transistor, respectively.
[0054] The primary windings of the first and second high-frequency isolation transformers are connected to the input terminal of the ground-side isolation resonant unit.
[0055] Preferably, the ground-side isolation resonant unit includes:
[0056] A first resonant capacitor, one end of which is connected to one end of the secondary coil of the first high-frequency isolation transformer, and the other end of which is connected to one end of the secondary coil of the second high-frequency isolation transformer.
[0057] A second resonant capacitor, one end of which is connected to one end of the first resonant capacitor, and the other end of which is connected to one end of the ground coil;
[0058] A third resonant capacitor, one end of which is connected to the other end of the first resonant capacitor, and the other end of which is connected to the other end of the ground coil.
[0059] Preferably, the vehicle-mounted resonant unit includes:
[0060] The vehicle end coil has one end connected to one end of a fourth resonant capacitor and the other end connected to one end of a fifth resonant capacitor.
[0061] A sixth resonant capacitor, one end of which is connected to the other end of the fourth resonant capacitor and one end of the first resonant inductor, the other end of which is connected to the other end of the fifth resonant capacitor and one end of the second resonant inductor, and the other ends of the first resonant inductor and the second resonant inductor are connected to the input terminal of the vehicle-mounted rectifier unit.
[0062] Preferably, the on-board charging terminal further includes an on-board control unit connected to the on-board rectifier unit, the on-board rectifier unit comprising:
[0063] The third power transistor has its source connected to the negative terminal of the vehicle battery, its drain connected to the anode of the seventh rectifier diode, its cathode connected to the anode of the vehicle battery, and its gate connected to the vehicle control unit.
[0064] The fourth power transistor has its source connected to one end of the sixth filter capacitor and the negative terminal of the vehicle battery, its drain connected to the anode of the eighth rectifier diode, its cathode connected to the other end of the sixth filter capacitor and the anode of the vehicle battery, and its gate connected to the vehicle control unit.
[0065] The above technical solution has the following advantages or beneficial effects:
[0066] 1) It adopts the Swiss rectifier topology, which overcomes the problems of low wireless charging efficiency, large grid pollution, narrow battery charging range, and large alignment error between ground and vehicle coils;
[0067] 2) It adopts single-phase and three-phase compatible charging, which meets the dual needs of users for three-phase AC fast charging and single-phase slow charging. It combines two charging devices into one charging device, reducing the number of charging devices and saving users space and costs. Attached Figure Description
[0068] Figure 1 This is a schematic diagram of the structure of the wireless charging system for electric vehicles in Example 1;
[0069] Figure 2 This is a schematic diagram of the structure of the wireless charging system for electric vehicles in Example 2;
[0070] Figure 3 This is a schematic diagram of the structure of the wireless charging system for electric vehicles in Example 3;
[0071] Figure 4 This is a schematic diagram of the structure of the wireless charging system for electric vehicles in Example 4. Detailed Implementation
[0072] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within the scope of the present invention.
[0073] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a wireless charging system for electric vehicles is provided, such as... Figures 1 to 4 As shown, it includes:
[0074] Ground charging terminal, the ground charging terminal includes:
[0075] The filter unit 11 has its input terminal connected to an external AC input power supply, and its output terminal connected to the input terminal of the SWISS rectifier unit 12. The SWISS rectifier unit 12 is used to convert the AC power output from the AC input power supply after filtering by the filter unit 11 into DC power.
[0076] The input terminal of the flow-controlled inverter unit 13 is connected to the output terminal of the SWISS rectifier unit 12, and is used to convert DC power into a high-frequency pulse signal.
[0077] Ground-end isolation resonant unit 14, the input end of which is connected to the output end of flow-controlled inverter unit 13, is used to convert high-frequency pulse signals into resonant signals and output them;
[0078] The vehicle-mounted charging terminal wirelessly connects to the ground charging terminal. The vehicle-mounted charging terminal includes:
[0079] The vehicle-mounted resonant unit 21 has its output connected to the input of the vehicle-mounted rectifier unit 22, and its output connected to the vehicle battery B. The vehicle-mounted resonant unit 21 is used to receive the resonant signal and convert it into a corresponding pulse signal, while the vehicle-mounted rectifier unit 22 is used to rectify the pulse signal and charge the vehicle battery.
[0080] Example 1
[0081] like Figure 1 As shown, the filter unit 11 includes:
[0082] The first filter inductor La1 has one end connected to the AC input power supply and the other end grounded through the first filter capacitor Ca1.
[0083] The second filter inductor La2 has one end connected to the AC input power supply and the other end grounded through the second filter capacitor Ca2.
[0084] The third filter inductor La3 has one end connected to the AC input power supply and the other end grounded through the third filter capacitor Ca3.
[0085] The other ends of the first filter inductor La1, the second filter inductor La2, and the third filter inductor La3 are also connected to the input terminal of the SWISS rectifier unit 12.
[0086] The AC input power supply is a three-phase AC power supply. Phase A of the three-phase AC power supply is connected to one end of the first filter inductor La1, phase B of the three-phase AC power supply is connected to one end of the second filter inductor La2, and phase C of the three-phase AC power supply is connected to one end of the third filter inductor La3.
[0087] Furthermore, the ground charging terminal also includes a ground control unit 15, connected to the SWISS rectifier unit 12, which includes:
[0088] The anode of the first rectifier diode Da1 is connected to the cathode of the second rectifier diode Da2 and the other end of the first filter inductor La1, respectively.
[0089] The anode of the third rectifier diode Da3 is connected to the cathode of the fourth rectifier diode Da4 and the other end of the second filter inductor La2.
[0090] The anode of the fifth rectifier diode Da5 is connected to the cathode of the sixth rectifier diode Da6 and the other end of the first filter inductor La1, respectively.
[0091] The first transistor Sa1 and the second transistor Sa2 share a common source. The drain of the first transistor Sa1 is connected to the anode of the first rectifier diode Da1 and the cathode of the second rectifier diode Da2.
[0092] The third transistor Sa3 and the fourth transistor Sa4 share the same source. The drain of the third transistor Sa3 is connected to the anode of the third rectifier diode Da3 and the cathode of the fourth rectifier diode Da4, respectively.
[0093] The fifth transistor Sa5 and the sixth transistor Sa6 share a common source. The drain of the fifth transistor Sa5 is connected to the anode of the fifth rectifier diode Da5 and the cathode of the sixth rectifier diode Da6, respectively.
[0094] The drain of the first power transistor Qp is connected to the cathodes of the first rectifier diode Da1, the third rectifier diode Da3 and the fifth rectifier diode Da5 respectively, and the source of the first power transistor Qp is connected to the cathode of the first freewheeling diode Dp.
[0095] The source of the second power transistor Qn is connected to the anodes of the second rectifier diode Da2, the fourth rectifier diode Da4 and the sixth rectifier diode Da6 respectively, and the drain of the second power transistor Qn is connected to the anode of the second freewheeling diode Dn.
[0096] The gates of the first power transistor Qp, the second power transistor Qn, the first transistor Sa1, the second transistor Sa2, the third transistor Sa3, the fourth transistor Sa4, the fifth transistor Sa5, and the sixth transistor Sa6 are respectively connected to the ground control unit 15;
[0097] The first step-down energy storage inductor Lp has one end connected to the cathode of the first freewheeling diode Dp, and the other end connected to the positive terminal of the fourth filter capacitor Cp.
[0098] The second step-down energy storage inductor Ln has one end connected to the anode of the second freewheeling diode Dn, and the other end connected to the cathode of the fifth filter capacitor Cn.
[0099] The positive terminal of the fifth filter capacitor Cn is connected to the negative terminal of the fourth filter capacitor Cp, the anode of the first freewheeling diode Dp, the cathode of the second freewheeling diode Dn, the drain of the second transistor Sa2, the drain of the fourth transistor Sa4, and the drain of the sixth transistor Sa6, respectively.
[0100] The other ends of the first buck energy storage inductor Lp and the second buck energy storage inductor Ln are also connected to the input terminal of the current control inverter unit 13.
[0101] Furthermore, the flow-controlled inverter unit 13 includes:
[0102] The drain of the seventh transistor Sa7 is connected to one output terminal of the SWISS rectifier unit, and the source of the seventh transistor Sa7 is connected to one end of the primary winding Ta1 of the first high-frequency isolation transformer.
[0103] The drain of the eighth transistor Sa8 is connected to one end of the primary winding Ta1 of the first high-frequency isolation transformer, and the source of the eighth transistor Sa8 is connected to the other output terminal of the SWISS rectifier unit.
[0104] The drain of the ninth transistor Sa9 is connected to one output terminal of the SWISS rectifier unit, and the source of the ninth transistor Sa9 is connected to the other end of the primary winding Ta1 of the first high-frequency isolation transformer through the first DC blocking capacitor Ca1.
[0105] The drain of the tenth transistor Sa10 is connected to the other end of the primary winding Ta1 of the first high-frequency isolation transformer through the first DC blocking capacitor Ca1, and the source of the tenth transistor Sa10 is connected to the other output terminal of the SWISS rectifier unit.
[0106] The eleventh transistor Sa11 has its drain connected to one output terminal of the SWISS rectifier unit, and its source connected to one end of the primary winding Ta2 of the second high-frequency isolation transformer.
[0107] The twelfth transistor Sa12 has its drain connected to one end of the primary winding Ta1 of the first high-frequency isolation transformer, and its source connected to the other output terminal of the SWISS rectifier unit.
[0108] The thirteenth transistor Sa13 has its drain connected to one output terminal of the SWISS rectifier unit, and its source is connected to the other end of the primary winding Ta2 of the second high-frequency isolation transformer through the second DC blocking capacitor Ca2.
[0109] The drain of the fourteenth transistor Sa14 is connected to the other end of the primary winding Ta2 of the second high-frequency isolation transformer through the second DC blocking capacitor Ca2, and the source of the fourteenth transistor Sa14 is connected to the other output terminal of the SWISS rectifier unit.
[0110] The ground control unit 15 is connected to the gates of the seventh transistor Sa7, the eighth transistor Sa8, the ninth transistor Sa9, the tenth transistor Sa10, the eleventh transistor Sa11, the twelfth transistor Sa12, the thirteenth transistor Sa13, and the fourteenth transistor Sa14, respectively.
[0111] The primary windings of the first and second high-frequency isolation transformers are connected to the input terminal of the ground-side isolation resonant unit 14.
[0112] Furthermore, the ground-side isolation resonant unit 14 includes:
[0113] The first resonant capacitor Cg1 is connected at one end to one end of the secondary coil Tb1 of the first high-frequency isolation transformer, and at the other end to one end of the secondary coil Tb2 of the second high-frequency isolation transformer. The other end of the secondary coil Tb1 of the first high-frequency isolation transformer is connected to the other end of the secondary coil Tb2 of the second high-frequency isolation transformer.
[0114] The second resonant capacitor Cg2 is connected to one end of the first resonant capacitor Cg1, and the other end of the second resonant capacitor Cg2 is connected to one end of the ground coil Lg.
[0115] The third resonant capacitor Cg3 is connected at one end to the other end of the first resonant capacitor Cg1, and at the other end of the third resonant capacitor Cg3 is connected to the other end of the ground coil Lg.
[0116] Furthermore, the on-board resonant unit 21 includes:
[0117] The end coil Lv is connected to one end of the fourth resonant capacitor Cv2, and the other end of the end coil Lv is connected to one end of the fifth resonant capacitor Cv3.
[0118] The sixth resonant capacitor Cv1 is connected to the other end of the fourth resonant capacitor Cv2 and the first resonant inductor Lv1. The other end of the sixth resonant capacitor Cv1 is connected to the other end of the fifth resonant capacitor Cv3 and the second resonant inductor Lv2. The other ends of the first resonant inductor Lv1 and the second resonant inductor Lv2 are connected to the input terminal of the vehicle-mounted rectifier unit 22.
[0119] Furthermore, the on-board charging terminal also includes an on-board control unit 23, connected to the on-board rectifier unit 22, which includes:
[0120] The third power transistor Qr1 has its source connected to the negative terminal of the car battery B, its drain connected to the anode of the seventh rectifier diode Da7, its cathode connected to the anode of the car battery B, and its gate connected to the vehicle control unit 15.
[0121] The source of the fourth power transistor Qr2 is connected to one end of the sixth filter capacitor Cd and the negative terminal of the car battery B, respectively. The drain of the fourth power transistor Qr2 is connected to the anode of the eighth rectifier diode Da8, and the cathode of the eighth rectifier diode Da8 is connected to the other end of the sixth filter capacitor Cd and the anode of the car battery B, respectively. The gate of the fourth power transistor Qr2 is connected to the vehicle control unit 23.
[0122] Specifically, in this embodiment, the definitions of each transistor and each power transistor are only for easy distinction. In actual application scenarios, each transistor and each power transistor can be a power semiconductor transistor including but not limited to MOSFET, SiC MOSFET, JEFT, bipolar transistor, IGBT (Insulated Gate Bipolar Transistor).
[0123] More specifically, when the external power input to the car wireless charging system is a three-phase AC power supply, the input power lines (yellow, green, and red) can be manually connected to terminals A, B, and C of this system. The three-phase AC power is input to an EMI (electromagnetic interference) filter (not covered in this technical solution and will not be described further here), and after filtering, it is connected to filter unit 11, and then to SWISS rectifier unit 12. SWISS rectifier unit 12, based on the SWISS rectifier topology, converts the three-phase AC power into DC voltage to power the subsequent current-controlled inverter unit 13 and the ground-side isolation resonant unit 14. SWISS rectifier unit 12 is a single-phase, three-phase AC / DC rectifier with power factor correction function, possessing unique advantages such as high power factor, low switching loss, low input harmonics, and high-efficiency regulation.
[0124] More specifically, the SWISS rectifier unit 12 consists of a four-quadrant, third harmonic current injection circuit network composed of a three-phase rectifier bridge and three sets of power transistors. This network is responsible for injecting low-frequency current into the system. Specifically, it switches the current path of the injection network at twice the power supply frequency, and then injects the current into the passive phase (the phase through which no current flows) through the high-frequency switching transistors Qp and Qn, the freewheeling diodes Dp and Dn, the step-down energy storage inductors Lp and Ln, and the negative terminal of the upper half bus and the positive terminal Cn of the lower half bus, i.e., the midpoint of the output bus of the SWISS rectifier unit 12. The difference in current flowing through the power switching transistors Qp and Qn is fed to the passive phase through an active third harmonic injection circuit network (a circuit composed of Sa1, Sa2, Sb1, Sb2, Sc1, and Sc2). In this way, the external injection circuit network and the modulation method of the high-frequency power switching transistors Qp and Qn can ensure that the DC bus voltage is adjustable across the entire range, that the voltages across the bus capacitors Cp and Cn are equal, and that the sinusoidal nature of the grid-side current is guaranteed, thereby reducing THD (Total Harmonic Distortion), increasing PF (Power Factor), and reducing pollution to the power grid.
[0125] More preferably, the first transistor Sa1, the second transistor Sa2, the third transistor Sa3, the fourth transistor Sa4, the fifth transistor Sa5, and the sixth transistor Sa6 can be common-source MOSFETs (metal-oxide-semiconductor field-effect transistors) in this embodiment, or they can be common-emitter IGBTs (insulated-gate transistors).
[0126] The SWISS rectifier unit 12 delivers the rectified DC power to the flow control inverter unit 13 to convert the DC power into a high-frequency pulse voltage, generate a high-frequency resonant pulse, and transmit the energy from the ground end to the vehicle end. The current-controlled inverter unit 13 includes two independent bridge inverters. The first inverter includes Sa7, Sa8, Sa9, Sa10, DC blocking capacitor Ca1, and the primary side of isolation transformer T1. It converts the DC voltage output from the SWISS rectifier unit 12 into a square wave voltage (e.g., 85kHz, the switching frequency in this embodiment) and a sinusoidal current signal, and transmits the energy to the ground-side isolation resonant unit 14. The second inverter includes Sa11, Sa12, Sa13, Sa14, DC blocking capacitor Ca2, and the primary side of isolation transformer T2. When the data is transmitted from the vehicle control unit 23 to the DSP (Digital Signal Processing) of the ground control unit 15 via WIFI, and the DSP receives a request from the battery to adjust the current or voltage, this inverter adjusts the PWM phase shift angle to change the output power according to the demand. This achieves a current-controlled inverter unit 13 with adjustable total output current (current control in this example, but voltage control is also possible).
[0127] The ground-side isolation resonant unit 14 is responsible for the high-frequency pulse signal sent by the flow control inverter unit 13. Through the series connection of the secondary side Tb1 and secondary side Tb2 of the transformer, Cg1, Cg2, Cg2, and the ground coil Lg, a high-frequency resonant network is formed to transform the high-frequency square wave signal into a sinusoidal high-voltage resonant signal, and the energy of the ground coil Lg is transmitted to the vehicle coil Lv.
[0128] The on-board resonant unit 21 is responsible for collecting the sinusoidal high-voltage resonant energy transmitted from the ground coil Lg into the on-board coil Lv. Through the on-board coils Lv, Cv2, Cv3, Cv1, Lv1, and Lv2 forming a high-frequency resonant network, the sinusoidal high-voltage resonant signal is converted into a low-voltage, high-current pulse signal, which is then sent to the on-board rectifier unit 22. The on-board rectifier unit 22 is responsible for rectifying the low-voltage, high-current pulse signal, converting it into DC voltage through rectifier diodes Da7 and Da8, controllable power MOSFETs Qr1 and Qr2, and filter capacitor Cd, to charge the car battery B1.
[0129] The ground control unit 15 is responsible for detecting the AC input voltage and current, and the DC output voltage and current, and sending them to the microprocessor of the ground control unit 15. The microprocessor outputs a PWM signal to the driver board, which drives the power transistor to turn on and off, so that the energy is converted from AC to DC, and then from DC to a high-frequency pulse signal. The sinusoidal high-voltage resonant signal is then continuously transmitted to the vehicle coil Lv through the vehicle-mounted resonant unit 21.
[0130] The vehicle control unit 23 is responsible for taking the sinusoidal high-voltage resonant signal of the ground coil Lg, sending it to the microprocessor of the vehicle control unit 23 through the vehicle-side resonant unit 21 and the current detection sensor to collect the weak signal, outputting a PWM signal, and controlling the power transistors Qr1 and Qr2 in the vehicle-side rectifier unit 22 to turn on and off, so as to realize the conversion of energy from low-voltage pulse signal to DC voltage to charge battery B1.
[0131] Example 2
[0132] like Figure 2 As shown, when the AC input power supply is a single-phase AC power supply, the live wire of the single-phase AC power supply is connected to one end of the first filter inductor La1, the second filter inductor La2, and the third filter inductor La3, respectively. The neutral wire of the single-phase AC power supply is connected to the drain of the second transistor Sa2, the fourth transistor Sa4, the sixth transistor S6a, the negative terminal of the fourth filter capacitor Cp, and the positive terminal of the fifth filter capacitor Cn, respectively. The rest of the circuit structure is the same as in Embodiment 1.
[0133] As can be seen from Embodiments 1 and 2, this technical solution adopts a charging method that is compatible with both single-phase and three-phase inputs. When the external power input to the car wireless charging system is a single-phase AC power supply, the input power line, yellow and blue wires can be manually connected to the L and N terminals of this system. The single-phase AC power is input to the EMI (electromagnetic interference) filter (not related to this technical solution, and will not be described in detail here), and after filtering, it is connected to the filter unit 11, and after filtering, it is connected to the SWISS rectifier unit 12.
[0134] In summary, this technical solution conveniently meets the dual needs of users: both three-phase AC fast charging (e.g., on highways or in parking lots) and single-phase slow charging (e.g., at home or on the road when encountering a power shortage). It combines two charging devices into one, reducing the need for a separate charging system and saving users space and costs. Meanwhile, the SWISS rectifier unit 12 uses power frequency regulation, resulting in low switching losses and low voltage stress on components. It employs two sets of dual-buck converters to achieve wide-range adjustment functionality. By combining two sets of current-controlled inverters and adjusting the PWM phase shift angle, it cleverly solves the problems of uncontrollable current magnitude and misalignment between the vehicle and the ground. Through these technical solutions, low cost, high efficiency, and wide-range adjustment functionality are achieved.
[0135] Example 3
[0136] like Figure 3 As shown, based on Embodiment 1, the circuit structure of the SWISS rectifier unit is further improved. Specifically, the ground charging terminal also includes a ground control unit 15, which is connected to the SWISS rectifier unit 12. The SWISS rectifier unit 12 includes:
[0137] The anode of the first rectifier diode Da1 is connected to the cathode of the second rectifier diode Da2 and the other end of the first filter inductor La1, respectively.
[0138] The anode of the third rectifier diode Da3 is connected to the cathode of the fourth rectifier diode Da4 and the other end of the second filter inductor La2.
[0139] The anode of the fifth rectifier diode Da5 is connected to the cathode of the sixth rectifier diode Da6 and the other end of the first filter inductor La1, respectively.
[0140] The first transistor Sa1 and the second transistor Sa2 share a common source. The drain of the first transistor Sa1 is connected to the anode of the first rectifier diode Da1 and the cathode of the second rectifier diode Da2.
[0141] The third transistor Sa3 and the fourth transistor Sa4 share the same source. The drain of the third transistor Sa3 is connected to the anode of the third rectifier diode Da3 and the cathode of the fourth rectifier diode Da4, respectively.
[0142] The fifth transistor Sa5 and the sixth transistor Sa6 share a common source. The drain of the fifth transistor Sa5 is connected to the anode of the fifth rectifier diode Da5 and the cathode of the sixth rectifier diode Da6, respectively.
[0143] The gates of the first transistor Sa1, the second transistor Sa2, the third transistor Sa3, the fourth transistor Sa4, the fifth transistor Sa5, and the sixth transistor Sa6 are respectively connected to the ground control unit 15;
[0144] The first step-down energy storage inductor Lp, one end of which is connected to the positive terminal of the fourth filter capacitor Cp;
[0145] The second step-down energy storage inductor Ln has one end connected to the negative terminal of the fifth filter capacitor Cn;
[0146] The positive terminal of the fifth filter capacitor Cn is connected to the negative terminal of the fourth filter capacitor Cp, the drain of the second transistor Sa2, the drain of the fourth transistor Sa4, and the drain of the sixth transistor Sa6, respectively.
[0147] The other ends of the first buck energy storage inductor Lp and the second buck energy storage inductor Ln are also connected to the input terminal of the current control inverter unit 13.
[0148] Based on this, a capacitor Cil is added to the current-controlled inverter unit 13. One end of the capacitor Cil is connected to the other end of the first step-down energy storage inductor Lp of the SWISS rectifier unit 12 and is connected to the drain of the thirteenth transistor Sa13, the drain of the seventh transistor Sa7, and the drain of the ninth transistor Sa9. The other end of the capacitor Cil is connected to the other end of the second step-down energy storage inductor Ln of the SWISS rectifier unit 12 and is connected to the source of the tenth transistor Sa10, the source of the twelfth transistor Sa12, and the source of the fourteenth transistor Sa14.
[0149] Specifically, in this embodiment, the SWISS rectifier unit adopts power frequency regulation, which has low switching loss and low device voltage stress. By using two sets of current-controlled inverters and adjusting the PWM phase shift angle, the problems of uncontrollable current magnitude and inaccurate alignment between vehicle and ground are cleverly solved. Through the above technical solutions, low-cost, high-efficiency and high-efficiency regulation functions are achieved.
[0150] Example 4
[0151] like Figure 4 As shown, based on Embodiment 3, when the AC input power supply is a single-phase AC power supply, the live wire of the single-phase AC power supply is connected to one end of the first filter inductor La1, the second filter inductor La2, and the third filter inductor La3, respectively. The neutral wire of the single-phase AC power supply is connected to the drain of the second transistor Sa2, the fourth transistor Sa4, the sixth transistor S6a, the negative terminal of the fourth filter capacitor Cp, and the positive terminal of the fifth filter capacitor Cn, respectively. The rest of the circuit structure is the same as in Embodiment 3.
[0152] As can be seen from Embodiments 3 and 4, this technical solution adopts a charging method that is compatible with both single-phase and three-phase inputs. When the external power input to the car wireless charging system is a single-phase AC power supply, the input power line, yellow and blue wires can be manually connected to the L and N terminals of this system. The single-phase AC power is input to the EMI (electromagnetic interference) filter (not related to this technical solution, and will not be described in detail here), and after filtering, it is connected to the filter unit 11, and after filtering, it is connected to the SWISS rectifier unit 12.
[0153] In summary, this technical solution conveniently meets the dual needs of users: both three-phase AC fast charging (e.g., on highways or in parking lots) and single-phase slow charging (e.g., at home or on the road when encountering a power shortage). It combines two charging devices into one, reducing the need for a separate charging system and saving users space and costs. Meanwhile, the SWISS rectifier unit 12 employs power frequency regulation, resulting in low switching losses and low voltage stress on components. By combining two sets of current-controlled inverters and adjusting the PWM phase shift angle, it cleverly solves the problems of uncontrollable current magnitude and misalignment between the vehicle and the ground. Through these technical solutions, low-cost, high-efficiency, and wide-range adjustment functions are achieved.
[0154] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present invention.
Claims
1. A wireless charging system for electric vehicles, characterized in that, include: Ground charging terminal, the ground charging terminal includes: A filtering unit is provided, the input of which is connected to an external AC input power supply, and the output of which is connected to the input of a SWISS rectifier unit. The SWISS rectifier unit is used to convert the AC power output from the AC input power supply after being filtered by the filtering unit into DC power. A flow-controlled inverter unit, the input of which is connected to the output of the SWISS rectifier unit, is used to convert the DC power into a high-frequency pulse signal; A ground-side isolation resonant unit, the input of which is connected to the output of the flow-controlled inverter unit, is used to convert the high-frequency pulse signal into a resonant signal and output it. The vehicle-mounted charging terminal is wirelessly connected to the ground-based charging terminal, and the vehicle-mounted charging terminal includes: The vehicle-mounted resonant unit has its output connected to the input of a vehicle-mounted rectifier unit, and the output of the vehicle-mounted rectifier unit is connected to the vehicle battery. The vehicle-mounted resonant unit is used to receive the resonant signal and convert it into a corresponding pulse signal. The vehicle-mounted rectifier unit is used to rectify the pulse signal and charge the vehicle battery. The filtering unit includes: A first filter inductor, one end of which is connected to the AC input power supply, and the other end of which is grounded through a first filter capacitor; The second filter inductor has one end connected to the AC input power supply and the other end grounded through the second filter capacitor. The third filter inductor has one end connected to the AC input power supply and the other end grounded through the third filter capacitor. The other ends of the first filter inductor, the second filter inductor, and the third filter inductor are also connected to the input terminal of the SWISS rectifier unit; The ground charging terminal also includes a ground control unit connected to the SWISS rectifier unit, which includes: The anode of the first rectifier diode is connected to the cathode of the second rectifier diode and the other end of the first filter inductor, respectively. The anode of the third rectifier diode is connected to the cathode of the fourth rectifier diode and the other end of the second filter inductor, respectively. The fifth rectifier diode, the anode of which is connected to the cathode of the sixth rectifier diode and the other end of the first filter inductor; The first transistor and the second transistor share a common source, and the drain of the first transistor is connected to the anode of the first rectifier diode and the cathode of the second rectifier diode, respectively. The third transistor shares a common source with the fourth transistor, and the drain of the third transistor is connected to the anode of the third rectifier diode and the cathode of the fourth rectifier diode, respectively. The fifth transistor shares a common source with the sixth transistor, and the drain of the fifth transistor is connected to the anode of the fifth rectifier diode and the cathode of the sixth rectifier diode, respectively. The first power transistor has its drain connected to the cathodes of the first rectifier diode, the third rectifier diode, and the fifth rectifier diode, respectively, and its source connected to the cathode of the first freewheeling diode. The second power transistor has its source connected to the anodes of the second rectifier diode, the fourth rectifier diode, and the sixth rectifier diode, respectively, and its drain connected to the anode of the second freewheeling diode. The gates of the first power transistor, the second power transistor, the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, and the sixth transistor are respectively connected to the ground control unit; The first step-down energy storage inductor has one end connected to the cathode of the first freewheeling diode and the other end connected to the positive terminal of the fourth filter capacitor. The second step-down energy storage inductor has one end connected to the anode of the second freewheeling diode and the other end connected to the cathode of the fifth filter capacitor. The positive terminal of the fifth filter capacitor is connected to the negative terminal of the fourth filter capacitor, the anode of the first freewheeling diode, the cathode of the second freewheeling diode, the drain of the second transistor, the drain of the fourth transistor, and the drain of the sixth transistor, respectively. The other ends of the first step-down energy storage inductor and the second step-down energy storage inductor are also connected to the input terminal of the flow-controlled inverter unit; Alternatively, the SWISS rectifier unit includes: The anode of the first rectifier diode is connected to the cathode of the second rectifier diode and the other end of the first filter inductor, respectively. The anode of the third rectifier diode is connected to the cathode of the fourth rectifier diode and the other end of the second filter inductor, respectively. The fifth rectifier diode, the anode of which is connected to the cathode of the sixth rectifier diode and the other end of the first filter inductor; The first transistor and the second transistor share a common source, and the drain of the first transistor is connected to the anode of the first rectifier diode and the cathode of the second rectifier diode, respectively. The third transistor shares a common source with the fourth transistor, and the drain of the third transistor is connected to the anode of the third rectifier diode and the cathode of the fourth rectifier diode, respectively. The fifth transistor shares a common source with the sixth transistor, and the drain of the fifth transistor is connected to the anode of the fifth rectifier diode and the cathode of the sixth rectifier diode, respectively. The gates of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, and the sixth transistor are respectively connected to the ground control unit; The first step-down energy storage inductor has one end connected to the positive terminal of the fourth filter capacitor; The second step-down energy storage inductor has one end connected to the negative terminal of the fifth filter capacitor; The positive terminal of the fifth filter capacitor is connected to the negative terminal of the fourth filter capacitor, the drain of the second transistor, the drain of the fourth transistor, and the drain of the sixth transistor, respectively. The other ends of the first step-down energy storage inductor and the second step-down energy storage inductor are also connected to the input terminal of the flow-controlled inverter unit.
2. The wireless charging system for electric vehicles according to claim 1, characterized in that, The AC input power supply is a three-phase AC power supply. Phase A of the three-phase AC power supply is connected to one end of the first filter inductor, phase B of the three-phase AC power supply is connected to one end of the second filter inductor, and phase C of the three-phase AC power supply is connected to one end of the third filter inductor.
3. The wireless charging system for electric vehicles according to claim 1, characterized in that, The AC input power supply is a single-phase AC power supply. The live wire of the single-phase AC power supply is connected to one end of the first filter inductor, the second filter inductor, and the third filter inductor, respectively. The neutral wire of the single-phase AC power supply is connected to the drain of the second transistor, the fourth transistor, the sixth transistor, the negative terminal of the fourth filter capacitor, and the positive terminal of the fifth filter capacitor, respectively.
4. The wireless charging system for electric vehicles according to claim 1, characterized in that, The flow-controlled inverter unit includes: The seventh transistor has its drain connected to one output terminal of the SWISS rectifier unit and its source connected to one end of the primary winding of the first high-frequency isolation transformer. The eighth transistor has its drain connected to one end of the primary winding of the first high-frequency isolation transformer and its source connected to the other output terminal of the SWISS rectifier unit. The ninth transistor has its drain connected to one output terminal of the SWISS rectifier unit, and its source connected to the other end of the primary winding of the first high-frequency isolation transformer via a first DC blocking capacitor. The tenth transistor has its drain connected to the other end of the primary winding of the first high-frequency isolation transformer via the first DC blocking capacitor, and its source connected to the other output terminal of the SWISS rectifier unit. The eleventh transistor has its drain connected to one output terminal of the SWISS rectifier unit and its source connected to one end of the primary winding of the second high-frequency isolation transformer. The twelfth transistor has its drain connected to one end of the primary winding of the first high-frequency isolation transformer, and its source connected to the other output terminal of the SWISS rectifier unit. The thirteenth transistor has its drain connected to one output terminal of the SWISS rectifier unit, and its source connected to the other end of the primary winding of the second high-frequency isolation transformer via a second DC blocking capacitor. The fourteenth transistor, the drain of which is connected to the other end of the primary winding of the second high-frequency isolation transformer through the second DC blocking capacitor, and the source of which is connected to the other output terminal of the SWISS rectifier unit; The ground control unit is connected to the gates of the seventh transistor, the eighth transistor, the ninth transistor, the tenth transistor, the eleventh transistor, the twelfth transistor, the thirteenth transistor, and the fourteenth transistor, respectively. The primary windings of the first and second high-frequency isolation transformers are connected to the input terminal of the ground-side isolation resonant unit.
5. The wireless charging system for electric vehicles according to claim 4, characterized in that, The ground-end isolation resonant unit includes: A first resonant capacitor, one end of which is connected to one end of the secondary coil of the first high-frequency isolation transformer, and the other end of which is connected to one end of the secondary coil of the second high-frequency isolation transformer. A second resonant capacitor, one end of which is connected to one end of the first resonant capacitor, and the other end of which is connected to one end of the ground coil; A third resonant capacitor, one end of which is connected to the other end of the first resonant capacitor, and the other end of which is connected to the other end of the ground coil.
6. The wireless charging system for electric vehicles according to claim 1, characterized in that, The vehicle-mounted resonant unit includes: The vehicle end coil has one end connected to one end of a fourth resonant capacitor and the other end connected to one end of a fifth resonant capacitor. A sixth resonant capacitor, one end of which is connected to the other end of the fourth resonant capacitor and one end of the first resonant inductor, the other end of which is connected to the other end of the fifth resonant capacitor and one end of the second resonant inductor, and the other ends of the first resonant inductor and the second resonant inductor are connected to the input terminal of the vehicle-mounted rectifier unit.
7. The wireless charging system for electric vehicles according to claim 6, characterized in that, The on-board charging terminal also includes an on-board control unit connected to the on-board rectifier unit, the on-board rectifier unit comprising: The third power transistor has its source connected to the negative terminal of the vehicle battery, its drain connected to the anode of the seventh rectifier diode, its cathode connected to the anode of the vehicle battery, and its gate connected to the vehicle control unit. The fourth power transistor has its source connected to one end of the sixth filter capacitor and the negative terminal of the vehicle battery, its drain connected to the anode of the eighth rectifier diode, its cathode connected to the other end of the sixth filter capacitor and the anode of the vehicle battery, and its gate connected to the vehicle control unit.