Electric vehicle wireless charging device

Abstract

The present invention discloses a wireless charging device for electric vehicles, comprising a wireless energy transmitting device located on the side of a charging pile and an on-board energy receiving device located on the side of the electric vehicle; the primary transmitting coil comprises two symmetrically arranged primary transmitting coils, each connected to two primary resonant circuits with identical structures, wherein a phase delay module is provided between one of the primary resonant circuits and a DC-AC high-frequency inverter circuit, and the phase delay module is used to make the real-time current directions in the two primary transmitting coils consistent; the primary transmitting coil adopts a multi-ring bipolar spiral coil, which comprises three mutually perpendicular annular coils, and a spiral coil is orthogonally provided on the annular coil, and there is no mutual conduction between the three annular coils and between the annular coil and the spiral coil; the present invention can reduce the problem of charging disconnection during wireless charging and improve the success rate of wireless charging.

Description

Technical Field

[0001] The present invention relates to an electric vehicle charging solution, and in particular to an electric vehicle wireless charging device. Background Art

[0002] Conventional electric vehicle charging piles are usually powered by a combination of mains electricity and solar energy, but the charging process requires a series of complex operations. As a new type of wireless charging application device, electric vehicle wireless charging piles charge electric vehicles through wireless charging technology, eliminating the need for owners to prepare their own charging cables and perform wiring operations, thus solving the problem of complex electric vehicle charging operations. However, existing electric vehicle charging piles use planar coils, the energy output of wireless charging devices is highly directional, and the wireless energy transmission efficiency of charging piles is low. Electric vehicle users often encounter charging disconnection when performing wireless charging docking, which hinders the promotion and application of electric vehicle wireless charging piles. In addition, the existing combination of mains electricity and solar energy power supply uses a mode switching circuit, which can only select a single mains electricity or solar power supply, and the efficiency of solar power supply is not high. Summary of the Invention

[0003] Purpose of the invention: In response to the above problems, the present invention proposes a wireless charging device for electric vehicles, which can reduce the problem of charging disconnection during wireless charging, improve the success rate of wireless charging, and further improve the efficiency of solar power supply.

[0004] Technical solution: The technical solution adopted by the present invention is a wireless charging device for electric vehicles, including a wireless energy transmitting device located on the charging pile side and an on-board energy receiving device located on the electric vehicle side; the wireless energy transmitting device includes a power supply module, a battery, a DC-AC high-frequency inverter circuit, a primary resonant circuit and a primary transmitting coil electrically connected in sequence; the primary transmitting coil includes two symmetrically arranged primary transmitting coils, each connected to two primary resonant circuits with the same structure, and a phase delay module is provided at the input end of one of the primary resonant circuits, and the phase delay module is used to make the real-time current direction of the two primary transmitting coils consistent; the primary transmitting coil of the primary resonant circuit A multi-ring bipolar spiral coil is used, which includes three mutually perpendicular ring coils, and a spiral coil is arranged on the ring coil in an orthogonal manner. There is no conduction between the three ring coils and between the ring coils and the spiral coils. The device adopts magnetic coupling resonant wireless charging technology, and realizes power transmission by achieving a resonant state through the primary side transmitting coil and the on-board secondary side receiving coil located in the on-board energy receiving device. During operation, the on-board secondary side receiving coil is located between the two primary side transmitting coils. The output end of the AC-DC rectifier filter circuit in the on-board energy receiving device is connected to the on-board battery, and the transmitted power is stored in the on-board battery for charging.

[0005] Among them, a toroidal coil is rectangular or circular and consists of several turns of conductive coils.

[0006] The on-board energy receiving device includes an on-board secondary receiving coil, a secondary resonant circuit and an AC-DC rectifier filter circuit electrically connected in sequence; the on-board secondary receiving coil adopts a planar ring coil, and when working, the on-board secondary receiving coil is close to the primary transmitting coil on the charging pile side.

[0007] The power supply module adopts a separate mains power supply or a separate solar power supply module, or a mains and solar collaborative power supply module. The device adopting the mains and solar collaborative power supply module also includes a main control unit. One mains and solar collaborative power supply module solution is: a power supply switching circuit is used to connect the solar cell power supply module and the mains port respectively, and the main control unit selects a separate mains power supply or a separate solar power supply by controlling the power supply switching circuit. Another mains and solar collaborative power supply module solution is: a power supply switching circuit with a switch array is used to connect the solar cell power supply module and the mains port respectively, and the main control unit adjusts the proportion of mains power supply and solar power supply by controlling the switch array in the power supply switching circuit. Specifically, a photoresistor is provided between the power supply switching circuit and the solar power supply output end. When there is sufficient light, the main control unit increases the output voltage of the solar energy by increasing the PWM voltage regulation duty cycle of the solar power supply device; when there is insufficient light, the main control unit increases the output voltage of the mains by increasing the mains PWM voltage regulation duty cycle.

[0008] Preferably, the main control unit is further configured to determine the charging status of the battery at the charging station by sampling the voltage and current of the primary resonant circuit within a unit time, and to promptly disconnect the charger when charging is complete. The main control unit is also connected to a liquid crystal module to display the current charging status. An optocoupler isolation circuit is provided between the primary resonant circuit and the main control unit. A lighting device is provided at the battery to provide illumination at night; the lighting device may be a light-emitting diode, a lamp, a display board, or a television screen.

[0009] Beneficial effects: Compared with the existing technology, the patent of this invention solves the problem of easy disconnection of electric vehicle charging. At the same time, it also proposes a symmetrically arranged multi-ring bipolar spiral coil model for existing counter-charging. By using this structure, the spatial electromagnetic field is greatly enhanced, the energy transmission efficiency is improved, and the electric vehicle can achieve multi-directional wireless autonomous charging within the charging range, solving the problem of disconnection of wireless charging piles. The use of solar energy to assist power generation can reduce the direct supply of electricity and reduce the cost of use. The wireless charging of electric vehicles can be achieved by scanning the code, which brings great convenience to the car owners. The patent of this invention is not limited to the placement location. Whether it is in a residential area, school, office building parking garage or bus stop, it has great application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a principle block diagram of the wireless charging device of the present invention;

[0011] Figure 2 It is the multi-ring bipolar spiral coil structure model of the present invention;

[0012] Figure 3 It is the charging pile human-computer interaction interface of the present invention;

[0013] Figure 4 The power supply switching circuit of the present invention;

[0014] Figure 5 This is a schematic diagram of the DSP peripheral structure;

[0015] Figure 6 This is the circuit diagram of the hardware interface between DSP and LCM320240;

[0016] Figure 7 This is the pinout diagram of the TLC5540;

[0017] Figure 8 This is the AD sampling working circuit diagram of TLC5540;

[0018] Figure 9 It is the overall design flow chart of the charging system software;

[0019] Figure 10 This is an Ansys Maxwell simulation comparison diagram of the multi-ring bipolar spiral coil described in the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] The electric vehicle wireless charging device of the present invention comprises a wireless energy transmitting device located on the charging pile side and an on-board energy receiving device located on the electric vehicle side. Figure 1As shown, the wireless energy transmitting device includes a power supply module 1, a battery 4, a DC-AC high-frequency inverter circuit 3, a primary resonant circuit 5, and a primary transmitting coil 6, which are electrically connected in sequence. The primary transmitting coil 6 adopts a multi-ring bipolar spiral coil, which transmits energy to the secondary receiving coil of the parked electric vehicle to be charged through magnetic coupling resonance. The on-board energy receiving device includes an on-board secondary receiving coil 7, a secondary resonant circuit 8, and an AC-DC rectifier filter circuit 9, which are electrically connected in sequence. The output end of the AC-DC rectifier filter circuit in the on-board energy receiving device is connected to the on-board battery 10, and the transmitted electrical energy is stored in the on-board battery for charging. During operation, the vehicle-mounted secondary receiving coil is close to the primary transmitting coil on the charging pile side, and magnetically coupled resonant wireless charging technology is used to utilize the coil resonance characteristics to achieve power transmission. When the high-frequency inverter frequency of the primary transmitting end of the system is consistent with the natural frequency of the primary transmitting coil and the frequency of the secondary receiving coil, the overall circuit is in a resonant state. The transmitting coil transmits high-frequency energy to the receiving coil through the generated spatial electromagnetic field. At this time, the circuit loop impedance is minimized and the transmission efficiency is maximized; then, the DC power is supplied to the load through the secondary receiving end circuit.

[0022] Preferably, a lighting device is provided at the battery 4, mainly to provide lighting at night. The battery supplies power to the light-emitting diode, which controls the light according to the light-control sensor, solving the problem of narrow vision during charging at night. The lighting device can be in the form of a light-emitting diode 2, a lighting lamp, a display board, a TV screen display, etc., and there is no fixed requirement. The high-frequency inverter circuit converts the direct current supplied by the battery into alternating current. The high-frequency inverter circuit adopts a full-bridge inverter circuit, has the ability to regulate power, is applicable to all series-parallel resonant circuits, and has a large transmission power. The main control unit 11 can also sample the voltage and current at the output end of the primary resonant circuit within a unit time through a pulse control program, calculate the real-time output power, and judge the load charging status based on the trend of the output power change.

[0023] like Figure 2The figure shows a schematic diagram of the structure of the primary transmitting coil, which uses a multi-ring bipolar spiral coil, including three mutually perpendicular toroidal coils. The spatial winding distribution of the toroidal coils can be rectangular, circular, or other commonly used shapes, and is composed of several turns of conductive coils. The multi-ring bipolar spiral coil described in the present invention is different from toroidal coils such as symmetrical structure coils and large-one-small structure coils. Based on the existing conductive coils, this coil improves the internal winding method of the coil, using a spiral coil to wrap around the toroidal coil in an orthogonal manner. Specifically, the inner winding coil 15 is wound into a toroidal coil on the coil plane, and the outer winding coil 16 is wound around the inner winding coil. Due to the different sizes and outer diameters of the coils, the patent of this invention does not impose any restrictions. The three toroidal coils and the toroidal coils and the spiral coils are guaranteed to be non-conductive with each other. During operation, this toroidal coil with an improved internal winding method will generate two magnetic fields, one is annular and confined within the toroidal plane; the other is polar and perpendicular to the toroidal plane. When this coil is placed orthogonally in the spatial axis, that is, forming the xy plane, yz plane, and xz plane, the spatial magnetic fields generated by different planes are perpendicular to their planes. Due to the improved winding method inside the conductor, under the conditions of the original spatial electromagnetic field, a part of the electromagnetic field energy is superimposed along the toroidal plane, causing the toroidal magnetic field to be further enhanced, the current in the toroidal coil to increase, and the transmission energy to be improved, thereby increasing the transmission efficiency.

[0024] like Figure 3 As shown, the electric vehicle wireless charging device includes two symmetrically arranged primary transmitting coils. During operation, the on-board secondary receiving coil is located between the two primary transmitting coils. The two primary transmitting coils are connected to two identical primary resonant circuits, ensuring that the two transmitting coils are in a synergistic enhancement state. To ensure this synergistic enhancement, this embodiment employs a phase delay module at the input end of one of the primary resonant circuits, specifically, a phase delay module between one primary resonant circuit and the DC / AC high-frequency inverter circuit. The phase delay module is used to adjust the phase of the input voltage so that the real-time current directions in the two primary transmitting coils are aligned, achieving a synergistic enhancement effect of the magnetic field. For example, in this embodiment, the phase difference is adjusted by 90° to achieve alignment. Conventional ring-shaped transmitting coils often experience disconnection when the electric vehicle load coil and the primary coil are not aligned. The symmetrical multi-ring bipolar transmitting coil described in the present invention effectively solves this problem: even if the primary and secondary coils are not aligned (i.e., not ideally matched), energy transfer between the transmitting and receiving coils is still possible, improving the charging experience while also ensuring continuous charging even in unstable conditions.

[0025] like Figure 10As shown, the Ansys Maxwell simulation platform is used to simulate the electromagnetic field distribution intensity around the multi-ring bipolar spiral coil and the ordinary planar coil. It can be found that the magnetic field intensity generated by the multi-ring bipolar spiral coil is greater than the planar magnetic field under the same conditions. Therefore, the multi-ring bipolar spiral coil is used to design the primary transmitting coil to improve the charging efficiency. Wireless energy transmission can be achieved within a larger charging range, which greatly improves the energy transmission compared to the previous planar charging coil. At the same time, there is no fixed requirement for the laying of wireless charging piles. If an ordinary planar wireless charging transmitting coil is used, the receiving coil of the load-end device will often fail to charge due to misalignment. The present invention greatly improves the matching degree and applicability of the wireless charging device.

[0026] Preferably, in order to prevent external signals from causing electromagnetic interference to the wireless charging coil circuit, the present invention further provides a magnetic isolation plate 17 on one side of the multi-ring bipolar coil, such as Figure 3 The material of the magnetic isolation plate 17 is generally selected to be ferrite or nanocrystal. The magnetic isolation plate provided at the transmitting end can enhance the magnetic field strength and have a high magnetic convergence effect. On the other hand, the magnetic isolation material has a heat dissipation function, which can dissipate the heat generated by the high-frequency circuit in time and reduce damage to the circuit board.

[0027] In terms of the design of the power supply module, the power supply module 1 can be a separate mains power supply or a separate solar power supply module, or the control module can select a separate mains power supply or a solar power supply. The wireless energy transmitting device also includes a main control unit 11, which is mainly used to switch the power supply mode between the mains power supply and the solar power supply. Figure 1 The figure shows a wireless charging device for electric vehicles that combines mains power and solar energy. The main control unit controls the power supply mode of the power supply switching circuit. The power supply module 1 includes a solar cell module, a solar controller, and a power supply switching circuit that are electrically connected in sequence. The power supply switching circuit is also connected to the mains power supply terminal, and the power supply switching circuit selects the mains power supply or the solar module power supply.

[0028] like Figure 4As shown, the present invention also proposes a power supply switching circuit that can achieve simultaneous power supply from mains electricity and solar energy, further improving solar energy utilization efficiency. Solar cell modules convert light energy into electrical energy, which is then stored in a battery via a power supply switching circuit. If external conditions prevent solar energy from supplying the battery, a power supply compensation circuit can be implemented, with the battery receiving power from the mains electricity. The device includes a main control unit, a power supply switching circuit connected to a solar cell power supply module and a mains power port. The main control unit controls the power supply switching circuit to allocate the power supply ratio between mains electricity and solar energy. Specifically, the main control unit utilizes a DSPTMS320LF2407 microprocessor, which is connected to a rectifier circuit and the output terminal of a solar power supply device controller. A photoresistor is provided between the mains electricity and the solar power supply output terminal. When weather conditions are poor or sunlight is insufficient, the mains electricity PWM voltage regulation duty cycle increases. At this time, the mains electricity output voltage is adjusted to compensate for the insufficient solar power supply, ensuring power supply stability. Direct solar power supply can accelerate damage to the electric vehicle battery due to the unstable conversion voltage. The buffering effect of the first battery extends the battery life of the electric vehicle.

[0029] like Figure 5 The main control unit 11 is preferably a DSPTMS320LF2407. The main control unit is connected to the peripheral LCM320240 liquid crystal module 12, which displays the current charging status through a control program. Figure 6 Shown is the circuit diagram of the hardware interface between DSP and LCM320240.

[0030] The main control unit 11 uses a TLC5540 or TLC2543 high-speed A / D converter to collect the voltage, current, and temperature of the primary resonant circuit, and also sets a protection circuit 13 (overcurrent, overvoltage, and undervoltage protection circuit) to prevent damage to the core board. Figure 7 The following is the pin arrangement diagram of TLC5540. Figure 8 This is the AD sampling circuit diagram of the TLC5540. An optocoupler isolation circuit 14 is added between the primary resonant circuit and the control unit DSPTMS320LF2407 to isolate the signal and protect the microprocessor control circuit. A hardware interface design using analog timing for digital I / O ports is used between the DSP and the LCD. The control program implementation primarily includes timing matching between the DSP and LCM320240, as well as system initialization (DSP and LCD initialization).

[0031] The TLC5540's AD sampling principle operates as follows: the circuit has two operating states: sampling and reading. When the master CPU issues a start command, RS flip-flop U8's Q = 0, and the circuit enters the sampling state. When TLC5540's OE = 0, data is released. Simultaneously, the clock signal CLK, via U4 and U7, controls the read / write control terminal WE and chip select terminal CS of memory U6, respectively, writing the collected data into the internal cells of memory U6. The address counter U5 is a multi-stage, presettable synchronous adder counter. The clock CLK drives U5 through a multiplexer, providing a new storage address after the sampled data stabilizes. When the address counter overflows, the high-bit output signal Q13 flips RS flip-flop U8, turning Q = 1, and the circuit begins reading data. The sampled data at the corresponding address appears on the memory data bus for the CPU to read.

[0032] like Figure 9 The figure shows the overall design flow chart of the charging system software. The program design process mainly includes: initialization, standby state, device matching and battery status detection. When the device is connected to the power supply, the system starts to power on to complete the system initialization. At this time, the system is in a standby low-power stage. The low-power stage is a solution for waiting for the completion of system initialization and the system to reduce power consumption while waiting for charging. The patent of this invention can support code scanning charging services, and adopts the Internet of Things technology + cloud platform + mobile terminal architecture. The system uses the Internet of Things technology to continuously collect data and monitor the charging pile sites and each charging pile connected to the system. The charging pile can be equipped with a WIFI module or a GPRS module to access the Internet. In combination with encryption technology and key distribution technology, it is directly connected to the cloud based on the TCP / IP data interaction protocol. Figure 4 The figure shows a schematic diagram of the charging station's human-machine interface. The current charging station can be operated by scanning a QR code with a mobile phone. When the charging electric vehicle enters the charging range of the primary coil, the charging device transitions from the system standby phase to the charging device matching phase. If the charging feedback voltage is greater than or less than the voltage range of the electric vehicle's battery, the system matching is unsuccessful, the cloud platform displays a matching failure, and the system transitions to a low-power standby phase; otherwise, the system transitions to charging. During the charging process, a pulse interval control program is used to periodically assess the battery status. When charging is complete, the system transitions to a low-power standby phase and notifies the cloud that charging is complete. If the electric vehicle leaves the charging range, the patented charging device automatically disconnects the power supply to the primary transmitting coil. Charging can only be resumed by rescanning the QR code. The service terminal platform will then display the charging status as complete. Users can view the location of available charging stations and the current charging status in real time through the app, effectively preventing theft of electricity.

Claims

1. A wireless charging device for electric vehicles, characterized in that: It includes a wireless energy transmitting device located on the charging pile side and an on-board energy receiving device located on the electric vehicle side; The wireless energy transmitting device includes a power supply module, a battery, a DC-AC high-frequency inverter circuit, a primary resonant circuit, and a primary transmitting coil electrically connected in sequence; the primary transmitting coil is two symmetrically arranged primary transmitting coils, each connected to two primary resonant circuits of the same structure, and a phase delay module is provided between one primary resonant circuit and the DC-AC high-frequency inverter circuit. The phase delay module is used to make the real-time current directions in the two primary transmitting coils consistent; the primary transmitting coil adopts a multi-ring bipolar spiral coil, and the multi-ring bipolar spiral coil includes three mutually perpendicular A toroidal coil is provided on the toroidal coil in an orthogonal manner, and there is no conduction between the three toroidal coils and between the toroidal coil and the spiral coil; the device adopts magnetic coupling resonant wireless charging technology, and realizes power transmission by achieving a resonant state between the primary transmitting coil and the on-board secondary receiving coil located in the on-board energy receiving device. When working, the on-board secondary receiving coil is located between the two primary transmitting coils; the output end of the AC-DC rectifier filter circuit in the on-board energy receiving device is connected to the on-board battery, and the transmitted power is stored in the on-board battery for charging.

2. The wireless charging device for electric vehicles according to claim 1, characterized in that: The on-board energy receiving device includes an on-board secondary receiving coil, a secondary resonant circuit and an AC-DC rectifier filter circuit electrically connected in sequence; the on-board secondary receiving coil adopts a planar ring coil, and when working, the on-board secondary receiving coil is close to the primary transmitting coil on the charging pile side.

3. The wireless charging device for electric vehicles according to claim 1, characterized in that: The annular coil is rectangular or circular and is composed of a plurality of turns of conductive coils.

4. The wireless charging device for electric vehicles according to claim 1, characterized in that: The power supply module adopts a separate mains power supply module or a separate solar power supply module, or adopts a mains power and solar power coordinated power supply module.

5. The wireless charging device for electric vehicles according to claim 4, characterized in that: The device also includes a main control unit. The mains and solar collaborative power supply module scheme is: a power supply switching circuit is used to connect the solar cell power supply module and the mains port respectively, and the main control unit controls the power supply switching circuit to select separate mains power supply or separate solar power supply.

6. The wireless charging device for electric vehicles according to claim 4, characterized in that: The device also includes a main control unit. The scheme of the AC and solar collaborative power supply module is: a power supply switching circuit with a switch array is used to connect the solar cell power supply module and the AC power port respectively. The main control unit adjusts the proportion of AC power supply and solar power supply by controlling the switch array in the power supply switching circuit.

7. The wireless charging device for electric vehicles according to claim 6, characterized in that: A photoresistor is provided between the power supply switching circuit and the solar power supply output end. When there is sufficient light, the main control unit increases the output voltage of the solar energy by increasing the PWM voltage regulation duty cycle of the solar power supply device; when there is insufficient light, the main control unit increases the output voltage of the mains by increasing the PWM voltage regulation duty cycle of the mains.

8. The wireless charging device for electric vehicles according to any one of claims 5 to 7, characterized in that: The main control unit determines the charging status of the battery on the charging pile side by sampling the voltage and current of the primary side resonant circuit within a unit time, and disconnects the charging in time when charging is completed; the main control unit is also connected to a liquid crystal module for displaying the current charging status.

9. The wireless charging device for electric vehicles according to claim 8, characterized in that: An optical coupling isolation circuit is provided between the primary resonant circuit and the main control unit.

10. The wireless charging device for electric vehicles according to claim 1, characterized in that: The battery is provided with a lighting device for providing lighting at night; the lighting device adopts a light emitting diode, a lighting lamp, a display board or a television screen.

Images