Electric vehicle wireless charging system based on id authentication of PDM characteristic wave

Abstract

The application relates to the technical field of electric vehicle wireless charging, and particularly discloses an electric vehicle wireless charging system based on PDM characteristic wave ID authentication, when an electric vehicle is parked in a charging area, the system transmits an electric energy signal with charging end ID information to the electric vehicle by controlling the pulse density of the charging end inverter switch, the electric vehicle identifies the ID signal and returns the electric vehicle's own ID signal after being connected with the ID signal, so that the identity authentication and communication connection of the electric vehicle and the charging end before charging are realized. The frequency (i.e. pulse density) of switch switching defines the identity ID of different charging ends, different switching frequencies correspond to different ID information, and the application has the advantages of high accuracy, simple detection and the like; based on the wireless electric energy transmission method, the switching frequency of the switch corresponds to different transmission electric energy values, the ID information of the charging end is transmitted to the electric vehicle in the form of electric energy, no other additional equipment is needed in the identity authentication process, the structure is simple, and cost is saved.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology for electric vehicles, and more particularly to a wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication. Background Technology

[0002] Wireless charging technology boasts advantages such as flexibility, reliability, and safety. Its applications are becoming increasingly widespread in fields such as drones, home appliances, and electric vehicles. To achieve optimal system energy efficiency and status monitoring, and to improve the performance of wireless charging systems, primary and secondary side communication is often required to facilitate information exchange. Furthermore, for multi-electric vehicle wireless charging systems, authentication and communication connection between the electric vehicle and the charging terminal are necessary before wireless charging begins to ensure the normal operation of the charging process.

[0003] However, due to channel interference issues in the communication connection of multiple electric vehicle wireless charging systems using traditional communication methods, the connection between electric vehicles and charging terminals becomes chaotic, causing the charging system to malfunction. Therefore, it is necessary to authenticate the ID information of the charging terminal and the electric vehicle before wireless charging. Summary of the Invention

[0004] This invention provides a wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication. The technical problem it solves is: how to authenticate the ID information of the charging terminal and the electric vehicle before wireless charging.

[0005] To address the above technical issues, this invention provides a wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication. The system includes a charging terminal and an electric vehicle. The charging terminal is equipped with a high-frequency inverter and a PDM modulation module. When the charging terminal senses an electric vehicle parked in its charging area, it controls the PDM modulation module to modulate the charging terminal's ID information into a PDM characteristic wave and apply it to the high-frequency inverter. The high-frequency inverter then transmits an electrical signal carrying the charging terminal's ID information to the electric vehicle. Upon receiving the electrical signal, the electric vehicle demodulates it to obtain the charging terminal's ID information and then sends its own ID information back to the charging terminal. Upon receiving the electric vehicle's ID information, the charging terminal establishes a communication connection with the electric vehicle.

[0006] Preferably, the system has M charging terminals, where M ≥ 2;

[0007] Each charging terminal is assigned a unique ID. When M ≤ T, T is the threshold number of charging terminals. The m-th charging terminal among the M charging terminals is modulated according to the following first modulation method:

[0008] In the first time sequence, a PDM characteristic wave with a pulse density of 1 is transmitted;

[0009] In the second timing sequence, the transmitted pulse density is P m =a1+bm, where a1 represents the initial value of the first pulse density, b represents the pulse density difference between two adjacent charging terminals, a1≥2 and is an integer, and b≥1 and is an integer.

[0010] Preferably, the electric vehicle is demodulated in the following manner:

[0011] After the electric vehicle detects the voltage signal of the first time sequence, it determines that the pulse density of the first time sequence is 1 based on the first correspondence between the voltage signal and the pulse density, and then determines to demodulate according to the following first demodulation method:

[0012] The voltage signal of the second timing is detected, and the pulse density of the second timing is determined according to the voltage density relationship between the voltage signal and the pulse density. Then, the ID information of the charging terminal is obtained according to the density ID relationship between the pulse density of the second timing and the ID information of the transmitting terminal.

[0013] Preferably, when M > T, the modulation scheme for the m-th charging terminal among the M charging terminals is as follows:

[0014] Divide the M charging terminals into N groups. Indicates rounding up;

[0015] In the first time sequence, a PDM characteristic wave with a pulse density of 2 is transmitted;

[0016] In the second time sequence, a PDM characteristic wave with a pulse density of R+2 is transmitted.

[0017] In the third timing sequence, the transmitted pulse density is P′ k =a2+bk, k=mT(R-1), a2 represents the initial value of the second pulse density, a2≥N.

[0018] Preferably, the electric vehicle is demodulated in the following manner:

[0019] After the electric vehicle detects the voltage signal of the first time sequence, it determines that the pulse density of the first time sequence is 2 based on the voltage density relationship, and then determines to demodulate according to the following second demodulation method:

[0020] The voltage signal of the second timing sequence is detected, and the pulse density of the second timing sequence is determined according to the voltage density relationship.

[0021] The voltage signal of the third time sequence is detected and the pulse density of the third time sequence is determined according to the voltage density relationship.

[0022] The ID information of the charging terminal is obtained based on the pulse density of the second timing sequence, the pulse density of the third timing sequence, and the pulse density ID relationship of the transmitter ID information.

[0023] Preferably, when the electric vehicle detects that the voltage signal of the first timing sequence is neither 1 nor 2, an alert is issued to move the electric vehicle to another charging area.

[0024] Preferably, the system further includes a main controller connected to the charging terminal;

[0025] After establishing a communication connection between the transmitter and the electric vehicle, the electric vehicle sends a charging request to the transmitter it is connected to. The transmitter sends its own ID information and the ID information of the electric vehicle it receives to the main controller via a WiFi hotspot. The main controller controls the charging line of the transmitter with the corresponding ID to be in standby mode. After the transmitter confirms that the interoperability information of the electric vehicle has been passed, it starts charging the electric vehicle.

[0026] Preferably, the M transmitters are arranged in an array.

[0027] Preferably, T≥20.

[0028] Preferably, T = 25, a1 = a2 = 5, b = 2.

[0029] The present invention provides a wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication. When an electric vehicle is parked in a charging area, the system transmits an electrical signal carrying the charging terminal's ID information to the electric vehicle by controlling the pulse density of the inverter switch at the charging terminal. The electric vehicle recognizes this ID signal, establishes a connection, and then returns its own ID signal, thus achieving identity authentication and communication connection between the electric vehicle and the charging terminal before charging. The beneficial effects of this invention are:

[0030] 1. Based on the inverter switching method, the identity ID of different charging terminals can be defined by the switching frequency (i.e. pulse density). Different switching frequencies correspond to different ID information, which has the advantages of high accuracy and simple detection.

[0031] 2. Based on the wireless power transmission method, the switching frequency corresponds to different transmitted power values, and the ID information of the charging terminal is transmitted to the electric vehicle in the form of electrical energy. No other additional equipment is required during the identity authentication process, the structure is simple and the cost is saved.

[0032] 3. The electric vehicle can identify the charging terminal's identity information by detecting the received electrical energy value. In the process of wireless power transmission, the power transmission speed is fast, so it has the advantage of fast identity authentication. When the electric vehicle receives the electrical energy signal with the charging terminal's ID information, it can communicate with it and has the advantages of high connection accuracy and no channel crosstalk problem. Attached Figure Description

[0033] Figure 1 This is a flowchart of the wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication provided in an embodiment of the present invention.

[0034] Figure 2 This is an example diagram of a PDM modulation input / output provided in an embodiment of the present invention;

[0035] Figure 3 This is a circuit diagram of an electric vehicle wireless charging system based on PDM characteristic waves for ID authentication provided in an embodiment of the present invention.

[0036] Figure 4 This is a structural diagram of a wireless charging system for electric vehicles with a 5×5 array of charging terminals provided in an embodiment of the present invention. Detailed Implementation

[0037] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the present invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0038] To authenticate the ID information of the charging terminal and the electric vehicle before wireless charging, this invention provides a wireless charging system for electric vehicles based on PDM characteristic waves. In this embodiment, the system includes a charging terminal and an electric vehicle. The charging terminal is equipped with a high-frequency inverter and a PDM modulation module. The system also includes a main controller connected to the charging terminal. Figure 1As shown in the flowchart, when the charging terminal senses an electric vehicle parked in its charging area, it controls the PDM modulation module to modulate the charging terminal's ID information into a PDM characteristic wave and apply it to the high-frequency inverter. The high-frequency inverter then transmits an energy signal carrying the charging terminal's ID information to the electric vehicle. After receiving the energy signal, the electric vehicle demodulates it to obtain the charging terminal's ID information and then sends its own ID information to the charging terminal. Upon receiving the electric vehicle's ID information, the charging terminal establishes a communication connection with the electric vehicle (e.g., a Wi-Fi connection). After establishing a communication connection between a transmitter and the electric vehicle, the electric vehicle sends a charging request to its connected transmitter via Wi-Fi. The transmitter sends its own ID information and the received electric vehicle's ID information to the main controller. The main controller then puts the charging line of the transmitter with the corresponding ID into standby mode. After the transmitter confirms that the interoperability information with the electric vehicle has been passed, it begins charging the electric vehicle.

[0039] PDM (Pulse Density Modulation) is a digital signal modulation technique used to convert analog signals into digital pulse sequences. The analog signal first needs to be discretely sampled, meaning the amplitude value of the signal is measured periodically over a time period. The sampling rate must be high enough to capture the high-frequency components of the analog signal. The sampled analog signal needs to be quantized, converting the amplitude value of each sample point into a digital value. Typically, a continuous amplitude range is divided into discrete levels, and each sample point is mapped to the nearest quantization level. In PDM modulation, each quantized digital value is encoded as a binary pulse, where a high level represents 1 and a low level represents 0. During encoding, each quantization level corresponds to a time interval called the pulse width. A key feature of PDM is the use of pulse density to represent the amplitude information of the analog signal. Pulse density refers to the number of pulses per unit time. The higher the amplitude of the analog signal, the higher the pulse density; the lower the amplitude of the analog signal, the lower the pulse density. PDM modulation offers advantages such as high signal accuracy, distortion-free transmission, wide dynamic range, low-cost implementation, and the advantages of digital signal processing. Figure 2 The figure shows an example of PDM modulated input and output voltage waveforms.

[0040] Topology of multiple electric vehicle wireless charging systems, such as Figure 3 As shown, an LCC-S type topology is adopted, and U in the figure in For DC power input, U out Load voltage, MOSFETs S1 to S4 form a full-bridge inverter circuit, L f1 C f1 C P and L P For a primary-edge compensation network, C S and L S For a secondary-side compensation network, where L Pand L S These represent the self-inductances of the primary and secondary coils, respectively; M is the mutual inductance between the coils; diodes D1 to D4 form the rectifier circuit; C is the filter capacitor; and R... L The load is determined by the different pulse densities of the inverter circuit's switching control signals, resulting in different electrical energy received by the electric vehicle. This difference can be used for identifying the electric vehicle and the charging station. The electric vehicle is equipped with a PDM demodulation module, which demodulates the transmitter's ID information based on the load voltage (i.e., the system output voltage).

[0041] This invention is also applicable to multiple charging terminals and multiple electric vehicles. The structure of a wireless charging system for electric vehicles with multiple charging terminals and multiple electric vehicles is as follows: Figure 4 As shown, Figure 4 It has 25 charging ports (arranged in a 5×5 array).

[0042] For a wireless charging system for an electric vehicle with M charging terminals, each charging terminal is assigned a unique ID. When M ≤ T, T is the threshold number of charging terminals. The m-th charging terminal among the M charging terminals is modulated according to the following first modulation method:

[0043] In the first time sequence, a PDM characteristic wave with a pulse density of 1 is transmitted;

[0044] In the second timing sequence, the transmitted pulse density is P m =a1+bm, where a1 represents the initial value of the first pulse density, b represents the pulse density difference between two adjacent charging terminals, a1≥2 and is an integer, and b≥1 and is an integer.

[0045] For example, when m = 10, a1 = 5, and b = 2, then in the first time sequence, a PDM characteristic wave with a pulse density of 1 is transmitted, and in the second time sequence, a pulse density of P is transmitted. 10 =5 + 2 * 10 = 25 PDM characteristic wave.

[0046] Electric vehicles are demodulated as follows:

[0047] After the electric vehicle detects the voltage signal of the first time sequence, it determines that the pulse density of the first time sequence is 1 based on the first correspondence between the voltage signal and the pulse density. Then, it determines that demodulation will be performed according to the following first demodulation method:

[0048] The voltage signal of the second timing is detected, and the pulse density of the second timing is determined according to the voltage density relationship between the voltage signal and the pulse density (which has been stored in the electric vehicle in advance). Then, the ID information of the charging end is obtained according to the pulse density of the second timing and the pulse density ID relationship between the transmitter ID information (which has been stored in the electric vehicle in advance).

[0049] When M is large, to avoid excessive pulse density causing more power consumption to the circuit, increasing the difficulty of modulation and demodulation, and causing other adverse effects, this embodiment also sets up a second modulation and demodulation method, namely:

[0050] When M > T, the modulation scheme for the m-th charging terminal out of the M charging terminals is as follows:

[0051] Divide the M charging terminals into N groups. Indicates rounding up;

[0052] In the first time sequence, a PDM characteristic wave with a pulse density of 2 is transmitted;

[0053] In the second time sequence, a PDM characteristic wave with a pulse density of R+2 is transmitted.

[0054] In the third timing sequence, the transmitted pulse density is P′ k =a2+bk, k=mT(R-1), a2 represents the initial value of the second pulse density, a2≥N.

[0055] For example, given M=100, T=25, a1=a2=5, b=2, m=65, then N=4, R=3. In this embodiment, the ID of the m-th charging terminal is its sequence number m. Therefore, for the m-th charging terminal, the second modulation method is used for modulation. In the first timing sequence, a PDM characteristic wave with a pulse density of 2 is transmitted; in the second timing sequence, a PDM characteristic wave with a pulse density of 5 is transmitted; and in the third timing sequence, a PDM characteristic wave with a pulse density of 35 is transmitted.

[0056] Electric vehicles are demodulated as follows:

[0057] After the electric vehicle detects the voltage signal of the first time sequence, it determines that the pulse density of the first time sequence is 2 based on the voltage density relationship. Therefore, it determines to demodulate according to the following second demodulation method:

[0058] The voltage signal of the second time sequence is detected and the pulse density of the second time sequence is determined according to the voltage density relationship;

[0059] The voltage signal of the third time sequence is detected and the pulse density of the third time sequence is determined based on the voltage density relationship;

[0060] The charging terminal's ID information is obtained based on the pulse density of the second time sequence, the pulse density of the third time sequence, and the pulse density ID relationship of the transmitter's ID information (which has been pre-stored in the electric vehicle).

[0061] When the electric vehicle detects that the voltage signal of the first timing sequence is neither 1 nor 2 (there may be a fault at the charging end), it will issue an alert to move the electric vehicle to another charging area.

[0062] The specific values ​​of T, a1, a2, b=2, and M mentioned above are merely illustrative examples. These parameters can be arbitrarily selected from the available range according to actual needs.

[0063] In summary, the electric vehicle wireless charging system based on PDM characteristic wave ID authentication provided in this embodiment of the invention, when an electric vehicle is parked in the charging area, transmits an electrical signal carrying the charging terminal's ID information to the electric vehicle by controlling the pulse density of the inverter switch at the charging terminal. The electric vehicle identifies this ID signal, establishes a connection, and then returns its own ID signal, thus achieving identity authentication and communication connection between the electric vehicle and the charging terminal before charging. The beneficial effects of this invention are:

[0064] 1. Based on the inverter switching method, the identity ID of different charging terminals can be defined by the switching frequency (i.e. pulse density). Different switching frequencies correspond to different ID information, which has the advantages of high accuracy and simple detection.

[0065] 2. Based on the wireless power transmission method, the switching frequency corresponds to different transmitted power values, and the ID information of the charging terminal is transmitted to the electric vehicle in the form of electrical energy. No other additional equipment is required during the identity authentication process, the structure is simple and the cost is saved.

[0066] 3. The electric vehicle can identify the charging terminal's identity information by detecting the received electrical energy value. In the process of wireless power transmission, the power transmission speed is fast, so it has the advantage of fast identity authentication. When the electric vehicle receives the electrical energy signal with the charging terminal's ID information, it can communicate with it and has the advantages of high connection accuracy and no channel crosstalk problem.

[0067] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A wireless charging system for electric vehicles based on PDM characteristic wavelet ID authentication, characterized in that, The system includes a charging terminal and an electric vehicle. The charging terminal is equipped with a high-frequency inverter and a PDM modulation module. When the charging terminal senses that an electric vehicle is parked in its charging area, it controls the PDM modulation module to modulate the ID information of the charging terminal into a PDM characteristic wave and apply it to the high-frequency inverter. The high-frequency inverter then transmits an electrical signal carrying the ID information of the charging terminal to the electric vehicle. After receiving the electrical signal, the electric vehicle demodulates it to obtain the ID information of the charging terminal, and then sends its own ID information to the charging terminal. After receiving the ID information of the electric vehicle, the charging terminal establishes a communication connection with the electric vehicle. The system has M charging terminals, where M ≥ 2; Each charging terminal is assigned a unique ID. When M > T, T is the threshold number of charging terminals. The modulation scheme for the m-th charging terminal out of the M charging terminals is as follows: Divide the M charging terminals into N groups, where N = , Indicates rounding up; In the first timing sequence, a PDM characteristic wave with a pulse density of 2 is transmitted; In the second timing sequence, a PDM characteristic wave with a pulse density of R+2 is transmitted, where R= ; In the third timing sequence, the transmitted pulse density is: , =mT(R-1), This indicates the initial value of the second pulse density. , This represents the pulse density difference between two adjacent charging terminals. And it is an integer.

2. The wireless charging system for electric vehicles based on PDM characteristic wave ID authentication according to claim 1, characterized in that, When M≤T, the m-th charging terminal among the M charging terminals is modulated according to the following first modulation method: In the first time sequence, a PDM characteristic wave with a pulse density of 1 is transmitted; In the second timing sequence, the transmitted pulse density is PDM characteristic wave, This indicates the initial value of the first pulse density. And it is an integer.

3. The wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication according to claim 2, characterized in that, The electric vehicle is demodulated in the following manner: After the electric vehicle detects the voltage signal of the first time sequence, it determines that the pulse density of the first time sequence is 1 based on the first correspondence between the voltage signal and the pulse density, and then determines to demodulate according to the following first demodulation method: The voltage signal of the second timing is detected, and the pulse density of the second timing is determined according to the voltage density relationship between the voltage signal and the pulse density. Then, the ID information of the charging terminal is obtained according to the density ID relationship between the pulse density of the second timing and the ID information of the transmitting terminal.

4. The wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication according to claim 3, characterized in that, The electric vehicle is demodulated in the following manner: After the electric vehicle detects the voltage signal of the first time sequence, it determines that the pulse density of the first time sequence is 2 based on the voltage density relationship, and then determines to demodulate according to the following second demodulation method: The voltage signal of the second timing sequence is detected, and the pulse density of the second timing sequence is determined according to the voltage density relationship. The voltage signal of the third time sequence is detected and the pulse density of the third time sequence is determined according to the voltage density relationship. The ID information of the charging terminal is obtained based on the pulse density of the second timing sequence, the pulse density of the third timing sequence, and the pulse density ID relationship of the transmitter ID information.

5. The wireless charging system for electric vehicles based on PDM characteristic waves for ID authentication according to claim 4, characterized in that, When the electric vehicle detects that the voltage signal of the first timing sequence is neither 1 nor 2, it issues a reminder to move the electric vehicle to another charging area.

6. The wireless charging system for electric vehicles based on PDM characteristic wave ID authentication according to claim 4, characterized in that, The system also includes a main controller connected to the charging terminal; After establishing a communication connection between the transmitter and the electric vehicle, the electric vehicle sends a charging request to the transmitter it is connected to. The transmitter sends its own ID information and the ID information of the electric vehicle it receives to the main controller via a WiFi hotspot. The main controller controls the charging line of the transmitter with the corresponding ID to be in standby mode. After the transmitter confirms that the interoperability information of the electric vehicle has been passed, it starts charging the electric vehicle.

7. The wireless charging system for electric vehicles based on PDM characteristic wave ID authentication according to claim 5, characterized in that: The M transmitters are arranged in an array.

8. The wireless charging system for electric vehicles based on PDM characteristic wave ID authentication according to claim 5, characterized in that: T≥20。 9. The wireless charging system for electric vehicles based on PDM characteristic wave ID authentication according to claim 8, characterized in that: T=25， ， 。

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