Electric vehicle wireless charging system for performing id authentication on basis of PDM characteristic wave

Abstract

An electric vehicle wireless charging system for performing identity (ID) authentication on the basis of a PDM characteristic wave. After an electric vehicle stops in a charging area, by means of controlling the pulse density of an inverter switch of a charging end, the system transmits to the electric vehicle an electric energy signal carrying ID information of the charging end, and the electric vehicle identifies an ID signal and is connected to the charging end and then returns an ID signal of the electric vehicle, such that ID authentication and communication connection between the electric vehicle and the charging end before charging are realized. IDs of different charging ends are defined by means of the switching frequencies of switches, and different switching frequencies correspond to different pieces of ID information, such that the advantages of high accuracy and simple detection are achieved. On the basis of a wireless electric energy transmission method, the switching frequencies of switches correspond to different electric energy transmission values, ID information of a charging end is transmitted to an electric vehicle by means of electric energy, and other additional devices are not required during an ID authentication process, such that the structure is simple, and the cost is saved on.

Description

Electric vehicle wireless charging system based on PDM characteristic wave for ID authentication Technical Field

[0001] The present invention relates to the technical field of electric vehicle wireless charging, and in particular to an electric vehicle wireless charging system for performing ID authentication based on PDM characteristic waves. Background Art

[0002] Wireless charging technology offers advantages such as flexibility, reliability, and safety. Its application is growing in areas such as drones, home appliances, and electric vehicles. To optimize system energy efficiency, monitor status, and improve wireless charging system performance, wireless charging systems often require communication between the primary and secondary sides to enable information exchange. Furthermore, for multi-EV wireless charging systems, authentication and communication between the EV and the charging terminal are required before wireless charging begins to ensure proper operation.

[0003] However, due to the problem of channel interference in the communication connection of multi-electric vehicle wireless charging systems using traditional communication methods, the connection between electric vehicles and charging terminals is confused, causing the charging system to work in disorder. Therefore, it is necessary to authenticate the ID information of the charging terminal and the electric vehicle before wireless charging of electric vehicles. Technical issues

[0004] The present invention provides an electric vehicle wireless charging system for performing ID authentication based on PDM characteristic waves, and solves the technical problem of how to perform ID information authentication between the charging terminal and the electric vehicle before wireless charging of the electric vehicle. Technical Solutions

[0005] To solve the above technical problems, the present invention provides an electric vehicle wireless charging system for ID authentication based on PDM characteristic waves, comprising a charging end and an electric vehicle, wherein the charging end is provided with a high-frequency inverter and a PDM modulation module. When the charging end senses that the electric vehicle is parked in its own charging area, the PDM modulation module is controlled to modulate the ID information of the charging end into a PDM characteristic wave and act on the high-frequency inverter. The high-frequency inverter transmits an electric energy signal with the ID information of the charging end to the electric vehicle; after receiving the electric energy signal, the electric vehicle demodulates the signal to obtain the ID information of the charging end, and then sends its own ID information to the charging end. After receiving the ID information of the electric vehicle, the charging end establishes a communication connection with the electric vehicle.

[0006] Preferably, the system is provided with M charging terminals, M ≥ 2;

[0007] Unique ID information is set for each charging terminal. When M≤T, T is the threshold number of charging terminals. The mth charging terminal among the M charging terminals is modulated according to the first modulation method as follows:

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

[0009] At the second timing, the pulse density is P m =a1+bm, where a1 represents the first pulse density starting value, 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 according to the first corresponding relationship between the voltage signal and the pulse density, and then determines to perform demodulation according to the following first demodulation method:

[0012] 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 between the voltage signal and the pulse density, and then the ID information of the charging end is obtained according to the density ID relationship between the pulse density of the second time sequence and the transmitter ID information.

[0013] Preferably, when M>T, the modulation mode of the mth charging terminal among the M charging terminals is:

[0014] The M charging terminals are divided into N groups, N= , Indicates rounding up;

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

[0016] In the second sequence, a PDM characteristic wave with a pulse density of R+2 is sent, R= ;

[0017] At the third timing, the pulse density is P' k =a2+bk, k=mT(R-1), a2 represents the starting 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 according to the voltage density relationship, and then determines to perform demodulation according to the following second demodulation method:

[0020] detecting a voltage signal of a second time sequence and determining a pulse density of the second time sequence according to the voltage density relationship;

[0021] detecting a voltage signal of a third time sequence and determining a pulse density of the third time sequence according to the voltage density relationship;

[0022] The ID information of the charging terminal is obtained according to the relationship between the pulse density of the second time sequence, the pulse density of the third time sequence and the pulse density ID of the transmitting terminal ID information.

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

[0024] Preferably, the system further comprises a main control machine connected to the charging terminal;

[0025] After establishing a communication connection between a group of the transmitters and the electric vehicle, the electric vehicle sends a charging request to the transmitter to which it is connected. The transmitter sends its own ID information and the ID information of the electric vehicle it receives to the main control machine via the WiFi hotspot. The main control machine controls the charging circuit of the transmitter corresponding to the ID to be in standby state. After the transmitter confirms that the interoperability information of the electric vehicle has passed, it starts charging the electric vehicle.

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

[0027] Preferably, T≥20.

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

[0029] The electric vehicle wireless charging system provided by the present invention uses PDM characteristic waves for ID authentication. When the electric vehicle is docked in the charging area, the system controls the pulse density of the inverter switch at the charging end to transmit an electric energy signal containing the charging end ID information to the electric vehicle. The electric vehicle recognizes this ID signal, connects to it, and then returns its own ID signal, thus achieving identity authentication and communication connection between the electric vehicle and the charging end before charging. The beneficial effects of the present 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 transmission power values, and the ID information of the charging end is transmitted to the electric vehicle in the form of electrical energy. No additional equipment is required during the identity authentication process, the structure is simple, and cost saving;

[0032] 3. Electric vehicles can identify the charger's identity by detecting the received power value. Wireless power transmission boasts a high power transmission speed, offering the advantage of fast authentication. When an electric vehicle receives a power signal containing the charger's ID information, it can establish a communication connection with it, offering advantages such as high connection accuracy and no channel crosstalk. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] 1 is a flowchart of a wireless charging system for electric vehicles for ID authentication based on PDM characteristic waves according to an embodiment of the present invention;

[0034] FIG2 is an example diagram of a PDM modulation input and output provided by an embodiment of the present invention;

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

[0036] FIG4 is a structural diagram of a wireless charging system for electric vehicles with charging terminals distributed in a 5×5 array according to an embodiment of the present invention. Modes for Carrying Out the Invention

[0037] The following describes the embodiments of the present invention in detail with reference to the accompanying drawings. The embodiments are provided for illustrative purposes only and are not to be construed as limiting the present invention. The accompanying drawings are provided for reference and illustration only and do not constitute a limitation on the scope of protection of the present invention. Many changes may 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, an embodiment of the present invention provides an electric vehicle wireless charging system that uses PDM characteristic waves for ID authentication. In this embodiment, the system includes a charging terminal and an electric vehicle, wherein the charging terminal is equipped with a high-frequency inverter and a PDM modulation module. The system also includes a host computer connected to the charging terminal. As shown in the flowchart of Figure 1, when the charging terminal senses that an electric vehicle is 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 applies it to the high-frequency inverter. The high-frequency inverter transmits an electric energy signal containing the charging terminal's ID information to the electric vehicle. After receiving the electric 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. After receiving the electric vehicle's ID information, the charging terminal establishes a communication connection (such as a WiFi connection) with the electric vehicle. After establishing a communication connection between a set of transmitters and the electric vehicle, the electric vehicle sends a charging request to the transmitter to which it is connected via WIFI. The transmitter sends its own ID information and the ID information of the electric vehicle it receives to the main control machine. The main control machine controls the charging circuit of the transmitter with the corresponding ID to the standby state. After the transmitter confirms that the interoperability information of the electric vehicle has passed, it starts charging the electric vehicle.

[0039] Pulse Density Modulation (PDM) is a digital signal modulation technique used to convert analog signals into digital pulse trains. The analog signal must first be discretely sampled, meaning its amplitude is measured periodically over a period of time. The sampling rate must be high enough to capture the high-frequency components of the analog signal. The sampled analog signal then needs to be quantized to convert the amplitude value at each sample point into a digital value. Typically, the 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 a 1 and a low level represents a 0. During encoding, each quantization level corresponds to a time period known as the pulse width. PDM is characterized by using pulse density to represent the amplitude information of the analog signal. Pulse density refers to the number of pulses per unit time. Higher analog signal amplitudes result in higher pulse density, while lower analog signal amplitudes result in lower 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 shows an example of the input and output voltage waveforms of PDM modulation.

[0040] The topology of the multi-electric vehicle wireless charging system is shown in Figure 3. It adopts the LCC-S topology. in is the DC power input, U out Load voltage, MOSFET S1~S4 form a full-bridge inverter circuit, L f1 、Cf1 、C P and L P is the primary side compensation network, C S and L S is the secondary side compensation network, where L P and L S are the self-inductance of the primary coil and the secondary coil respectively, M is the mutual inductance between the coils, diodes D1~D4 form a rectifier circuit, C is the filter capacitor, R L The load. The different pulse densities of the inverter circuit's switching control signals result in different amounts of power received by the electric vehicle, allowing for identification between the electric vehicle and the charging terminal. The electric vehicle is equipped with a PDM demodulation module, which demodulates the load voltage (i.e., the system output voltage) to obtain the transmitter's ID information.

[0041] The present invention is also applicable to multiple charging terminals and multiple electric vehicles. The structure of the electric vehicle wireless charging system with multiple charging terminals and multiple electric vehicles is shown in FIG4 , in which 25 charging terminals (arranged in a 5×5 array) are provided.

[0042] For an electric vehicle wireless charging system with M charging terminals, unique ID information is set for each charging terminal. When M ≤ T, T is the threshold number of charging terminals. The mth charging terminal among the M charging terminals is modulated according to the first modulation method as follows:

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

[0044] At the second timing, the pulse density is P m =a1+bm, where a1 represents the starting value of the first pulse density, b represents the difference in pulse density 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, b=2, then in the first time sequence, a PDM characteristic wave with a pulse density of 1 is sent, and in the second time sequence, a PDM characteristic wave with a pulse density of P is sent. 10 =5+2*10=25 PDM characteristic wave.

[0046] The electric vehicle is 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 according to the first corresponding relationship between the voltage signal and the pulse density, and then determines to perform demodulation according to the following first demodulation method:

[0048] 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 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 time sequence and the pulse density ID relationship of the transmitting end ID information (which has been stored in the electric vehicle in advance).

[0049] When M is large, in order to avoid excessive pulse density causing more consumption on the circuit, increasing the difficulty of modulation and demodulation, and causing other adverse effects, this embodiment also provides a second modulation and demodulation mode, namely:

[0050] When M>T, the modulation mode for the mth charging terminal among the M charging terminals is:

[0051] Divide M charging terminals into N groups, N= , Indicates rounding up;

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

[0053] In the second sequence, a PDM characteristic wave with a pulse density of R+2 is sent, R= ;

[0054] At the third timing, the pulse density is P' k =a2+bk, k=mT(R-1), a2 represents the starting value of the second pulse density, a2≥N.

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

[0056] The electric vehicle is 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 according to the voltage density relationship, and then determines to perform demodulation according to the following second demodulation method:

[0058] detecting a voltage signal of a second time sequence and determining a pulse density of the second time sequence according to a voltage density relationship;

[0059] detecting a voltage signal of a third time sequence and determining a pulse density of the third time sequence according to a voltage density relationship;

[0060] The ID information of the charging terminal is obtained according to the pulse density of the second time sequence, the pulse density of the third time sequence and the pulse density ID relationship of the transmitting terminal ID information (which has been stored in the electric vehicle in advance).

[0061] When the electric vehicle detects that the voltage signal of the first time sequence is neither 1 nor 2 (a fault may occur at the charging end), a reminder is issued to move the electric vehicle to another charging area.

[0062] The specific values ​​of T, a1, a2, b, and M are for illustration only and can be arbitrarily selected within the optional range of these parameters according to actual needs.

[0063] In summary, the electric vehicle wireless charging system based on PDM characteristic wave ID authentication provided by the embodiment of the present invention, when the electric vehicle is docked in the charging area, transmits an electric energy signal with the charging terminal ID information to the electric vehicle by controlling the pulse density of the charging terminal inverter switch. The electric vehicle recognizes this ID signal and connects with it, 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 the present 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 transmission power values, and the ID information of the charging end is transmitted to the electric vehicle in the form of electrical energy. No additional equipment is required during the identity authentication process, the structure is simple, and cost saving;

[0066] 3. Electric vehicles can identify the identity information of the charging end by detecting the received electric energy value. During the wireless power transmission process, the power transmission speed is fast, so it has the advantage of fast identity authentication speed. When the electric vehicle receives the power signal with the charging end ID information, it can communicate with it, which has the advantages of high connection accuracy and no channel crosstalk problems.

[0067] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. An electric vehicle wireless charging system for ID authentication based on PDM characteristic waves, characterized in that: It includes a charging terminal and an electric vehicle, wherein the charging terminal is provided with a high-frequency inverter and a PDM modulation module. When the charging terminal senses that the electric vehicle is parked in its charging area, the PDM modulation module is controlled to modulate the ID information of the charging terminal into a PDM characteristic wave and act on the high-frequency inverter. The high-frequency inverter transmits an electric energy signal with the ID information of the charging terminal to the electric vehicle. After receiving the electric energy signal, the electric vehicle demodulates the signal 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.

2. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 1 is characterized in that: The system is provided with M charging terminals, M≥2; Unique ID information is set for each charging terminal. When M≤T, T is the threshold number of charging terminals. The mth charging terminal among the M charging terminals is modulated according to the following first modulation mode: In the first timing sequence, a PDM characteristic wave with a pulse density of 1 is sent; In the second timing, the pulse density is P m =a1+bm, a1 represents the first pulse density starting value, b represents the pulse density difference between two adjacent charging terminals, a1≥2 and is an integer, b≥1 and is an integer.

3. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 2 is characterized in that: The electric vehicle is demodulated as follows: 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 according to the first corresponding relationship between the voltage signal and the pulse density, and then determines to perform demodulation according to the following first demodulation mode: 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 between the voltage signal and the pulse density, and then the ID information of the charging end is obtained according to the density ID relationship between the pulse density of the second time sequence and the ID information of the transmitting end.

4. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 3 is characterized in that: When M>T, the modulation mode of the mth charging terminal among the M charging terminals is: Divide the M charging terminals into N groups, N= ， Indicates rounding up; At the first timing, a PDM characteristic wave with a pulse density of 2 is sent; In the second timing, a PDM characteristic wave with a pulse density of R+2 is sent, R= ； At the third timing, the pulse density is P' k =a2+bk, k=mT(R-1), a2 represents the starting value of the second pulse density, a2≥N.

5. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 4 is characterized in that: The electric vehicle is demodulated as follows: 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 according to the voltage density relationship, and then determines to perform demodulation according to the following second demodulation mode: Detecting a voltage signal of a second time sequence and determining a pulse density of the second time sequence according to the voltage density relationship; Detecting a voltage signal of a third time sequence and determining a pulse density of the third time sequence according to the voltage density relationship; The ID information of the charging terminal is obtained according to the pulse density of the second time sequence, the pulse density of the third time sequence and the pulse density ID of the transmitting terminal ID information.

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

7. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 5 is characterized in that: The system also includes a main control machine connected to the charging terminal; After establishing a communication connection between a group of the transmitters and the electric vehicle, the electric vehicle sends a charging request to the transmitter to which it is connected. The transmitter sends its own ID information and the ID information of the electric vehicle it receives to the main control machine via the WiFi hotspot. The main control machine controls the charging line of the transmitter corresponding to the ID to be in standby mode. After the transmitter confirms that the interoperability information of the electric vehicle has passed, it starts charging the electric vehicle.

8. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 6 is characterized in that: The M transmitting ends are arranged in an array.

9. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 6 is characterized in that: T≥20。 10. The electric vehicle wireless charging system for ID authentication based on PDM characteristic waves according to claim 9 is characterized in that: T=25, a1=a2=5, b=2.

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