A dual-channel wireless energy supply system and its communication-free power control method

Abstract

The present invention discloses a dual-channel wireless energy supply system and a communication-free power control method thereof, which relates to the field of wireless power transmission technology. The system includes a primary transmitting end and a secondary receiving end. The primary transmitting end and the secondary receiving end jointly construct a fundamental main power channel CH1 and a third harmonic channel CH2. The primary transmitting end and the secondary receiving end realize the coupled transmission of energy and signal through a dual-channel magnetic coupling structure. The method of the present invention adjusts the phase of the third harmonic current through the active rectification circuit of the secondary receiving end, and transmits the load state to the primary transmitting end in the form of a phase offset. After the primary transmitting end detects the phase information, it adjusts the duty cycle of the full-bridge inverter through a closed loop to realize adaptive control of the system output power. The present invention uses the harmonic channel to complete the communication-free transmission of the load state, and combines the phase information to perform closed-loop regulation and expand the power range of ZVS to achieve stable and efficient wireless power transmission control.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power transmission, and in particular to a dual-channel wireless power supply system and a communication-free power control method thereof. Background Art

[0002] Wireless Power Transfer (WPT) technology holds broad application prospects in areas such as electric vehicle charging, industrial automation, and consumer electronics. In the electric vehicle sector in particular, wireless charging is becoming a key development direction, as it eliminates mechanical contact, improves charging convenience, and enhances system durability. However, to achieve reliable power control, most existing WPT systems still rely on a communication link between the primary side (transmitter) and the secondary side (receiver). Wireless communication methods, such as Bluetooth, Wi-Fi, and radio frequency identification, are used to transmit load information or feedback power commands. These communication methods are susceptible to interference in complex electromagnetic environments, leading to control failures. Furthermore, their communication modules increase the system's hardware cost and control complexity. Existing communication-dependent WPT control solutions are limited in applications requiring high reliability and low system complexity, such as rail transit and industrial mobile equipment.

[0003] On the other hand, existing WPT systems typically use a fundamental resonant channel for primary power transmission, but achieving zero voltage switching (ZVS) in full-bridge inverters in the low- to medium-power range presents significant challenges. Failure to achieve ZVS significantly increases converter switching losses, reducing overall system efficiency and lifespan. Furthermore, in applications such as electric vehicles, the system must contend with non-ideal operating conditions such as dynamic changes in battery load impedance and coil position deviation, further exacerbating the control system's adaptability challenges.

[0004] To address these issues, research has proposed power regulation without communication. However, most approaches still rely on voltage or current amplitude to infer load status, resulting in insufficient robustness and regulation accuracy. Furthermore, technical bottlenecks remain in switch optimization and low-power operation stability.

[0005] Therefore, there is an urgent need for a control method that does not require communication, has high dynamic adaptability and low complexity, and can achieve power regulation and switching optimization through a new feedback mechanism without changing the main topology of the system. Summary of the Invention

[0006] In order to solve the problems of existing wireless power transmission systems being highly dependent on communication modules, having complex power regulation methods, having poor system stability, and having difficulty in achieving zero-voltage switching of inverters in the low-power range, the present invention proposes a dual-channel wireless power supply system and a communication-free power control method thereof, which can achieve stable and reliable power regulation without the need for communication equipment, while expanding the operating range of the inverter's zero-voltage switch, improving system efficiency and load adaptability, and thus solving the above-mentioned problems.

[0007] The present application discloses a dual-channel wireless energy supply system, comprising a primary-side transmitting end and a secondary-side receiving end;

[0008] The primary transmitting end includes a full-bridge inverter composed of a first bridge arm H1 and a second bridge arm H2, and a DC voltage is connected in parallel on the input side of the full-bridge inverter. and the first capacitor , the midpoint of the first bridge arm H1 and the midpoint of the second bridge arm H2 The primary fundamental wave main power channel is connected between them, and the midpoint of the first bridge arm H1 A primary third harmonic channel is connected to the reference ground g;

[0009] The secondary side receiving end includes a diode rectifier half-bridge H3 and an active rectifier half-bridge H4 connected in parallel, and a second capacitor is connected in parallel on the output side of the secondary side receiving end. and the third capacitor The series circuit, diode rectifier half bridge H3 midpoint With the second capacitor , the third capacitor midpoint of a series circuit The secondary fundamental wave main power channel is connected between the active rectifier half bridge H4 midpoint With the second capacitor , the third capacitor midpoint of a series circuit There is a secondary side third harmonic channel connected between them;

[0010] The primary transmitting end and the secondary receiving end realize the coupled transmission of energy and signal through a dual-channel magnetic coupling structure.

[0011] Preferably, the primary side fundamental wave main power channel and the secondary side fundamental wave main power channel constitute a fundamental wave main power channel CH1, and the primary side third harmonic channel and the secondary side third harmonic channel constitute a third harmonic channel CH2;

[0012] The midpoint of the first bridge arm H1 and the midpoint of the second bridge arm H2 A fourth capacitor is connected between and the first primary coil , the midpoint of the first bridge arm H1 A fifth capacitor is connected between the reference ground and the second primary coil , diode rectifier half bridge H3 midpoint With the second capacitor , the third capacitor midpoint of a series circuit A sixth capacitor is connected between and the first secondary coil , active rectifier half bridge H4 midpoint With the second capacitor , the third capacitor midpoint of a series circuit A seventh capacitor is connected between and the second secondary coil .

[0013] Preferably, the dual-channel magnetic coupling structure includes a first primary coil , Second primary coil , the first secondary coil and the second secondary coil ;

[0014] The first primary coil and the first secondary coil It is a square coil, the second primary coil and the second secondary coil It is an 8-shaped coil, the first primary coil and the second primary coil Stacked, first secondary coil and the second secondary coil Stack.

[0015] Preferably, the primary third harmonic channel is sequentially connected to a first zero-crossing sampling module ZCD1 and a primary controller FPGA-A;

[0016] The secondary side fundamental wave main power channel is connected in sequence to the second zero crossing sampling module ZCD2 and the secondary side controller FPGA-B;

[0017] The secondary-side third harmonic channel is sequentially connected to the third zero-crossing sampling module ZCD3 and the secondary-side controller FPGA-B.

[0018] Preferably, the output end of the secondary side receiving end is connected to a voltage sensor VS and a current sensor CS, and both the voltage sensor VS and the current sensor CS are connected to the secondary side controller FPGA-B.

[0019] The present application also discloses a non-communication power control method for a dual-channel wireless energy supply system, which is applicable to the above-mentioned dual-channel wireless energy supply system and includes the following steps:

[0020] S1, at the secondary side receiving end, according to the actual output power and setting target power The error power signal between Generate a phase shift angle control instruction, and use the phase shift angle control instruction to make the secondary third harmonic current of the secondary third harmonic channel Phase Producing phase shift ;

[0021] S2, the secondary side receiving end shifts the phase obtained by S1 through the third harmonic channel CH2 Transmitted to the primary transmitting end, the transmission relying on the frequency response characteristics of the third harmonic channel, without the need for a communication device;

[0022] S3. In the primary transmitting end, detect and calculate the primary third harmonic current And the primary third harmonic channel port voltage The phase difference between and the phase difference with the reference Compare and obtain the primary third harmonic current The phase error signal ;

[0023] S4, according to the primary third harmonic current The phase error signal , adjust the duty cycle of the full-bridge inverter , realize closed-loop regulation of the fundamental wave main power channel CH1 power;

[0024] S5. By superimposing the third harmonic current and the fundamental current, the zero voltage switching operating range of the primary-side transmitter full-bridge inverter is extended.

[0025] Preferably, said S1 comprises the following steps:

[0026] S11, use the voltage sensor VS and current sensor CS to collect the rectifier output voltage in real time and rectified output current ;

[0027] S12. Calculate actual output power and set the target power Compare and get the error power signal ;

[0028] S13, the error power signal Input the proportional-integral control module in the secondary side controller FPGA-B to generate the phase shift angle control instruction and ;

[0029] S14, according to the phase shift angle control instruction and Control the conduction timing of the switch devices in the active rectifier half-bridge H4, so that the secondary third harmonic current in the secondary third harmonic channel Phase Producing phase shift .

[0030] Preferably, said S3 comprises the following steps:

[0031] S31, collect the primary third harmonic current in the primary third harmonic channel of the primary transmitting end And the primary third harmonic channel port voltage ;

[0032] S32, using the method of combining zero-crossing detection with low-pass filtering, the primary third harmonic current The zero crossing point is converted into a digital pulse sequence and the phase , primary third harmonic channel port voltage Phase The phase of the switching signal output by the corresponding controller is replaced by the phase of the primary third harmonic current. The pulse sequence and the primary third harmonic channel port voltage Phase Calculate the phase difference between voltage and current ;

[0033] S33, the phase difference Phase difference from the set reference Compare and calculate the phase error signal of the primary transmitter .

[0034] Preferably, said S4 comprises the following steps:

[0035] The phase error signal Input the proportional-integral control module in the primary side controller FPGA-A to generate the change value of the phase shift duty cycle , adjust the duty cycle of the full-bridge inverter in the primary transmitter , realizing real-time power adjustment of fundamental wave main power channel CH1.

[0036] Preferably, the S5 comprises the following steps:

[0037] The primary third harmonic current Injected through the first bridge arm H1, and the primary fundamental current By superimposing the first bridge arm H1, the ZVS conduction current condition is achieved in the low power range, thereby extending the zero voltage switching operating range of the full-bridge inverter.

[0038] Beneficial effects of the present invention:

[0039] (1) No communication module is required, and the structure is simpler. Harmonic current phase offset is used as feedback information, and no communication equipment such as Bluetooth and Wi-Fi is required, which reduces system complexity and cost and improves anti-interference ability.

[0040] (2) Strong power adaptive regulation capability. The secondary side receiver adjusts the harmonic phase through error driving, and the primary side (transmitter) detects and controls the power output in real time, forming a complete closed loop, which is suitable for application scenarios with frequent load changes;

[0041] (3) Assist in achieving zero voltage switching. By introducing the third harmonic current, the ZVS operating range of the primary-side transmitter inverter in the low-power region is expanded, effectively reducing switching losses and improving system efficiency.

[0042] (4) Strong structural versatility. This method is applicable to typical dual-channel wireless energy transmission systems, compatible with the H-type full-bridge structure at the primary transmitter and the hybrid rectification structure at the secondary receiver, and is easy to integrate and promote;

[0043] (5) Wide range of applicable scenarios. It is suitable for high-power wireless energy supply systems such as wireless charging of electric vehicles, industrial robots, and contactless power supply for rail transportation, and has good adaptability and robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the topology of a dual-channel wireless power transmission system applicable to the control method of the present invention;

[0045] Figure 2 This is a schematic structural diagram of the dual-channel magnetic coupler of the present invention;

[0046] Figure 3 This is a control flow chart of the wireless power transmission power control method based on third harmonic phase feedback according to the present invention;

[0047] Figure 4 It is the zero-crossing detection and digital low-pass filtering implementation scheme of the present invention;

[0048] Figure 5 This is a working waveform diagram of the system of the present invention achieving zero voltage switching (ZVS) state within the full power range;

[0049] Figure 6 This is the experimental waveform for verifying the effectiveness of the wireless power transmission power control method based on third harmonic phase feedback described in the present invention. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of this application more clear, the application is further described in detail below with reference to the accompanying drawings and examples.

[0051] An embodiment of the present application discloses a dual-channel wireless energy supply system, including a primary transmitting end and a secondary receiving end, which together construct a fundamental wave main power channel CH1 and a third harmonic channel CH2. The fundamental wave main power channel CH1 is used for main energy transmission, and the third harmonic channel CH2 is used for feedback control and undertakes part of the power transmission function. The specific structure of the dual-channel wireless energy supply system in this embodiment is as follows: Figure 1 shown.

[0052] The primary transmitting end includes a full-bridge inverter composed of a first bridge arm H1 and a second bridge arm H2 to drive two resonant branches, the fundamental main power channel CH1 and the third harmonic channel CH2. The first bridge arm H1 includes a first switching device connected in series. and the second switching device , the midpoint of the first bridge arm H1 Located in the first switching device and the second switching device The second bridge arm H2 includes a third switching device connected in series. and the fourth switching device , the midpoint of the second bridge arm H2 Located in the third switch device and the fourth switching device The midpoint of the first bridge arm H1 and the midpoint of the second bridge arm H2 A fourth capacitor is connected between and the first primary coil , the fourth capacitor and the first primary coil Connect in series. The midpoint of the first bridge arm H1 A fifth capacitor is connected between the reference ground and the second primary coil , there is a fifth capacitor and the second primary coil Connect in series. The midpoint of the first bridge arm H1 and the midpoint of the second bridge arm H2 The circuit between them is the primary fundamental wave main power channel, and the midpoint of the first bridge arm H1 is The circuit between the reference ground g is the primary third harmonic channel. The full-bridge inverter input side is connected in parallel with a DC voltage and the first capacitor , DC voltage and the first capacitor Parallel. Primary DC side input current The first capacitor Charge and supply energy to the first bridge arm H1 and the second bridge arm H2.

[0053] The secondary side receiving end includes a diode rectifier half bridge H3 and an active rectifier half bridge H4 connected in parallel. The diode rectifier half bridge H3 includes a first diode connected in series. and the second diode , diode rectifier half bridge H3 midpoint Located in the first diode and the second diode The active rectifier half-bridge H4 includes a first active switching device connected in series and a second active switching device , active rectifier half bridge H4 midpoint Located in the first active switching device and a second active switching device A second capacitor is connected in parallel to the output side of the secondary receiving end. and the third capacitor The series circuit, diode rectifier half bridge H3 midpoint With the second capacitor , the third capacitor midpoint of a series circuit A sixth capacitor is connected between and the first secondary coil , the sixth capacitor and the first secondary coil Series, active rectifier half bridge H4 midpoint With the second capacitor , the third capacitor midpoint of a series circuit A seventh capacitor is connected between and the second secondary coil , the seventh capacitor and the second secondary coil Series. Diode rectifier half bridge H3 midpoint With the second capacitor , the third capacitor midpoint of a series circuit The circuit between is the secondary side fundamental wave main power channel, the active rectifier half bridge H4 midpoint With the second capacitor , the third capacitor midpoint of a series circuit The circuit between is the secondary side third harmonic channel. Secondary side DC input current For load Energy supply.

[0054] The fundamental main power channel of the primary side and the fundamental main power channel of the secondary side constitute the fundamental main power channel CH1, and the primary third harmonic channel and the secondary third harmonic channel constitute the third harmonic channel CH2. Among them, the fundamental main power channel CH1 is driven by the full-bridge inverter and is connected to the fundamental resonant network ( 、 、 、 ) transmits fundamental power. The third harmonic channel CH2 is powered by the half-bridge inverter H1 and is connected to the third harmonic resonant network ( 、 、 、 ) transmits the third harmonic feedback signal. The secondary side receiving end uses a diode half-bridge rectifier H3 to rectify the fundamental power and rectify the fundamental frequency power into a DC voltage to supply the load. The phase of the third harmonic channel CH2 is regulated by the active rectifier half-bridge H4 to achieve closed-loop power regulation without communication. A supporting capacitor is used on the input side (the first capacitor ) to provide a stable DC voltage, the secondary side receiving end output side uses a second capacitor and the third capacitor Connect in series to reduce output voltage ripple and provide a neutral potential point .

[0055] The energy and signal are coupled and transferred between the primary transmitting end and the secondary receiving end through a dual-channel magnetic coupling structure. Figure 2 As shown, the dual-channel magnetic coupling structure includes a first primary coil , Second primary coil , the first secondary coil and the second secondary coil The primary transmitting end and the secondary receiving end are composed of two independent winding systems. and the first secondary coil It is a square coil, forming the fundamental wave main power channel CH1. and the second secondary coil It is an 8-shaped coil, forming the third harmonic channel CH2, which is used for phase feedback and partial power transmission. and the second primary coil of the third harmonic channel coil Stacked, the fundamental channel coil of the secondary receiving end and the first secondary coil and the second secondary coil of the third harmonic channel coil The stacking solution reduces the overall footprint and also eliminates the interference between different channels due to the 8-shaped coil characteristics of the third harmonic channel. The mutual inductance between them avoids the mutual interference of different channels, which affects the transmission power and signal transmission.

[0056] At the same time, the mutual inductance between the primary and secondary sides of the same channel is not affected. Figure 1 and Figure 2 As shown, It is the main mutual inductance of the fundamental main power channel CH1, ensuring power transmission efficiency; The mutual inductance of the third harmonic channel CH2 is used for signal feedback and partial harmonic power transmission. In order to make CH1 work at the fundamental frequency and CH2 work at the third harmonic frequency, the system resonance parameters need to be configured as follows:

[0057]

[0058] in, is the angular frequency of the fundamental main power current, in rad / s. Similarly, the angular frequency of the third harmonic current is .

[0059] In order to provide a hardware foundation for the subsequent control method, the dual-channel wireless energy supply system in this embodiment is equipped with a signal acquisition device, specifically as follows Figure 1 As shown. At the primary transmitting end, the primary third harmonic channel is connected to the first zero-crossing sampling module ZCD1 and the primary controller FPGA-A in sequence. At the secondary receiving end, the secondary third harmonic channel is connected to the third zero-crossing sampling module ZCD3 and the secondary controller FPGA-B in sequence. Load The output end of the secondary side receiving end is set, and the output end of the secondary side receiving end is also connected to a voltage sensor VS and a current sensor CS, and both the voltage sensor VS and the current sensor CS are connected to the secondary side controller FPGA-B.

[0060] In another embodiment of the present application, a non-communication power control method for a dual-channel wireless energy supply system is also disclosed. The method is applicable to the above-mentioned dual-channel wireless energy supply system. The specific process is as follows: Figure 3 When the dual-channel wireless energy supply system starts, the primary side transmitter full-bridge inverter (H1 and H2) operates at the fundamental frequency. , driving the fundamental resonant network ( 、 、 、 ) to achieve wireless power transmission. The secondary side receiving diode rectifier half bridge H3 converts the received fundamental power into a DC voltage , used to power the load. Simultaneously, the third harmonic channel CH2 is driven by the active rectifier half-bridge H4, establishing a feedback signal path. Specifically, the communication-free power control method for the dual-channel wireless energy supply system disclosed in this embodiment includes two stages: Stage 1 and Stage 2.

[0061] Phase 1

[0062] like Figure 3 As shown in (a), the primary side controller FPGA-A, the corresponding reference clock is Clock A. The initial setting duty cycle is (Recommended value is 0.3), generating control signal To drive the switching devices in the primary side transmitter full bridge inverter , generating the primary fundamental wave main power channel port voltage And the primary third harmonic channel port voltage At the primary transmitting end, the primary controller FPGA-A is responsible for outputting the first switching device and the second switching device The switching waveform of the primary side is obtained by using zero-crossing detection and digital low-pass filtering (ZCD-DLPF). Perform zero-crossing detection and obtain the primary third harmonic current Cycle .

[0063] Current zero-crossing detection and digital low-pass filtering solutions such as Figure 4 As shown, the current entering the current sampling is , through a 1:40 current transformer TA, the sampling current is reduced to 1 / 40, and the sampling output current is obtained , the sampled output current is converted to Converted into voltage signal . The voltage signal Combined with the comparator TLV3502 to convert the current Zero-crossing pulse , and input into the FPGA I / O. After the FPGA detects the level change of the corresponding I / O, it passes through a low-pass digital filter DLPF to reduce the interference of the zero-crossing pulse. and cycle After the low-pass digital filter DLPF, the zero-crossing phase is output and cycle The FPGA model used in this embodiment is EP3C25E144I7N.

[0064] For the above primary third harmonic current Cycle Perform 2048 consecutive samplings to determine whether the change is less than the third harmonic period. (Fundamental period If the condition is met for 2048 consecutive samples, the initialization of the primary transmitter is determined to be complete. Otherwise, the sampling times are recalculated until the current cycle change value is less than the fundamental wave period for 2048 consecutive samples. 1 / 3 of the primary third harmonic current The periodic change value is expressed as:

[0065]

[0066] in, and is the primary third harmonic current The two adjacent cycles detected after the low-pass digital filter DLPF are used to calculate the change value of the two adjacent cycles. .

[0067] like Figure 3 As shown in (b), the secondary side controller FPGA-B, the corresponding reference clock is Clock B. The first diode in the diode rectifier half bridge H3 is driven , the second diode and the first active switching device in the active rectifier half-bridge H4 , the second active switching device , making it in diode rectification mode (DRM). At this time, the secondary side third harmonic channel is only used as a power channel. Zero crossing detection and digital low-pass filtering (ZCD-DLPF) are used to sample the secondary side fundamental current respectively. and the secondary third harmonic current Zero-crossing period and Similarly, when the above two cycles and Keep less than the fundamental period within 2048 samples and the third harmonic period The error range of 5% indicates that the secondary side receiving end is initialized. The periodic change value of each current is:

[0068]

[0069] in, and is the secondary side fundamental current The two adjacent cycles detected after the low-pass digital filter DLPF are used to calculate the two adjacent secondary fundamental currents. Change value of the cycle . and is the secondary third harmonic current The two adjacent cycles detected after the low-pass digital filter DLPF are used to calculate the third harmonic current of the two adjacent secondary sides. Change value of the cycle .

[0070] After initialization is completed, the secondary side fundamental current and the secondary third harmonic current Phase difference Stored to the FPGA controller's memory as .in The calculation formula is as follows:

[0071]

[0072] in, is the secondary third harmonic current The real-time phase, is the secondary side fundamental current The real-time phase.

[0073] Phase 2

[0074] Phase 2 is the real-time power regulation phase, such as Figure 3 As shown in (c), (d), and (e), the following steps are included:

[0075] S1, at the secondary side receiving end, according to the actual output power and setting target power The error power signal between Generate a phase shift angle control instruction, and use the phase shift angle control instruction to make the secondary third harmonic current of the secondary third harmonic channel Real-time phase Producing phase shift .

[0076] S11, use the voltage sensor VS and current sensor CS to collect the rectifier output voltage in real time and rectified output current .

[0077] S12, using the rectifier output voltage and rectified output current Calculate actual output power , and the actual output power and setting target power Compare and get the error power signal .

[0078] S13, the error power signal Input the proportional-integral (PI) control module in the secondary side controller FPGA-B to generate the phase shift angle control instruction and .

[0079] S14, according to the phase shift angle control instruction and Control the conduction timing of the switch devices in the active rectifier half-bridge H4, so that the secondary third harmonic current in the secondary third harmonic channel Real-time phase Producing phase shift .

[0080] Specifically, according to the phase shift angle control instruction and Calculate the secondary harmonic port voltage Relative secondary third harmonic current Phase shift angle . And according to the secondary side fundamental current detected by the secondary side receiving end Phase as a reference, combined with the stored phase difference , calculate the secondary third harmonic current Real-time phase , the calculation formula is as follows:

[0081]

[0082] Combined with the proportional-integral control module, the Real-time adjustments and , and then adjust the first active switching device in real time and a second active switching device phase, thus generating the secondary third harmonic current Real-time phase Producing phase shift Phase Shift It is used to feedback the power change of the secondary side receiving end. At the same time, the third harmonic channel CH2 has the ability to transmit power to the load. Transfer some power.

[0083] S2, the secondary side receiving end shifts the phase obtained by S1 through the third harmonic channel CH2 Transmission to the primary transmitter relies on the frequency response characteristics of the third harmonic channel and does not require a communication device.

[0084] Third harmonic channel CH2 independent transmission Due to the series resonance characteristics, the phase offset information is directly transmitted to the primary transmitting end along with the current waveform, so no communication device is required.

[0085] S3. In the primary transmitting end, detect and calculate the primary third harmonic current And the primary third harmonic channel port voltage The phase difference between and the phase difference with the reference Compare and obtain the primary third harmonic current The phase error signal .

[0086] S31, collect the primary third harmonic current in the primary third harmonic channel of the primary transmitting end And the primary third harmonic channel port voltage .

[0087] S32, the primary transmitting end samples the primary third harmonic current through the first zero-crossing sampling module ZCD1. The zero crossing point of the primary side harmonic current is detected by combining zero crossing detection with low-pass filtering. The zero crossing point is converted into a digital pulse sequence and the phase Primary third harmonic channel port voltage Phase The switch signal output by the corresponding controller ( and ) is replaced by the phase of the primary third harmonic channel. The primary third harmonic channel port voltage is calculated as and the primary third harmonic current Phase difference , the calculation formula is as follows:

[0088]

[0089] S33, the phase difference The reference phase difference from the system setting (According to the ZVS boundary or dynamic changes in power requirements) to compare and obtain the primary side phase error signal The purpose of the reference phase difference is to select the appropriate harmonic phase according to the current duty cycle to improve the ZVS condition and ensure that the system can achieve ZVS at different power levels. The calculation formula of the reference phase difference in this embodiment is as follows:

[0090]

[0091] S4, according to the phase error signal , adjust the duty cycle of the full-bridge inverter , realizing closed-loop regulation of the fundamental wave main power channel CH1 power.

[0092] The primary phase error signal Input the proportional-integral control module in the primary side controller FPGA-A, which outputs the duty cycle of the full-bridge inverter Adjustment instructions , used to control the third switching device of the second bridge arm H2 and the fourth switching device Generate new full-bridge inverter duty cycle , realizing closed-loop regulation of the fundamental main power channel CH1.

[0093] S5. By superimposing the third harmonic current and the fundamental current, the zero voltage switching operating range of the primary-side transmitter full-bridge inverter is extended.

[0094] The third harmonic channel CH2 is connected through an independent resonant network ( and ) and the bridge arm midpoint of the primary side transmitter full-bridge inverter (point and point ) to form the primary fundamental current of the fundamental main power channel CH1 The superimposed composite current path provides sufficient discharge current before the full-bridge inverter switch, achieving zero voltage at the device port. Injected through the first bridge arm H1, and the primary fundamental current By superimposing, the first bridge arm H1 has the ZVS conduction current condition in the low power range, extending the zero voltage switching operating range of the full-bridge inverter and improving the system efficiency. The resonant frequency of the third harmonic channel CH2 is three times that of the fundamental main power channel CH1, ensuring that the two channels are decoupled from each other and work independently, avoiding the third harmonic current ( and ) interferes with the fundamental power transmission.

[0095] like Figure 5 As shown, this embodiment uses the third harmonic current Assists in optimizing the ZVS characteristics of the full-bridge inverter, enabling the switching devices to achieve zero voltage switching in a wider power range, reducing switching losses and improving system efficiency. Figure 5 (a) shows the ZVS situation of the traditional WPT system. The switching devices at the primary transmitting end 、 Only fundamental current , and the duty cycle When the comparison is small, ZVS cannot be achieved, resulting in additional switching losses. Figure 5 (b) shows the third harmonic current on the primary side of the solution proposed in this application. Under the action of The system automatically adjusts the primary third harmonic current according to formula (7). phase, so that at different duty cycles Down, and Superposition current The ZVS condition of the first bridge arm H1 is met, and wide-range soft switching is achieved.

[0096] Through the above control method, the system not only realizes dynamic power closed-loop regulation without communication, but also significantly expands the ZVS operating range of the primary-side transmitter inverter, improves the system's operating efficiency and reliability, and is suitable for complex application scenarios.

[0097] In a specific embodiment, the effectiveness of the present application is verified by experiments. The test conditions of the experimental platform are: configure the fundamental frequency 100kHz, the third harmonic frequency 300kHz, the input voltage The voltage is 400V and the rated power of the experiment is 1.7kW. Figure 6 As shown in (a), after the system starts, it completes initialization after a short phase 1 and then enters the dynamic power control phase (phase 2). In phase 2, when the system changes the given voltage When using the non-communication power control method of the dual-channel wireless energy supply system proposed in the embodiment of the present application, the system output voltage can adjust the voltage The output is 252V-180V-252V, realizing power closed-loop control without communication. Figure 6 As shown in (b), after the system starts and completes the initialization of phase 1, it enters the dynamic power control phase (phase 2). In phase 2, when the system load When dynamic changes occur, the non-communication power control method of the dual-channel wireless energy supply system proposed in the application embodiment is used to ensure that the system output voltage can maintain a stable voltage output of 252V, realizing power communication-free closed-loop control. When the load power exceeds 50%, the system efficiency can reach more than 93.5%, and the peak efficiency reaches 94.39%. Under light load conditions, the system still maintains the inverter ZVS conduction, verifying the effectiveness of the harmonic-assisted ZVS mechanism.

[0098] The communication-free power control method for the dual-channel wireless power supply system proposed in this application is applicable to wireless power transmission systems that do not require communication equipment. It can achieve adaptive power regulation under non-ideal working conditions such as load changes and coupling offsets, and maintain the stability and high efficiency of the system output. In addition, the dual-channel wireless power supply system proposed in this application is applicable to high-power application scenarios including but not limited to wireless charging of electric vehicles, wireless power supply of mobile robots, and contactless power supply for rail transit. The dual-channel magnetic coupling structure adopted can reduce the dependence on the precise alignment of the primary and secondary receiving coils under the condition of simultaneous transmission of power and control information, thereby improving the practicality, efficiency and deployment flexibility of the wireless power supply system.

[0099] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A dual-channel wireless energy supply system, characterized in that: Including the primary side transmitter and the secondary side receiver; The primary transmitting end includes a full-bridge inverter composed of a first bridge arm H1 and a second bridge arm H2, and a DC voltage is connected in parallel on the input side of the full-bridge inverter. and the first capacitor , the midpoint of the first bridge arm H1 and the midpoint of the second bridge arm H2 The primary fundamental wave main power channel is connected between them, and the midpoint of the first bridge arm H1 A primary third harmonic channel is connected to the reference ground g; The secondary side receiving end includes a diode rectifier half-bridge H3 and an active rectifier half-bridge H4 connected in parallel, and a second capacitor is connected in parallel on the output side of the secondary side receiving end. and the third capacitor The series circuit, diode rectifier half bridge H3 midpoint With the second capacitor , the third capacitor midpoint of a series circuit The secondary fundamental wave main power channel is connected between the active rectifier half bridge H4 midpoint With the second capacitor , the third capacitor midpoint of a series circuit There is a secondary side third harmonic channel connected between them; The primary transmitting end and the secondary receiving end realize the coupled transmission of energy and signal through a dual-channel magnetic coupling structure.

2. The dual-channel wireless energy supply system according to claim 1, characterized in that: The primary side fundamental wave main power channel and the secondary side fundamental wave main power channel constitute the fundamental wave main power channel CH1, and the primary side third harmonic channel and the secondary side third harmonic channel constitute the third harmonic channel CH2; The midpoint of the first bridge arm H1 and the midpoint of the second bridge arm H2 A fourth capacitor is connected between and the first primary coil , the midpoint of the first bridge arm H1 A fifth capacitor is connected between the reference ground and the second primary coil , diode rectifier half bridge H3 midpoint With the second capacitor , the third capacitor midpoint of a series circuit A sixth capacitor is connected between and the first secondary coil , active rectifier half bridge H4 midpoint With the second capacitor , the third capacitor midpoint of a series circuit A seventh capacitor is connected between and the second secondary coil .

3. The dual-channel wireless energy supply system according to claim 2, characterized in that: The dual-channel magnetic coupling structure includes a first primary coil , Second primary coil , the first secondary coil and the second secondary coil ; The first primary coil and the first secondary coil It is a square coil, the second primary coil and the second secondary coil It is an 8-shaped coil, the first primary coil and the second primary coil Stacked, first secondary coil and the second secondary coil Stack.

4. The dual-channel wireless energy supply system according to claim 3, characterized in that: The primary third harmonic channel is connected in sequence to the first zero-crossing sampling module ZCD1 and the primary controller FPGA-A; The secondary side fundamental wave main power channel is connected in sequence to the second zero crossing sampling module ZCD2 and the secondary side controller FPGA-B; The secondary-side third harmonic channel is sequentially connected to the third zero-crossing sampling module ZCD3 and the secondary-side controller FPGA-B.

5. The dual-channel wireless energy supply system according to claim 4, characterized in that: The output end of the secondary side receiving end is connected to a voltage sensor VS and a current sensor CS, and both the voltage sensor VS and the current sensor CS are connected to the secondary side controller FPGA-B.

6. A non-communication power control method for a dual-channel wireless energy supply system, characterized in that: The dual-channel wireless energy supply system according to any one of claims 1 to 5 comprises the following steps: S1, at the secondary side receiving end, according to the actual output power and setting target power The error power signal between Generate a phase shift angle control instruction, and use the phase shift angle control instruction to make the secondary third harmonic current of the secondary third harmonic channel Phase Producing phase shift ; S2, the secondary side receiving end shifts the phase obtained by S1 through the third harmonic channel CH2 Transmitted to the primary transmitting end, the transmission relying on the frequency response characteristics of the third harmonic channel, without the need for a communication device; S3. In the primary transmitting end, detect and calculate the primary third harmonic current And the primary third harmonic channel port voltage The phase difference between and the phase difference with the reference Compare and obtain the primary third harmonic current The phase error signal ; S4, according to the primary third harmonic current The phase error signal , adjust the duty cycle of the full-bridge inverter , realize closed-loop regulation of the fundamental wave main power channel CH1 power; S5. By superimposing the third harmonic current and the fundamental current, the zero voltage switching operating range of the primary-side transmitter full-bridge inverter is extended.

7. The non-communication power control method of the dual-channel wireless energy supply system according to claim 6, characterized in that: Said S1 comprises the following steps: S11, use the voltage sensor VS and current sensor CS to collect the rectifier output voltage in real time and rectified output current ; S12. Calculate actual output power and set the target power Compare and get the error power signal ; S13, the error power signal Input the proportional-integral control module in the secondary side controller FPGA-B to generate the phase shift angle control instruction and ; S14, according to the phase shift angle control instruction and Control the conduction timing of the switch devices in the active rectifier half-bridge H4, so that the secondary third harmonic current in the secondary third harmonic channel Phase Producing phase shift .

8. The non-communication power control method of the dual-channel wireless energy supply system according to claim 7, characterized in that: The S3 includes the following steps: S31, collect the primary third harmonic current in the primary third harmonic channel of the primary transmitting end And the primary third harmonic channel port voltage ; S32, using the method of combining zero-crossing detection with low-pass filtering, the primary third harmonic current The zero crossing point is converted into a digital pulse sequence and the phase , primary third harmonic channel port voltage Phase The phase of the switching signal output by the corresponding controller is replaced by the phase of the primary third harmonic current. The pulse sequence and the primary third harmonic channel port voltage Phase Calculate the phase difference between voltage and current ; S33, the phase difference Phase difference from the set reference Compare and calculate the phase error signal of the primary transmitter .

9. The non-communication power control method of the dual-channel wireless energy supply system according to claim 8, characterized in that: The S4 comprises the following steps: The phase error signal Input the proportional-integral control module in the primary side controller FPGA-A to generate the change value of the phase shift duty cycle , adjust the duty cycle of the full-bridge inverter in the primary transmitter , realizing real-time power adjustment of fundamental wave main power channel CH1.

10. The non-communication power control method of the dual-channel wireless energy supply system according to claim 9, characterized in that: The S5 comprises the following steps: The primary third harmonic current Injected through the first bridge arm H1, and the primary fundamental current By superimposing the first bridge arm H1, the ZVS conduction current condition is achieved in the low power range, thereby extending the zero voltage switching operating range of the full-bridge inverter.

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