Active resonance wireless power supply system receiving end based on boost circuit and control method thereof

Abstract

The invention provides an active resonance wireless power supply system receiving end based on a boost circuit and a control method thereof, the receiving end comprises a transmitting device and a receiving device, the transmitting device comprises a transmitting coil Lp, an inverter and an LCC transmitting side compensation structure connected with the transmitting coil Lp, the receiving device comprises a receiving coil, a rectifier bridge part, a boost inductor LB, a first change-over switch S1, a diode and an output compensation capacitor, the receiving coil is connected with the rectifier part, a receiving side capacitor is omitted, the rectifier part is connected with the boost inductor LB, the other side of the boost inductor LB is connected with the anode of the diode and the first change-over switch S1, and the output compensation capacitor is connected with the diode. And the cathode of the diode is connected with the output compensation capacitor Cout. According to the system, the boost topology is utilized, active resonance of the receiving side is achieved through a composite control strategy, the problem of wireless power supply detuning is solved, the reactive power is low, the system efficiency in the full power range can be kept at a high level, and meanwhile the power density of the system can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power supply, and in particular to a boost circuit-based active resonant wireless power supply system receiving end and a control method thereof. Background Art

[0002] The multi-track wireless power system is an innovative system based on Wireless Power Transfer (WPT) technology, designed to overcome the shortcomings of traditional wired electrical connections. Its exceptional reliability and portability have led to its widespread application in mobile electronics, implantable medical devices, and electric vehicles. In semiconductor factories, this technology is primarily used in overhead hoist transfer (OHT) production lines, meeting the demands of high-precision, dust-free handling.

[0003] OHT systems in semiconductor factories require highly flexible transport units to improve production efficiency. Existing wireless power supply devices often use a three-stage cascade structure consisting of a resonant section, a rectifier, and a DC converter, making it difficult to reduce the size of the receiving side.

[0004] In practical applications, the reduced efficiency and insufficient stability caused by detuning have not been effectively addressed. Therefore, this technology solves many challenges in practical applications and provides strong support for the upgrading of wireless power technology. Summary of the Invention

[0005] (1) Technical problems solved In response to the shortcomings of the existing technology, the present invention provides a boost circuit-based active resonant wireless power supply system receiving end and a control method thereof. The boost-based active resonant topology is used to realize the organic combination of receiving-side resonance, rectification and voltage stabilization, and the composite control strategy is proposed to realize constant voltage output and active resonance. When the system faces detuning, mutual inductance and load changes, stable and efficient constant voltage output can still be achieved. The circuit structure is simple, the transmission efficiency is stable, the cost is low, and modular production is possible.

[0006] (2) Technical solution To achieve the above objectives, the present invention is implemented through the following technical solutions: A boost circuit-based active resonant wireless power supply system receiving end and a control method thereof, comprising: A boost circuit-based active resonant wireless power supply system receiver and a corresponding control method are proposed. The wireless power supply receiver achieves resonance correction and voltage stabilization output through the switching of the boost topology to provide energy to the load. The receiver includes a transmitter and a receiver. The transmitting device includes a transmitting coil, an inverter, and an LCC transmitting side compensation structure connected thereto.

[0007] The receiving device includes a receiving coil, a rectifier bridge part, a boost inductor L B , a first switching switch S1, a diode and an output compensation capacitor, the receiving coil is connected to the rectifier part, eliminating the receiving side capacitor, the rectifier part is connected to the boost inductor LB, the other side of the boost inductor is connected to the diode anode and the first switching switch S1, and the cathode of the diode is connected to the output compensation capacitor Cout. By switching the first switching switch S1, the wireless power supply receiving end can achieve constant voltage power supply within a specific transmission distance and a wide load range, and has anti-detuning characteristics.

[0008] Furthermore, the active resonant output voltage relationship satisfies: where Vin is the induced voltage of the receiving side inductor, and its expression is: where M is the mutual inductance of the transmitting coil and the receiving coil, I P is the transmitting coil current.

[0009] Furthermore, the transmitting coil includes a primary inductor and a coil internal resistance connected in series.

[0010] Furthermore, the receiving coil includes a secondary inductor and a coil internal resistance connected in series.

[0011] To solve the above technical problems, the present invention provides a control method under different coupling, different input frequencies and different load conditions, the method comprising the steps of: The frequency and phase information of the transmitting coil current are detected, and the active resonant operating frequency is obtained through the frequency and phase information. The collected information is sent to the hysteresis current control module to generate the corresponding PWM.

[0012] The output voltage is detected and compared with the voltage reference value. The error is sent to the PI controller to generate a current reference value which is sent to the hysteresis current control module. The corresponding control signal is generated through the PWM module.

[0013] The hysteresis current generates a current signal reference value based on the collected data, and sets upper and lower current reference limits based on the preset hysteresis bandwidth. When the actual current value exceeds the upper current reference value, the switching signal is adjusted to close the first switch S1; when the current value is less than the lower current reference value, the switching signal is adjusted to open the first switch S1. This ensures that the active resonant receiving end system is in a zero phase angle state.

[0014] To prevent the active resonant part from having an excessively high frequency during initial startup, duty cycle feedforward control is introduced to reduce the PWM control frequency of the first and third switches, thereby increasing the control speed of the system.

[0015] (3) Beneficial effects By switching the first switching switch S1, the wireless power supply receiving end can achieve constant voltage power supply within a specific transmission distance and a wide load range, and has anti-detuning characteristics. The system of the present invention uses a boost topology and realizes active resonance on the receiving side through a composite control strategy to solve the problem of wireless power supply detuning, so that the reactive power is low, the system efficiency can be maintained at a high level within the entire power range, and the system power density can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings.

[0017] Figure 1 This is a control principle diagram of an active resonant receiving end of an active resonant wireless power supply system based on a boost circuit and a control method thereof of the present invention; Figure 2 This is a schematic diagram of the hysteresis current control principle in a receiving end of an active resonant wireless power supply system based on a boost circuit and a control method thereof according to the present invention; Figure 3 This is a block diagram of a control method in a receiving end of an active resonant wireless power supply system based on a boost circuit and a control method thereof of the present invention; Figure 4 This is a block diagram of a control method for a receiving end of an active resonant wireless power supply system based on a boost circuit and a control method thereof of the present invention; Figure 5 This is a flow chart of a boost circuit-based active resonant wireless power supply system receiving end and a control method thereof of the present invention. DETAILED DESCRIPTION

[0018] The embodiments of the present application provide a boost circuit-based active resonant wireless power supply system receiving end and a control method thereof to solve the problems of reduced efficiency and insufficient stability caused by detuning in the prior art. The boost-based active resonant topology is used to achieve an organic combination of receiving-side resonance, rectification and voltage stabilization, and a composite control strategy is proposed to achieve constant voltage output and active resonance.

[0019] Example 1 The technical solution in the embodiment of the present application is to solve the problems of reduced efficiency and insufficient stability caused by the above-mentioned detuning. The overall idea is as follows: like Figure 1 As shown, in order to solve the problems existing in the prior art, the present invention provides an active resonant wireless power supply system receiving end based on a boost circuit and a control method thereof. A boost circuit-based active resonant wireless power supply system receiver and a corresponding control method are proposed. The wireless power supply receiver achieves resonance correction and voltage stabilization output through the switching of the boost topology to provide energy to the load. The receiver includes a transmitter and a receiver. The transmitting device includes a transmitting coil, an inverter, and an LCC transmitting side compensation structure connected thereto.

[0020] The receiving device includes a receiving coil, a rectifier bridge part, a boost inductor L B , the first switching switch S1, the diode and the output compensation capacitor, the receiving coil is connected to the rectifier part, eliminating the receiving side capacitor, the rectifier part and the boost inductor L B The other side of the boost inductor is connected to the anode of the diode and the first switching switch S1, and the cathode of the diode is connected to the output compensation capacitor Cout. By switching the first switching switch S1, the wireless power receiving end can achieve constant voltage power supply within a specific transmission distance and a wide load range, and has anti-detuning characteristics. The system of the present invention utilizes a boost topology and a composite control strategy to achieve active resonance on the receiving side, solving the problem of wireless power detuning. This reduces reactive power, maintains high system efficiency across the entire power range, and improves system power density.

[0021] The transmitting side topology adopts LCC, and its transmitting coil L p The upper current has nothing to do with the receiving side. Once the inverter voltage is fixed, its current does not change. The expression is: , where U x1 is the voltage generated by the inverter, L f is the resonant inductor on the transmitting side. Its operating angular frequency It is determined by the inverter output, and the transmitter side resonance parameters satisfy the formula: , where L s For the receiving coil.

[0022] Therefore, the induced voltage expression of the receiving coil is: , U s is the induced voltage of the receiving coil, M is the mutual inductance, I p is the transmitting coil current. The active resonant inductor current reference value can be expressed as: . Among them U s V is the voltage induced by the receiving coil. o is the output voltage, V ref is the reference voltage, G F (s) is the feedforward control transfer function, and its expression is: , where Cout is the output capacitor, R L is the equivalent load, R iis the current sampling resistor, D is the duty cycle, and s is the complex frequency.

[0023] Feedforward control allows for quick response to receiving coil fluctuations. ref is the voltage reference value. G v (s) is the transfer function of the voltage outer loop, which can be expressed as: , where k p is the proportionality coefficient, k i is the integral coefficient, and s is the complex frequency.

[0024] The principle diagram of hysteresis current control is as follows: Figure 2 As shown, the hysteresis current control generates the current upper and lower limits according to the current reference value, which can be expressed as i max =i ref *(1+K h ), i min =i ref *(1-K h ), where i ref is the current reference value, K h The hysteresis bandwidth is hysteresis-bandwidth. The inductor current is sampled in real time and compared with the upper and lower limits of the hysteresis current. When the inductor current is greater than the upper limit of the current reference value, the switch signal is adjusted to turn on the first switch and turn off the third switch. When the current is less than the lower limit of the current reference value, the switch signal is adjusted to turn on the third switch and turn off the first switch. This puts the active resonant receiving end system in a zero-phase state. The second switching switch S2 and the fourth switching switch S4 detect the receiving side inductor current, compare it with the reference value to obtain a control signal, and control the switch through the PWM module to achieve active resonance effect at a lower switching frequency, reduce switching loss and improve efficiency.

[0025] According to the current hysteresis control, the active resonant circuit has the following four states, such as Figure 3 As shown. According to the switching status, it can be listed: Among them, L eq is the equivalent inductance of the receiving coil, i L is the receiving side current, U s is the input voltage, u o is the output voltage, and the corresponding on-time can be expressed as: Where t1 is the on-time of the switching switch, representing the energy storage time of the inductor, 2h is the set hysteresis bandwidth, which is equal to imax-imin, and Leq is the receiving-side inductance.

[0026] Therefore, the hysteresis control switching frequency can be obtained as: Among them U o is the output voltage, h is the hysteresis bandwidth, L eq is the equivalent inductance of the receiving coil, and D is the duty cycle of the switching switch. o =0, f s Taking the maximum value, the maximum switching frequency is: where u s is the induced voltage of the receiving coil, h is the hysteresis bandwidth, L s is the equivalent inductance of the receiving coil.

[0027] That is, when the system is just started, the system output voltage is zero or small, and the system switching frequency will reach the maximum. In order to avoid this situation, the system introduces duty cycle feedforward control. The control block diagram is as follows Figure 4 As shown in the figure, the proposed composite control method can achieve safe and stable system startup.

[0028] Where V ref Is the reference value of the system output, and the actual value of the output voltage V o The output voltage error is obtained by comparison and then passed through the outer loop controller G v (s), the output is multiplied by the receiving side voltage reference phase to generate the current reference value, I ref , hysteresis current control is used as inner loop control, the schematic diagram is as follows Figure 2 As shown, by generating the upper and lower limits of the current hysteresis loop, the inductor current is controlled to keep the phase with the input voltage, so that the reactive power is balanced. The relevant logic flow chart is shown in Figure 5 shown.

[0029] From the above analysis, it can be seen that the active resonant receiving end and the control method thereof of the present invention can output a constant voltage in the case of system parameter detuning, transmission distance and load changes without primary and secondary side communication within the coupling range. It is suitable for dynamic wireless power supply of various loads such as motors, lithium batteries, and lead-acid batteries. The advantages of the present invention are obvious and worthy of promotion.

[0030] Finally, it should be noted that the above embodiments are merely examples for the purpose of illustrating the present invention and are not intended to limit the embodiments. Those skilled in the art will readily appreciate that other variations or modifications based on the above description are possible. It is not necessary and impossible to provide an exhaustive list of all embodiments. However, obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A boost circuit-based active resonant wireless power supply system receiving end, comprising a transmitting device and a receiving device, characterized in that: The transmitting device includes a transmitting coil L p , inverter, and the LCC transmitter-side compensation structure connected to it, The receiving device includes a receiving coil, a rectifier bridge part, a boost inductor L B , a first switching switch S1, a diode and an output compensation capacitor, The receiving coil is connected to the rectifier part, eliminating the capacitor on the receiving side. The rectifier part is connected to the boost inductor L B connected, boost inductor L B The other side is connected to the anode of the diode and the first switch S1, and the cathode of the diode is connected to the output compensation capacitor C out connected.

2. The active resonant wireless power supply system receiving end based on a boost circuit and the control method thereof according to claim 1, characterized in that: The active resonant output voltage relationship satisfies: , where V o is the output voltage, V in is the induced voltage of the receiving-side inductor, and its expression is: ,in M is the mutual inductance between the transmitting coil and the receiving coil, I P is the transmitting coil current, is the angular frequency of the system and j is a complex unit.

3. The active resonant wireless power supply system receiving end based on a boost circuit and the control method thereof according to claim 1, characterized in that: The transmitting side compensation structure adopts LCC, and its transmitting coil L p The upper current has nothing to do with the receiving side. Once the inverter voltage is fixed, its current does not change. The expression is: , where U x1 is the voltage generated by the inverter, L f is the transmitting side resonant inductor, and its operating angular frequency It is determined by the inverter output, and the transmitter side resonance parameters satisfy the formula: , where L s For the receiving coil.

4. The active resonant wireless power supply system receiving end based on a boost circuit and the control method thereof according to claim 1, characterized in that: The receiving coil includes a secondary inductor and a coil internal resistance connected in series.

5. The active resonant wireless power supply system receiving end based on a boost circuit and the control method thereof according to claim 1, characterized in that: The transmitting coil includes a transmitting coil inductor L connected in series. p and the internal resistance of the transmitting coil, the induced voltage expression of the receiving coil is: , U s is the induced voltage of the receiving coil, M is the mutual inductance, I p is the transmitting coil current.

6. The active resonant wireless power supply system receiving end based on a boost circuit and the control method thereof according to claim 1, characterized in that: The active resonant inductor current reference value can be expressed as: , where Us is the induced voltage of the input receiving coil, V o is the output voltage, V ref is the reference voltage, G F (s) is the feedforward control transfer function, and its expression is: , where Cout is the output capacitor, R L is the equivalent load, R i is the current sampling resistor, D is the duty cycle, s is the complex frequency, and through feedforward control, it can quickly respond to the fluctuation of the receiving coil. ref is the voltage reference value, G v (s) is the transfer function of the voltage outer loop, which can be expressed as: , where k p is the proportionality coefficient, k i is the integral coefficient, and s is the complex frequency.

7. The active resonant wireless power supply system receiving end based on a boost circuit and the control method thereof according to claim 2, characterized in that: Through feedforward control, it can quickly respond to the fluctuation of the receiving coil, V ref is the voltage reference value. G v (s) is the transfer function of the voltage outer loop, which can be expressed as: , where k p is the proportionality coefficient, k i is the integral coefficient, and s is the complex frequency.

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