Active resonance wireless power supply system receiving device and system and control method thereof

Abstract

The invention belongs to the technical field of wireless power supply, and provides an active resonance wireless power supply system receiving device, an active resonance wireless power supply system receiving system and a control method of the active resonance wireless power supply system receiving device. Compared with a Vienna structure, the system has the advantages of being simple in structure, small in device number and low in switching loss, is higher in efficiency in high-frequency application, is particularly suitable for scenes with high requirements for light load efficiency and system compactness, and is more suitable for being expanded into a two-way wireless power transmission system due to the fact that the system has natural two-way conduction capacity.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless power supply, and in particular relates to an active resonant wireless power supply system receiving device, system and control method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] 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.

[0004] 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.

[0005] Furthermore, in actual applications, the reduced efficiency and instability caused by detuning have not been effectively addressed. Previous technologies have mostly used a method of adding or removing capacitance by switching to counteract the effects of detuning. However, in the face of system detuning, load variations, and mutual inductance fluctuations, resonance and efficient transmission cannot be guaranteed when system inductance parameter deviations occur. This results in inefficient and instability issues caused by detuning, parameter drift, and load parameter variations during actual operation. The Vienna structure offers high power handling capabilities and excellent boost characteristics when implementing an active resonant receiver. Its output voltage can reach more than twice the input voltage, making it suitable for applications requiring high output voltage levels. It also offers high control accuracy, facilitating high-power rectification control. However, it suffers from issues such as the inability to achieve bidirectional energy flow, complex control strategies, a large number of components, and high system costs. Summary of the Invention

[0006] In order to solve at least one technical problem existing in the above-mentioned background technology, the first aspect of the present invention provides an active resonant wireless power supply system receiving device, which can still achieve a constant voltage stable output system in the face of system detuning, load changes, and mutual inductance fluctuations.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: A receiving device for an active resonant wireless power supply system includes a receiving coil coupled to a transmitting coil, a first switch, a second switch, a third switch, a fourth switch, an output compensation capacitor, and a controller, wherein the first ends of the first and second switches are connected to the first ends of the output compensation capacitor and the resistor, the second end of the first switch is respectively connected to the third switch and the first end of the receiving coil, the second end of the second switch is respectively connected to the first end of the fourth switch and the second end of the receiving coil, and the second ends of the third and fourth switches are connected to the second end of the compensation capacitor; The controller is configured to: compare the current on the transmitting coil with the upper and lower limits of the hysteresis current; when the current is greater than the upper limit of the hysteresis current, generate a first switch PWM signal to control the first switch to be turned on and the third switch to be turned off; when the current is less than the lower limit of the current reference value, generate a second switch PWM signal to control the third switch to be turned on and the first switch to be turned off; The current on the receiving coil is compared with the reference ground current. When the current on the receiving coil is greater than the reference ground current, a third PWM signal is generated to control the second switch to be turned on. When the current on the receiving coil is less than the reference ground current, a fourth PWM signal is generated to control the fourth switch to be turned on.

[0008] As an embodiment, the controller is further configured to: compare the output voltage of the receiving side with the reference voltage. If the output voltage and the reference voltage are different, a voltage error is generated, and the generated voltage error is used to update the upper and lower limits of the hysteresis current in the hysteresis current control module.

[0009] As an implementation method, the generated voltage error is used to update the upper and lower limits of the hysteresis current in the hysteresis current control module, including: passing the generated voltage error through an outer loop controller, multiplying the output of the outer loop controller by the sine value of the receiving side voltage reference phase to generate a current reference value, and calculating the upper and lower limits of the hysteresis current based on the current reference value.

[0010] As an embodiment, the controller is further configured to: introduce duty cycle feedforward control, and add a duty cycle fixed value after the hysteresis current control output.

[0011] As an implementation method, the upper and lower limits of the hysteresis current are calculated as follows: , , , , in, Indicates the upper limit of the hysteresis current, Indicates the lower limit of the hysteresis current, represents half of the hysteresis bandwidth, Represents the reference value of the hysteresis current, where is the induced voltage input to the receiving coil, is the feedforward control transfer function, and its expression is: ,in, represents the transfer function from input voltage to output voltage, represents the closed-loop transfer function of the inner current loop, represents the sampling resistance coefficient, represents the output capacitance value, represents the equivalent load, represents the duty cycle, Indicates the complex frequency representation, and can quickly respond to the fluctuation of the receiving coil through feedforward control. is the true value of the output voltage, is the output voltage reference value, is the transfer function of the voltage outer loop, represents the mutual inductance between the receiving coil and the transmitting coil, Indicates the current value passing through the transmitting coil.

[0012] In order to solve the above problems, the second aspect of the present invention provides an active resonant wireless power supply system, which can still achieve constant voltage and stable output in the face of system detuning, load changes, and mutual inductance fluctuations.

[0013] In order to achieve the above object, the present invention adopts the following technical solutions: An active resonant wireless power supply system includes a transmitting device and the active resonant wireless power supply receiving device described in Example 1, wherein the transmitting device includes a full-bridge inverter circuit and a transmitting coil, and the full-bridge inverter circuit includes four switching switches, wherein the switching switch and Form a pair of bridge arms and switch 、 Another pair of bridge arms is formed, and the transmitting coil and the receiving coil are electromagnetically coupled; The controller is configured to compare the current on the transmitting coil The upper and lower limits of the hysteresis current on the transmitting side are determined, and corresponding switch control signals are generated according to different comparison results in different cycles. Based on the generated switch control signals, the opening and closing of the four switching switches of the full-bridge inverter circuit are controlled.

[0014] As an embodiment, the controller is configured to: compare the current on the transmitting coil with the upper and lower limits of the hysteresis current on the transmitting side, and in the positive half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the transmitting side switch is controlled. and toggle switch Open; In the negative half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the second switch is controlled and the third toggle switch When the current on the transmitting coil When it is within the hysteresis current range on the transmitting side, the previous state is maintained.

[0015] As an embodiment, the transmitting end further includes an LCC transmitting side compensation module; the LCC transmitting side compensation module includes an inductor ,capacitance ,capacitance ,resistance and transmitting coil , where the inductor The first end is connected to and The second end is connected to the capacitor The first end of the capacitor The second end is connected to the transmitting coil The first end of the transmitting coil The second end is connected to the resistor The first end of the resistor The second end is connected to 、 Between the bridge arms, the capacitor The first end of the inductor is connected to and capacitors Between, the capacitor The second end is connected to the resistor The second end.

[0016] In order to solve the above problems, the third aspect of the present invention provides an active resonant wireless power receiving control method, which can still achieve a constant voltage stable output system in the face of system detuning, load changes, and mutual inductance fluctuations.

[0017] In order to achieve the above object, the present invention adopts the following technical solutions: An active resonant wireless power receiving control method, based on the active resonant wireless power receiving device described in the first aspect, comprises the following steps: Compare the current on the transmitting coil with the upper and lower limits of the hysteresis current. When the current is greater than the upper limit of the hysteresis current, generate a first switch PWM signal to control the first switch to be turned on and the third switch to be turned off; when the current is less than the lower limit of the current reference value, generate a second switch PWM signal to control the third switch to be turned on and the first switch to be turned off; The current on the receiving coil is compared with the reference ground current. When the current on the receiving coil is greater than the reference ground current, a third PWM signal is generated to control the second switch to be turned on. When the current on the receiving coil is less than the reference ground current, a fourth PWM signal is generated to control the fourth switch to be turned on.

[0018] In order to solve the above problems, the fourth aspect of the present invention provides an active resonant wireless power receiving control method, which can still achieve a constant voltage stable output system in the face of system detuning, load changes, and mutual inductance fluctuations.

[0019] In order to achieve the above object, the present invention adopts the following technical solutions: An active resonant wireless power supply control method, based on the active resonant wireless power supply system of the second aspect, comprises the following steps: Transmitter control includes: comparing the current on the transmitting coil and the upper and lower limits of the hysteresis current on the transmitting side, and in different cycles, according to different comparison results, generate corresponding switch control signals, and control the opening and closing of the four switches of the full-bridge inverter circuit based on the generated switch control signals; The receiving end control includes: comparing the current on the transmitting coil with the upper and lower limits of the hysteresis current. When the current is greater than the upper limit of the hysteresis current, generating a first switch PWM signal to control the first switch to be turned on and the third switch to be turned off; when the current is less than the lower limit of the current reference value, generating a second switch PWM signal to control the third switch to be turned on and the first switch to be turned off; The current on the receiving coil is compared with the reference ground current. When the current on the receiving coil is greater than the reference ground current, a third PWM signal is generated to control the second switch to be turned on. When the current on the receiving coil is less than the reference ground current, a fourth PWM signal is generated to control the fourth switch to be turned on.

[0020] The beneficial effects of the present invention are: 1. The active resonant wireless power receiving end provided by this invention utilizes a composite control strategy to modulate a fully controlled bridge circuit to achieve a combined system with zero-phase transmission and regulated voltage output. This system can maintain a stable constant voltage output even in the face of system detuning, load variations, and mutual inductance fluctuations. Compared to the Vienna structure, it offers advantages such as a simpler structure, fewer components, and lower switching losses. It is more efficient in high-frequency applications and is particularly suitable for scenarios requiring high light-load efficiency and system compactness. Furthermore, its inherent bidirectional conductivity makes it more suitable for expansion into a bidirectional wireless power transmission system.

[0021] 2. This invention adopts an active resonance method, directly eliminating the capacitor on the receiving side. Through PWM modulation of the switching tube, the system can be infinitely adjusted, achieving receiving-side system resonance at any time, thereby ensuring resonance and efficient transmission even when the system inductance parameters deviate. This provides strong support for the upgrading of wireless power supply technology.

[0022] 3. The system of the present invention utilizes only transmitting and receiving coils and a double-sided full-bridge topology to achieve a frequency-adjustable, wide-range output wireless power system with strong detuning resistance. This solves the detuning issue in wireless power supply, reduces reactive power, maintains high system efficiency across the entire power range, and significantly improves system power density.

[0023] Advantages of additional aspects of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 This is a control principle diagram of an active resonance receiving device provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of the hysteresis current control principle provided by an embodiment of the present invention; Figure 3 This is a diagram of the receiving side operating state provided by an embodiment of the present invention; Figure 4 This is a block diagram of output voltage regulation control and active resonance control including feedforward control provided by an embodiment of the present invention; Figure 5 This is a control principle diagram of an active resonant wireless power supply system provided by an embodiment of the present invention; Figure 6 This is a diagram of the operating state of the transmitting side provided by an embodiment of the present invention; Figure 7 This is a flow chart of an active resonant wireless power receiving control method according to an embodiment. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] In the present invention, terms such as "fixed connection," "connected," and "connection" should be interpreted broadly to mean a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediary. Relevant researchers or technicians in this field may determine the specific meanings of these terms in the present invention based on specific circumstances, and they should not be construed as limitations of the present invention.

[0030] The Vienna structure has a large power handling capacity and good boost characteristics when realizing an active active resonant receiving end. Its output voltage can reach more than twice the input voltage, which is suitable for application scenarios with high requirements for output voltage levels, and has high control accuracy, which is convenient for realizing high-power rectification control; but it has problems such as the inability to realize bidirectional energy flow, complex control strategy, large number of components, and high system cost. The active resonant wireless power receiving device provided by the present invention is a composite system that uses a composite control strategy to modulate a fully controlled bridge circuit to realize zero-phase angle transmission and regulated output of the system. In the face of system detuning, load changes, and mutual inductance fluctuations, a system with constant voltage and stable output can still be achieved. At the same time, the bridgeless topology structure of the present invention has the advantages of simple structure, small number of components, and low switching loss. It is more efficient in high-frequency applications and is particularly suitable for scenarios with high requirements for light-load efficiency and system compactness. And because it has a natural bidirectional conduction capability, it is more suitable for expansion into a two-way wireless power transmission system.

[0031] As an embodiment of the present disclosure, Figure 1 This is the control principle diagram of the active resonant wireless power receiving device, such as Figure 1 As shown, the receiving device includes a control unit, a receiving coil , first switch , Second switch , the third switch , the fourth switch , output compensation capacitor ,resistance and resistors ; The first switch and the second toggle switch The first terminal and output compensation capacitor and resistors The first end of the first switch is connected to The second ends of the switches are connected to the third and receiving coil The first end of the second switch The second ends of the switches are connected to the fourth The first end of the receiving coil The second end of the third switch and the fourth toggle switch The second end is connected to the load resistor The second terminal and compensation capacitor the second end; By switching the first toggle switch , Second switch , the third switch , the fourth switch , which enables the wireless power supply receiver to achieve constant voltage power supply within a specific transmission distance and a wide load range.

[0032] The control unit includes a hysteresis current control module, a hysteresis update module and a feedforward control module; Wherein, the hysteresis current control module is configured to: compare the transmitting coil Current on and hysteresis current upper and lower limits, when the current Greater than the upper limit of the hysteresis current When the first switch PWM signal is generated, the first switch is controlled Open, the third switch Close; when the current value is Less than the current reference value When the lower limit is reached, a second switch PWM signal is generated to control the third switch Open, first switch Close; thereby making the active resonant receiving end system in a zero phase angle state; Specifically, in the hysteresis current control module, the calculation process of the hysteresis current upper and lower limits includes: The topology of the transmitting device adopts LCC, and its transmitting coil Current on Regardless of the receiving side, once the voltage of the DC / AC inverter module is fixed, its current does not change, and the expression is: , in, Indicates the output voltage of the transmitter inverter. Indicates the inductance of the transmitting coil, Indicates the operating frequency of the transmitting coil, its operating frequency It is determined by the output of the inverter module, and the resonance parameters on the transmitting side satisfy the formula: , in, Indicates capacitance Capacitance value, Indicates capacitance Capacitance value, Indicates the inductance of the receiving coil, Indicates the receiving side filter capacitor.

[0033] Therefore, the induced voltage expression of the receiving coil is: , The active resonant output voltage relationship on the receiving side satisfies: , in, represents the mutual inductance between the receiving coil and the transmitting coil, Indicates the current value passing through the transmitting coil; The active resonant inductor current reference value can be expressed as: , in, Indicates the upper limit of the hysteresis current, Indicates the lower limit of the hysteresis current, represents half of the hysteresis bandwidth, Represents the reference value of the hysteresis current, where is the induced voltage input to the receiving coil, is the feedforward control transfer function, and its expression is: ,in, represents the transfer function from input voltage to output voltage, represents the closed-loop transfer function of the inner current loop, represents the sampling resistance coefficient, represents the output capacitance value, represents the equivalent load, represents the duty cycle, The complex frequency representation allows for rapid response to receiving coil fluctuations through feedforward control. is the true value of the output voltage, is the output voltage reference value, is the transfer function of the voltage outer loop, and the controller transfer function can be expressed as: ,in, represents the proportionality coefficient, represents the integral coefficient; The principle diagram of hysteresis current control is as follows: Figure 2 As shown, the hysteresis current control is based on the current reference value , calculate the upper and lower limits of the hysteresis current, expressed as: , in, Indicates the upper limit of the hysteresis current, Indicates the lower limit of the hysteresis current, represents half of the hysteresis bandwidth, Indicates the hysteresis current reference value.

[0034] The hysteresis update module is configured to: compare the output voltage of the receiving side and reference voltage , output voltage and reference voltage If they are different, it means that a voltage error has occurred, and the error will be used to update the upper and lower limits of the hysteresis current in the hysteresis current control module; Specifically, in the hysteresis update module, the system output voltage reference value and the actual value of the output voltage The output voltage error is obtained and passed through the outer loop controller , the outer loop controller The output of the current reference is multiplied by the sine value of the receiving side voltage reference phase to generate the current reference value. ,in, Is the system output voltage reference value, and the output voltage actual value The output voltage error is obtained by comparison. After passing through the outer loop controller Gv(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; By using the updated hysteresis current upper and lower limits, the inductor current is controlled to keep its phase with the input voltage, achieving reactive power balance. This achieves active resonance at a lower switching frequency, reducing switching losses and improving efficiency.

[0035] The feedforward control module is configured to: introduce duty cycle feedforward control and add a duty cycle fixed value after the hysteresis current control output; Specifically, according to the current hysteresis control, the active resonant circuit has the following four states: Figure 3 As shown: In the positive half cycle of the induced voltage on the receiving side, there are two states: Figure 3 Middle state (a) The third switch on the receiving side With the fourth toggle switch Open, inductor Leq energy storage, Figure 3 Middle state (b) First switch on the receiving side With the fourth toggle switch When it is turned on, the induced voltage and inductance supply power to the load at the same time; In the negative half cycle of the induced voltage on the receiving side, Figure 3 Middle state (c) first switch on the receiving side With the second toggle switch Open, inductive energy storage, Figure 3 Middle state (d) Second switch on the receiving side With the fourth toggle switch When the circuit is turned on, the induced voltage and inductance supply power to the load at the same time.

[0036] According to the switching status, the following can be listed: , , The corresponding opening time can be expressed as: , , in, represents the load current, Indicates the input induced voltage on the receiving side, is the on-time of the first switch and the second switch, representing the inductor energy storage time, where is the set hysteresis bandwidth, which is equal to , is the receiving side inductor.

[0037] Therefore, the hysteresis control switching frequency can be obtained as: , Wherein, D is the duty cycle of the second switch.

[0038] When the output voltage =0, Taking the maximum value, the maximum switching frequency is: ; Therefore, if Figure 4 As shown in the figure, duty cycle feedforward control is introduced, and a fixed duty cycle value is added after the hysteresis current control output; 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 at this time. In order to avoid this situation, the system introduces duty cycle feedforward control to reduce the switching frequency when the system is just started.

[0039] As an embodiment of the present disclosure, Figure 5 As shown, this embodiment provides an active resonant wireless power supply system, which includes a transmitting device, a receiving device and a control device; The transmitting device includes a transmitting end voltage stabilizing power supply , DC / AC inverter module, LCC transmitter side compensation module and transmitter coil; Among them, the DC / AC inverter module adopts a full-bridge inverter circuit, which consists of 4 MOS tubes. 、 、 and Composition, MOS tube in full bridge circuit and Composed of a pair of bridge arms, MOS tube 、 Composing another pair of bridge arms, the four MOS tubes are controlled by the driving circuit to form an inverter circuit; The LCC transmitter side compensation module includes an inductor ,capacitance ,capacitance ,resistance and transmitting coil , where the inductor The first end is connected to and The second end is connected to the capacitor The first end of the capacitor The second end is connected to the transmitting coil The first end of the transmitting coil The second end is connected to the resistor The first end of the resistor The second end is connected to 、 Between the bridge arms, the capacitor The first end of the inductor is connected to and capacitors Between, the capacitor The second end is connected to the resistor the second end; Reduce 4 MOS tubes through LCC transmitter side compensation module 、 、 and The switching loss is reduced to achieve zero voltage soft switching.

[0040] The transmitting end is configured to: compare the current on the transmitting coil and the upper and lower limits of the hysteresis current on the transmitting side, and in different cycles, according to different comparison results, generate corresponding switch control signals, and control the opening and closing of the four switches of the full-bridge inverter circuit based on the generated switch control signals; Specifically, the transmitting end is configured to compare the current on the transmitting coil with the upper and lower limits of the hysteresis current on the transmitting side, and in the positive half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the transmitting side switch is controlled. and toggle switch Open; In the negative half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the switch is controlled and toggle switch When the current on the transmitting coil When it is within the hysteresis current range on the transmitting side, the previous state is maintained.

[0041] like Figure 6 The figure shows the operating state diagram of the transmitting side, which includes four states, among which (b) is the current on the transmitting coil in the positive half cycle. The switch conduction state when the current on the transmitting coil is greater than the upper limit of the hysteresis current on the transmitting side, (a) is in the positive half cycle, when the current on the transmitting coil The switch is on when the current is less than the lower limit of the hysteresis current on the transmitting side; (c) is the current on the transmitting coil in the negative half cycle The switch conduction state when the current on the transmitting coil is greater than the upper limit of the hysteresis current on the transmitting side, (d) is in the negative half cycle, when the current on the transmitting coil The switch is in the on state when the hysteresis current is less than the lower limit of the transmitting side.

[0042] The receiving end is configured to execute the above-mentioned control method for the active resonant wireless power receiving device. For the specific control strategy, please refer to the process of the above-mentioned embodiment.

[0043] As another embodiment of the present disclosure, a control method corresponding to an active resonant wireless power supply system based on a Vienna circuit is as follows: Figure 7 As shown, the active resonant wireless power supply control method based on the Vienna circuit includes the following steps: Step 1: Compare the current on the transmitting coil and the upper and lower limits of the hysteresis current on the transmitting side, and in different cycles, according to different comparison results, generate corresponding switch control signals, and control the opening and closing of the four switches of the full-bridge inverter circuit based on the generated switch control signals; Specifically, compare the current on the transmitting coil with the upper and lower limits of the hysteresis current on the transmitting side. In the positive half cycle, when the current on the transmitting coil is When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch Open; When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the transmitting side switch is controlled. and toggle switch Open; In the negative half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the second switch is controlled and the third toggle switch When the current on the transmitting coil When it is within the hysteresis current range on the transmitting side, the previous state is maintained.

[0044] Step 2: Real-time sampling of the inductor current and collecting the transmitting coil Current on ; Step 3: Attach the Transmitter Coil Current on Compare with the upper and lower limits of the hysteresis current. Greater than the upper limit of the hysteresis current When the first switch PWM signal is generated, the first switch is controlled Open, the third switch closure; In this embodiment, the calculation process of the upper and lower limits of the hysteresis current includes: The topology of the transmitting device adopts LCC, and its transmitting coil Current on Regardless of the receiving side, once the voltage of the DC / AC inverter module is fixed, its current does not change, and the expression is: , in, Indicates the output voltage of the transmitter-side inverter, Indicates the inductance of the transmitting coil, Indicates the operating frequency of the transmitting coil, its operating frequency It is determined by the output of the inverter module, and the resonance parameters on the transmitting side satisfy the formula: , in, Indicates capacitance Capacitance value, Indicates capacitance Capacitance value, Indicates the inductance of the receiving coil, Indicates the receiving side filter capacitor.

[0045] Therefore, the induced voltage expression of the receiving coil is: ; in, represents the mutual inductance between the receiving coil and the transmitting coil, Indicates the current value passing through the transmitting coil; The active resonant inductor current reference value can be expressed as: , in, Indicates the upper limit of the hysteresis current, Indicates the lower limit of the hysteresis current, represents half of the hysteresis bandwidth, Represents the reference value of the hysteresis current, where is the induced voltage input to the receiving coil, is the feedforward control transfer function, and its expression is: ,in, represents the transfer function from input voltage to output voltage, represents the closed-loop transfer function of the inner current loop, represents the sampling resistance coefficient, represents the output capacitance value, represents the equivalent load, represents the duty cycle, The complex frequency representation allows for rapid response to receiving coil fluctuations through feedforward control. is the true value of the output voltage, is the output voltage reference value, is the transfer function of the voltage outer loop, which can be expressed as: ,in, represents the proportionality coefficient, represents the integral coefficient; The principle diagram of hysteresis current control is as follows: Figure 2 As shown, the hysteresis current control is based on the current reference value , calculate the upper and lower limits of the hysteresis current, expressed as: , in, Indicates the upper limit of the hysteresis current, Indicates the lower limit of the hysteresis current, represents half of the hysteresis bandwidth, Indicates the hysteresis current reference value; When the current value is Less than the current reference value When the lower limit is reached, a second switch PWM signal is generated to control the third switch Open, first switch Close; thereby making the active resonant receiving end system in a zero phase angle state; Step 4: Sample the output voltage on the receiving side , compare the output voltage and reference voltage , if the output voltage and reference voltage If they are not the same, it means that a voltage error has occurred. The error will be used to update the upper and lower limits of the hysteresis current. Repeat steps 1 to 3 based on the updated upper and lower limits of the hysteresis current. The purpose is to achieve constant voltage stable output through the cooperation of the voltage outer loop control.

[0046] Specifically, the system output voltage reference value and the actual value of the output voltage The output voltage error is obtained and passed through the outer loop controller , the outer loop controller The output of the current reference is multiplied by the sine value of the receiving side voltage reference phase to generate the current reference value. ,in, Is the system output voltage reference value, and the output voltage actual value The output voltage error is obtained by comparison. After passing through the outer loop controller Gv(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 in the figure, the updated hysteresis current upper and lower limits are used to control the inductor current to keep it in phase with the input voltage, achieving reactive power balance. This achieves active resonance at a lower switching frequency, reducing switching losses and improving efficiency.

[0047] Step 5: Introduce duty cycle feedforward control and add a fixed duty cycle value after the hysteresis current control output; 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 to reduce the switching frequency when the system is just started.

[0048] One end of the second control unit is connected to the receiving coil , the other end is connected to the second switch and the fourth toggle switch ; Step 6: Collect the receiving coil on the receiving side Current on , when the receiving coil Current on Greater than the reference ground current, a third PWM signal is generated to control the second switch When the receiving coil is turned on Current on is less than the reference ground current, generating a fourth PWM signal to control the fourth switch Activated.

[0049] 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.

[0050] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A receiving device for an active resonant wireless power supply system, comprising a receiving coil coupled to a transmitting coil, a first switch, a second switch, a third switch, a fourth switch, an output compensation capacitor, and a controller, wherein: The first ends of the first switch and the second switch are connected to the first end of the output compensation capacitor and the first end of the resistor, the second end of the first switch is connected to the third switch and the first end of the receiving coil respectively, the second end of the second switch is connected to the first end of the fourth switch and the second end of the receiving coil respectively, and the second ends of the third switch and the fourth switch are connected to the second end of the compensation capacitor; The controller is configured to: compare the current on the transmitting coil with the upper and lower limits of the hysteresis current, and when the current is greater than the upper limit of the hysteresis current, generate a first switch PWM signal to control the first switch to be turned on and the third switch to be turned off; When the current is less than the lower limit of the current reference value, a second switch PWM signal is generated to control the third switch to be turned on and the first switch to be turned off; The current on the receiving coil is compared with the reference ground current. When the current on the receiving coil is greater than the reference ground current, a third PWM signal is generated to control the second switch to be turned on. When the current on the receiving coil is less than the reference ground current, a fourth PWM signal is generated to control the fourth switch to be turned on.

2. The active resonant wireless power supply system receiving device according to claim 1, characterized in that: The controller is further configured to compare the output voltage of the receiving side with a reference voltage. If the output voltage and the reference voltage are different, a voltage error is generated, and the generated voltage error is used to update the hysteresis current upper and lower limits in the hysteresis current control module.

3. The active resonant wireless power supply system receiving device according to claim 1, wherein: The generated voltage error is used to update the hysteresis current upper and lower limits in the hysteresis current control module, including: passing the generated voltage error through an outer loop controller, multiplying the output of the outer loop controller by the sine value of the receiving side voltage reference phase to generate a current reference value, and calculating the hysteresis current upper and lower limits based on the current reference value.

4. The active resonant wireless power supply system receiving device according to claim 1, wherein: The controller is further configured to introduce duty cycle feedforward control and add a duty cycle fixed value after the hysteresis current control output.

5. The active resonant wireless power supply system receiving device according to claim 1, wherein: The upper and lower limits of the hysteresis current are calculated as follows: ， ， ， ， in, Indicates the upper limit of the hysteresis current, Indicates the lower limit of the hysteresis current, represents half of the hysteresis bandwidth, Represents the reference value of the hysteresis current, where is the induced voltage input to the receiving coil, is the feedforward control transfer function, and its expression is: ,in, represents the transfer function from input voltage to output voltage, represents the closed-loop transfer function of the inner current loop, represents the sampling resistance coefficient, represents the output capacitance value, represents the equivalent load, represents the duty cycle, Indicates the complex frequency representation, and can quickly respond to the fluctuation of the receiving coil through feedforward control. is the true value of the output voltage, is the output voltage reference value, is the transfer function of the voltage outer loop, represents the mutual inductance between the receiving coil and the transmitting coil, Indicates the current value passing through the transmitting coil.

6. An active resonant wireless power supply system, comprising a transmitting device and an active resonant wireless power supply system receiving device according to claims 1-5, wherein the transmitting device comprises a full-bridge inverter circuit and a transmitting coil, and the full-bridge inverter circuit comprises four switches, wherein: Toggle switch and Form a pair of bridge arms and switch 、 Another pair of bridge arms is formed, and the transmitting coil and the receiving coil are electromagnetically coupled; The controller is configured to compare the current on the transmitting coil The upper and lower limits of the hysteresis current on the transmitting side are determined, and corresponding switch control signals are generated according to different comparison results in different cycles. Based on the generated switch control signals, the opening and closing of the four switching switches of the full-bridge inverter circuit are controlled.

7. The active resonant wireless power supply system according to claim 6, characterized in that: The controller is configured to compare the current on the transmitting coil with the upper and lower limits of the hysteresis current on the transmitting side, and in the positive half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the transmitting side switch is controlled. and toggle switch Open; In the negative half cycle, when the current on the transmitting coil When the hysteresis current is greater than the upper limit of the transmitting side, the transmitting side switch is controlled and toggle switch When the current on the transmitting coil When the hysteresis current is less than the lower limit of the transmitting side, the second switch is controlled and the third toggle switch When the current on the transmitting coil When it is within the hysteresis current range on the transmitting side, the previous state is maintained.

8. The active resonant wireless power supply system according to claim 6, wherein: The transmitting end also includes an LCC transmitting side compensation module; the LCC transmitting side compensation module includes an inductor ,capacitance ,capacitance ,resistance and transmitting coil , where the inductor The first end is connected to and The second end is connected to the capacitor The first end of the capacitor The second end is connected to the transmitting coil The first end of the transmitting coil The second end is connected to the resistor The first end of the resistor The second end is connected to 、 Between the bridge arms, the capacitor The first end of the inductor is connected to and capacitors Between, the capacitor The second end is connected to the resistor The second end.

9. An active resonant wireless power receiving control method, characterized in that: The active resonant wireless power receiving device according to any one of claims 1 to 5 comprises the following steps: Comparing the current on the transmitting coil with the upper and lower limits of the hysteresis current, when the current is greater than the upper limit of the hysteresis current, generating a first switch PWM signal to control the first switch to be turned on and the third switch to be turned off; When the current is less than the lower limit of the current reference value, a second switch PWM signal is generated to control the third switch to be turned on and the first switch to be turned off; The current on the receiving coil is compared with the reference ground current. When the current on the receiving coil is greater than the reference ground current, a third PWM signal is generated to control the second switch to be turned on. When the current on the receiving coil is less than the reference ground current, a fourth PWM signal is generated to control the fourth switch to be turned on.

10. An active resonant wireless power supply control method, characterized in that: An active resonant wireless power supply system according to any one of claims 6 to 8 comprises the following steps: Transmitter control includes: comparing the current on the transmitting coil and the upper and lower limits of the hysteresis current on the transmitting side, and in different cycles, according to different comparison results, generate corresponding switch control signals, and control the opening and closing of the four switches of the full-bridge inverter circuit based on the generated switch control signals; The receiving end control includes: comparing the current on the transmitting coil with the upper and lower limits of the hysteresis current. When the current is greater than the upper limit of the hysteresis current, generating a first switch PWM signal to control the first switch to be turned on and the third switch to be turned off; when the current is less than the lower limit of the current reference value, generating a second switch PWM signal to control the third switch to be turned on and the first switch to be turned off; The current on the receiving coil is compared with the reference ground current. When the current on the receiving coil is greater than the reference ground current, a third PWM signal is generated to control the second switch to be turned on. When the current on the receiving coil is less than the reference ground current, a fourth PWM signal is generated to control the fourth switch to be turned on.

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