A wireless charging system and output voltage regulation method thereof

Abstract

The present invention relates to a wireless charging system, comprising: an information detection module for detecting the relative position of a receiving coil and a transmitting coil in an electric energy transmission module; an electric energy transmission module for wirelessly transmitting electric energy supplied by a power grid to a receiving end of a wireless charging system to charge a battery; a transmitting end compensation element switching control system for distinguishing the working mode of a switching controller according to the detected position information of the receiving coil, including starting a power supply mode and terminating a power supply mode. The present invention also discloses an output voltage regulation method for a wireless charging system. The present invention is based on a standard LCC compensation topology and an improved LCC compensation topology, and uses a control switch to switch the corresponding compensation inductor or capacitor to achieve regulation of the system output voltage gain, thereby improving the stability of the system output voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging, and in particular to a wireless charging system and an output voltage regulation method thereof. Background Art

[0002] As a new type of battery charging technology, wireless charging mainly realizes wireless transmission of electric energy through electromagnetic coupling between the transmitting and receiving coils. Compared with traditional wired charging methods, wireless charging has the advantages of convenience, safety, reliability, and weather resistance, so it has a wide range of application prospects, including portable electronic devices, medical implants, electric vehicles and other fields. With the development of battery technology, wireless charging technology has become a hot topic of research and is gradually moving towards commercialization.

[0003] In order to meet the requirements of constant voltage output characteristics, the current wireless charging system can maintain the stability of the output voltage at the receiving end as long as the system input voltage, the inductance of the transceiver coil and the parameter value of the compensation element remain unchanged. However, in the actual charging process, the coupling degree between the transceiver coils of the system is reduced due to the coil offset, which affects the output characteristics of the system. Therefore, in order to maintain a stable output voltage, the control module is generally used to adjust the size and phase of the transmitter input voltage, or adjust the system operating frequency. However, this will reduce the energy transmission efficiency of the system to a certain extent, resulting in excessive energy loss. Summary of the invention

[0004] The primary purpose of the present invention is to provide a wireless charging system that improves the stability of the system output voltage, ensures that the wireless charging system always operates in a resonant state, and improves the energy transmission efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a wireless charging system, comprising:

[0006] An information detection module is used to detect the relative position of the receiving end coil and the transmitting end coil in the power transmission module, detect the input current of the transmitting end, and transmit the offset signal of the receiving end coil and the transmitting end coil and the input current signal in the transmitting end coil to the switching controller of the transmitting end compensation element switching control system;

[0007] An electric energy transmission module is used to wirelessly transmit the electric energy supplied by the power grid to the receiving end of the wireless charging system to charge the battery;

[0008] The transmitter compensation element switching control system is used to determine the working mode of the switching controller according to the detected receiving end coil position information, including the start power supply mode and the end power supply mode; during the startup operation of the switching controller, the switching mode of the numerical gear of the transmitter compensation element is determined according to the detected signal of the transmitter input current, including the upshift operation and the downshift operation, and the corresponding gear switching instruction is sent to the compensation element parameter regulator. According to the instruction signal, the parameter regulator controls the adjustable inductance, capacitance or compensation element control switch to switch the value of the transmitter compensation inductance or capacitance, and connects the corresponding compensation inductance or capacitance to the power transmission module.

[0009] The information detection module comprises:

[0010] The coil position detection device is composed of two position sensors installed on the front and rear sides of the transmitting end coil, which is used to detect the motion state information of the power pickup coil and transmit the offset between the receiving end power pickup coil and the center of the transmitting end power supply rail coil to the switching controller;

[0011] The current sensor is used to detect the input current of the system transmitting end coil and transmit the current signal to the switching controller.

[0012] The power transmission module comprises:

[0013] The transmitting end power conversion circuit is composed of a rectifier circuit, a Boost power factor correction PFC circuit, a Buck voltage regulator circuit and a high-frequency inverter circuit; it is used to convert the AC power from the power grid into AC power with controllable voltage and frequency, and inject it into the transmitting end coil;

[0014] The receiving end power conversion circuit, which consists of a rectifier filter circuit and a DC-DC circuit, is used to convert the AC power induced in the receiving end coil into DC power and provide a stable charging voltage for the battery load through the DC-DC circuit control;

[0015] The transceiver coil system includes a receiving coil and a transmitting coil, and realizes wireless transmission of energy in the air gap through electromagnetic coupling between the transmitting coil and the receiving coil;

[0016] A transceiver compensation network module, used to improve wireless charging efficiency, system active power and power factor, including a transmitter compensation network and a receiver compensation network, wherein the transmitter compensation network adopts a standard LCC compensation topology or an improved LCC compensation topology, and the receiver compensation network adopts a series compensation topology;

[0017] The standard LCC compensation topology is divided into two types. One is a standard LCC compensation topology using adjustable inductance and capacitance, wherein the adjustable inductance is L' 0调, the capacitance is C' 0调 , C' 1调 Another is a standard LCC compensation topology using a compensation element to control the switch, wherein the compensation element control switch is S' A , S' B and S' C The improved LCC compensation topology is divided into two types, one is an improved LCC compensation topology using an adjustable capacitor, wherein the adjustable capacitor is C t调 , C 0调 , C 1调 Another is an improved LCC compensation topology using a compensation element to control the switch, wherein the compensation element control switch includes S A , S B and S C ; When the transmitter compensation network adopts the standard LCC compensation topology, the standard LCC compensation topology and the series compensation topology together constitute the standard LCC-S compensation topology; when the transmitter compensation network adopts the improved LCC compensation topology, the improved LCC compensation topology and the series compensation topology together constitute the improved LCC-S compensation topology;

[0018] The transmitting end compensation element switching control system comprises:

[0019] A switching controller is used to switch the compensation element connected to the main circuit of the transmitter according to the change of the input current of the transmitter, so as to adjust the compensation inductance or capacitance value;

[0020] The compensation element parameter regulator is used to execute the instructions of the switching controller, control the adjustable inductance, capacitance or compensation element control switch, perform numerical switching on the corresponding transmitter compensation inductance or capacitance, and connect the corresponding compensation inductance or capacitance to the transmitter power conversion circuit and the transmitter coil to complete the power transmission of the transmitter.

[0021] The standard LCC-S compensation topology of the standard LCC compensation topology using the compensation element to control the switch includes a compensation inductor L0, a first compensation capacitor C0 at the transmitting end, a second compensation capacitor C1 at the transmitting end, and a compensation capacitor C2 at the receiving end; wherein the compensation inductor L0 is in the form of a matrix inductor and is connected to the control switch S' A connected, by switching the control switch S' A The value of the compensation inductor L0 is switched, and the two together constitute a compensation inductor that can be switched, denoted as L 0开关 ; The first compensation capacitor C0 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S' B connected, by switching the control switch S' B The value of the first compensation capacitor C0 is switched, and the two together constitute a compensation capacitor that can be switched, denoted as C0开关 The second compensation capacitor C1 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S' C connected, by switching the control switch S' C The value of C1 is switched, and the two together form a compensation capacitor that can be switched, denoted as C 1开关 ; One end of the switchable compensation inductor L0 is connected to the input voltage U in The positive pole of the switchable compensation inductor L 0开关 The other end is connected to the compensation capacitor C which can be switched 0开关 , Compensation capacitor C that can be switched 1开关 One end of C 1开关 The other end is connected in series with one end of the transmitting coil L1, and C 0开关 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed, and the system input current is I in , the current in the transmitting coil is I1, the current in the series loop where the receiving coil is located is I2, and the voltage across the equivalent load is U out ;

[0022] The standard LCC-S compensation topology using the standard LCC compensation topology with adjustable inductance and capacitance includes a transmitter compensation inductor L' 0调 , the first compensation capacitor C' at the transmitting end 0调 , the second compensation capacitor C' at the transmitting end 1调 , and receiving end compensation capacitor C2; power supply U in The positive electrode and the transmitter compensation inductor L' 0调 One end is connected to the transmitter compensation inductor L' 0调 The other end is connected to the first compensation capacitor C' 0调 , the second compensation capacitor C' at the transmitting end 1调 One end is connected to the transmitter end, and the second compensation capacitor C' 1调 The other end is connected in series with one end of the transmitting coil L1, and the first compensation capacitor C' 0调 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed, and the system input current is I in, the current in the transmitting coil is I1, the current in the series loop where the receiving coil is located is I2, and the voltage across the equivalent load is U out .

[0023] The improved LCC-S compensation topology of the improved LCC compensation topology using the compensation element to control the switch includes a transmitter compensation inductor L0, a transmitter first compensation capacitor C t , the second compensation capacitor C0 at the transmitting end, the third compensation capacitor C1 at the transmitting end, and the compensation capacitor C2 at the receiving end; wherein the first compensation capacitor C t It adopts matrix inductor and controls the switch S A connected, by switching the control switch S A To achieve the first compensation capacitor C t The two together constitute a compensation capacitor that can be switched, denoted as C t开关 ; The second compensation capacitor C0 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S B connected, by switching the control switch S B The value of C0 can be switched, and the two together constitute a compensation capacitor that can be switched. 0开关 The third compensation capacitor C1 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S C connected, by switching the control switch S C The value of C1 can be switched, and the two together constitute a compensation capacitor that can be switched. 1开关 ; One end of the transmitter compensation inductor L0 is connected to the input voltage U in The positive electrode of the transmitter compensation inductor L0 and the other end of the compensation capacitor C that can be switched t开关 One end of C t开关 The other end is connected to the compensation capacitor C which can be switched 0开关 , Compensation capacitor C that can be switched 1开关 One end of C 1开关 The other end is connected in series with one end of the transmitting coil L1, and C 0开关 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed. The current in the transmitting coil is I1, the current in the series circuit where the receiving coil is located is I2, and the voltage across the equivalent load is U out ;

[0024] The improved LCC-S compensation topology using the improved LCC compensation topology with adjustable capacitors includes a transmitter compensation inductor L0, a transmitter first compensation capacitor C t调 , the second compensation capacitor C at the transmitting end 0调 , the third compensation capacitor C at the transmitting end 1调 , and the receiving end compensation capacitor C2; one end of the transmitting end compensation inductor L0 is connected to the input voltage U in The positive pole of the transmitter compensation inductor L0 and the other end of the transmitter first compensation inductor C t调 One end of the transmitter is connected to the first compensation inductor C t调 The other end is connected to the second compensation capacitor C 0调 , the third compensation capacitor C at the transmitting end 1调 One end of the transmitter is connected to the third compensation capacitor C 1调 The other end of the transmitting end second compensation capacitor C0 and the other end of the transmitting end coil L1 are connected in series with the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed. The current in the transmitting coil is I1, the current in the series circuit where the receiving coil is located is I2, and the voltage across the equivalent load is U out .

[0025] Another object of the present invention is to provide an output voltage regulation method for a wireless charging system, the method comprising the following steps in sequence:

[0026] (1) A circuit model of a wireless charging system is established based on a standard LCC-S compensation topology and an improved LCC-S compensation topology, respectively, and the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the standard LCC-S compensation topology is analyzed, and the relationship between the compensation component parameter and the coil inductance when the system works in a resonant state is analyzed; the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the improved LCC-S compensation topology is analyzed, and the relationship between the compensation component parameter and the coil inductance when the system works in a resonant state is analyzed; the standard LCC-S compensation topology refers to that the transmitter compensation network adopts the standard LCC compensation topology and the receiver compensation network adopts the series compensation topology; the improved LCC-S compensation topology refers to that the transmitter compensation network adopts the improved LCC compensation topology and the receiver compensation network adopts the series compensation topology;

[0027] (2) According to different compensation topologies adopted by the transmitter of the system, the numerical range of the compensation component parameters of the transmitter of the wireless charging system with the standard LCC-S compensation topology and the numerical range of the compensation component parameters of the transmitter of the wireless charging system with the improved LCC-S compensation topology are designed respectively based on the relationship between the corresponding voltage gain and the compensation component parameter value;

[0028] (3) According to the compensation topology adopted by the transmitter of the system, the corresponding switching controller is designed: first, the collected signal of the center position of the transmitting and receiving coils is transmitted to the switching controller to start / stop the power supply to the transmitting coil; second, the collected transmitter input current signal is input into the switching controller, and the current output voltage gain is calculated according to the transmitter input voltage value, coil inductance, and load resistance; then, the obtained voltage gain signal is transmitted to the switching controller, and the standard voltage gain value and the actual voltage gain signal fed back in real time are compared to determine the target numerical gear of the compensation element, and the compensation element target numerical gear signal is sent to the compensation element parameter regulator; finally, the compensation element parameter regulator sends an instruction to switch the compensation element parameters, controls the adjustable inductor, capacitor or compensation element control switch to switch the corresponding compensation inductor or capacitor value, and realizes the control of the compensation element parameter adjustment of the wireless charging system.

[0029] Analyzing the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the improved LCC-S compensation topology in step (1), and analyzing the relationship between the compensation component parameter and the coil inductance when the system operates in a resonant state specifically refers to:

[0030] Output voltage gain H u The relationship between compensation component parameters and coil inductance is:

[0031]

[0032] Among them, ω is the system operating frequency, L0 is the transmitter compensation inductance, C t is the compensation capacitor connected in series with L0; λ=1 / (ω 2 L0C t ) is the compensation capacitor C t Regulation coefficient: In the improved LCC-S compensation topology, if the system input voltage and the series compensation inductor L0 remain unchanged, the above relationship is simplified to:

[0033] H u L0 / M0=μ·p

[0034] Among them, μ = 1 / (1-λ) is the compensation coefficient of the mutual inductance change of the coupling coil, p = M / M0 is the mutual inductance change coefficient, M and M0 are the mutual inductance of the coupling coil at the current position and the position directly opposite to the transmitting and receiving coils respectively;

[0035] Analyzing the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the standard LCC-S compensation topology in step (1), and analyzing the relationship between the compensation component parameter and the coil inductance when the system operates in a resonant state specifically refers to:

[0036] Output voltage gain H u The relationship between compensation component parameters and coil inductance is:

[0037]

[0038] Among them, M is the mutual inductance of the coupling coil at the current position, and L0 is the compensation inductance of the transmitting end.

[0039] The numerical range of the transmitter compensation component parameters of the wireless charging system with the improved LCC-S compensation topology designed in step (2) specifically includes:

[0040] When the transceiver coil offset causes the coupling coil mutual inductance to fluctuate, assuming the mutual inductance value at the current position is: M i =p i M0, p i is the mutual inductance variation coefficient. By changing the compensation capacitance value at the transmitting end, the output voltage gain of the system is adjusted. Let the capacitance value C of the current gear be ti =q i C0, then at the initial resonant frequency, C t The change in value is expressed as the capacitance adjustment coefficient λ i And the mutual inductance change compensation coefficient μ i Changes:

[0041]

[0042] Among them, i is the current gear of the compensation element, q is the capacitance C t At the same time, in order to meet the resonance condition, the capacitor C needs to be adjusted synchronously. 0改 and C 1改 for:

[0043]

[0044] Therefore, the reference capacitor C1 and the capacitor C ti Connect in series to get the capacitance C 1改 ; Through the coupling coil mutual inductance variation coefficient p i And the mutual inductance change compensation coefficient μ i , determine the value i of the required compensation element, and thus obtain the compensation capacitor C t , C 0改 and C 1改 The values ​​of each gear; among them, C 0改, C 1改 They are the values ​​of the transmitter compensation capacitors C0 and C1 after gear adjustment;

[0045] The numerical range of the transmitter compensation component parameters of the wireless charging system with the standard LCC-S compensation topology designed in step (2) specifically includes:

[0046] When the transceiver coil offset causes the coupling coil mutual inductance to fluctuate, assuming the mutual inductance value at the current position is: M i =p i M0, p i is the mutual inductance variation coefficient, then the system output voltage gain is: H u =p i M0 / L 0改 ; where L 0改 is the value of the transmitter compensation inductor L0 after the gear adjustment; at this time, the transmitter compensation inductor value can be changed to make L 0改i =a i L0, thereby adjusting the output voltage gain of the system:

[0047]

[0048] Where i is the compensation capacitor C 0改 The numerical position, a is the compensation inductance L 0改 The adjustment coefficient represents the ratio of the mutual inductance value of the coupling coil at the current gear to the mutual inductance value L0 at the initial moment; at the same time, in order to make the system work in a resonant state, the compensation capacitor C needs to be adjusted synchronously 0改 , C 1改 :

[0049]

[0050] Therefore, the initial capacitance C1 and the capacitance C 串 =C0 / (1-p) in series, we get the capacitance C 1改 ; Through the coupling coil mutual inductance variation coefficient p i And the voltage gain, determine the value of the compensation element i, and thus get the compensation inductance L 0改 And the capacitor C 0改 , C 1改 The values ​​of each gear.

[0051] In step (3), designing a transmitter compensation element switching controller according to the improved LCC-S compensation topology specifically includes the following steps:

[0052] 3a1) Startup control:

[0053] In the process of the receiving coil gradually approaching the transmitting coil, when the position sensor installed on the front side of the transmitting coil detects that the receiving coil has arrived, the position sensor sends a start signal and transmits it to the switching controller, controls the initial compensation network to connect to the main circuit, and the corresponding transmitting coil is in a power supply state; when the position sensor installed on the rear side of the transmitting coil detects that the receiving coil has completely left, the coil position sensor sends a termination signal and transmits it to the switching controller, at which time the compensation network is cut off, and the corresponding transmitting coil is in an idle state;

[0054] 3b1) System input current detection and feedback control:

[0055] In the improved LCC-S compensation topology, the relationship between the system input current and voltage gain is:

[0056]

[0057] Among them, ξ i =H u / H u0 =μ i p i is the system output voltage gain coefficient, H u0 is the reference value of voltage gain; in the current detection and switching control link, the voltage gain coefficient when the transmitting and receiving coils are facing each other is taken as the reference value ξ0, let ξ i =ξ0=1;

[0058] 3c1) The parameter switching of the compensation element controlled in step (3) is specifically as follows: according to the compensation element target value gear signal sent by the switching controller, the upshift / downshift operation of the compensation element value is determined; the compensation element parameter regulator controls the adjustable capacitor or the compensation element control switch to switch the value of the transmitter compensation capacitor, and the compensation capacitor C of the corresponding value gear is set. t , C 0改 , C 1改 Connect to the power transmission module;

[0059] In step (3), designing a transmitter compensation element switching controller according to a standard LCC-S compensation topology specifically includes the following steps:

[0060] 3a2) Startup control:

[0061] In the process of the receiving coil gradually approaching the transmitting coil, when the position sensor installed on the front side of the transmitting coil detects that the receiving coil has arrived, the position sensor sends a start signal and transmits it to the switching controller, controls the initial compensation network to connect to the main circuit, and the corresponding transmitting coil is in a power supply state; when the position sensor installed on the rear side of the transmitting coil detects that the receiving coil has completely left, the coil position sensor sends a termination signal and transmits it to the switching controller, at which time the compensation network is cut off, and the corresponding transmitting coil is in an idle state;

[0062] 3b2) System input current detection and feedback control link

[0063] In the LCC-S compensation topology described, the relationship between the system input current and the voltage gain is:

[0064]

[0065] Among them, κ i =H u / H u0 =p i / a i is the system output voltage gain coefficient, H u0 is the reference value of voltage gain; in the current detection and switching control link, the voltage gain coefficient when the transmitting and receiving coils are facing each other is taken as the reference value κ0, and κ i =κ0=1;

[0066] 3c2) The compensation element switch switching controlled in step (3) is specifically as follows: according to the compensation element target value gear signal sent by the switching controller, the upshift / downshift operation of the compensation element value is determined; the compensation element parameter regulator controls the adjustable inductance, capacitance or compensation element control switch to switch the value of the transmitter compensation inductance and capacitance, and the compensation inductance L of the corresponding value gear is set. 0改 And the compensation capacitor C 0改 , C 1改 Connect to the power transmission module.

[0067] It can be seen from the above technical solutions that the beneficial effects of the present invention are as follows: first, compared with the traditional wireless charging system, the present invention is based on the standard LCC compensation topology and the improved LCC compensation topology, and uses an adjustable inductor, capacitor or compensation element control switch to perform numerical switching on the corresponding compensation inductor or capacitor, thereby adjusting the system output voltage gain and improving the stability of the system output voltage; secondly, in the wireless charging system with standard LCC-S compensation or improved LCC-S compensation, the transmitter compensation inductor L is controlled. 0改 And the compensation capacitor C 0改 , C 1改 Or the transmitter compensation capacitor C t, C 0改 , C 1改 The synchronous transformation of the numerical value ensures that the wireless charging system always works in a resonant state, which is beneficial to improving the efficiency of energy transmission; thirdly, by detecting the input current of the transmitter to control the switching of the numerical gear of the transmitter compensation element, the communication between the transmitter and the receiver is avoided and the control system is simplified; fourthly, the numerical gear of the transmitter compensation element set to cope with the change of the mutual inductance of the coupling coil has a more uniform adjustment ratio, and by using adjustable inductors and capacitors, the output voltage gain can be theoretically adjusted steplessly. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a structural schematic diagram of a wireless charging system;

[0069] Figure 2 The present invention adopts a standard LCC compensation topology with adjustable inductance and capacitance;

[0070] Figure 3 The present invention adopts a standard LCC compensation topology in which the compensation element controls the switch;

[0071] Figure 4 The present invention adopts an improved LCC compensation topology with adjustable capacitors;

[0072] Figure 5 The improved LCC compensation topology of the present invention adopts a compensation element to control the switch;

[0073] Figure 6 The equivalent circuit diagram of the standard LCC-S compensation topology using adjustable inductance and capacitance of the present invention;

[0074] Figure 7 The equivalent circuit diagram of the standard LCC-S compensation topology using compensation elements to control switches in the present invention;

[0075] Figure 8 The equivalent circuit diagram of the improved LCC-S compensation topology using adjustable capacitors of the present invention;

[0076] Fig. 9 The equivalent circuit diagram of the improved LCC-S compensation topology using compensation elements to control switches according to the present invention;

[0077] Fig.10 The output voltage regulation control block diagram of the wireless charging system using the improved LCC-S compensation topology;

[0078] Fig.11 The output voltage regulation control block diagram of a wireless charging system using a standard LCC-S compensation topology;

[0079] Fig.12 ,13 , 14 are the transmitter compensation capacitors C t With S A Combination, C0 and S B Combination, C1 and S C Combined capacitance matrix plot. DETAILED DESCRIPTION

[0080] like Figure 1 As shown, a wireless charging system includes:

[0081] The information detection module 1 is used to detect the relative position of the receiving end coil and the transmitting end coil in the power transmission module, detect the input current of the transmitting end, and transmit the offset signal of the receiving end coil and the transmitting end coil and the input current signal in the transmitting end coil to the switching controller of the transmitting end compensation element switching control system 4;

[0082] An electric energy transmission module is used to wirelessly transmit the electric energy supplied by the power grid to the receiving end of the wireless charging system to charge the battery;

[0083] The transmitter compensation element switching control system 4 is used to determine the working mode of the switching controller according to the detected receiving end coil position information, including the start power supply mode and the end power supply mode; during the startup operation of the switching controller, the switching mode of the numerical gear of the transmitter compensation element is determined according to the detected signal of the transmitter input current, including the upshift operation and the downshift operation, and the corresponding gear switching instruction is sent to the compensation element parameter regulator. According to the instruction signal, the parameter regulator controls the adjustable inductance, capacitance or compensation element control switch to switch the value of the transmitter compensation inductance or capacitance, and connects the corresponding compensation inductance or capacitance to the power transmission module.

[0084] The information detection module 1 comprises:

[0085] The coil position detection device is composed of two position sensors installed on the front and rear sides of the transmitting end coil, which is used to detect the motion state information of the power pickup coil and transmit the offset between the receiving end power pickup coil and the center of the transmitting end power supply rail coil to the switching controller;

[0086] The current sensor is used to detect the input current of the system transmitting end coil and transmit the current signal to the switching controller.

[0087] The power transmission module comprises:

[0088] The transmitting end power conversion circuit 2 is composed of a rectifier circuit, a Boost power factor correction PFC circuit, a Buck voltage regulator circuit and a high-frequency inverter circuit; it is used to convert the AC power from the power grid into AC power with controllable voltage and frequency, and inject it into the transmitting end coil;

[0089] The receiving end power conversion circuit 3, which is composed of a rectifier filter circuit and a DC-DC circuit, is used to convert the AC power induced in the receiving end coil into DC power, and provide a stable charging voltage for the battery load through the control of the DC-DC circuit;

[0090] The transceiver coil system includes a receiving coil and a transmitting coil, and realizes wireless transmission of energy in the air gap through electromagnetic coupling between the transmitting coil and the receiving coil;

[0091] A transceiver compensation network module, used to improve wireless charging efficiency, system active power and power factor, including a transmitter compensation network and a receiver compensation network, wherein the transmitter compensation network adopts a standard LCC compensation topology or an improved LCC compensation topology, and the receiver compensation network adopts a series compensation topology;

[0092] The standard LCC compensation topology is divided into two types. One is the standard LCC compensation topology using adjustable inductance and capacitance, such as Figure 2 As shown, wherein the adjustable inductance is L' 0调 , the capacitance is C' 0调 , C' 1调 ; The other is the standard LCC compensation topology that uses compensation components to control switches, such as Figure 3 As shown, the compensation element is controlled to open as S' A , S' B and S' C , the corresponding compensation inductor L0, compensation capacitor C0 and C1 are in the form of matrix inductor and matrix capacitor; the improved LCC compensation topology is divided into two types, one is an improved LCC compensation topology using adjustable capacitors, such as Figure 4 As shown, the adjustable capacitor is C t调 , C 0调 , C 1调 ; Another is an improved LCC compensation topology that uses compensation elements to control switches, such as Figure 5 As shown, wherein the compensation element control switch includes S A , S B and S C , the corresponding compensation capacitor C t, C0 and C1 are in the form of matrix capacitors; when the transmitter compensation network adopts the standard LCC compensation topology, the standard LCC compensation topology and the series compensation topology together constitute the standard LCC-S compensation topology; when the transmitter compensation network adopts the improved LCC compensation topology, the improved LCC compensation topology and the series compensation topology together constitute the improved LCC-S compensation topology;

[0093] The transmitting end compensation element switching control system 4 comprises:

[0094] A switching controller is used to switch the compensation element connected to the main circuit of the transmitter according to the change of the input current of the transmitter, so as to adjust the compensation inductance or capacitance value;

[0095] The compensation element parameter regulator is used to execute the instructions of the switching controller, control the adjustable inductance, capacitance or compensation element control switch, perform numerical switching on the corresponding transmitter compensation inductance or capacitance, and connect the corresponding compensation inductance or capacitance to the transmitter power conversion circuit 2 and the transmitter coil to complete the power transmission of the transmitter.

[0096] like Figure 7 As shown, the standard LCC-S compensation topology of the standard LCC compensation topology using the compensation element to control the switch includes a compensation inductor L0, a first compensation capacitor C0 at the transmitting end, a second compensation capacitor C1 at the transmitting end, and a compensation capacitor C2 at the receiving end; wherein the compensation inductor L0 is in the form of a matrix inductor and is connected to the control switch S' A connected, by switching the control switch S' A The value of the compensation inductor L0 is switched, and the two together constitute a compensation inductor that can be switched, denoted as L 0开关 ; The first compensation capacitor C0 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S' B connected, by switching the control switch S' B The value of the first compensation capacitor C0 is switched, and the two together constitute a compensation capacitor that can be switched, denoted as C 0开关 The second compensation capacitor C1 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S' C connected, by switching the control switch S' C The value of C1 is switched, and the two together form a compensation capacitor that can be switched, denoted as C 1开关 ; One end of the switchable compensation inductor L0 is connected to the input voltage U in The positive pole of the switchable compensation inductor L 0开关 The other end is connected to the compensation capacitor C which can be switched 0开关 , Compensation capacitor C that can be switched 1开关 One end of C1开关 The other end is connected in series with one end of the transmitting coil L1, and C 0开关 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed, and the system input current is I in , the current in the transmitting coil is I1, the current in the series loop where the receiving coil is located is I2, and the voltage across the equivalent load is U out ;

[0097] like Figure 6 As shown, the standard LCC-S compensation topology using the standard LCC compensation topology with adjustable inductance and capacitance includes a transmitter compensation inductor L' 0调 , the first compensation capacitor C' at the transmitting end 0调 , the second compensation capacitor C' at the transmitting end 1调 , and receiving end compensation capacitor C2; power supply U in The positive electrode and the transmitter compensation inductor L' 0调 One end is connected to the transmitter compensation inductor L' 0调 The other end is connected to the first compensation capacitor C' 0调 , the second compensation capacitor C' at the transmitting end 1调 One end is connected to the transmitter end, and the second compensation capacitor C' 1调 The other end is connected in series with one end of the transmitting coil L1, and the first compensation capacitor C' 0调 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed, and the system input current is I in , the current in the transmitting coil is I1, the current in the series loop where the receiving coil is located is I2, and the voltage across the equivalent load is U out .

[0098] like Fig. 9 As shown, the improved LCC-S compensation topology of the improved LCC compensation topology using the compensation element to control the switch includes a transmitter compensation inductor L0, a transmitter first compensation capacitor C t , the second compensation capacitor C0 at the transmitting end, the third compensation capacitor C1 at the transmitting end, and the compensation capacitor C2 at the receiving end; wherein the first compensation capacitor C t It adopts matrix inductor and controls the switch S Aconnected, by switching the control switch S A To achieve the first compensation capacitor C t The two together constitute a compensation capacitor that can be switched, denoted as C t开关 The second compensation capacitor C0 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S B connected, by switching the control switch S B The value of C0 can be switched, and the two together constitute a compensation capacitor that can be switched. 0开关 The third compensation capacitor C1 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S C connected, by switching the control switch S C The value of C1 can be switched, and the two together constitute a compensation capacitor that can be switched. 1开关 ; One end of the transmitter compensation inductor L0 is connected to the input voltage U in The positive electrode of the transmitter compensation inductor L0 and the other end of the compensation capacitor C that can be switched t开关 One end of C t开关 The other end is connected to the compensation capacitor C which can be switched 0开关 , Compensation capacitor C that can be switched 1开关 One end of C 1开关 The other end is connected in series with one end of the transmitting coil L1, and C 0开关 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed. The current in the transmitting coil is I1, the current in the series circuit where the receiving coil is located is I2, and the voltage across the equivalent load is U out ;

[0099] like Figure 8 As shown, the improved LCC compensation topology using adjustable capacitors includes a transmitter compensation inductor L0, a transmitter first compensation capacitor C t调 , the second compensation capacitor C at the transmitting end 0调 , the third compensation capacitor C at the transmitting end 1调 , and the receiving end compensation capacitor C2; one end of the transmitting end compensation inductor L0 is connected to the input voltage U in The positive pole of the transmitter compensation inductor L0 and the other end of the transmitter first compensation inductor C t调 One end of the transmitter is connected to the first compensation inductor C t调 The other end is connected to the second compensation capacitor C 0调, the third compensation capacitor C at the transmitting end 1调 One end of the transmitter is connected to the third compensation capacitor C 1调 The other end of the transmitting end second compensation capacitor C0 and the other end of the transmitting end coil L1 are connected in series with the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed. The current in the transmitting coil is I1, the current in the series circuit where the receiving coil is located is I2, and the voltage across the equivalent load is U out .

[0100] The method comprises the following steps in order:

[0101] (1) A circuit model of a wireless charging system is established based on a standard LCC-S compensation topology and an improved LCC-S compensation topology, respectively, and the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the standard LCC-S compensation topology is analyzed, and the relationship between the compensation component parameter and the coil inductance when the system works in a resonant state is analyzed; the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the improved LCC-S compensation topology is analyzed, and the relationship between the compensation component parameter and the coil inductance when the system works in a resonant state is analyzed; the standard LCC-S compensation topology refers to that the transmitter compensation network adopts the standard LCC compensation topology and the receiver compensation network adopts the series compensation topology; the improved LCC-S compensation topology refers to that the transmitter compensation network adopts the improved LCC compensation topology and the receiver compensation network adopts the series compensation topology;

[0102] (2) According to different compensation topologies adopted by the transmitter of the system, the numerical range of the compensation component parameters of the transmitter of the wireless charging system with the standard LCC-S compensation topology and the numerical range of the compensation component parameters of the transmitter of the wireless charging system with the improved LCC-S compensation topology are designed respectively based on the relationship between the corresponding voltage gain and the compensation component parameter value;

[0103] (3) According to the compensation topology adopted by the transmitter of the system, the corresponding switching controller is designed: first, the collected signal of the center position of the transmitting and receiving coils is transmitted to the switching controller to start / stop the power supply to the transmitting coil; second, the collected transmitter input current signal is input into the switching controller, and the current output voltage gain is calculated according to the transmitter input voltage value, coil inductance, and load resistance; then, the obtained voltage gain signal is transmitted to the switching controller, and the standard voltage gain value and the actual voltage gain signal fed back in real time are compared to determine the target numerical gear of the compensation element, and the compensation element target numerical gear signal is sent to the compensation element parameter regulator; finally, the compensation element parameter regulator sends an instruction to switch the compensation element parameters, controls the adjustable inductor, capacitor or compensation element control switch to switch the corresponding compensation inductor or capacitor value, and realizes the control of the compensation element parameter adjustment of the wireless charging system.

[0104] Embodiment 1

[0105] Analyzing the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the improved LCC-S compensation topology in step (1), and analyzing the relationship between the compensation component parameter and the coil inductance when the system operates in a resonant state specifically refers to:

[0106] Output voltage gain H u The relationship between compensation component parameters and coil inductance is:

[0107]

[0108] Among them, ω is the system operating frequency, L0 is the transmitter compensation inductance, C t is the compensation capacitor connected in series with L0; λ=1 / (ω 2 L0C t ) is the compensation capacitor C t Regulation coefficient: In the improved LCC-S compensation topology, if the system input voltage and the series compensation inductor L0 remain unchanged, the above relationship is simplified to:

[0109] H u L0 / M0=μ·p (2)

[0110] Among them, μ = 1 / (1-λ) is the compensation coefficient of the mutual inductance change of the coupling coil, p = M / M0 is the mutual inductance change coefficient, M and M0 are the mutual inductance of the coupling coil at the current position and the position directly opposite to the transmitting and receiving coils respectively;

[0111] The numerical range of the transmitter compensation component parameters of the wireless charging system with the improved LCC-S compensation topology designed in step (2) specifically includes:

[0112] When the transceiver coil offset causes the coupling coil mutual inductance to fluctuate, assuming the mutual inductance value at the current position is: M i =p i M0, p i Mutual inductance variation coefficient 20% ≤ p i ≤100%, by changing the compensation capacitance value of the transmitter, the output voltage gain of the system is adjusted; let the capacitance value C of the current gear ti =q i C0, then at the initial resonant frequency, C t The change in value is expressed as the capacitance adjustment coefficient λ i And the mutual inductance change compensation coefficient μ i Changes:

[0113]

[0114] Among them, i is the current gear of the compensation element, and each numerical gear of the compensation element corresponds to a mutual inductance value change range; q is the capacitance C t At the same time, in order to meet the resonance condition, the capacitor C needs to be adjusted synchronously. 0改 and C 1改 for:

[0115]

[0116] Therefore, the reference capacitor C1 and the capacitor C ti Connect in series to get the capacitance C 1改 ; Through the coupling coil mutual inductance variation coefficient p i And the mutual inductance change compensation coefficient μ i , determine the value i of the required compensation element, and thus obtain the compensation capacitor C t , C 0改 and C 1改 The values ​​of each gear; among them, C 0改 , C 1改 They are the values ​​of the transmitter compensation capacitors C0 and C1 after gear adjustment;

[0117] According to the adjustment gear corresponding to the current mutual inductance value of the coupling coil, set the transmitter compensation capacitor C t , C 0改 and C 1改 The numerical range is as shown in Table 1:

[0118] Table 1 Variable values ​​of compensation capacitors at each level

[0119]

[0120] According to the capacitance values ​​in Table 1, determine the compensation capacitor C t The structure, such as Fig.12As shown, the capacitor C b =2*C0,C c =3*C0,C d =5*C0,C e =C0 / 2, C f =C0 / 3, each capacitance value is expressed as a multiple of the initial value C0 of the parallel compensation capacitance at the transmitting end. In addition, the compensation element control switch S is set A , S B , S C To control and adjust the value of the transmitter compensation capacitor, where: control switch S A Including switch S A0 ~S A10 Used to adjust the value of the capacitor Ct and control the switch S B Including switch S B0 ~S B9 To adjust the capacitance C 0改 The numerical position of the control switch S C Including switch S C0 ~S C10 To adjust the capacitance C 1改 The value range of compensation capacitor C t There are nine numerical positions, which are respectively controlled by switch S A0 ~S A10 When adding the compensation capacitor C t When the value of changes, in order to ensure that the transmitter system works in a resonant state, the capacitor C can be determined according to formula (4) 0改 And the capacitor C 1改 The values ​​of each gear position are shown in Table 1, and the corresponding switch switching scheme is determined. Fig.13 The transmitter compensation capacitor C 0改 The structure, Fig.14 The compensation capacitor C 1改 The reference capacitor C1 and the compensation capacitor C t According to the combination scheme of each compensation capacitor, the switch closure status of each capacitor level is determined, and the results are shown in Table 2.

[0121] Table 2 The switches required to control the closing of each compensation capacitor position

[0122]

[0123] In step (3), designing a transmitter compensation element switching controller according to the improved LCC-S compensation topology specifically includes the following steps:

[0124] 3a1) Startup control:

[0125] In the process of the receiving coil gradually approaching the transmitting coil, when the position sensor installed on the front side of the transmitting coil detects that the receiving coil has arrived, the position sensor sends a start signal and transmits it to the switching controller, controls the initial compensation network to connect to the main circuit, and the corresponding transmitting coil is in a power supply state; when the position sensor installed on the rear side of the transmitting coil detects that the receiving coil has completely left, the coil position sensor sends a termination signal and transmits it to the switching controller, at which time the compensation network is cut off, and the corresponding transmitting coil is in an idle state;

[0126] 3b1) System input current detection and feedback control:

[0127] In the improved LCC-S compensation topology, the relationship between the system input current and the voltage gain is:

[0128]

[0129] Among them, ξ i =H u / H u0 =μ i p i is the system output voltage gain coefficient, H u0 is the reference value of voltage gain; in the current detection and switching control link, the voltage gain coefficient when the transmitting and receiving coils are facing each other is taken as the reference value ξ0, let ξ i =ξ0=1; therefore, when the system input voltage remains unchanged, the transmitter input current value can be detected by the current sensor, and the system output voltage gain coefficient can be compared with the standard value 1 to determine whether to shift up or down the compensation element parameter value.

[0130] In actual operation, when the system obtains a stable output voltage gain at time t, the system output voltage gain coefficient is ξ0. Then the input current value can be detected at time t and time t+Δt respectively as I in (t) and I in (t+Δt), the measured value is transmitted to the switching controller, and the change of the mutual inductance value is determined by comparing the input current values ​​before and after the two measurements, and the gear of the transmitter compensation capacitance value is switched. in (t)>I in (t+Δt), the system input current gradually decreases, and the system output voltage gain coefficient ξ i <1, at this time the system output voltage is lower than the standard value, and the value of the transmitter compensation capacitor value needs to be gradually increased until the voltage gain coefficient ξ i Close to 1. The specific process of this control scheme is as follows Fig.10 shown.

[0131] 3c1) The parameter switching of the compensation element controlled in step (3) is specifically as follows: according to the compensation element target value gear signal sent by the switching controller, the upshift / downshift operation of the compensation element value is determined; the compensation element parameter regulator controls the adjustable capacitor or the compensation element control switch to switch the value of the transmitter compensation capacitor, and the compensation capacitor C of the corresponding value gear is set. t , C 0改 , C 1改 Connect to the power transmission module.

[0132] Embodiment 2

[0133] Analyzing the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the standard LCC-S compensation topology in step (1), and analyzing the relationship between the compensation component parameter and the coil inductance when the system operates in a resonant state specifically refers to:

[0134] Output voltage gain H u The relationship between compensation component parameters and coil inductance is:

[0135]

[0136] Among them, M is the mutual inductance of the coupling coil at the current position, and L0 is the compensation inductance of the transmitting end.

[0137] The numerical range of the transmitter compensation component parameters of the wireless charging system with the standard LCC-S compensation topology designed in step (2) specifically includes:

[0138] When the transceiver coil offset causes the coupling coil mutual inductance to fluctuate, assuming the mutual inductance value at the current position is: M i =p i M0, p i is the mutual inductance variation coefficient, 20%≤p i ≤100%, then the system output voltage gain is: H u =p i M0 / L 0改 ; where L 0改 is the value of the transmitter compensation capacitor L0 after the gear adjustment; at this time, the compensation inductance value of the transmitter can be changed to make L 0改i =a i L0, thereby adjusting the output voltage gain of the system:

[0139]

[0140] Where i is the compensation capacitor C 0改 Each numerical position of the compensation element corresponds to a mutual inductance value variation range; a is the compensation inductance L 0改The adjustment coefficient represents the ratio of the mutual inductance of the coupling coil at the current gear to the mutual inductance L0 at the initial moment; therefore, in order to maintain the output voltage gain H u To ensure stability, you only need to ensure that p / a remains unchanged. Set the transmitter compensation inductance L according to the adjustment gear corresponding to the current coupling coil mutual inductance value. 0改 And the capacitor C 0改 , C 1改 The numerical range is as shown in Table 3.

[0141] Table 3 Values ​​of each gear of inductance-capacitance and parameter combination scheme

[0142]

[0143] At the same time, in order to make the system work in a resonant state, the compensation capacitor C needs to be adjusted synchronously. 0改 , C 1改 :

[0144]

[0145] Therefore, the initial capacitance C1 and the capacitance C 串 =C0 / (1-p) in series, we get the capacitance C 1改 ; Through the coupling coil mutual inductance variation coefficient p i And the voltage gain, determine the value of the compensation element i, and thus get the compensation inductance L 0改 And the capacitor C 0改 , C 1改 The values ​​of each gear.

[0146] In step (3), designing a transmitter compensation element switching controller according to a standard LCC-S compensation topology specifically includes the following steps:

[0147] 3a2) Startup control:

[0148] In the process of the receiving end coil gradually approaching the transmitting end guide rail coil, when the position sensor installed on the front end side of the transmitting end coil detects that the receiving end coil has arrived, the position sensor sends a start signal and transmits it to the switching controller, controlling the initial compensation network to connect to the main circuit, and the corresponding transmitting end coil is in a power supply state; when the position sensor installed on the rear end side of the transmitting end coil detects that the receiving end coil has completely left, the coil position sensor sends a termination signal and transmits it to the switching controller, at which time the compensation network is cut off, and the corresponding transmitting end coil is in an idle state;

[0149] 3b2) System input current detection and feedback control link

[0150] In the LCC-S compensation topology described, the relationship between the system input current and the voltage gain is:

[0151]

[0152] Among them, κ i =H u / H u0 =p i / a i is the system output voltage gain coefficient, H u0 is the reference value of voltage gain; in the current detection and switching control link, the voltage gain coefficient when the transmitting and receiving coils are facing each other is taken as the reference value κ0, and κ i =κ0=1; therefore, when the system input voltage remains unchanged, the transmitter input current value can be detected by the current sensor, and the system output voltage gain coefficient can be compared with the standard value 1 to determine whether to shift up or down the compensation element parameter value.

[0153] In actual operation, when the system obtains a stable output voltage gain at time t, the system output voltage gain coefficient is κ0. Then the input current value can be detected at time t and time t+Δt respectively as I in (t) and I in (t+Δt), the measured value is transmitted to the switching controller, and the change of the mutual inductance value is determined by comparing the input current values ​​before and after the two measurements, and the gear of the transmitter compensation capacitance value is switched. in (t)>I in (t+Δt), the system input current gradually decreases, and the system output voltage gain coefficient κ i <1, at this time the system output voltage is lower than the standard value, and the transmitter compensation capacitor value C needs to be gradually increased t , until the voltage gain factor κ i Close to 1. The specific process of this control scheme is as follows Fig.11 shown.

[0154] 3c2) Compensation element controlled in step (3)

[0155] The switch switching is specifically as follows: according to the compensation element target value gear signal sent by the switching controller, the upshift / downshift operation of the compensation element value is determined; the compensation element parameter regulator controls the adjustable inductance, capacitance or compensation element control switch to switch the values ​​of the transmitter compensation inductance and capacitance, and the compensation inductance L of the corresponding value gear is set. 0改 And the compensation capacitor C 0改 , C 1改 Connect to the power transmission module.

[0156] In summary, the present invention is based on the standard LCC compensation topology and the improved LCC compensation topology, uses a control switch to switch the corresponding compensation inductor or capacitor to adjust the system output voltage gain, and improves the stability of the system output voltage; controls the transmitter compensation capacitor C t , C 0改 , C 1改 The synchronous transformation of the numerical value ensures that the wireless charging system always works in a resonant state, which is beneficial to improving the efficiency of energy transmission; by detecting the input current of the transmitter to control the switching of the numerical gear of the transmitter compensation element, the communication between the transmitter and the receiver is avoided and the control system is simplified; the numerical gear of the transmitter compensation element set to cope with the change of the mutual inductance of the coupling coil has a more uniform adjustment ratio, which can theoretically achieve stepless adjustment of the output voltage gain.

Claims

1. A wireless charging system, characterized in that: include: An information detection module is used to detect the relative position of the receiving end coil and the transmitting end coil in the power transmission module, detect the input current of the transmitting end, and transmit the offset signal of the receiving end coil and the transmitting end coil and the input current signal in the transmitting end coil to the switching controller of the transmitting end compensation element switching control system; An electric energy transmission module is used to wirelessly transmit the electric energy supplied by the power grid to the receiving end of the wireless charging system to charge the battery; The transmitter compensation element switching control system is used to determine the working mode of the switching controller according to the detected receiving coil position information, including starting the power supply mode and terminating the power supply mode; During the startup operation of the switching controller, the switching mode of the value gear of the transmitter compensation element is judged according to the signal of the detected transmitter input current, including upshift operation and downshift operation, and the corresponding gear switching instruction is sent to the compensation element parameter regulator. According to the instruction signal, the parameter regulator switches the value of the transmitter compensation inductance or capacitance by controlling the adjustable inductance, capacitance or compensation element control switch, and connects the corresponding compensation inductance or capacitance to the power transmission module; The information detection module comprises: The coil position detection device is composed of two position sensors installed on the front and rear sides of the transmitting end coil, which is used to detect the motion state information of the power pickup coil and transmit the offset between the receiving end power pickup coil and the center of the transmitting end power supply rail coil to the switching controller; A current sensor is used to detect the input current of the system transmitting end coil and transmit the current signal to the switching controller; The power transmission module comprises: The transmitting end power conversion circuit is composed of a rectifier circuit, a Boost power factor correction PFC circuit, a Buck voltage regulator circuit and a high-frequency inverter circuit; it is used to convert the AC power from the power grid into AC power with controllable voltage and frequency, and inject it into the transmitting end coil; The receiving end power conversion circuit, which consists of a rectifier filter circuit and a DC-DC circuit, is used to convert the AC power induced in the receiving end coil into DC power and provide a stable charging voltage for the battery load through the DC-DC circuit control; The transceiver coil system includes a receiving coil and a transmitting coil, and realizes wireless transmission of energy in the air gap through electromagnetic coupling between the transmitting coil and the receiving coil; The transceiver compensation network module is used to improve the wireless charging efficiency, system active power and power factor, including a transmitter compensation network and a receiver compensation network, wherein the transmitter compensation network adopts a standard LCC compensation topology or an improved LCC compensation topology, and the receiver compensation network adopts a series compensation topology; the standard LCC compensation topology is divided into two types, one is a standard LCC compensation topology using adjustable inductance and capacitance, wherein the adjustable inductance is L' 0调 , the capacitance is C' 0调 , C' 1调 Another is a standard LCC compensation topology using a compensation element to control the switch, wherein the compensation element control switch is S' A , S' B and S' C The improved LCC compensation topology is divided into two types, one is an improved LCC compensation topology using an adjustable capacitor, wherein the adjustable capacitor is C t调 , C 0调 , C 1调 Another is an improved LCC compensation topology using a compensation element to control the switch, wherein the compensation element control switch includes S A , S B and S C ; When the transmitter compensation network adopts the standard LCC compensation topology, the standard LCC compensation topology and the series compensation topology together constitute the standard LCC-S compensation topology; when the transmitter compensation network adopts the improved LCC compensation topology, the improved LCC compensation topology and the series compensation topology together constitute the improved LCC-S compensation topology; The transmitting end compensation element switching control system comprises: A switching controller is used to switch the compensation element connected to the main circuit of the transmitter according to the change of the input current of the transmitter, so as to adjust the compensation inductance or capacitance value; The compensation element parameter regulator is used to execute the instructions of the switching controller, control the adjustable inductance, capacitance or compensation element control switch, perform numerical switching on the corresponding transmitter compensation inductance or capacitance, and connect the corresponding compensation inductance or capacitance to the transmitter power conversion circuit and the transmitter coil to complete the power transmission of the transmitter.

2. The wireless charging system according to claim 1, characterized in that: The standard LCC-S compensation topology of the standard LCC compensation topology using compensation elements to control switches includes a compensation inductor L0, a first compensation capacitor C0 at the transmitting end, a second compensation capacitor C1 at the transmitting end, and a compensation capacitor C2 at the receiving end; Among them, the compensation inductor L0 adopts the form of matrix inductor and is connected with the control switch S' A connected, by switching the control switch S' A The value of the compensation inductor L0 is switched, and the two together constitute a compensation inductor that can be switched, denoted as L 0开关 ; The first compensation capacitor C0 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S' B connected, by switching the control switch S' B The value of the first compensation capacitor C0 is switched, and the two together constitute a compensation capacitor that can be switched, denoted as C 0开关 The second compensation capacitor C1 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S' C connected, by switching the control switch S' C The value of C1 is switched, and the two together form a compensation capacitor that can be switched, denoted as C 1开关 ; One end of the switchable compensation inductor L0 is connected to the input voltage U in The positive pole of the switchable compensation inductor L 0开关 The other end is connected to the compensation capacitor C which can be switched 0开关 , Compensation capacitor C that can be switched 1开关 One end of C 1开关 The other end is connected in series with one end of the transmitting coil L1, and C 0开关 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed, and the system input current is I in , the current in the transmitting coil is I1, the current in the series loop where the receiving coil is located is I2, and the voltage across the equivalent load is U out ; The standard LCC-S compensation topology using the standard LCC compensation topology with adjustable inductance and capacitance includes a transmitter compensation inductor L' 0调 , the first compensation capacitor C' at the transmitting end 0调 , the second compensation capacitor C' at the transmitting end 1调 , and receiving end compensation capacitor C2; power supply U in The positive electrode and the transmitter compensation inductor L' 0调 One end is connected to the transmitter end compensation inductor L' 0调 The other end is connected to the first compensation capacitor C' 0调 , the second compensation capacitor C' at the transmitting end 1调 One end is connected to the transmitter end, and the second compensation capacitor C' 1调 The other end is connected in series with one end of the transmitting coil L1, and the first compensation capacitor C' 0调 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed, and the system input current is I in , the current in the transmitting coil is I1, the current in the series loop where the receiving coil is located is I2, and the voltage across the equivalent load is U out .

3. The wireless charging system according to claim 1, characterized in that: The improved LCC-S compensation topology of the improved LCC compensation topology using the compensation element to control the switch includes a transmitter compensation inductor L0, a transmitter first compensation capacitor C t , a second compensation capacitor C0 at the transmitting end, a third compensation capacitor C1 at the transmitting end, and a compensation capacitor C2 at the receiving end; Among them, the first compensation capacitor C at the transmitting end t It adopts matrix inductor and controls the switch S A connected, by switching the control switch S A To achieve the first compensation capacitor C t The two together constitute a compensation capacitor that can be switched, denoted as C t开关 ; The second compensation capacitor C0 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S B connected, by switching the control switch S B The value of C0 can be switched, and the two together constitute a compensation capacitor that can be switched. 0开关 The third compensation capacitor C1 at the transmitting end adopts a matrix capacitor form and is connected to the control switch S C connected, by switching the control switch S C The value of C1 can be switched, and the two together constitute a compensation capacitor that can be switched. 1开关 ; One end of the transmitter compensation inductor L0 is connected to the input voltage U in The positive electrode of the transmitter compensation inductor L0 and the other end of the compensation capacitor C that can be switched t开关 One end of C t开关 The other end is connected to the compensation capacitor C which can be switched 0开关 , Compensation capacitor C that can be switched 1开关 One end of C 1开关 The other end is connected in series with one end of the transmitting coil L1, and C 0开关 The other end of the transmitting coil L1 is connected to the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed. The current in the transmitting coil is I1, the current in the series circuit where the receiving coil is located is I2, and the voltage across the equivalent load is U out ; The improved LCC-S compensation topology of the improved LCC compensation network using adjustable capacitors includes a transmitter compensation inductor L0, a transmitter first compensation capacitor C t调 , the second compensation capacitor C at the transmitting end 0调 , the third compensation capacitor C at the transmitting end 1调 , and the receiving end compensation capacitor C2; one end of the transmitting end compensation inductor L0 is connected to the input voltage U in The positive pole of the transmitter compensation inductor L0 and the other end of the transmitter first compensation inductor C t调 One end of the transmitter is connected to the first compensation inductor C t调 The other end is connected to the second compensation capacitor C 0调 , the third compensation capacitor C at the transmitting end 1调 One end of the transmitter is connected to the third compensation capacitor C 1调 The other end of the transmitting end second compensation capacitor C0 and the other end of the transmitting end coil L1 are connected in series with the input voltage U in The negative pole of the transmitting coil L1 and the receiving coil L2 are electromagnetically coupled, the mutual inductance of the coupling coils is M, the receiving coil L2, the receiving compensation capacitor C2, and the equivalent load R L A series circuit is formed. The current in the transmitting coil is I1, the current in the series circuit where the receiving coil is located is I2, and the voltage across the equivalent load is U out .

4. The output voltage regulation method of the wireless charging system according to any one of claims 1 to 3, characterized in that: The method comprises the following steps in order: (1) The circuit models of the wireless charging system are established based on the standard LCC-S compensation topology and the improved LCC-S compensation topology, respectively. The relationship between the voltage gain and the compensation component parameter value of the wireless charging system with the standard LCC-S compensation topology is analyzed, and the relationship between the compensation component parameters and the coil inductance when the system works in a resonant state is analyzed. The relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the improved LCC-S compensation topology is analyzed, and the relationship between the compensation component parameters and the coil inductance when the system works in a resonant state is analyzed; the standard LCC-S compensation topology means that the transmitter compensation network adopts the standard LCC compensation topology, and the receiver compensation network adopts the series compensation topology; the improved LCC-S compensation topology means that the transmitter compensation network adopts the improved LCC compensation topology, and the receiver compensation network adopts the series compensation topology; (2) According to different compensation topologies adopted by the transmitter of the system, the numerical range of the compensation component parameters of the transmitter of the wireless charging system with the standard LCC-S compensation topology and the numerical range of the compensation component parameters of the transmitter of the wireless charging system with the improved LCC-S compensation topology are designed respectively based on the relationship between the corresponding voltage gain and the compensation component parameter value; (3) According to the compensation topology adopted by the system transmitter, the corresponding switching controller is designed: first, the collected signal of the center position of the transmitting and receiving coils is transmitted to the switching controller to start / stop supplying power to the transmitting coil; Secondly, the collected transmitter input current signal is input into the switching controller, and the current output voltage gain is calculated according to the transmitter input voltage value, coil inductance, and load resistance; then, the obtained voltage gain signal is transmitted to the switching controller, the standard voltage gain value and the actual voltage gain signal fed back in real time are compared, the target numerical gear of the compensation element is determined, and a compensation element target numerical gear signal is sent to the compensation element parameter regulator; finally, the compensation element parameter regulator sends an instruction to switch the compensation element parameters, controls the adjustable inductor, capacitor or compensation element control switch to switch the corresponding compensation inductance or capacitance value, and realizes the control of the compensation element parameter adjustment of the wireless charging system.

5. The output voltage regulation method of the wireless charging system according to claim 4, characterized in that: Analyzing the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the improved LCC-S compensation topology in step (1), and analyzing the relationship between the compensation component parameter and the coil inductance when the system operates in a resonant state specifically refers to: Output voltage gain H u The relationship between compensation component parameters and coil inductance is: Among them, ω is the system operating frequency, L0 is the transmitter compensation inductance, C t is the compensation capacitor connected in series with L0; λ=1 / (ω 2 L0C t ) is the compensation capacitor C t Regulation coefficient: In the improved LCC-S compensation topology, if the system input voltage and the series compensation inductor L0 remain unchanged, the above relationship is simplified to: H u L0 / M0=μ·p Among them, μ = 1 / (1-λ) is the compensation coefficient of the mutual inductance change of the coupling coil, p = M / M0 is the mutual inductance change coefficient, M and M0 are the mutual inductance of the coupling coil at the current position and the position directly opposite to the transmitting and receiving coils respectively; Analyzing the relationship between the voltage gain and the compensation component parameter value of the wireless charging system of the standard LCC-S compensation topology in step (1), and analyzing the relationship between the compensation component parameter and the coil inductance when the system operates in a resonant state specifically refers to: Output voltage gain H u The relationship between compensation component parameters and coil inductance is: Among them, M is the mutual inductance of the coupling coil at the current position, and L0 is the compensation inductance of the transmitting end.

6. The output voltage regulation method of the wireless charging system according to claim 4, characterized in that: The numerical range of the transmitter compensation component parameters of the wireless charging system with the improved LCC-S compensation topology designed in step (2) specifically includes: When the transceiver coil offset causes the coupling coil mutual inductance to fluctuate, assuming the mutual inductance value at the current position is: M i =p i M0, p i is the mutual inductance variation coefficient. By changing the compensation capacitance value at the transmitting end, the output voltage gain of the system is adjusted. Let the capacitance value C of the current gear be ti =q i C0, then at the initial resonant frequency, C t The change in value is expressed as the capacitance adjustment coefficient λ i And the mutual inductance change compensation coefficient μ i Changes: Among them, i is the current gear of the compensation element, q is the capacitance C t At the same time, in order to meet the resonance condition, the capacitor C needs to be adjusted synchronously. 0改 and C 1改 for: Therefore, the reference capacitor C1 and the capacitor C ti Connect in series to get the capacitance C 1改 ; Through the coupling coil mutual inductance variation coefficient p i And the mutual inductance change compensation coefficient μ i , determine the value i of the required compensation element, and thus obtain the compensation capacitor C t , C 0改 and C 1改 The values ​​of each gear; among them, C 0改 , C 1改 They are the values ​​of the transmitter compensation capacitors C0 and C1 after gear adjustment; The numerical range of the transmitter compensation component parameters of the wireless charging system with the standard LCC-S compensation topology designed in step (2) specifically includes: When the transceiver coil offset causes the coupling coil mutual inductance to fluctuate, assuming the mutual inductance value at the current position is: M i =p i M0, p i is the mutual inductance variation coefficient, then the system output voltage gain is: H u =p i M0 / L 0改 ; where L 0改 is the value of the transmitter compensation inductor L0 after the gear adjustment; at this time, the transmitter compensation inductor value can be changed to make L 0改i =a i L0, thereby adjusting the output voltage gain of the system: Where i is the compensation capacitor C 0改 The numerical position, a is the compensation inductance L 0改 The adjustment coefficient represents the ratio of the mutual inductance value of the coupling coil at the current gear to the mutual inductance value L0 at the initial moment; at the same time, in order to make the system work in a resonant state, the compensation capacitor C needs to be adjusted synchronously 0改 , C 1改 : Therefore, the initial capacitance C1 and the capacitance C 串 =C0 / (1-p) in series, we get the capacitance C 1改 ; Through the coupling coil mutual inductance variation coefficient p i And the voltage gain, determine the value of the compensation element i, and thus get the compensation inductance L 0改 And the capacitor C 0改 , C 1改 The values ​​of each gear.

7. The output voltage regulation method of the wireless charging system according to claim 4, characterized in that: In step (3), designing a transmitter compensation element switching controller according to the improved LCC-S compensation topology specifically includes the following steps: 3a1) Startup control: In the process of the receiving coil gradually approaching the transmitting coil, when the position sensor installed on the front side of the transmitting coil detects that the receiving coil has arrived, the position sensor sends a start signal and transmits it to the switching controller, controls the initial compensation network to connect to the main circuit, and the corresponding transmitting coil is in a power supply state; when the position sensor installed on the rear side of the transmitting coil detects that the receiving coil has completely left, the coil position sensor sends a termination signal and transmits it to the switching controller, at which time the compensation network is cut off, and the corresponding transmitting coil is in an idle state; 3b1) System input current detection and feedback control: In the improved LCC-S compensation topology, the relationship between the system input current and the voltage gain is: Among them, ξ i =H u / H u0 =μ i p i is the system output voltage gain coefficient, H u0 is the reference value of voltage gain; in the current detection and switching control link, the voltage gain coefficient when the transmitting and receiving coils are facing each other is taken as the reference value ξ0, let ξ i =ξ0=1; 3c1) The parameter switching of the compensation element controlled in step (3) is specifically as follows: according to the compensation element target value gear signal sent by the switching controller, the upshift / downshift operation of the compensation element value is determined; the compensation element parameter regulator controls the adjustable capacitor or the compensation element control switch to switch the value of the transmitter compensation capacitor, and the compensation capacitor C of the corresponding value gear is set. t , C 0改 , C 1改 Connect to the power transmission module; In step (3), designing a transmitter compensation element switching controller according to a standard LCC-S compensation topology specifically includes the following steps: 3a2) Startup control: In the process of the receiving coil gradually approaching the transmitting coil, when the position sensor installed on the front side of the transmitting coil detects that the receiving coil has arrived, the position sensor sends a start signal and transmits it to the switching controller, controls the initial compensation network to connect to the main circuit, and the corresponding transmitting coil is in a power supply state; when the position sensor installed on the rear side of the transmitting coil detects that the receiving coil has completely left, the coil position sensor sends a termination signal and transmits it to the switching controller, at which time the compensation network is cut off, and the corresponding transmitting coil is in an idle state; 3b2) System input current detection and feedback control link In the LCC-S compensation topology described, the relationship between the system input current and the voltage gain is: Among them, κ i =H u / H u0 =p i / a i is the system output voltage gain coefficient, H u0 is the reference value of voltage gain; in the current detection and switching control link, the voltage gain coefficient when the transmitting and receiving coils are facing each other is taken as the reference value κ0, and κ i =κ0=1; 3c2) The compensation element switch switching controlled in step (3) is specifically as follows: according to the compensation element target value gear signal sent by the switching controller, the upshift / downshift operation of the compensation element value is determined; the compensation element parameter regulator controls the adjustable inductance, capacitance or compensation element control switch to switch the value of the transmitter compensation inductance and capacitance, and the compensation inductance L of the corresponding value gear is set. 0改 And the compensation capacitor C 0改 , C 1改 Connect to the power transmission module.

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