ECPT system based on bilateral LC and bilateral LCLC hybrid compensation network

Abstract

The invention discloses an ECPT system based on a bilateral LC and bilateral LCLC hybrid compensation network, and relates to the technical field of wireless electric energy transmission, the ECPT system comprises an electric energy transmitting end and an electric energy receiving end, two sets of coupling mechanisms of which the cross coupling capacitance can be neglected respectively use bilateral LC and bilateral LCLC topologies for compensation, and the two are connected with an inverter and a load through series input and series output combination. The bilateral LC compensation topology and the bilateral LCLC compensation topology both adopt constant current mode matching, the system can achieve the constant current output characteristic irrelevant to the load, and due to the fact that the output characteristics of the two compensation topologies and the coupling mutual capacitance CM are in a complementary relation, the system can basically achieve constant power output under the change of the coupling mutual capacitance CM. And good anti-coupling mechanism deviation performance is shown.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless power transmission, in particular to an ECPT system based on a double-sided LC and double-sided LCLC hybrid compensation network. Background Art

[0002] The working principle of the electric-field coupled power transfer (ECPT) technology is that the DC input passes through the high-frequency inverter circuit and the transmitter resonant compensation circuit to obtain high-frequency and high-voltage AC power. Under its action, an interactive electric field is formed between the two pairs of plates of the coupling mechanism. These metal plates constitute an equivalent coupling capacitor to provide a complete electrical circuit for the ECPT system. Under the action of the interactive electric field, a displacement current is generated that "flows" through the plates, and then passes through the resonant compensation circuit and the rectifier and filter circuit at the receiving end to convert it into the form of electrical energy required by the load, ultimately realizing wireless transmission of electrical energy.

[0003] ECPT technology has the following advantages: 1) The coupling mechanism uses lightweight metal as the transmitting and receiving electrodes, showing the advantages of lightness, thinness and good plasticity; 2) ECPT technology uses alternating electric fields to achieve energy transmission, and the system can achieve power transmission across metal barriers; 3) Compared with the magnetically coupled wireless power transmission system, the eddy current loss caused by the ECPT system on the surrounding metal foreign matter can be ignored.

[0004] The coupling mutual capacitance formed by the coupling mechanism is the key parameter for the ECPT system to achieve wireless power transmission, and the coupling mutual capacitance CM is mainly determined by the facing area between the emitter plate and the receiver plate, the relative dielectric constant of the dielectric material and the relative distance. Therefore, when the emitter plate and the receiver plate are offset to a certain extent, the facing area will be reduced, resulting in a reduction in the coupling mutual capacitance, which will in turn affect the ECPT system.

[0005] At present, there are still few analyses on the anti-drift characteristics of electric field coupling wireless charging. Harbin Institute of Technology proposed a new electric field coupling mechanism, completed the energy transfer topology design based on the LCLC-LC resonant compensation network, and modeled and analyzed the system. The results show that the system transmission power is 223.3W, the overall efficiency is 80.6%, and the output power and efficiency are basically constant when the receiving plate moves arbitrarily in the area above the transmitting plate. However, in this design, the coupling capacitor is kept basically unchanged to achieve the anti-drift effect, and it cannot achieve the anti-drift effect when the coupling capacitor changes. The Kunming Branch of the 705th Institute of China Shipbuilding Industry Corporation proposed a UUV (Unmanned Underwater Vehicle) electric field coupling wireless power transmission system with anti-drift and leakage electric field shielding characteristics. The system is a new five-level plate-type coupling mechanism suitable for UUV. Taking the EC-WPT system with double-sided LC compensation as an example, the calculation method of the system output parameters is given. The results show that 74W of power transmission is achieved in the experiment with an efficiency of 85.6%, and when the energy receiving end is offset from three dimensions, the output power and efficiency of the system change very little. However, the coupling mechanism design of its five plates ensures that when the energy receiving end moves or rotates within a certain range, the facing area between the emitter plate and the receiving plate remains unchanged, which is conducive to achieving anti-offset. It is not suitable for the situation where the facing area between the emitter plate and the receiving plate changes due to offset.

[0006] It can be seen that the anti-offset performance of the current electric field coupling wireless charging system is relatively limited, and it is impossible to achieve stable output under the change of coupling mutual capacitance (coupling mechanism offset). Summary of the invention

[0007] In view of the above existing problems, the present invention is proposed.

[0008] Therefore, the present invention provides an ECPT system based on bilateral LC and bilateral LCLC hybrid compensation networks, and solves the technical problem of how to achieve stable output of the electric field coupled wireless charging system under the change of coupling mutual capacitance, so that the system has good anti-offset performance.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0010] The present invention provides an ECPT system based on a bilateral LC and a bilateral LCLC hybrid compensation network, comprising: an electric energy transmitting end and an electric energy receiving end;

[0011] The electric energy transmitting end includes an inverter, two pairs of emitter plates, and a transmitting end compensation network connected between the inverter and the two pairs of emitter plates, wherein the transmitting end compensation network includes a transmitting end LC compensation network and a transmitting end LCLC compensation network connected in series, wherein the transmitting end LC compensation network is connected to the first pair of emitter plates, and the transmitting end LCLC compensation network is connected to the second pair of emitter plates;

[0012] The electric energy receiving end includes a rectifier, two pairs of receiving plates, and a receiving end compensation network connected between the rectifier and the two pairs of receiving plates, wherein the receiving end compensation network includes a receiving end LC compensation network and a receiving end LCLC compensation network connected in series, wherein the receiving end LC compensation network is connected to the first pair of receiving plates, and the receiving end LCLC compensation network is connected to the second pair of receiving plates.

[0013] As a preferred solution of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network described in the present invention, the power transmitting end is powered by a DC power supply E dc Providing electric energy, the voltage-type full-bridge inverter converts direct current into high-frequency alternating current to supply the subsequent circuit, wherein the voltage-type full-bridge inverter is composed of power MOSFETS1-S4.

[0014] As a preferred solution of the ECPT system based on bilateral LC and bilateral LCLC hybrid compensation networks described in the present invention, wherein: the first pair of emitter plates and the first pair of receiving plates constitute a first set of coupling mechanisms, and the second pair of emitter plates and the second pair of receiving plates constitute a second set of coupling mechanisms.

[0015] As a preferred solution of the ECPT system based on the bilateral LC and bilateral LCLC hybrid compensation networks described in the present invention, it includes:

[0016] Compensation inductance L 11 , compensation capacitor C ex11 The transmitting end LC compensation network of the first coupling mechanism is composed of the compensation inductor L f1 and compensation inductor L p1 , compensation capacitor C ex12 and compensation capacitor C f1 The transmitting end LCLC compensation network of the second coupling mechanism is formed, and the compensation inductor L p1 and the compensation capacitor C ex12 The second pair of emitter plates of the second set of coupling mechanisms are connected, and the emitter end LC compensation network of the first set of coupling mechanisms and the emitter end LCLC compensation network of the second set of coupling mechanisms are connected in series.

[0017] As a preferred solution of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network described in the present invention, wherein: the compensation inductor L p1 It consists of two parts of inductance, including the first part of inductance L 12 And the inductance value and compensation inductance L f1 Same as the second remaining inductor.

[0018] As a preferred solution of the ECPT system based on the bilateral LC and bilateral LCLC hybrid compensation networks described in the present invention, it includes:

[0019] Compensation inductance L 21 , compensation capacitor C ex21 The receiving end LC compensation network of the first coupling mechanism is composed of a compensation inductor L s1 and compensation inductor L f2 , compensation capacitor C ex22 and compensation capacitor C f2 The receiving end LCLC compensation network of the second coupling mechanism is formed, and the compensation inductor L s1 and the compensation capacitor C ex22 The second pair of receiving plates of the second set of coupling mechanisms are connected, and the receiving end LC compensation network of the first set of coupling mechanisms and the receiving end LCLC compensation network of the second set of coupling mechanisms are connected in series and reversely.

[0020] As a preferred solution of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network described in the present invention, wherein: the compensation inductor L s1 It consists of two parts of inductance, including the first part of inductance L 22 And the inductance value and compensation inductance L f2 Same as the second remaining inductor.

[0021] As a preferred solution of the ECPT system based on the bilateral LC and bilateral LCLC hybrid compensation networks described in the present invention, wherein: the transmitter compensation network and the receiver compensation network satisfy the relationship:

[0022]

[0023] Where, ω represents the system operating angular frequency, C 11 =C in11 +C ex11 , C in11 represents the capacitance of the first pair of emitter plates of the first set of coupling mechanisms, C 12 =C in12 +C ex12 , C in12 represents the capacitance of the second pair of emitter plates of the first set of coupling mechanisms, C 21 =C in21 +C ex21 , C in21 Represents the capacitance of the first pair of receiving plates of the first coupling mechanism, C 22 =C in22 +C ex22 , C in22 Represents the capacitance of the second pair of receiving plates of the first coupling mechanism.

[0024] As a preferred solution of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network described in the present invention, wherein: the compensation inductor L f1 and the compensation capacitor C f1 To meet the resonance relationship, the compensation inductor L f2 With the compensation capacitor C f2 Satisfies the resonance relationship, that is, ω 2 L f1 C f1 =1,ω 2 L f2 C f2 =1.

[0025] As a preferred solution of the ECPT system based on the bilateral LC and bilateral LCLC hybrid compensation networks described in the present invention, it also includes:

[0026] The compensation inductor L f1 With the compensation inductor L f2 equal to the compensation inductance L 11 With the compensation inductor L 21 equal to the compensation inductance L p1 The first part of the inductor L 12 With the compensation inductor L s1 The first part of the inductor L 22 equal;

[0027] The capacitance C of the first pair of emitter plates of the first set of coupling mechanisms in11 The capacitance C of the first pair of receiving plates of the first coupling mechanism in21 Equal, the capacitance C of the second pair of emitter plates of the first set of coupling mechanisms in12 The capacitance C of the second pair of receiving plates of the first coupling mechanism in22 equal;

[0028] The compensation capacitor C ex11 With the compensation capacitor C ex21 equal, the compensation capacitor C ex12 With the compensation capacitor C ex22 equal.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides an ECPT system based on a bilateral LC and bilateral LCLC hybrid compensation network, wherein two sets of coupling mechanisms with negligible cross-coupling capacitance between each other are compensated using bilateral LC and bilateral LCLC topologies respectively, and then the two are connected in series input and output combination with inverter and load. Both the bilateral LC and bilateral LCLC compensation topologies adopt constant current mode tuning, and the system can achieve constant current output characteristics that are independent of the load, and because the output characteristics of the two compensation topologies used are complementary to the coupling mutual capacitance CM, the system can basically achieve constant power output under the change of coupling mutual capacitance CM, showing good anti-coupling mechanism offset performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0031] Figure 1 The overall circuit diagram of an ECPT system based on a bilateral LC and bilateral LCLC hybrid compensation network according to an embodiment of the present invention;

[0032] Figure 2 A circuit diagram of an ECPT system of ISOS hybrid compensation based on a bilateral LC and bilateral LCLC hybrid compensation network of an ECPT system according to an embodiment of the present invention;

[0033] Figure 3 A diagram of an equivalent controlled voltage source model of a coupling mechanism of an ECPT system based on a double-sided LC and double-sided LCLC hybrid compensation network according to an embodiment of the present invention;

[0034] Figure 4 An equivalent circuit diagram of a coupling mechanism equivalent controlled voltage source model of an ECPT system based on a bilateral LC and bilateral LCLC hybrid compensation network according to an embodiment of the present invention;

[0035] Figure 5 The C of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network according to an embodiment of the present invention M1 (C M2 )=50pF system input and output waveform diagram;

[0036] Figure 6 The C of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network according to an embodiment of the present invention M1 (CM2 )=40pF system input and output waveform diagram;

[0037] Figure 7 The C of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network according to an embodiment of the present invention M1 (C M2 )=30pF system input and output waveform diagram;

[0038] Figure 8 The C of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network according to an embodiment of the present invention M1 (C M2 )=25pF system input and output waveforms;

[0039] Fig. 9 The C of the ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network according to an embodiment of the present invention M1 (C M2 )=20pF system input and output waveform diagram;

[0040] Fig.10 A diagram showing changes in system output power when coupling mutual capacitance of an ECPT system based on a bilateral LC and bilateral LCLC hybrid compensation network according to an embodiment of the present invention is reduced;

[0041] Fig.11 The existing ECPT system based on the ECPT system of the bilateral LC and bilateral LCLC hybrid compensation network according to an embodiment of the present invention is coupled with the mutual capacitance C M The change of output power under the condition of reduction;

[0042] Fig.12 The existing ECPT system based on the ECPT system of the bilateral LC and bilateral LCLC hybrid compensation network according to an embodiment of the present invention is coupled with the mutual capacitance C M Inverter output voltage and current waveform under reduction. DETAILED DESCRIPTION

[0043] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0044] Example 1

[0045] Reference Figure 1 to Figure 4As one embodiment of the present invention, an ECPT system based on a double-sided LC and double-sided LCLC hybrid compensation network is provided.

[0046] like Figure 2 The circuit diagram of the ECPT system with input series output series (ISOS) hybrid compensation is shown. When compensation topology 1 and compensation topology 2 are both constant current output topologies, then:

[0047]

[0048] Among them, I in1 (I in2 ), V in1 (V in2 ) are the input current and input voltage of the two compensation topologies, I o1 (I o2 ), V o1 (V o2 ) are the output voltage and output current of the two compensation topologies, subscript 1 corresponds to compensation topology 1, and subscript 2 corresponds to compensation topology 2; V in ,I in Input AC voltage and current for the system, V o ,I o is the system output AC voltage and current, R eq is the equivalent load. G1 and G2 are the constant current output gains of compensation topologies 1 and 2 respectively.

[0049] According to the above formula, the constant current output gain G of the ECPT system with ISOS hybrid compensation is:

[0050]

[0051] When the constant current output gains G1 and G2 of compensation topologies 1 and 2 increase with the mutual capacitance C of the electric field coupling mechanism M When the change shows an opposite trend, by reasonably setting the value of the compensation parameter, it can be achieved when the mutual capacitance C of the electric field coupling mechanism M The constant current output gain of the system remains basically unchanged when it changes within a certain range, that is, the ECPT system with ISOS hybrid compensation can achieve good anti-offset performance.

[0052] According to the above analysis, the embodiment of the present invention provides an ECPT system based on a double-sided LC and double-sided LCLC hybrid compensation network. The entire ECPT system is divided into two parts: a power transmitting end and a power receiving end. Figure 1 shown.

[0053] In an embodiment of the present application, the electric energy transmitting end includes an inverter, two pairs of emitter plates, and a transmitting end compensation network connected between the inverter and the two pairs of emitter plates, the transmitting end compensation network includes a transmitting end LC compensation network and a transmitting end LCLC compensation network connected in series, wherein the transmitting end LC compensation network is connected to the first pair of emitter plates, and the transmitting end LCLC compensation network is connected to the second pair of emitter plates;

[0054] The electric energy receiving end includes a rectifier, two pairs of receiving plates, and a receiving end compensation network connected between the rectifier and the two pairs of receiving plates, wherein the receiving end compensation network includes a receiving end LC compensation network and a receiving end LCLC compensation network connected in series, wherein the receiving end LC compensation network is connected to the first pair of receiving plates, and the receiving end LCLC compensation network is connected to the second pair of receiving plates;

[0055] The first pair of emitter plates and the first pair of receiver plates constitute a first set of coupling mechanisms, and the second pair of emitter plates and the second pair of receiver plates constitute a second set of coupling mechanisms.

[0056] It should be noted that the system of the present invention generates an alternating electric field through two sets of quadrupole plate coupling mechanisms to form a "displacement current" to achieve wireless transmission of electric energy. The power transmitting end of the system is powered by a DC power supply E dc To provide electric energy, the voltage-type full-bridge inverter converts direct current into high-frequency alternating current to supply the subsequent circuit, wherein the voltage-type full-bridge inverter is composed of power MOSFETS1~S4.

[0057] Furthermore, the compensation inductance L 11 , compensation capacitor C ex11 The transmitter LC compensation network that constitutes the first coupling mechanism compensates the inductance L f1 and compensation inductor L p1 , compensation capacitor C ex12 and compensation capacitor C f1 The transmitter LCLC compensation network that constitutes the second coupling mechanism compensates the inductance L p1 and compensation capacitor C ex12 The second pair of emitter plates connected to the second set of coupling mechanisms play the role of filtering, reactive power compensation, and voltage pumping, and the LC compensation network at the emitter end of the first set of coupling mechanisms and the LCLC compensation network at the emitter end of the second set of coupling mechanisms are connected in series; wherein the compensation inductor L p1 It consists of two parts of inductance, including the first part of inductance L 12 And the inductance value and compensation inductance L f1 Same as the second remaining inductor.

[0058] Furthermore, the two pairs of plates of the two coupling mechanisms generate "displacement current" under the excitation of high-frequency and high-voltage alternating current, thereby transmitting electrical energy from the transmitting end to the receiving end, compensating the inductance L 21, compensation capacitor C ex21 The receiving end LC compensation network of the first coupling mechanism is used to compensate the inductance L s1 and compensation inductor L f2 , compensation capacitor C ex22 and compensation capacitor C f2 The receiving end LCLC compensation network that constitutes the second coupling mechanism compensates the inductance L s1 and compensation capacitor C ex22 The second pair of receiving plates of the second set of coupling mechanisms are connected, and the receiving end LC compensation network of the first set of coupling mechanisms and the receiving end LCLC compensation network of the second set of coupling mechanisms are connected in series and reversely, which plays the role of impedance matching. The rectifier filter (composed of diodes D1 to D4) converts AC power into DC power through the filter capacitor C f After filtering, it supplies the load R L ; Among them, the compensation inductance L s1 It consists of two parts of inductance, including the first part of inductance L 22 And the inductance value and compensation inductance L f2 Same as the second remaining inductor.

[0059] Furthermore, in the ISOS hybrid compensation ECPT system, the input currents of compensation topology 1 and compensation topology 2 are the same. For the bilateral LC compensation topology, its output voltage lags behind the input current by 90°, while the output voltage of the bilateral LCLC compensation topology leads the input current by 90°, that is, the output voltages of the two compensation topologies are opposite, so the output terminals of the two compensation networks need to be connected in series and reversed. Both sets of quadrupole plate coupling mechanisms can be equivalent to a controlled voltage source model, such as Figure 3 As shown. The circuit relationship is:

[0060]

[0061] Among them, C M is the coupling mutual capacitance of the first or second set of coupling mechanisms, is the coupling coefficient of the first or second set of coupling mechanisms, V tx 、V rx are the equivalent voltages of the transmitting and receiving ends of the first or second coupling mechanism, respectively, C tx , C rx are the equivalent capacitance of the transmitting end and the equivalent capacitance of the receiving end of the first or second set of coupling mechanisms, respectively, C in1 , C ex1 is the capacitance of the two emitter plates of the first or second set of coupling mechanisms, C1 is C in1 and C ex1 The sum of C in2 , C ex2 is the capacitance of the two receiving plates of the first or second set of coupling mechanisms, C in2 Cin2 , C ex2 When these parameters also have subscripts 1 or 2, the parameters with subscript 1 correspond to the first set of coupling mechanisms, and the parameters with subscript 2 correspond to the second set of coupling mechanisms.

[0062] In the embodiment of the present application, the L of the double-sided LC and double-sided LCLC compensation is 11 , compensation inductance L p1 The first part of the inductor L 12 (Compensation inductance L p1 The remaining inductance value is equal to the compensation inductance L f1 Same), L 21 , compensation inductance L s1 Part of L 22 (Compensation inductance L s1 The remaining inductance value is equal to the compensation inductance L f2 The same) are respectively related to C in the equivalent controlled voltage source of the corresponding coupling mechanism tx and C rx Series resonance, that is, the relationship is satisfied:

[0063] Where, ω represents the system operating angular frequency, C 11 =C in11 +C ex11 , C in11 represents the capacitance of the first pair of emitter plates of the first set of coupling mechanisms, C 12 =C in12 +C ex12 , C in12 represents the capacitance of the second pair of emitter plates of the first set of coupling mechanisms, C 21 =C in21 +C ex21 , C in21 Represents the capacitance of the first pair of receiving plates of the first coupling mechanism, C 22 =C in22 +C ex22 , C in22 Represents the capacitance of the second pair of receiving plates of the first coupling mechanism.

[0064] Furthermore, the equivalent circuit of the double-sided LC+LCLC ISOS hybrid compensation ECPT system is as follows: Figure 4 As shown, where: C M1 , C M2 are the coupling mutual capacitance of the first set of coupling mechanisms and the second set of coupling mechanisms, respectively, and k c1 , k c2 are the coupling coefficients of the first and second coupling mechanisms, I1 and I 31 are the currents at the transmitting end of the first and second coupling mechanisms, I2 and I41 are the currents at the receiving ends of the first and second coupling mechanisms, Z1 and Z 31 are respectively the reflected impedance of the receiving end to the transmitting end of the second set of coupling mechanisms, and I3 and I4 are respectively the compensation inductors L f1 and L f2 The current at the receiving end of the first and second coupling mechanisms, V in is the inverter output voltage, V out is the equivalent load R eq V1 and V3 are the input voltages of the first and second coupling mechanisms respectively, and V2 and V4 are the output voltages of the first and second coupling mechanisms respectively.

[0065] Based on Kirchhoff's voltage theorem (KVL) and current theorem (KCL), the equivalent circuit of the ECPT system can be listed as follows:

[0066]

[0067] Among them, the compensation inductor L f1 and compensation capacitor C f1 Satisfy the resonance relationship and compensate the inductance L f2 With compensation capacitor C f2 Satisfies the resonance relationship, that is, ω 2 L f1 C f1 =1,ω 2 L f2 C f2 =1; then according to the LCL resonant network characteristics, we can get:

[0068]

[0069] Combining the above two equations, we can get the system output current -I2 calculation formula:

[0070]

[0071] Among them, G iLC , G iLCLC are the output gains of the bilateral LC network and the bilateral LCLC, respectively;

[0072] It should be noted that the above formula verifies that the ECPT system based on bilateral LC and bilateral LCLC hybrid compensation networks provided by the present invention meets the basic characteristics of the ISOS hybrid compensation system, can achieve a constant current output characteristic that is independent of the load, and at the same time, when the coupling mutual capacitance CM1 (CM2) is reduced within a certain range, the output current remains basically unchanged, thereby achieving good anti-offset performance.

[0073] Example 2

[0074] Reference Figure 5 to Figure 12 Based on the previous embodiment, this embodiment provides an application example of an ECPT system based on bilateral LC and bilateral LCLC hybrid compensation networks to verify and illustrate the technical effects used in this method.

[0075] To verify that the bilateral LC+LCLC ISOS hybrid compensation ECPT system can achieve a constant current output characteristic that is independent of the load while satisfying the coupling mutual capacitance C M1 (C M2 ) decreases within a certain range, the output current remains basically unchanged, achieving good anti-offset performance. This embodiment builds a circuit model of the system based on the Matlab / Simulink simulation platform. The system parameters are shown in Table 1, and f is the system operating frequency.

[0076] According to the parameters in Table 1, the coupling mutual capacitance C is obtained by simulation. M1 (C M2 ) Reduce the load and inverter output voltage and current waveforms as follows Figures 5 to 9 As shown, the system output power is Fig.10 shown.

[0077] Table 1: System parameters.

[0078]

[0079]

[0080] Figure 5 Shows C M1 (C M2 )=50pF, where Figure 5 (a) and (b) are the load voltage and current waveforms and the inverter output voltage and current waveforms respectively;

[0081] Figure 6 Shows C M1 (C M2 )=40pF, where Figure 6 (a) and (b) are the load voltage and current waveforms and the inverter output voltage and current waveforms respectively;

[0082] Figure 7 Shows C M1 (C M2 )=30pF, where Figure 7 (a) and (b) are the load voltage and current waveforms and the inverter output voltage and current waveforms respectively;

[0083] Figure 8 Shows C M1 (C M2)=25pF, where Figure 8 (a) and (b) are the load voltage and current waveforms and the inverter output voltage and current waveforms respectively;

[0084] Fig. 9 Shows C M1 (C M2 )=20pF, where Fig. 9 (a) and (b) are the load voltage and current waveforms and the inverter output voltage and current waveforms respectively;

[0085] Depend on Figures 5 to 9 It can be seen that under different coupling mutual capacitances, the system inverter output current slightly lags behind the output voltage, and the input impedance is weakly inductive, which facilitates the realization of zero voltage switching (ZVS); when the coupling mutual capacitance gradually decreases, the system input current will not produce an overcurrent risk.

[0086] Fig.10 The change of system output power under the reduction of coupling mutual capacitance is shown. Fig.10 It can be seen that before the coupling mutual capacitance is reduced to 50% of the original coupling mutual capacitance, the system can ensure that the output power fluctuation does not exceed 10%, which verifies that the ECPT system based on the bilateral LC and bilateral LCLC hybrid compensation network provided by the present invention has good anti-offset performance; and as the coupling mutual capacitance is further reduced, the system output power gradually decreases without causing the risk of overvoltage and overcurrent.

[0087] Existing ECPT systems usually use separate bilateral LC compensation to achieve load-independent constant current output characteristics. M The output power under the reduced Fig.11 As shown, the inverter output voltage and current are as follows Fig.12 As shown. It can be seen that in the process of reducing the coupling mutual capacitance of the ECPT system with bilateral LC compensation, the system output power first increases and then decreases, and the variation range is more than 50% compared with the output power under the original coupling mutual capacitance, so the system does not have anti-offset performance. In addition, in the process of reducing the coupling mutual capacitance of the ECPT system with bilateral LC compensation, the system inverter output current leads the output voltage, the input impedance is weakly capacitive, and the capacitance increases with the reduction of the coupling mutual capacitance, which is easy to damage the inverter.

[0088] Experimental results show that the ECPT system based on bilateral LC and bilateral LCLC hybrid compensation networks proposed in the present invention has good anti-offset performance and can achieve a constant current output characteristic that is independent of the load. It can effectively solve the problem of large changes in system output power caused by the reduction of coupling mutual capacitance due to the offset of the coupling mechanism.

[0089] In summary, the present invention provides an ECPT system based on a bilateral LC and bilateral LCLC hybrid compensation network. Two sets of coupling mechanisms with negligible cross-coupling capacitance use bilateral LC and bilateral LCLC topologies for compensation respectively, and then the two are connected in series input and output combination with inverter and load. Both the bilateral LC and bilateral LCLC compensation topologies adopt constant current mode tuning. The system can achieve constant current output characteristics that are independent of the load, and because the output characteristics of the two compensation topologies used are consistent with the coupling mutual capacitance C M They are complementary, so the system can basically achieve coupling mutual capacitance C M Constant power output under changing conditions shows good anti-coupling mechanism offset performance.

[0090] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. ECPT system based on bilateral LC and bilateral LCLC hybrid compensation networks, It is characterized in that The system comprises an electric energy transmitting end and an electric energy receiving end: The electric energy transmitting end includes an inverter, two pairs of emitter plates, and a transmitting end compensation network connected between the inverter and the two pairs of emitter plates, wherein the transmitting end compensation network includes a transmitting end LC compensation network and a transmitting end LCLC compensation network connected in series, wherein the transmitting end LC compensation network is connected to the first pair of emitter plates, and the transmitting end LCLC compensation network is connected to the second pair of emitter plates; The electric energy receiving end includes a rectifier, two pairs of receiving plates, and a receiving end compensation network connected between the rectifier and the two pairs of receiving plates, wherein the receiving end compensation network includes a receiving end LC compensation network and a receiving end LCLC compensation network connected in series, wherein the receiving end LC compensation network is connected to the first pair of receiving plates, and the receiving end LCLC compensation network is connected to the second pair of receiving plates.

2. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 1, It is characterized in that The electric energy transmitting end is powered by a DC power supply E dc The voltage-type full-bridge inverter converts direct current into high-frequency alternating current to supply the subsequent circuit, wherein the voltage-type full-bridge inverter is composed of power MOSFETS 1 ~S 4 composition.

3. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 2, It is characterized in that The first pair of emitter plates and the first pair of receiver plates constitute a first set of coupling mechanisms, and the second pair of emitter plates and the second pair of receiver plates constitute a second set of coupling mechanisms.

4. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 3, It is characterized in that include: Compensation inductance L 11 , compensation capacitor C ex11 The transmitting end LC compensation network of the first coupling mechanism is composed of the compensation inductor L f1 and compensation inductor L p1 , compensation capacitor C ex12 and compensation capacitor C f1 The transmitting end LCLC compensation network of the second coupling mechanism is formed, and the compensation inductor L p1 and the compensation capacitor C ex12 The second pair of emitter plates of the second set of coupling mechanisms are connected, and the emitter end LC compensation network of the first set of coupling mechanisms and the emitter end LCLC compensation network of the second set of coupling mechanisms are connected in series.

5. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 4, It is characterized in that The compensation inductor L p1 It consists of two parts of inductance, including the first part of inductance L 12 And the inductance value and compensation inductance L f1 Same as the second remaining inductor.

6. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 3, It is characterized in that include: Compensation inductance L 21 , compensation capacitor C ex21 The receiving end LC compensation network of the first coupling mechanism is composed of a compensation inductor L s1 and compensation inductor L f2 , compensation capacitor C ex22 and compensation capacitor C f2 The receiving end LCLC compensation network of the second coupling mechanism is formed, and the compensation inductor L s1 and the compensation capacitor C ex22 The second pair of receiving plates of the second set of coupling mechanisms are connected, and the receiving end LC compensation network of the first set of coupling mechanisms and the receiving end LCLC compensation network of the second set of coupling mechanisms are connected in series and reversely.

7. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 6, It is characterized in that The compensation inductor L s1 It consists of two parts of inductance, including the first part of inductance L 22 And the inductance value and compensation inductance L f2 Same as the second remaining inductor.

8. The ECPT system based on the double-sided LC or double-sided LCLC hybrid compensation network as claimed in any one of claims 5 or 7, It is characterized in that The transmitter compensation network and the receiver compensation network satisfy the relationship: Where, ω represents the system operating angular frequency, C 11 =C in11 +C ex11 , C in11 represents the capacitance of the first pair of emitter plates of the first set of coupling mechanisms, C 12 =C in12 +C ex12 , C in12 represents the capacitance of the second pair of emitter plates of the first set of coupling mechanisms, C 21 =C in21 +C ex21 , C in21 Represents the capacitance of the first pair of receiving plates of the first coupling mechanism, C 22 =C in22 +C ex22 , C in22 Represents the capacitance of the second pair of receiving plates of the first coupling mechanism.

9. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 8, It is characterized in that The compensation inductor L f1 and the compensation capacitor C f1 To meet the resonance relationship, the compensation inductor L f2 With the compensation capacitor C f2 Satisfies the resonance relationship, that is, ω 2 L f1 C f1 =1,ω 2 L f2 C f2 =1.

10. The ECPT system based on the double-sided LC and double-sided LCLC hybrid compensation network as claimed in claim 9, It is characterized in that Also includes: The compensation inductor L f1 With the compensation inductor L f2 equal to the compensation inductance L 11 With the compensation inductor L 21 equal to the compensation inductance L p1 The first part of the inductor L 12 With the compensation inductor L s1 The first part of the inductor L 22 equal; The capacitance C of the first pair of emitter plates of the first set of coupling mechanisms in11 The capacitance C of the first pair of receiving plates of the first coupling mechanism in21 Equal, the capacitance C of the second pair of emitter plates of the first set of coupling mechanisms in12 The capacitance C of the second pair of receiving plates of the first coupling mechanism in22 equal; The compensation capacitor C ex11 With the compensation capacitor C ex21 equal, the compensation capacitor C ex12 With the compensation capacitor C ex22 equal.

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