Single-line electric field coupling type wireless power transmission system based on dual-frequency reconfigurable topology

Abstract

The invention provides a single-line electric field coupling type wireless power transmission system based on a dual-frequency reconfigurable topology. Comprising a direct-current voltage source, a high-frequency inverter circuit, a transmitting end compensation circuit, a transmitting polar plate, a receiving polar plate, a receiving end compensation circuit, a diode rectifying circuit, a direct-current side filter capacitor and a load connected with the direct-current side filter capacitor in parallel, the transmitting end compensation circuit comprises a transmitting end inductor and a first double-frequency compensation network. The receiving end compensation circuit comprises a receiving end inductor, a second double-frequency compensation network, a third double-frequency compensation network and a fourth double-frequency compensation network. In addition, the invention also provides a corresponding method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wireless power transmission, and particularly relates to a single-line electric field coupling type wireless power transmission system and method based on a dual-frequency reconfigurable topology, which can realize constant-current / constant-voltage charging functions independent of changes in loads and coupling capacitances. BACKGROUND

[0002] Wireless power transmission (WPT) technology can realize efficient transmission of electric energy without physical contact. Compared with wired power transmission, WPT has higher safety, better convenience and user experience. In recent years, WPT technology has been widely used in electric vehicles, electric toothbrushes, automated guided vehicles, biomedical implants and robots. WPT technology can be generally divided into three categories, such as inductive power transmission (IPT) based on electromagnetic induction principle, capacitive power transmission (CPT) based on capacitive wireless power transmission principle, and coupled magnetic resonance power transmission (CMRPT) based on electromagnetic coupling resonance energy transmission technology principle. Among them, CPT is an electric-field coupled wireless power transmission (EC-WPT) technology, which has received more and more attention in recent years.

[0003] EC-WPT technology has the characteristics of light coupling structure, flexible coupling plate design and low eddy current loss. However, the traditional EC-WPT system has the problem of complicated coupling mechanism, and needs two pairs of metal plates to realize a complete circuit loop, which seriously restricts its application in mobile devices and dynamic power transmission. Unlike the traditional EC-WPT system, single-line EC-WPT (SEC-WPT) technology only needs one pair of coupling plates for power transmission, and does not need a physical return path, that is, it does not need another pair of metal plates to provide a current return path. It has the advantages of more flexible coupling mechanism, more compact, smaller space occupation, and avoidance of cross-coupling of different coupling plates. The main principle of the SEC-WPT system is that the parasitic capacitances of the transmitting end, the coupling plate and the receiving end form a complete circuit.

[0004] However, the research on SEC-WPT is still in its infancy, and there are still many aspects to be studied, such as realizing constant-current (CC) and constant-voltage (CV) charging and improving the anti-offset capability of single coupling plate, in order to improve the application potential of SEC-WPT technology in dynamic wireless charging and mobile device wireless charging. SUMMARY

[0005] To make up for the deficiencies of the prior research, the application provides a single-wire electric field coupling type wireless electric energy transmission system based on a dual-frequency reconfigurable topology. By changing the resonant frequency of the system through a controller, the switching of the LC-LCLC topology structure of the constant current charging mode and the LC-CLC topology structure of the constant voltage charging mode can be realized, and then the constant current and constant voltage charging independent of the load and the coupling capacitance change can be realized, thereby greatly improving the performance of the system against the coupling structure offset and greatly reducing the control complexity.

[0006] According to a first aspect of the present disclosure, a single-wire electric field coupling type wireless electric energy transmission system based on a dual-frequency reconfigurable topology is disclosed, which comprises a DC voltage source, a high-frequency inverter circuit, a transmitting end compensation circuit, a transmitting plate, a receiving plate, a receiving end compensation circuit, a diode rectifier circuit, a DC side filter capacitor, and a load connected in parallel with the DC side filter capacitor connected in sequence, wherein the transmitting end compensation circuit comprises a transmitting end inductor and a first dual-frequency compensation network, the first end of the transmitting end inductor is connected with the first output end of the high-frequency inverter circuit, the second end of the transmitting end inductor is connected with the transmitting plate, and the second end of the transmitting end inductor is also connected with the first end of the first dual-frequency compensation network, the second end of the first dual-frequency compensation network is connected with the second output end of the high-frequency inverter circuit, wherein the receiving end compensation circuit comprises a receiving end inductor, a second dual-frequency compensation network, a third dual-frequency compensation network, and a fourth dual-frequency compensation network, wherein the first end of the receiving end inductor is connected with the receiving plate, the first end of the receiving end inductor is also connected with the first end of the second dual-frequency compensation network, the second end of the receiving end inductor is connected with the first end of the third dual-frequency compensation network, the second end of the receiving end inductor is also connected with the first end of the fourth dual-frequency compensation network, the second end of the second dual-frequency compensation network is connected with the second end of the third dual-frequency compensation network, the second end of the second dual-frequency compensation network is also connected with the second input end of the diode rectifier circuit, and the second end of the fourth dual-frequency compensation network is connected with the first input end of the diode rectifier circuit.

[0007] In some embodiments, the first dual-frequency compensation network comprises a first capacitor and a first LC parallel circuit connected in series with the first capacitor.

[0008] In some embodiments, the second dual-frequency compensation network comprises a second capacitor and a second LC parallel circuit connected in series with the second capacitor.

[0009] In some embodiments, the third dual-frequency compensation network comprises a third capacitor and a third LC parallel circuit connected in series with the third capacitor.

[0010] In some embodiments, the fourth dual-frequency compensation network comprises a fourth inductor and a fourth LC parallel circuit connected in series with the fourth inductor.

[0011] In some embodiments, the LC parallel circuit comprises one capacitor and one inductor connected in parallel.

[0012] In some embodiments, the emitter plate and the receiver plate are respectively composed of a single aluminum plate.

[0013] In some embodiments, the emitter plate and the receiver plate form a single-wire electric field coupling structure.

[0014] In some embodiments, the high-frequency inverter circuit comprises a first bridge arm composed of a first switch tube and a third switch tube, and a second bridge arm composed of a second switch tube and a fourth switch tube, wherein the first output terminal of the high-frequency inverter circuit is led out from the midpoint of the first bridge arm of the high-frequency inverter circuit, and the second output terminal of the high-frequency inverter circuit is led out from the midpoint of the second bridge arm of the high-frequency inverter circuit.

[0015] In some embodiments, the diode rectifier circuit comprises a first bridge arm composed of a first diode and a third diode, and a second bridge arm composed of a second diode and a fourth diode, wherein the first input terminal of the diode rectifier circuit is led in from the midpoint of the first bridge arm of the diode rectifier circuit, and the second input terminal of the diode rectifier circuit is led in from the midpoint of the second bridge arm of the diode rectifier circuit.

[0016] In some embodiments, the system can realize constant-current charging mode and constant-voltage charging mode independent of the load and the coupling capacitance between the emitter plate and the receiver plate.

[0017] In some embodiments, in the constant-current charging mode, the topology of the system is LC-LCLC.

[0018] In some embodiments, in the constant-current charging mode, the first double-frequency compensation network is equivalent to a capacitor C tcc , the second double-frequency compensation network is equivalent to a capacitor C rcc1 , the third double-frequency compensation network is equivalent to a capacitor C rcc2 , and the fourth double-frequency compensation network is equivalent to an inductor L r1 , wherein the emitter inductor L t and the capacitor C tcc form a first resonance loop, satisfying formula (1), and the receiver inductor L r , the capacitor C rcc1 , the capacitor C rcc2 , and the inductor L r1 form a second resonance loop, satisfying formula (2),

[0019]

[0020]

[0021] wherein ω cc is the system angular frequency at the constant-current resonance frequency, satisfying ωcc = 2p f cc , f cc is the resonant frequency in constant current charging mode.

[0022] In some embodiments, in constant current charging mode, the output current I o of the system satisfies formula (3),

[0023]

[0024] wherein according to formula (3), the output current I o of the system is determined only by the voltage U dc of the DC voltage source, the angular frequency w cc of the system in constant current resonant frequency, the transmitting end inductance L t , the equivalent capacitance C rcc1 of the second dual-frequency compensation network, and the equivalent capacitance C rcc2 of the third dual-frequency compensation network, and is irrelevant to the load and the coupling capacitance.

[0025] In some embodiments, in constant voltage charging mode, the topology of the system is LC-CLC.

[0026] In some embodiments, in constant voltage charging mode, the first dual-frequency compensation network is equivalent to a capacitance C tcv , the second dual-frequency compensation network is equivalent to a capacitance C rcv1 , the third dual-frequency compensation network is equivalent to a capacitance C rcv2 , and the fourth dual-frequency compensation network is equivalent to a short circuit, wherein the transmitting end inductance L t and the capacitance C tcv form a third resonant loop, the receiving end inductance L r , the capacitance C rcv1 , and the capacitance C rcv2 form a fourth resonant loop, and formula (4) is satisfied,

[0027]

[0028]

[0029] wherein w cv is the angular frequency of the system in constant voltage resonant frequency, w cv = 2p f cv , f cv is the resonant frequency in constant voltage charging mode.

[0030] In some embodiments, in constant voltage charging mode, the output voltage U o of the system satisfies formula (6),

[0031]

[0032] wherein, according to equation (6), the output voltage U of the system is determined by the voltage C of the DC voltage source o only by the voltage C of the DC voltage source dc , the equivalent capacitance C of the first dual-frequency compensation network tcv and the equivalent capacitance C of the second dual-frequency compensation network rcv1 , and is independent of the load and the coupling capacitance.

[0033] In some embodiments, the system further comprises a controller, and the controller changes the resonant frequency of the system to realize the switching between the constant-current charging mode and the constant-voltage charging mode.

[0034] According to another aspect of the present disclosure, the present disclosure further discloses a single-wire electric field coupled wireless power transmission method based on a dual-frequency reconfigurable topology, which is implemented on the system of any one of the above-mentioned systems, and when the system works in the constant-current charging mode, the resonant frequency of the system is set to a first resonant frequency, and when the system works in the constant-voltage charging mode, the resonant frequency of the system is set to a second resonant frequency.

[0035] In some embodiments, the first resonant frequency and the second resonant frequency are set by the controller of the system.

[0036] The summary is provided to introduce a selection of concepts in a simplified form, which will be further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Other aspects and advantages of the present disclosure will be described in the following embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0037] The description refers to the accompanying drawings that show, in a comprehensive and enabling manner, the present disclosure directed to one of ordinary skill in the art, and include the best mode of making and using the present system and method, in which:

[0038] Figure 1 A schematic diagram of a single-wire electric field coupled wireless power transmission system based on a dual-frequency reconfigurable topology according to an embodiment of the present disclosure is shown;

[0039] Figure 2 A schematic diagram of the equivalent LC-LCLC structure of the system working at the f cc resonant frequency according to an embodiment of the present disclosure is shown;

[0040] Figure 3 A schematic diagram of the equivalent LC-CLC structure of the system working at the f cv resonant frequency according to an embodiment of the present disclosure is shown;

[0041] Figure 4 Fig. 6 shows a simulation result diagram of load mutation under resonant frequency according to the disclosed embodiment of the present application; cc

[0042] Figure 5 Fig. 6 shows a simulation result diagram of load mutation under resonant frequency according to the disclosed embodiment of the present application; cv

[0043] Figure 6 Fig. 6 shows a simulation result diagram of load mutation under resonant frequency according to the disclosed embodiment of the present application; cc

[0044] Figure 7 Fig. 6 shows a simulation result diagram of load mutation under resonant frequency according to the disclosed embodiment of the present application; cv

[0045] Figure 8 Fig. 6 shows a simulation result diagram of load mutation under resonant frequency according to the disclosed embodiment of the present application; DETAILED DESCRIPTION

[0046] Reference will now be made in detail to embodiments of the present disclosure, one or more examples of which are illustrated in the drawings. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, to the extent that various examples have been described with the term “exemplify,” this terminology is used merely for convenience and to number the examples with either other implementations. Nothing in this detailed description is meant to teach or suggest that the unrecited examples are examples out of a series of preferred or advantageous implementations. Furthermore, the examples are provided by way of explanation of the technology not limitation thereof. In fact, it will be apparent to those skilled in the art that modifications and variations to the present technology can be made without departing from its scope or spirit. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield still a further embodiment. Thus, it is intended that this disclosure covers such modifications and variations as come within the scope of the appended claims and their equivalents. Numerical and letter designations are used in the DETAILED DESCRIPTION to refer to features in the drawings. Like or similar designations in the drawings and description have been used to indicate like or similar elements.

[0047] ​​​​As used herein, the terms "first", "second", and "third" can be used interchangeably to distinguish one component from another and do not necessarily have to refer to a single component or position of importance. The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Terms such as "coupled," "connected," "fixed," "attached," and the like refer to direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless indicated otherwise. The terms "comprises," "comprising," "comprised of," "comprising of," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but can include other features not expressly listed or inherent to such process, method, article, or apparatus. In addition, "or" is both inclusive and exclusive, unless expressly stated otherwise. For example, either or both of A or B satisfies condition A or B: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and A and B are both true (or exist).

[0048] The term "approximately" as used herein means "about," "substantially," "near," or "essentially," and includes values within 10% greater or less than the value being described. When used in the context of an angle or direction, these terms include an angle or direction within 10 degrees greater or less than the angle or direction being described. For example, "substantially perpendicular" includes a direction that deviates from perpendicular by 10 degrees in either direction (e.g., clockwise or counterclockwise).

[0049] The benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that can cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

[0050] Figure 1 A schematic diagram of a single-wire electric field coupled wireless power transfer system 100 based on a dual-frequency reconfigurable topology according to embodiments of the present disclosure is shown. The system 100 includes a DC voltage source U dc , a high-frequency inverter circuit 110, a transmitting end compensation circuit 120, a transmitting plate P1, a receiving plate P2, a receiving end compensation circuit 150, a diode rectifier circuit 160, and a DC side filter capacitor C dc and a load R dc coupled in parallel to the DC side filter capacitor C L .

[0051] In Figure 1In the illustrated embodiment, the high frequency inverter circuit 110 includes a first bridge leg formed by switch S1 and switch S3, and a second bridge leg formed by switch S2 and switch S4. Switches S1 and S3 are located at the upper and lower bridge legs of the first bridge leg, respectively, and switches S2 and S4 are located at the upper and lower bridge legs of the second bridge leg, respectively. The junction of the upper and lower bridge legs of the first bridge leg defines the midpoint of the first bridge leg of the high frequency inverter circuit 110, and the junction of the upper and lower bridge legs of the second bridge leg defines the midpoint of the second bridge leg of the high frequency inverter circuit 110. In some embodiments, the high frequency inverter circuit can have a more complex dual bridge leg structure, for example, the upper and lower bridge legs of the first bridge leg and the upper and lower bridge legs of the second bridge leg can each be formed by two or more switches, which have two output terminals and are capable of converting direct current to high frequency alternating current.

[0052] In Figure 1 In the illustrated embodiment, the diode rectifier circuit 160 includes a first bridge leg formed by diode D1 and diode D3, and a second bridge leg formed by diode D2 and diode D4. Diodes D1 and D3 are located at the upper and lower bridge legs of the first bridge leg, respectively, and diodes D2 and D4 are located at the upper and lower bridge legs of the second bridge leg, respectively. The junction of the upper and lower bridge legs of the first bridge leg defines the midpoint of the first bridge leg of the diode rectifier circuit 160, and the junction of the upper and lower bridge legs of the second bridge leg defines the midpoint of the second bridge leg of the diode rectifier circuit 160. The diode rectifier circuit can also be other structures known in the art, which have two input terminals and are capable of converting alternating current to direct current.

[0053] The transmitting end compensation circuit 120 includes a transmitting end inductor L t and a dual frequency compensation network DFCN1. DFCN is the abbreviation of Dual-Frequency Compensation Network. The dual frequency compensation network DFCN1 includes a capacitor C ts , a capacitor C tp and an inductor L tp , wherein C tp and L tp are connected in parallel as a first LC parallel circuit, and C ts is connected in series with the first LC parallel circuit. The receiving end compensation circuit 150 includes a receiving end inductor L r , a dual frequency compensation network DFCN2, DFCN3 and DFCN4. The dual frequency compensation network DFCN2 includes a capacitor C ss2 , a capacitor C sp2 and an inductor L sp2 , wherein C sp2 and L sp2 are connected in parallel as a second LC parallel circuit, and C ss2It is connected in series with the second LC parallel circuit. The dual-frequency compensation network DFCN3 includes capacitor C. ss3 C sp3 and inductor L sp3 C sp3 and L sp3 The parallel connection forms the third LC parallel circuit, C ss3 It is connected in series with the third LC parallel circuit. The dual-frequency compensation network DFCN4 includes an inductor L. ss4 Capacitor C sp4 and inductor L sp4 C sp4 and L sp4 The parallel connection forms the fourth LC parallel circuit, L ss4 It is connected in series with the fourth LC parallel circuit. In some embodiments, the dual-frequency compensation networks DFCN1, DFCN2, DFCN3, and DFCN4 can be implemented by other equivalent circuits.

[0054] The emitting electrode P1 and the receiving electrode P2 are each composed of a single aluminum plate. In the embodiments of this disclosure, the emitting electrode P1 and the receiving electrode P2 form a single-line electric field coupling structure, eliminating the need for an additional pair of electrode plates to achieve a current return path.

[0055] exist Figure 1 In the embodiment, the transmitting inductor L t The first terminal is connected to the first output terminal of the high-frequency inverter circuit 110, and the transmitting inductor L t The second terminal is connected to the emitter plate P1, and the emitter inductance L t The second terminal is also connected to the first terminal of DFCN1, and the second terminal of DFCN1 is connected to the second output terminal of the high-frequency inverter circuit 110. The first output terminal of the high-frequency inverter circuit 110 is led out from the midpoint of its first bridge arm, and its second output terminal is led out from the midpoint of its second bridge arm. The first terminal of DFCN1 is located in the series-connected C... ts In the parallel circuit with the first LC, near C ts And it is located away from the side of the first LC parallel circuit. The second terminal of DFCN1 is located at the C in series connection. ts In the parallel circuit with the first LC circuit, the circuit is closer to the first LC circuit and farther from C. ts One side.

[0056] exist Figure 1 In the embodiment, the receiving end inductor L r The first end is connected to the receiving plate P2, and the receiving end inductor L r The first end is also connected to the first end of DFCN2, and the receiving end inductor L r The second terminal is connected to the first terminal of DFCN3, and the receiving end inductor L rThe second end of the DFCN2 is coupled to the first end of the DFCN3, and the second end of the DFCN2 is also coupled to the second input end of the diode rectifier circuit 160, and the second end of the DFCN4 is coupled to the first input end of the diode rectifier circuit 160. The first input end of the diode rectifier circuit 160 is introduced from the midpoint of the first bridge arm, and the second input end is introduced from the midpoint of the second bridge arm. The first end of the DFCN2 is located in the series-coupled C ss2 and the second LC parallel circuit close to C ss2 and far away from the second LC parallel circuit. The second end of the DFCN2 is located in the series-coupled C ss2 and the second LC parallel circuit close to the second LC parallel circuit and far away from C ss2 . The first end of the DFCN3 is located in the series-coupled C ss3 and the third LC parallel circuit close to C ss3 and far away from the third LC parallel circuit. The second end of the DFCN3 is located in the series-coupled C ss3 and the third LC parallel circuit close to the third LC parallel circuit and far away from C ss3 . The first end of the DFCN4 is located in the series-coupled L ss4 and the fourth LC parallel circuit close to L ss4 and far away from the fourth LC parallel circuit. The second end of the DFCN4 is located in the series-coupled L ss4 and the fourth LC parallel circuit close to the fourth LC parallel circuit and far away from L ss4 .

[0057] The direct current input voltage U dc of the system 100 passes through the high-frequency inverter circuit 110 to generate high-frequency alternating current, and through the voltage boosting effect of the transmitting end compensation circuit 120, an alternating electric field is formed between the coupling structure composed of the transmitting plate P1 and the receiving plate P2, and under the action of the alternating electric field, displacement current is generated to realize wireless transmission of electric energy.

[0058] Figure 2 The schematic diagram of the equivalent LC-LCLC structure 200 of the system 100 working at the f cc resonant frequency according to the disclosed embodiment of the application is shown. As Figure 2 shown, when the frequency of the high-frequency alternating current generated by the high-frequency inverter circuit 110 is f cc , the DFCN1 can be equivalent to a capacitor C tcc at this frequency, which is in complete resonance with the transmitting inductor L t . Therefore, the transmitting end compensation circuit 120 is an LC topology. The DFCN2 can be equivalent to a capacitor C rcc1DFCN3 can be equivalent to a capacitor C at this frequency rcc2 DFCN4 can be equivalent to an inductor L at this frequency r1 Thus, the receiving end compensation circuit 150 is an LCLC topology. At this time, the transmitting end compensation circuit 120 and the receiving end compensation circuit 150 constitute an LC-LCLC topology.

[0059] In the LC-LCLC topology, there are two resonant loops: the transmitting end inductor L t and the capacitor C tcc constitute a first resonant loop; while the receiving end inductor L r , the capacitor C rcc1 , the capacitor C rcc2 and the inductor L r1 constitute a second resonant loop. Therefore, the first resonant loop and the second resonant loop respectively satisfy the following formulas (1) and (2):

[0060]

[0061]

[0062] where ω cc is the system angular frequency at the constant current resonance frequency, satisfying ω cc = 2πf cc , f cc is the resonance frequency in the constant current charging mode.

[0063] The output current Io of the LC-LCLC topology in the constant current charging mode is:

[0064]

[0065] Formula (3) shows that the output current I o of the system 100 is only determined by the voltage U dc of the DC voltage source, the system angular frequency ω cc at the constant current resonance frequency, the transmitting end inductor L t , the receiving end capacitor C rcc1 and C rcc2 , and is irrelevant to the load R L and the coupling capacitor. The coupling capacitor mainly refers to the coupling capacitor between the transmitting plate P1 and the receiving plate P2. In actual charging applications, the transmitting plate P1 and the receiving plate P2 may be misaligned, and the misalignment will cause the coupling capacitor between the two to change, thereby causing the charging current or voltage of the existing system to be unstable. In contrast, even in the case of misalignment of the transmitting plate P1 and the receiving plate P2 (i.e., the coupling capacitor changes), the system 100 of the present application can still achieve constant current and constant voltage charging, enhancing its robustness.

[0066] Figure 3 Fig. 1 shows a schematic diagram of a system 100 according to an embodiment of the present application, which works at a resonant frequency f cv . Fig. 2 shows a schematic diagram of an equivalent LC-CLC structure 300 of the system 100 at the resonant frequency f Figure 3 . As shown in Fig. 2, when the frequency of the high-frequency AC generated by the high-frequency inverter circuit 110 is f cv , the DFCN1 is equivalent to a capacitor C tcv at this frequency, and completely resonates with the transmitting-end inductor L t . Thus, the transmitting-end compensation circuit 120 is an LC topology. The DFCN2 is equivalent to a capacitor C rcv1 at this frequency, the DFCN3 is equivalent to a capacitor C rcv2 at this frequency, and the DFCN4 is equivalent to a short circuit at this frequency. Thus, the receiving-end compensation circuit 150 is a CLC topology. At this time, the transmitting-end compensation circuit 120 and the receiving-end compensation circuit 150 constitute an LC-CLC topology.

[0067] In the LC-CLC topology, there are two resonant loops: the third resonant loop composed of the transmitting-end inductor L t and the capacitor C tcv ; and the fourth resonant loop composed of the receiving-end inductor L r , the capacitor C rcv1 and the capacitor C rcv2 . Therefore, the third resonant loop and the fourth resonant loop respectively satisfy the following formulas (4) and (5):

[0068]

[0069]

[0070] where ω cv is the angular frequency of the system at the constant-voltage resonant frequency, satisfying ω cv = 2πf cv , and f cv is the resonant frequency in the constant-voltage charging mode.

[0071] The output voltage U o of the LC-CLC topology in the constant-voltage charging mode is:

[0072]

[0073] Formula (6) shows that the output voltage U o of the system 100 is only determined by the voltage U dc of the DC voltage source, the transmitting-end capacitor C tcv and the receiving-end capacitor C rcv1 , and is independent of the load R L and the coupling capacitor.

[0074] To verify the feasibility of the above system 100, in a specific embodiment, a simulation of the system 100 is built, the resonant frequency f cc is 500 kHz, the resonant frequency f cv is 650 kHz, and the system parameters designed specifically are shown in Table 1.

[0075] Table 1 System parameters

[0076]

[0077]

[0078] Figure 4 The simulation results of the load mutation under the resonant frequency f cc according to the disclosed embodiments of the present application are shown. Figure 4 The waveforms of the input voltage U L , the input current I t , the output voltage U o , and the output current I o are shown when the load R t suddenly changes from 30 Ω to 45 Ω and then back to 30 Ω in the constant current charging mode. It can be seen from Figure 4 that the output current I o changes slightly when the load changes, but quickly stabilizes at about 1.75 A. Therefore, the output current I o is not affected by the load step change in the constant current charging mode.

[0079] Figure 5 The simulation results of the load mutation under the resonant frequency f cv according to the disclosed embodiments of the present application are shown. Figure 5 The waveforms of the input voltage U t , the input current I t , the output voltage U o , and the output current I o are shown when the load R L suddenly changes from 80 Ω to 100 Ω and then back to 80 Ω in the constant voltage charging mode. It can be seen from Figure 5 that the output voltage U o remains stable when the load changes and is not affected by the load step change.

[0080] Figure 4 and Figure 5This demonstrates that the proposed single-wire electric field coupled wireless power transfer system 100 based on dual-frequency reconfigurable topology can operate simultaneously at two different resonant frequencies, achieving load-independent constant current charging and constant voltage charging.

[0081] Figure 6 This illustrates an embodiment of the invention, operating in f cc A schematic diagram of the simulation results of the sudden change in coupling capacitance at the resonant frequency. Figure 6 The load R is shown in constant current charging mode. L When the capacitance is 30Ω, the input voltage U changes abruptly from 600pF to 450pF. t and input current I t and output voltage U o and output current I o The waveform. From Figure 6 It can be seen that the output current I o It is relatively stable and unaffected by changes in coupling capacitance.

[0082] Figure 7 This illustrates an embodiment of the invention, operating in f cv A schematic diagram of the simulation results of the sudden change in coupling capacitance at the resonant frequency. Figure 7 The load R is shown in constant voltage charging mode. L When the capacitance is 80Ω, the input voltage U changes abruptly from 600pF to 450pF. t and input current I t and output voltage U o and output current I o The waveform. From Figure 7 It can be seen that the output voltage U o It remains stable at 90V and is unaffected by changes in the coupling capacitance.

[0083] Figure 6 and Figure 7 This demonstrates that the proposed single-wire electric field coupled wireless power transfer system 100 based on dual-frequency reconfigurable topology can operate simultaneously at two different resonant frequencies, achieving constant current charging and constant voltage charging independent of the coupling capacitor.

[0084] Figures 4 to 7 Experimental results fully demonstrate that the proposed single-wire electric field-coupled wireless power transfer system based on dual-frequency reconfigurable topology exhibits output independent of load and coupling capacitance variations in both constant-current and constant-voltage charging modes. This superiority provides a promising solution for dynamic charging of mobile devices.

[0085] The application provides a single-line electric field coupling type wireless power transmission system based on a dual-frequency reconfigurable topology. A single-capacitive coupling plate (i.e., only one pair of capacitive coupling plates) can effectively reduce the land occupation volume and flexibility of the coupling structure. Based on the dual-frequency reconfigurable topology, constant current and constant voltage charging can be simultaneously realized, and the resonant frequency of the system is changed through the controller of the system. Through the switching of the control frequency, autonomous management of the two charging functions is realized, which greatly reduces the control complexity. In addition, the offset of the coupling plate has no effect on the output current and voltage of the system, which is beneficial to the application to dynamic wireless charging scenarios.

[0086] Figure 8 A schematic diagram of a single-line electric field coupling type wireless power transmission method 800 based on a dual-frequency reconfigurable topology according to the disclosed embodiment of the application is shown. In block 810, the system 100 works in a constant current charging mode, and the resonant frequency of the system 100 is set to a first resonant frequency f cc In block 820, the system 100 works in a constant voltage charging mode, and the resonant frequency of the system 100 is set to a second resonant frequency f cv The first resonant frequency f cc and the second resonant frequency f cv are preferably realized by the controller of the system 100.

[0087] The present disclosure solves the problems of insufficient research on constant current and constant voltage charging of a single-line electric field coupling type wireless power transmission system and anti-offset of a single-capacitive coupling plate. The system and method disclosed in the application can be applied to the fields of automatic guided vehicle wireless charging, electric vehicle wireless charging, etc.

[0088] This specification discloses examples, including the best mode, and enables any person skilled in the art to practice the present disclosure, including making and using any devices or systems and performing any incorporated methods. The patent scope of the present disclosure is defined by the claims, and can include other examples that can be conceived by those skilled in the art. If these other examples include structural elements that are not different from the literal expression of the claims, or include equivalent structural elements that are not substantially different from the literal expression of the claims, the scope of the claims covers these other examples.

Claims

1. A single-wire electric field-coupled wireless power transfer system based on a dual-frequency reconfigurable topology, the system comprising: The following components are connected in sequence: a DC voltage source, a high-frequency inverter circuit, a transmitter compensation circuit, a transmitter plate, a receiver plate, a receiver compensation circuit, a diode rectifier circuit, a DC-side filter capacitor, and a load connected in parallel with the DC-side filter capacitor. The transmitter compensation circuit includes a transmitter inductor and a first dual-frequency compensation network. A first end of the transmitter inductor is connected to a first output terminal of the high-frequency inverter circuit. A second end of the transmitter inductor is connected to the transmitter plate. The second end of the transmitter inductor is also connected to a first end of the first dual-frequency compensation network. The second end of the first dual-frequency compensation network is connected to a second output terminal of the high-frequency inverter circuit. The receiving end compensation circuit includes a receiving end inductor, a second dual-frequency compensation network, a third dual-frequency compensation network, and a fourth dual-frequency compensation network. The first end of the receiving end inductor is connected to the receiving plate. The first end of the receiving end inductor is also connected to the first end of the second dual-frequency compensation network. The second end of the receiving end inductor is connected to the first end of the third dual-frequency compensation network. The second end of the receiving end inductor is also connected to the first end of the fourth dual-frequency compensation network. The second end of the second dual-frequency compensation network is connected to the second end of the third dual-frequency compensation network. The second end of the second dual-frequency compensation network is also connected to the second input terminal of the diode rectifier circuit. The second end of the fourth dual-frequency compensation network is connected to the first input terminal of the diode rectifier circuit.

2. The system according to claim 1, wherein, The first dual-frequency compensation network includes a first capacitor and a first LC parallel circuit connected in series with the first capacitor.

3. The system according to claim 1, wherein, The second dual-frequency compensation network includes a second capacitor and a second LC parallel circuit connected in series with the second capacitor.

4. The system according to claim 1, wherein, The third dual-frequency compensation network includes a third capacitor and a third LC parallel circuit connected in series with the third capacitor.

5. The system according to claim 1, wherein, The fourth dual-frequency compensation network includes a fourth inductor and a fourth LC parallel circuit connected in series with the fourth inductor.

6. The system according to any one of claims 2 to 5, wherein, An LC parallel circuit consists of a capacitor and an inductor connected in parallel.

7. The system according to claim 1, wherein, The transmitting electrode and the receiving electrode are each composed of a single aluminum plate.

8. The system according to claim 1, wherein, The transmitting electrode and the receiving electrode form a single-line electric field coupling structure.

9. The system according to claim 1, wherein, The high-frequency inverter circuit includes a first bridge arm composed of a first switch and a third switch, and a second bridge arm composed of a second switch and a fourth switch. The first output terminal of the high-frequency inverter circuit is led out from the midpoint of the first bridge arm, and the second output terminal of the high-frequency inverter circuit is led out from the midpoint of the second bridge arm.

10. The system according to claim 1, wherein, The diode rectifier circuit includes a first bridge arm composed of a first diode and a third diode and a second bridge arm composed of a second diode and a fourth diode. The first input terminal of the diode rectifier circuit is introduced from the midpoint of the first bridge arm of the diode rectifier circuit, and the second input terminal of the diode rectifier circuit is introduced from the midpoint of the second bridge arm of the diode rectifier circuit.

11. The system according to claim 1, wherein, The system can achieve constant current charging mode and constant voltage charging mode independent of the load and coupling capacitor, wherein the coupling capacitor is the coupling capacitor between the emitter plate and the receiver plate.

12. The system according to claim 11, wherein, In the constant current charging mode, the topology of the system is LC-LCLC.

13. The system according to claim 12, wherein, In the constant current charging mode, the first dual-frequency compensation network is equivalent to a capacitor C. tcc The second dual-frequency compensation network is equivalent to capacitor C. rcc1 The third dual-frequency compensation network is equivalent to capacitor C. rcc2 The fourth dual-frequency compensation network is equivalent to an inductor L. r1 Wherein, the transmitting end inductor L t With capacitor C tcc The first resonant circuit is formed, satisfying formula (1), and the receiving end inductance L r Capacitor C rcc1 Capacitor C rcc2 and inductor L r1 This forms a second resonant circuit that satisfies formula (2). Where, ω cc Let ω be the system angular frequency at the constant current resonant frequency, satisfying ω cc =2πf cc f cc The resonant frequency in the constant current charging mode is denoted as .

14. The system according to claim 13, wherein, In the constant current charging mode, the output current I of the system o Satisfies formula (3), Wherein, according to formula (3), the output current I of the system o The voltage U of the DC voltage source alone dc The system angular frequency ω at the constant current resonant frequency. cc The transmitting end inductor L t The equivalent capacitance C of the second dual-frequency compensation network rcc1 The equivalent capacitance C of the third dual-frequency compensation network rcc2 The decision is made regardless of the load and the coupling capacitor.

15. The system according to claim 11, wherein, In the constant voltage charging mode, the topology of the system is LC-CLC.

16. The system according to claim 15, wherein, In the constant voltage charging mode, the first dual-frequency compensation network is equivalent to a capacitor C. tcv The second dual-frequency compensation network is equivalent to capacitor C. rcv1 The third dual-frequency compensation network is equivalent to capacitor C. rcv2 The fourth dual-frequency compensation network is equivalent to a short circuit, wherein the transmitting end inductor L t With capacitor C tcv The third resonant circuit is formed, satisfying formula (4), and the receiving end inductance L r Capacitor C rcv1 and capacitor C rcv2 This forms the fourth resonant circuit, satisfying formula (5). Where, ω cv The system angular frequency at the constant voltage resonant frequency satisfies ω cv =2πf cv f cv The resonant frequency is the frequency in the constant voltage charging mode.

17. The system according to claim 16, wherein, In the constant voltage charging mode, the output voltage U of the system o Satisfies formula (6), Wherein, according to formula (6), the output voltage U of the system o The voltage U of the DC voltage source alone dc The equivalent capacitance C of the first dual-frequency compensation network tcv The equivalent capacitance C of the second dual-frequency compensation network rcv1 The decision is made regardless of the load and the coupling capacitor.

18. The system according to claim 11, the system further comprising a controller, wherein the controller changes the resonant frequency of the system to achieve switching between the constant current charging mode and the constant voltage charging mode.

19. A single-wire electric field coupled wireless power transfer method based on dual-frequency reconfigurable topology, wherein the method is implemented on the system according to any one of claims 1 to 18, wherein when the system operates in constant current charging mode, the resonant frequency of the system is set as a first resonant frequency, and when the system operates in constant voltage charging mode, the resonant frequency of the system is set as a second resonant frequency.

20. The method according to claim 19, wherein, The first resonant frequency and the second resonant frequency are set by the controller of the system.

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