An inductive wireless power transmission system realizing constant current and constant voltage output switching

Abstract

The present invention discloses an inductive wireless power transmission system for realizing constant current and constant voltage output switching, including a DC power supply, a high-frequency inverter, a primary compensation network, a primary coil, a secondary coil, a secondary compensation network, and a rectifier filter circuit. A constant current and constant voltage switching part is added to the primary side, including an AC input, a series compensation capacitor, a series coil, and a switching switch connected in series in sequence. The primary compensation network needs to ensure that the current flowing through the secondary coil is constant when the switching switch is closed. This system can realize constant current and constant voltage switching by controlling the opening or closing of the switching switch. The proposed method can realize the switching of charging modes under the condition of unchanged frequency, which is conducive to the stable operation of the system, and solves the problems of too many devices added in the existing control methods, increased control cost and complexity, and simply and conveniently realizes the switching of constant current and constant voltage charging modes.

Description

Technical Field

[0001] The invention relates to an inductive wireless power transmission system for realizing constant current and constant voltage output switching, belonging to the field of electric energy change. Background Art

[0002] Inductive wireless power transmission technology transmits power to electrical equipment safely and reliably through magnetic fields in a non-contact manner, avoiding the problems of leakage, contact electric sparks, and dangers in humid environments that exist in traditional plug-in power transmission systems. This technology has been widely used in electric vehicles, AGVs, built-in medical devices, and portable electronic products.

[0003] The main components and working process of the existing wireless charging system are shown in the attached figure. Figure 2 As shown: the industrial frequency AC power is converted into DC power through rectification, and then converted into high-frequency AC power through the inverter. The high-frequency AC power is injected into the primary coil to generate an alternating high-frequency magnetic field. The secondary coil induces an induced electromotive force in this high-frequency magnetic field. The electromotive force is converted into DC power again after high-frequency rectification to provide electrical energy to the load.

[0004] At present, the most common load is the battery, but the equivalent resistance of the battery is constantly changing, and its charging process includes two charging stages: constant current and constant voltage. That is, the constant current mode is used in the initial charging stage, so that the battery voltage can rise rapidly; when the battery voltage reaches the required value, the charging mode is changed to constant voltage mode to maintain voltage stability, so that the charging current gradually decreases until the current is cut off, and the charging is completed. This charging method requires that the wireless power transmission system for charging the battery can provide constant current and voltage, which can not only realize safe and reliable charging of the battery, but also extend the battery life and charge and discharge times.

[0005] There are currently three common methods for inductive wireless power transfer systems to achieve constant current and constant voltage switching charging: 1. "Mickel Budhia, Grant A. Covic, John T. Boys, Design and Optimization of Circular Magnetic Structures for Lumped Inductive Power Transfer Systems" proposed the use of variable frequency control methods, that is, the wireless power transfer system can achieve constant voltage and constant current output at different frequencies. However, this method will cause frequency bifurcation, resulting in unstable system operation. 2. "Chen Guodong, Research on Constant Current Technology of Contactless Power Transmission System" pointed out that a DC-DC DC converter can be added after the secondary rectifier output for adjustment, but this method is not suitable for large load changes in order to avoid the occurrence of the limit duty cycle, and the newly added DC conversion circuit increases the system volume. 3. Introducing closed-loop negative feedback control in the circuit, "Zhu Wang, Research on Constant Current and Constant Voltage Wireless Charging System" proposed the use of phase shift control method, but this method will also add too many devices, increase control costs and complexity. Summary of the invention

[0006] Purpose of the invention: In view of the above-mentioned prior art, an inductive wireless power transmission system is proposed to realize constant current and constant voltage output switching, which can realize the switching of charging mode without changing the frequency.

[0007] Technical solution: An inductive wireless power transmission system for realizing constant current and constant voltage output switching, comprising a sending module, a receiving module, and a constant current and constant voltage switching module, wherein the sending module comprises a DC power supply, a high-frequency inverter, a primary compensation network, and a primary coil connected in sequence, and the receiving module comprises a secondary coil, a secondary compensation network, a rectifier filter circuit, and a load connected in sequence; the constant current and constant voltage switching module comprises a series circuit formed by connecting a capacitor C, an excitation coil L, and a switching switch S, and also comprises an excitation source and a controller K of the switching switch S; wherein the excitation coil L and the primary coil share a primary magnetic core, the excitation coil L and the secondary coil are coupled through a mutual inductance M2, and the primary coil and the secondary coil are coupled through a mutual inductance M1; a constant current flows through the primary coil at an operating frequency ω0.

[0008] Furthermore, the series circuit of the constant current and constant voltage switching module is connected in parallel to the output end of the high frequency inverter, that is, the output of the high frequency inverter is used as an excitation source, and the capacitor C and the excitation coil L resonate at the system operating frequency.

[0009] Furthermore, the constant current and constant voltage switching module also includes a high-frequency inverter H, and the series circuit of the constant current and constant voltage switching module is connected in parallel to the output end of the high-frequency inverter H, and the input end of the high-frequency inverter H is connected in parallel to the output end of the DC power supply, that is, the DC power supply and the high-frequency inverter H are cascaded as an excitation source, and the capacitor C and the excitation coil L resonate at the system operating frequency.

[0010] Furthermore, the series circuit of the constant current and constant voltage switching module is short-circuited, and the excitation coil L is coupled with the primary coil through the mutual inductance M3, that is, an induced potential is generated in the excitation coil through the mutual inductance M3 as an excitation source, and the capacitor C and the excitation coil L resonate at the system operating frequency.

[0011] Furthermore, the primary coil is connected in series with a passive element Z, the constant current and constant voltage switching module is connected in parallel at both ends of the passive element Z, and the capacitor C, the excitation coil L and the passive element Z of the constant current and constant voltage switching module resonate at the system operating frequency.

[0012] Furthermore, the series circuit of the constant current and constant voltage switching module is short-circuited, and one of the nodes is connected to one end of the primary coil, the primary coil and the excitation coil of the constant current and constant voltage switching module are coupled inductors, the mutual inductance is M3, and the capacitor C and the excitation coil L resonate at the system operating frequency.

[0013] Furthermore, the sending module also includes an inductor L1, which is connected in series with the primary coil. The series circuit of the constant current and constant voltage switching module is also connected in series with an inductor L2. The inductor L1 and the inductor L2 are coupled inductors, and the mutual inductance is M3. The capacitor C, the excitation coil L and the inductor L2 of the constant current and constant voltage switching module resonate at the system operating frequency.

[0014] Furthermore, the parameters of the compensation capacitor C1 in the constant current branch of the primary compensation network satisfy the input impedance angle Among them, Z in is the input impedance, I m Indicates taking the imaginary part, R e It means taking the real part.

[0015] Furthermore, the switch S is a MOSFET, an IGBT or a thyristor.

[0016] Furthermore, a constant current is passed through the primary coil at an operating frequency ω0 by controlling or transforming the compensation network, and the compensation network transformation method uses a voltage source to excite a series primary compensation network, wherein the primary compensation network is an LCC structure or a CL structure or a CLC structure or an LCL structure or an LC structure, and the secondary compensation network is an LCC structure or an LCL structure or an S structure.

[0017] Beneficial effects: The present invention proposes an inductive wireless power transmission system that realizes constant current and constant voltage output switching. It only needs to add a constant current and constant voltage switching circuit composed of a capacitor, a switch and a coil in the primary circuit. The circuit structure is simple and the cost is low. During operation, it only needs to simply control the switching of the switch to realize the switching of the circuit output constant current and constant voltage. The control is simple, convenient and reliable. There is no complicated control strategy, and there is no need for the primary circuit to communicate with the primary circuit. And the system can output constant current and constant voltage that are independent of the load at the same operating frequency, meeting the requirements of constant current charging in the initial stage and constant voltage charging in the later stage of the battery. The system works at one frequency point, and there will be no frequency bifurcation phenomenon, and the system works stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the topological circuit of an inductive wireless power transmission system that realizes constant current and constant voltage output switching;

[0019] Figure 2 It is a schematic diagram of the main components of an existing wireless charging system;

[0020] Figure 3 From left to right are the schematic diagram of LC compensation network, the schematic diagram of CL compensation network, the schematic diagram of CLC compensation network, the schematic diagram of LCL compensation network, and the schematic diagram of LCC compensation network;

[0021] Figure 4 is a schematic diagram of Embodiment 1 of the present invention;

[0022] Figure 5 yes Figure 4 Schematic diagram of the fundamental wave equivalent circuit;

[0023] Figure 6 is a constant current output characteristic curve of the circuit simulation result of the first embodiment;

[0024] Figure 7 is a constant voltage output characteristic curve of the circuit simulation result of the first embodiment;

[0025] Figure 8 is a schematic diagram of a second embodiment of the present invention;

[0026] Fig. 9 yes Figure 8 Schematic diagram of the fundamental wave equivalent circuit;

[0027] Fig.10 is a schematic diagram of Embodiment 3 of the present invention;

[0028] Fig.11 yes Fig.10 Schematic diagram of the fundamental wave equivalent circuit;

[0029] Fig.12is a schematic diagram of a fourth embodiment of the present invention;

[0030] Fig.13 yes Fig.12 Schematic diagram of the fundamental wave equivalent circuit of the constant current and constant voltage switching module;

[0031] Fig.14 is a schematic diagram of Embodiment 5 of the present invention;

[0032] Fig.15 yes Fig.14 Schematic diagram of the fundamental wave equivalent circuit;

[0033] Fig.16 is a schematic diagram of a sixth embodiment of the present invention;

[0034] Fig.17 yes Fig.16 Schematic diagram of the fundamental wave equivalent circuit;

[0035] Fig.18 is a schematic diagram of Embodiment 7 of the present invention;

[0036] Fig.19 yes Fig.18 Schematic diagram of the fundamental wave equivalent circuit;

[0037] Fig. 20 is a schematic diagram of Embodiment 8 of the present invention;

[0038] Fig.21 yes Fig. 20 Schematic diagram of the fundamental wave equivalent circuit;

[0039] Fig. 22 Schematic diagram of the ninth embodiment of the present invention

[0040] Fig.23 yes Fig. 22 Schematic diagram of the fundamental wave equivalent circuit;

[0041] Fig.24 is a schematic diagram of a tenth embodiment of the present invention;

[0042] Fig.25 yes Fig.24 Schematic diagram of the fundamental wave equivalent circuit of the constant current and constant voltage switching module;

[0043] Fig.26 is a schematic diagram of the eleventh embodiment of the present invention;

[0044] Fig. 27 yes Fig.26 Schematic diagram of the fundamental wave equivalent circuit;

[0045] Fig.28 is a schematic diagram of a twelfth embodiment of the present invention;

[0046] Fig.29 yes Fig.28 Schematic diagram of the fundamental wave equivalent circuit;

[0047] Fig.30 is a schematic diagram of Embodiment 13 of the present invention;

[0048] Fig.31 yes Fig.30 Schematic diagram of the fundamental wave equivalent circuit;

[0049] Fig.32 is a schematic diagram of a fourteenth embodiment of the present invention;

[0050] Fig.33 yes Fig.32 Schematic diagram of the fundamental wave equivalent circuit;

[0051] Fig.34 is a schematic diagram of the fifteenth embodiment of the present invention;

[0052] Fig.35 yes Fig.34 Schematic diagram of the fundamental wave equivalent circuit;

[0053] Fig.36 is a schematic diagram of a sixteenth embodiment of the present invention;

[0054] Fig.37 yes Fig.36 Schematic diagram of the fundamental wave equivalent circuit of the constant current and constant voltage switching module;

[0055] Fig.38 is a schematic diagram of Embodiment 17 of the present invention;

[0056] Fig.39 yes Fig.38 Schematic diagram of the fundamental wave equivalent circuit;

[0057] Fig.40 is a schematic diagram of Embodiment 18 of the present invention;

[0058] Fig.41 yes Fig.40 Schematic diagram of the fundamental wave equivalent circuit;

[0059] The main symbols in the figure are: 1—DC power supply, 2—high frequency inverter, 3—primary compensation network, 4—primary coil, 5—secondary coil, 6—secondary compensation network, 7—rectifier filter network, 8—load, 9—constant current and constant voltage switching module, C—series capacitor in the constant current and constant voltage switching module, L—excitation coil in the constant current and constant voltage switching module, S—switch, K—controller, — Fundamental equivalent AC voltage in constant current and constant voltage switching module, L f1 —Primary series compensation inductor, C f1 —Primary parallel compensation capacitor, C1 —Primary series compensation capacitor, L p—Primary coil, L s —Secondary coil, C2—Secondary series compensation capacitor, C f2 —Secondary parallel compensation capacitor, L f2 —Secondary side series compensation inductor, R—Load resistance, V in - DC power supply, — Fundamental equivalent voltage on the inverter output side, —Fundamental equivalent current on the inverter output side, —Flowing through L f1 The fundamental equivalent current, —Flowing through L p The fundamental equivalent current, —Flowing through L s The fundamental equivalent current, —Rectified input side fundamental equivalent current, —Rectified input side fundamental wave equivalent voltage, —The fundamental equivalent current flowing through L, I o —Output current, V o —Output voltage, R E —Equivalent load resistance of rectifier and filter circuit. DETAILED DESCRIPTION

[0060] The present invention will be further explained below in conjunction with the accompanying drawings.

[0061] like Figure 1 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching includes a sending module, a receiving module, and a constant current and constant voltage switching module. The sending module includes a DC power supply 1, a high-frequency inverter 2, a primary compensation network 3, and a primary coil 4 connected in sequence, and the receiving module includes a secondary coil 5, a secondary compensation network 6, a rectifier filter circuit 7, and a load 8 connected in sequence. The constant current and constant voltage switching module includes a series circuit formed by connecting a capacitor C, an excitation coil L, and a switching switch S, and also includes an excitation source and a controller K of the switching switch S. Among them, the excitation coil L and the primary coil 4 share the primary magnetic core, and the excitation coil L and the secondary coil 5 are coupled through a mutual inductance M2; a constant current flows through the primary coil 4 at an operating frequency ω0, and the capacitor C and the excitation coil L can resonate at the system operating frequency.

[0062] To improve system efficiency, the system generally works near the resonant frequency point. The resonant inductor current is approximately sinusoidal. The fundamental wave approximation analysis method can be used to replace all variables in the resonant network with their fundamental wave components. The high-frequency inverter output is equivalent to an AC voltage source. When the rectifier filter circuit is continuously turned on, the midpoint voltage and current of the rectifier bridge are always in phase, and the rectifier filter circuit is equivalent to a load resistor R E , satisfying R E =8 / π2 R L , R L There are many optional circuits for the high frequency inverter 2, including push-pull, half-bridge, full-bridge circuits, etc. There are also many optional circuits for the rectifier filter circuit 7, including bridge rectification, full-wave rectification, half-wave rectification, current doubler rectification, voltage doubler rectification, etc.

[0063] The present invention realizes that a constant current flows through the primary coil 4 at the operating frequency ω0 by controlling or transforming the compensation network. The compensation network transformation adopts a voltage source to excite the series primary compensation network 3. The primary compensation network in the present invention can be an LC, CL, CLC, LCL, or LCC structure. Figure 3 Next, the present invention will be explained in detail through 18 embodiments, taking LCC as the primary compensation network, LCC, LCL, and S as the secondary compensation networks respectively.

[0064] Among them, embodiments 1 to 6 form a group, and their circuit topology structures of the primary and secondary compensation networks are both LCC structures; embodiments 7 to 12 form a group, and their circuit topology structures of the primary compensation network are LCC structures, and the secondary compensation network is LCL structures; embodiments 13 to 18 form a group, and their circuit topology structures of the primary compensation network are LCC structures, and the secondary compensation network is S structures. The specific difference between the six embodiments in each group lies in the specific structure of their constant voltage and constant current switching circuits and the different connection methods with the main circuit.

[0065] Example 1

[0066] like Figure 4 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching includes a DC power supply V in , high frequency inverter 2, primary compensation network 3, primary coil L p , secondary coil L s , secondary compensation network 6, rectifier filter circuit 7 and load 8, and also includes a constant current constant voltage switching module 9. The primary compensation network 3 is LCC compensation, and the compensation capacitor C1 and the primary coil L p After connecting in series with C f1 Connect in parallel and then connect with the compensation inductor L f1 After the series connection, the whole is directly connected in parallel with the inverter bridge output. The secondary compensation network 6 also uses LCC compensation. s After connecting in series with the compensation capacitor C2 and C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0067] The constant current and constant voltage switching module 9 includes a series circuit formed by connecting a capacitor C, an excitation coil L, and a switch S. The excitation coil L and the secondary coil L s The switching switch S is coupled by mutual inductance M2, and the switching switch S is connected to the controller K. The constant current and constant voltage switching module 9 also includes an excitation source. In this embodiment, the series circuit is connected in parallel to the output end of the high-frequency inverter 2, that is, the output of the high-frequency inverter 2 is used as an excitation source. The switching switch S is used to switch the two working modes of the wireless power transmission topology constant current output and constant voltage output. The opening / closing of the switching switch S is controlled by the controller K, and the switching switch S is a MOSFET or an IGBT or a thyristor. Among them, the capacitor C is a capacitor or a plurality of inductors and capacitors connected in series and / or in parallel.

[0068] Figure 5 Given Figure 4 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0069]

[0070] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0071]

[0072] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0073] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0074]

[0075] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0076] In addition, in order to achieve ZVS of the primary switch tube and improve the efficiency of the high-frequency inverter, it is necessary to design the compensation parameter C1 so that the input impedance Z in Weakly sensitive That is, the corresponding input impedance angle Among them, I m Indicates taking the imaginary part, R e It means taking the real part, and simplifying it, the capacitance of C1 should be designed to satisfy:

[0077]

[0078] In equations (1), (2), (3), and (4), ω0 is the resonant angular frequency of the system.

[0079] In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby achieving the switching between constant current and constant voltage output.

[0080] In this embodiment, when the above conditions are met, a set of specific parameters can be designed through calculation: L f1 46.1μH, C f1 is 76.05nF, C1 is 7.5nF, C is 10.02nF, L f2 46.1μH, C f2 is 76.05nF, C2 is 11.5nF, L p , L s The value of L is equal to 350μH, and the coupling coefficients k1 and k2 are both 0.2. The input DC power supply V in The load resistance is 400V and the load resistance varies from 5 to 40Ω. Substitute the parameters into the constructed circuit for simulation. The simulation results are as follows: Figure 6 , Figure 7 shown.

[0081] Figure 6 This is the curve of the output current changing with the load when the switch is turned off. At this time, the output current remains basically unchanged;

[0082] Figure 7 When the switch is closed, the output voltage changes with the load. At this time, the output voltage remains basically unchanged. Figure 6 Figure 7 It can be seen that by controlling the opening / closing of the switching switch S, the inductive wireless charging system can be controlled to achieve constant current and constant voltage switching.

[0083] Example 2

[0084] like Figure 8 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from Example 1 only in that: the constant current and constant voltage switching module also includes a high-frequency inverter H, the series circuit of the constant current and constant voltage switching module is connected in parallel to the output end of the high-frequency inverter H, and the input end of the high-frequency inverter H is connected in parallel to the output end of the DC power supply 1, that is, the DC power supply 1 and the high-frequency inverter H are cascaded as an excitation source.

[0085] Fig. 9 Given Figure 8 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0086]

[0087] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0088]

[0089] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0090] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0091]

[0092] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0093] In addition, in order to achieve ZVS of the primary switch tube and improve the efficiency of the high-frequency inverter, it is necessary to design the compensation parameter C1 so that the input impedance Z in Weakly sensitive That is, the corresponding input impedance angle Simplified, the capacitance of C1 should be designed to meet the following requirements:

[0094]

[0095] In equations (5), (6), (7), and (8), ω0 is the resonant angular frequency of the system.

[0096] In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby achieving the switching between constant current and constant voltage output.

[0097] Example 3

[0098] like Fig.10 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from Example 1 only in that: the series circuit of the constant current and constant voltage switching module is short-circuited, and the excitation coil L of the constant current and constant voltage switching module is coupled with the primary coil 4 through the mutual inductance M3, that is, the induced potential is generated in the excitation coil through the mutual inductance M3 as the excitation source.

[0099] Fig.11 Given Fig.10 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0100]

[0101] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0102]

[0103] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0104] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0105]

[0106] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0107] In addition, in order to achieve ZVS of the primary switch tube and improve the efficiency of the high-frequency inverter, it is necessary to design the compensation parameter C1 so that the input impedance Z in Weakly sensitive That is, the corresponding input impedance angle Simplified, the capacitance of C1 should be designed to meet the following requirements:

[0108]

[0109] In equations (9), (10), (11), and (12), ω0 is the resonant angular frequency of the system.

[0110] In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby achieving the switching between constant current and constant voltage output.

[0111] Example 4

[0112] like Fig.12 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from Example 1 only in that: the primary coil 4 is connected in series with a passive element Z, the constant current and constant voltage switching module is connected in parallel at both ends of the passive element Z, and the capacitor C, the excitation coil L and the passive element Z of the constant current and constant voltage switching module resonate at the system operating frequency.

[0113] It should be noted that when the passive component Z is a capacitor, the capacitor in the series circuit of the constant current and constant voltage switching module can be omitted. In this embodiment, the passive component Z shares the compensation capacitor C1 located in the constant current branch of the primary compensation network 3. Specifically: the excitation coil L of the constant current and constant voltage switching module is connected in parallel to the two ends of the compensation capacitor C1 located in the constant current branch of the primary compensation network 3, and the excitation coil L and the secondary coil L sThe two are coupled through mutual inductance M2.

[0114] Fig.13 Given Fig.12 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0115]

[0116] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0117]

[0118] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0119] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage is independent of the load resistance and the output is a constant voltage characteristic.

[0120] In equations (13) and (14), ω0 is the resonant angular frequency of the system.

[0121] In this example, the controller K controls the switching switch S to switch on / off, thereby achieving the switching between constant current and constant voltage output.

[0122] Example 5

[0123] like Fig.14 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from Example 1 only in that: the series circuit of the constant current and constant voltage switching module is short-circuited, and one of the nodes is connected to one end of the primary coil 4, the primary coil 4 and the excitation coil L of the constant current and constant voltage switching module are coupled inductors, and the mutual inductance is M3; the excitation coil L and the secondary coil L s The two are coupled through mutual inductance M2.

[0124] Fig.15 Given Fig.14 The fundamental wave equivalent circuit. In this embodiment, the parameters of the resonant element satisfy:

[0125]

[0126] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0127]

[0128] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0129] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0130]

[0131] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0132] In addition, in order to achieve ZVS of the primary switch tube and improve the efficiency of the high-frequency inverter, it is necessary to design the compensation parameter C1 so that the input impedance Z in Weakly sensitive That is, the corresponding input impedance angle Simplified, the capacitance of C1 should be designed to meet the following requirements:

[0133]

[0134] In equations (15), (16), (17), and (18), ω0 is the resonant angular frequency of the system.

[0135] In this example, the controller K controls the switching switch S to switch on / off, thereby achieving the switching between constant current and constant voltage output.

[0136] Example 6

[0137] like Fig.16 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from Example 1 only in that: the sending module also includes an inductor L1, the inductor L1 is connected in series with the primary coil 4, and the series circuit of the constant current and constant voltage switching module is also connected in series with an inductor L2, the inductor L1 and the inductor L2 are coupled inductors, and the mutual inductance is M3; the excitation coil L and the secondary coil L s The two are coupled through mutual inductance M2.

[0138] Fig.17 Given Fig.16 The fundamental wave equivalent circuit. In this embodiment, the parameters of the resonant element satisfy:

[0139]

[0140] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0141]

[0142] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0143] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0144]

[0145] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0146] In addition, in order to achieve ZVS of the primary switch tube and improve the efficiency of the high-frequency inverter, it is necessary to design the compensation parameter C1 so that the input impedance Z in Weakly sensitive That is, the corresponding input impedance angle Simplified, the capacitance of C1 should be designed to meet the following requirements:

[0147]

[0148] In equations (19), (20), (21), and (22), ω0 is the resonant angular frequency of the system.

[0149] In this example, the controller K controls the switching switch S to switch on / off, thereby achieving the switching between constant current and constant voltage output.

[0150] Example 7

[0151] like Fig.18 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 1 only in that the secondary side compensation network 6 adopts LCL compensation, and the secondary coil L s With C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier and filter circuit 7.

[0152] Fig.19 Given Fig.18 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element meet the conditions:

[0153]

[0154] The switching process of the constant current / constant voltage output and the design of the compensation parameter C1 of this embodiment are the same as those of the first embodiment.

[0155] Example 8

[0156] like Fig. 20 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 2 in that the secondary side compensation network 6 adopts LCL compensation, and the secondary coil L s With C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier and filter circuit 7.

[0157] Fig.21 Given Fig. 20 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0158]

[0159] The switching process of the constant current / constant voltage output and the design of the compensation parameter C1 of this embodiment are the same as those of the second embodiment.

[0160] Example 9

[0161] like Fig. 22 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 3 only in that the secondary side compensation network 6 adopts LCL compensation, and the secondary coil L s With C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier and filter circuit 7.

[0162] Fig.23 Given Fig. 22 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0163]

[0164] The switching process of the constant current / constant voltage output and the design of the compensation parameter C1 of this embodiment are the same as those of the third embodiment.

[0165] Example 10

[0166] like Fig.24 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 4 only in that the secondary side compensation network 6 adopts LCL compensation, and the secondary coil L s With C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier and filter circuit 7.

[0167] Fig.25 Given Fig.24The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0168]

[0169] The switching process of the constant current / constant voltage output in this embodiment is the same as that in the fourth embodiment.

[0170] Embodiment 11

[0171] like Fig.26 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 5 in that the secondary side compensation network 6 adopts LCL compensation, and the secondary coil L s With C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier and filter circuit 7.

[0172] Fig. 27 Given Fig.26 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0173]

[0174] The switching process of the constant current / constant voltage output and the design of the compensation parameter C1 of this embodiment are the same as those of the fifth embodiment.

[0175] Example 12

[0176] like Fig.28 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 6 in that the secondary side compensation network 6 adopts LCL compensation, and the secondary coil L s With C f2 Connect in parallel and then connect with the compensation inductor L f2 Series connection, L f2 The output is connected to the rectifier and filter circuit 7.

[0177] Fig.29 Given Fig.28 The fundamental wave equivalent circuit. In this embodiment, the parameters of the resonant element satisfy:

[0178]

[0179] The switching process of the constant current / constant voltage output and the design of the compensation parameter C1 of this embodiment are the same as those of the sixth embodiment.

[0180] Embodiment 13

[0181] like Fig.30As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 1 only in that the secondary side compensation network 6 adopts S compensation, and the secondary coil L s Connected in series with capacitor C2, the output of capacitor C2 is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0182] Fig.31 Given Fig.30 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0183]

[0184] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0185]

[0186] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0187] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0188]

[0189] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0190] The design of the compensation parameter C1 in this embodiment is the same as that in Embodiment 1. In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby realizing the switching between constant voltage and constant current output.

[0191] Embodiment 14

[0192] like Fig.32 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 2 only in that the secondary side compensation network 6 adopts S compensation, and the secondary coil L s Connected in series with capacitor C2, the output of capacitor C2 is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0193] Fig.33 Given Fig.32The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0194]

[0195] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0196]

[0197] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0198] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0199]

[0200] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0201] The design of the compensation parameter C1 in this embodiment is the same as that in Embodiment 2. In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby realizing the switching between constant voltage and constant current output.

[0202] Embodiment 15

[0203] like Fig.34 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 3 only in that the secondary side compensation network 6 adopts S compensation, and the secondary coil L s Connected in series with capacitor C2, the output of capacitor C2 is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0204] Fig.35 Given Fig.34 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0205]

[0206] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0207]

[0208] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0209] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0210]

[0211] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0212] The design of the compensation parameter C1 in this embodiment is the same as that in Embodiment 3. In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby realizing the switching between constant voltage and constant current output.

[0213] Example 16

[0214] like Fig.36 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 4 only in that the secondary side compensation network 6 adopts S compensation, and the secondary coil L s Connected in series with capacitor C2, the output of capacitor C2 is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0215] Fig.37 Given Fig.36 The fundamental wave equivalent circuit of the constant current and constant voltage switching module, the parameters of the resonant element in this embodiment meet the following requirements:

[0216]

[0217] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0218]

[0219] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0220] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current is independent of the load resistance and the output has a constant current characteristic.

[0221] In this example, the controller K controls the switching switch S to be turned on / off, thereby achieving the switching between constant voltage and constant current output.

[0222] Embodiment 17

[0223] like Fig.38 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 5 only in that the secondary side compensation network 6 adopts S compensation, and the secondary coil L s Connected in series with capacitor C2, the output of capacitor C2 is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0224] Fig.39 Given Fig.38 The fundamental wave equivalent circuit, the parameters of the resonant element in the embodiment of the present invention satisfy:

[0225]

[0226] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0227]

[0228] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0229] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0230]

[0231] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0232] The design of the compensation parameter C1 in this embodiment is the same as that in Embodiment 5. In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby realizing the switching between constant voltage and constant current output.

[0233] Embodiment 18

[0234] like Fig.40 As shown, an inductive wireless power transmission system for realizing constant current and constant voltage output switching is different from the embodiment 5 only in that the secondary side compensation network 6 adopts S compensation, and the secondary coil L sConnected in series with capacitor C2, the output of capacitor C2 is connected to the rectifier filter circuit 7, the primary coil L p With the secondary coil L s The two are coupled through mutual inductance M1.

[0235] Fig.41 Given Fig.40 The fundamental wave equivalent circuit, in this embodiment, the parameters of the resonant element satisfy:

[0236]

[0237] When the switch S is turned off, it can be deduced from the basic circuit theory that at the resonant frequency ω0, the output voltage of the inductive wireless power transfer topology is:

[0238]

[0239] It can be seen that at this time the output voltage has nothing to do with the load resistance, and the output has a constant voltage characteristic.

[0240] When the switch S is closed, the equivalent AC excitation of the constant current and constant voltage switching module is for It can be deduced from the basic circuit theory that at the resonant frequency ω0, the output current of the inductive wireless power transfer topology is:

[0241]

[0242] It can be seen that at this time the output current has nothing to do with the load resistance, and the output has a constant current characteristic.

[0243] The design of the compensation parameter C1 in this embodiment is the same as that in Embodiment 6. In this embodiment, the controller K controls the switching switch S to be turned on / off, thereby realizing the switching between constant voltage and constant current output.

[0244] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An inductive wireless power transmission system for realizing constant current and constant voltage output switching, characterized in that: The invention comprises a sending module, a receiving module and a constant current and constant voltage switching module, wherein the sending module comprises a DC power supply (1), a high frequency inverter (2), a primary compensation network (3) and a primary coil (4) connected in sequence, and the receiving module comprises a secondary coil (5), a secondary compensation network (6), a rectifier filter circuit (7) and a load (8) connected in sequence; the constant current and constant voltage switching module comprises a series circuit formed by connecting a capacitor C, an excitation coil L and a switching switch S, and also comprises an excitation source and a controller K of the switching switch S; wherein the excitation coil L and the primary coil (4) share a primary magnetic core, the excitation coil L and the secondary coil (5) are coupled through a mutual inductance M2, and the primary coil (4) and the secondary coil (5) are coupled through a mutual inductance M1; a constant current flows through the primary coil (4) at an operating frequency ω0; The compensation network transformation method adopts a voltage source to excite a series primary compensation network (3), wherein the primary compensation network (3) is an LCC structure or a CL structure or a CLC structure or an LCL structure or an LC structure, and the secondary compensation network (6) is an LCC structure or an LCL structure or an S structure; The series circuit of the constant current and constant voltage switching module is connected in parallel to the output end of the high frequency inverter (2), and the capacitor C and the excitation coil L resonate at the system operating frequency; Or, the constant current and constant voltage switching module further comprises a high frequency inverter H, the series circuit of the constant current and constant voltage switching module is connected in parallel to the output end of the high frequency inverter H, the input end of the high frequency inverter H is connected in parallel to the output end of the DC power supply (1), and the capacitor C and the excitation coil L resonate at the system operating frequency; Or, the primary coil (4) is connected in series with a passive element Z, and the constant current and constant voltage switching module is connected in parallel at both ends of the passive element Z. The capacitor C, the excitation coil L and the passive element Z of the constant current and constant voltage switching module resonate at the system operating frequency.

2. The inductive wireless power transmission system for realizing constant current and constant voltage output switching according to claim 1, characterized in that: The parameters of the compensation capacitor C1 located in the constant current branch of the primary compensation network (3) satisfy the input impedance angle , where Z in is the input impedance, I m Indicates taking the imaginary part, R e It means taking the real part.

3. The inductive wireless power transmission system for realizing constant current and constant voltage output switching according to any one of claims 1-2, characterized in that: The switch S is a MOSFET, an IGBT or a thyristor.

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