Asymmetric S-S resonance compensation circuit and resonance compensation parameter value calculation method

Abstract

The invention relates to the technical field of electrical engineering, in particular to an asymmetric S-S resonance compensation circuit and a resonance compensation parameter value calculation method. Comprising a transmitting side circuit and a receiving side circuit, wherein the transmitting side circuit comprises an excitation source Uin, a transmitting side resonance compensation capacitor C1 and a transmitting coil inductor L1; the receiving side circuit comprises a receiving side resonance compensation capacitor C2, a load resistor RL and a receiving coil inductor L2, the capacitance value of the transmitting side resonance compensation capacitor C1 and the capacitance value of the receiving side resonance compensation capacitor C2 are not equal, C1 is not equal to C2, so that asymmetric resonance compensation is formed; wireless energy transmission is realized between the transmitting coil inductor L1 and the receiving coil inductor L2 through a mutual inductor M; according to the circuit, by adjusting the capacitance values of the transmitting side resonance compensation capacitor C1 and the receiving side resonance compensation capacitor C2 and the working angular frequency of the system, the output shows the constant voltage source characteristic.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical engineering, and in particular to an asymmetric SS resonance compensation circuit and a resonance compensation parameter value calculation method. Background Art

[0002] As a new energy transmission method, wireless energy transmission technology has received extensive attention and research in recent years due to its remarkable features such as being able to get rid of mechanical constraints, no need for plug-in links, no exposed conductors, and no risk of electric shock due to leakage. This technology has shown broad application prospects in many fields such as electric vehicles, consumer electronics, household appliances, and implantable medical devices.

[0003] In wireless energy transmission systems, the use of resonant compensation circuits is particularly important in order to improve transmission power and efficiency. The power factor of the system can be effectively improved through the reasonable configuration of compensation devices such as inductors and capacitors, thereby achieving higher energy transmission efficiency. Among them, series resonant compensation (SS compensation) has been widely used in wireless energy transmission systems due to its advantages such as simple circuit structure (only capacitors are needed as compensation devices) and easy calculation of resonant parameters.

[0004] However, the traditional SS compensation topology has an obvious limitation, that is, its output characteristics are constant current source characteristics. This means that if the output needs to be converted into a constant voltage source characteristic to meet certain specific application requirements, an additional DC-DC conversion circuit must be added. This not only increases the complexity of the system, but may also reduce the overall energy transmission efficiency. Summary of the invention

[0005] The present invention provides an asymmetric SS resonance compensation circuit, which aims to enable a wireless energy transmission device to have constant voltage source characteristics by changing the SS compensation topology resonance parameters, thereby reducing system complexity.

[0006] To achieve the above object, the technical solution of the present invention is:

[0007] An asymmetric SS resonance compensation circuit includes a transmitting side circuit and a receiving side circuit, wherein:

[0008] The transmitting side circuit includes an excitation source Uin, a transmitting side resonant compensation capacitor C1 and a transmitting coil inductor L1;

[0009] The receiving side circuit includes the receiving side resonant compensation capacitor C2, the load resistor R L and the receiving coil inductor L2, wherein the capacitance values ​​of the transmitting side resonant compensation capacitor C1 and the receiving side resonant compensation capacitor C2 are not equal C1≠C2, so as to form an asymmetric resonant compensation;

[0010] Wireless energy transmission is achieved between the transmitting coil inductance L1 and the receiving coil inductance L2 through mutual inductance M;

[0011] The circuit makes the output present a constant voltage source characteristic by adjusting the capacitance values ​​of the transmitting side resonant compensation capacitor C1 and the receiving side resonant compensation capacitor C2, as well as the working angular frequency of the system.

[0012] A method for calculating a resonance compensation parameter value, the method is based on an asymmetric SS resonance compensation circuit, specifically:

[0013] Based on the resonance compensation theory of wireless energy transmission system, the SS compensation output expression is derived;

[0014]

[0015] The transmitting side circuit includes an excitation source U in , transmitting side resonant compensation capacitor C1, and transmitting coil inductor L1. The receiving side circuit includes receiving side resonant compensation capacitor C2, load resistor R L and receiving coil inductance L2, M is the mutual inductance between the transmitting coil and the receiving coil;

[0016] and , combined with the above formula, we can get:

[0017]

[0018] in:

[0019]

[0020] To achieve constant voltage output, the load voltage R should not appear in the expression of voltage gain G. L , that is, G is independent of the load; when the following relationship is satisfied, G can be independent of the load.

[0021]

[0022] At this time, the expression of voltage gain G is as follows:

[0023]

[0024] After finishing, we can get:

[0025] (1)

[0026] For a certain wireless energy transmission system, the transmitting coil inductance L1, the receiving coil inductance L2, and the mutual inductance M between the transmitting coil and the receiving coil are all known quantities, and the voltage gain G is the design value. Therefore, there are three unknown quantities in the formula: the system operating angular frequency , transmitting side resonant compensation capacitor C1 and receiving side resonant compensation capacitor C2;

[0027] To confirm , C1 and C2, it is also necessary to introduce an auxiliary equation, which is the relationship between output efficiency, capacitor voltage stress value, inductor current stress value and frequency.

[0028] Furthermore, the auxiliary equation is an asymmetric resonant compensation circuit topology provided with resistors R1 and R2, and the system output efficiency is , R1 is the internal resistance of the primary coil, and R2 is the internal resistance of the secondary coil;

[0029]

[0030] Available

[0031]

[0032] To make output efficiency The highest value can be obtained by taking the derivative of the above formula to confirm the maximum value, and then combined with formula (1), the solution is , C1 and C2, that is:

[0033] (2)

[0034] Since in a specific system, the numerical solution of formula (2) can be obtained by substituting the determined parameters of the transmitting coil inductance L1, the receiving coil inductance L2, the mutual inductance M between the transmitting coil and the receiving coil, and the voltage gain G into the formula.

[0035] The beneficial effects achieved by the present invention are:

[0036] The present invention discloses an asymmetric SS resonant compensation circuit, which changes the resonant parameter calculation method of the SS compensation topology and uses asymmetric compensation capacitor parameters, so that the output of the SS compensation topology can directly have constant voltage source characteristics. This improvement not only reduces the complexity of the system, but also significantly improves the overall efficiency of the wireless energy transmission system. At the same time, the resonant parameter calculation method of the present invention can also effectively avoid the problem of infinite current on the transmitting side when the load on the receiving side is open in the traditional SS compensation topology, further enhancing the stability and safety of the system.

[0037] A method for calculating a resonance compensation parameter value is provided. The above method is used to calculate the resonance compensation parameter so that ∆1≠0 and ∆2≠0, that is, the transmitting side and the receiving side are in an incomplete resonance state. When the receiving side load is open-circuited, the transmitting side impedance is not zero, so the transmitting side current is not infinite, thereby avoiding the problem of infinite transmitting side current caused by the receiving side open-circuited in the traditional SS compensation topology. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0039] Figure 1 This is a structural diagram of an asymmetric SS resonance compensation circuit.

[0040] Figure 2 Output constant pressure characteristic diagram for the system.

[0041] Figure 3 It is an asymmetric resonant compensation circuit topology (including coil internal resistance).

[0042] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0045] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0046] like Figures 1 to 3 As shown, the present invention provides an asymmetric SS resonance compensation circuit.

[0047] SS compensation topology such as Figure 1 As shown (ignore the internal resistance of the coil). The transmitting side circuit includes the excitation source U in , transmitting side resonant compensation capacitor C1, and transmitting coil inductor L1. The receiving side circuit includes receiving side resonant compensation capacitor C2, load resistor R L and the receiving coil inductance L2 (L1 and L2 may not be equal). M is the mutual inductance between the transmitting coil and the receiving coil.

[0048] according to Figure 2 The equations that specifically satisfy the circuit structure can be listed as follows:

[0049]

[0050] AndU o =I2R L , combined with the above formula, we can get:

[0051]

[0052] in:

[0053]

[0054] To achieve constant voltage output, the load voltage R should not appear in the expression of voltage gain G. L , that is, G is independent of the load; when the following relationship is satisfied, G can be independent of the load.

[0055]

[0056] At this time, the expression of voltage gain G is as follows:

[0057]

[0058] After finishing, we can get:

[0059] (1)

[0060] For a certain wireless energy transmission system, the transmitting coil inductance L1, the receiving coil inductance L2, and the mutual inductance M between the transmitting coil and the receiving coil are all known quantities, and the voltage gain G is the design value. Therefore, there are three unknown quantities in the formula: the system operating angular frequency , transmitting side resonant compensation capacitor C1 and receiving side resonant compensation capacitor C2.

[0061] To confirm , C1 and C2, and an auxiliary equation needs to be introduced. The auxiliary equation can be determined according to the requirements. The auxiliary equation is the relationship between the output efficiency, the capacitor voltage stress value, the inductor current stress value and the frequency;

[0062] For example, the system output efficiency is required The highest system topology is Figure 3 The asymmetric resonant compensation circuit topology (including coil internal resistance) is shown (C1≠C2), where R1 is the primary coil internal resistance and R2 is the secondary coil internal resistance.

[0063]

[0064] Available

[0065]

[0066] To make output efficiency The highest value can be obtained by taking the derivative of the above formula to confirm the maximum value, and then combined with formula (1), the solution is , C1 and C2, that is:

[0067] (2)

[0068] Since equation (2) is relatively complex, in a specific system, after the determined parameters of the transmitting coil inductance L1, the receiving coil inductance L2, the mutual inductance M between the transmitting coil and the receiving coil, and the voltage gain G are substituted, the numerical solution of the equation can be obtained using software (such as MATLAB).

[0069] In addition, the above method is used to calculate the resonance compensation parameters so that ∆1≠0 and ∆2≠0, that is, the transmitting side and the receiving side are in an incomplete resonance state. When the receiving side load is open-circuited, the transmitting side impedance is not zero, so the transmitting side current is not infinite, avoiding the problem of infinite transmitting side current caused by open-circuit receiving side in the traditional SS compensation topology.

[0070] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An asymmetric SS resonance compensation circuit, characterized in that: It includes a transmitting side circuit and a receiving side circuit, wherein: The transmitting side circuit includes an excitation source Uin, a transmitting side resonant compensation capacitor C1 and a transmitting coil inductor L1; The receiving side circuit includes the receiving side resonant compensation capacitor C2, the load resistor R L and the receiving coil inductor L2, wherein the capacitance values ​​of the transmitting side resonant compensation capacitor C1 and the receiving side resonant compensation capacitor C2 are not equal C1≠C2, so as to form an asymmetric resonant compensation; Wireless energy transmission is achieved between the transmitting coil inductance L1 and the receiving coil inductance L2 through mutual inductance M; The circuit makes the output present a constant voltage source characteristic by adjusting the capacitance values ​​of the transmitting side resonant compensation capacitor C1 and the receiving side resonant compensation capacitor C2, as well as the working angular frequency of the system.

2. A method for calculating a resonance compensation parameter value, characterized in that: The method is based on an asymmetric SS resonance compensation circuit, specifically: Based on the resonance compensation theory of wireless energy transmission system, the SS compensation output expression is derived; The transmitting side circuit includes an excitation source U in , transmitting side resonant compensation capacitor C1, and transmitting coil inductor L1. The receiving side circuit includes receiving side resonant compensation capacitor C2, load resistor R L and receiving coil inductance L2, M is the mutual inductance between the transmitting coil and the receiving coil; and , combined with the above formula, we can get: in: To achieve constant voltage output, the load voltage R should not appear in the expression of voltage gain G. L , that is, G is independent of the load; when the following relationship is satisfied, G can be independent of the load. At this time, the expression of voltage gain G is as follows: After finishing, we can get: （1） For a certain wireless energy transmission system, the transmitting coil inductance L1, the receiving coil inductance L2, and the mutual inductance M between the transmitting coil and the receiving coil are all known quantities, and the voltage gain G is the design value. Therefore, there are three unknown quantities in the formula: the system operating angular frequency , transmitting side resonant compensation capacitor C1 and receiving side resonant compensation capacitor C2; To confirm , C1 and C2, it is also necessary to introduce an auxiliary equation, which is the relationship between output efficiency, capacitor voltage stress value, inductor current stress value and frequency.

3. A method for calculating a resonance compensation parameter value according to claim 2, characterized in that: The auxiliary equation is an asymmetric resonant compensation circuit topology with resistors R1 and R2, and the system output efficiency , R1 is the internal resistance of the primary coil, and R2 is the internal resistance of the secondary coil; Available To make output efficiency The highest value can be obtained by taking the derivative of the above formula to confirm the maximum value, and then combined with formula (1), the solution is , C1 and C2, that is: (2) Since in a specific system, the numerical solution of formula (2) can be obtained by substituting the determined parameters of the transmitting coil inductance L1, the receiving coil inductance L2, the mutual inductance M between the transmitting coil and the receiving coil, and the voltage gain G into the formula.

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