A parameter design method and system of constant-voltage LCC-C (CL) 2 topology

Abstract

The application relates to the technical field of wireless power transmission and discloses a constant-voltage type LCC-C(CL) 2 topology parameter design method and system, which comprises the following specific steps: S1: constructing a topology equivalent circuit of a constant-voltage type LCC-C(CL) 2 ; S2: introducing a parameter representing the ratio of inductance to capacitance; constructing an efficiency formula of the LCC-C(CL) 2 and an efficiency intersection expression of the efficiency formula of the LCC-S topology according to the topology equivalent circuit and the parameter; S3: obtaining optimal parameters according to the efficiency intersection expression. The application solves the problem that the prior art is not applicable to the LCC-C(CL) 2 , and has the characteristics of strong anti-offset capability and the capability of maintaining efficiency under variable load working conditions.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and more specifically, to a parameter design method and system for a constant voltage LCC-C(CL)2 topology. Background Technology

[0002] In recent years, various electronic and electrical equipment have experienced rapid popularization and development, leading to new demands from users for the safety and reliability of power transmission. Traditional plug-in power transmission technology poses safety hazards such as sparks and high-voltage electric shocks during charging, reducing system safety, reliability, and lifespan, and failing to meet the safety requirements of some special industrial applications. Unlike traditional power transmission methods that rely on direct contact with metal wires, wireless transmission technology utilizes magnetic fields, lasers, or microwaves as energy transmission media, eliminating the need for direct electrical contact between the power grid and the device. This effectively overcomes the inherent defects and problems of traditional direct metal wire power supply, significantly reducing the reliance on wires and connection ports. Wireless power transmission systems have been extensively explored and researched by scholars due to their numerous advantages, including safety, electrical isolation, low maintenance, convenience, and the ability to operate in special environments and weather conditions. The transmitting and receiving coils of a wireless power transmission system need to be in a state of resonance, often requiring a resonant frequency in the megahertz (MHz) range to achieve the required transmission power. Wireless power transmission systems utilize the air gap of a loosely coupled transformer to transfer electrical energy from the transmitting coil to the receiving coil. In practice, a larger air gap results in a smaller coupling coefficient, a smaller magnetizing inductance, and a larger leakage inductance, which in turn leads to a smaller output current, lower output power, increased reactive power, and lower power factor and transmission efficiency.

[0003] To improve the transmission characteristics, enhance the transmission capacity, and increase efficiency of a wireless power transmission system, capacitors are typically added to the primary and secondary sides to construct four basic single-resonant compensation networks (SS, SP, PS, and PP) with the transmitting and receiving coils. These compensation circuits counteract the leakage inductance of loosely coupled transformers. However, the characteristics of single-resonant compensation circuits are generally affected by load or mutual inductance, and soft switching is difficult to achieve, resulting in significant reactive power. Later, inductors were added to the single-resonant compensation topology to form higher-order compensation topologies LCC-S and LCC-LCC. While these compensated for the difficulty in soft switching of single-resonant topologies, they still suffer from weak offset resistance and rapid efficiency degradation under varying load conditions. The latest proposed LCC-C(CL)2 topology improves offset resistance and efficiency under varying load conditions to some extent, but there is currently little research and application of it, and the impact of component parameters on the overall circuit characteristics remains unknown.

[0004] Existing technology provides a parameter design method for wireless power transfer systems based on LCC-S topology. Without introducing additional compensation circuits, the method utilizes the inherent characteristics of the coils to achieve the anti-offset capability of the mutual inductance value M during parameter design. By optimizing the primary input inductance L1 and the DC bus voltage value Vdc, the method maximizes the efficiency of the perturbation observation method in the constant current and constant voltage stages, while simultaneously considering the voltage and current stress constraints of the resonant inductor and capacitor, resulting in high utilization of the coupled network parameters.

[0005] However, existing technologies still have the problem of not being applicable to LCC-C(CL)2. How to invent a parameter design method applicable to LCC-C(CL)2 is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the problem that existing technologies are not applicable to LCC-C(CL)2, this invention provides a parameter design method and system based on a constant-voltage LCC-C(CL)2 topology, which features strong anti-offset capability and the ability to maintain efficiency under variable load conditions.

[0007] To achieve the above-mentioned objectives of this invention, the technical solution adopted is as follows:

[0008] A parameter design method based on a constant-voltage LCC-C(CL)2 topology includes the following specific steps:

[0009] S1: Constructing a constant-voltage LCC-C(CL) 2 The topological equivalent circuit;

[0010] S2: Introduce a parameter representing the ratio of inductance to capacitance; construct LCC-C(CL) based on the topological equivalent circuit and parameters. 2 The efficiency formula and the efficiency intersection expression of the LCC-S topology;

[0011] S3: Obtain the optimal parameters based on the efficiency intersection expression.

[0012] Preferably, a constant-voltage LCC-C(CL) type 2 The topological equivalent circuit includes the power supply U in Inductor Lp, Capacitor C p Inductor L T Capacitor C T Resistor R2, Inductor L R Capacitor C R Resistor R3, first equivalent voltage I R Z M The second equivalent voltage I T Z M The first secondary circuit and the second secondary circuit; in the topological equivalent circuit, U inOne end of Lp is connected to one end of C, and the other end of Lp is connected to C. p C T One end is connected; C T The other end and L T One end is electrically connected; L T The other end and I R Z M One end is connected; I R Z M The other end is connected to one end of R2; the other end of R2 is connected to C. p and U in The other end is connected; I T Z M One end and L R One end is connected, L R The other end and C R One end is connected, C R The other end is connected to the first secondary circuit, the first secondary circuit is connected to the second secondary circuit, one end of R3 is connected to the first secondary circuit, and the other end of R3 is connected to I. T Z M connect.

[0013] Furthermore, the first secondary circuit includes the first secondary circuit equivalent inductance L. C1 Capacitor C1; The second secondary circuit includes the equivalent inductance L of the second secondary circuit. C2 Capacitor C2, Inductor internal resistance R L L C1 One end is respectively connected to C R The other end is connected to C1; L C2 One end is connected to one end of C2 and R respectively. L One end of C1 is connected; the other end of C1 is connected to the other end of C2 and R respectively. L The other end is connected.

[0014] Furthermore, LCC-C(CL) 2 The equivalent load R of the secondary circuit of the topological equivalent circuit is:

[0015]

[0016] Furthermore, by introducing the parameter λ, which represents the ratio of inductance to capacitance, C2 = λC1, R = λ 2 R L .

[0017] Furthermore, in step S2, LCC-C (CL) is constructed based on the topological equivalent circuit and parameter λ. 2 The efficiency formulas for the equivalent circuit and the LCC-S topology, and the expression for the efficiency intersection point; specifically:

[0018] S201: Considering R2, R3, and the equivalent load R, we obtain LCC-C(CL). 2 The efficiency formula for the topology is η1:

[0019]

[0020] Where M is the mutual inductance value and ω is the frequency;

[0021] S202: Obtain the efficiency formula η2 for the LCC-S topology:

[0022]

[0023] S203: Make LCC-C(CL) 2 The efficiency formula for the topology is equal to that for the LCC-S topology, thus yielding the expression for the intersection of the efficiencies of the two topologies:

[0024]

[0025] Furthermore, in step S2, R is also calculated based on the efficiency intersection expression. L Taking the derivative, we obtain the expression for the optimal load value:

[0026]

[0027] From the expression for the optimal load value, we know that:

[0028] When 0 < λ < 1, as the load increases, the rate at which the efficiency reaches its maximum value slows down, and the corresponding impedance increases; when the load is... In the interval, the efficiency of λ = 1 is higher than that of 0 < λ < 1; the load is in In the interval, 0 < λ < 1 is more efficient than λ = 1;

[0029] When λ > 1, as the load increases, the efficiency rises to its maximum value more quickly, and the corresponding impedance decreases; when the load is... In the interval, the efficiency of λ > 1 is higher than that of λ = 1; the load is in In the interval, λ = 1 is more efficient than λ > 1;

[0030] Furthermore, in step S3, the optimal parameters are obtained based on the expression for the optimal load value. The specific steps are as follows:

[0031] S301: Confirmation of constant voltage type LCC-C(CL) 2 If the operating condition is a strongly coupled environment, proceed to step S302; if the load range of the operating condition is a weakly coupled environment, proceed to step S303.

[0032] S302: Assume λ > 1, substitute the maximum value of the load range, ω, and M into the efficiency intersection expression to obtain the optimal parameter λ;

[0033] S303: Assume 0 < λ < 1, substitute the minimum value of the load range, ω, and M into the efficiency intersection expression to obtain the optimal parameter λ.

[0034] Furthermore, in step S3, after obtaining the optimal parameter λ, the optimal L that enables the secondary circuit to fully resonate is calculated based on the optimal parameter λ. C1 C1, L C2 C2.

[0035] A constant-voltage LCC-C(CL) based 2 The topology parameter design system includes an equivalent circuit module, an efficiency focus expression module, and an optimal parameter module;

[0036] The equivalent circuit module is used to construct a constant-voltage LCC-C (CL). 2 The topological equivalent circuit;

[0037] The efficiency focus expression module is used to introduce parameters representing the ratio of inductance to capacitance; based on the topological equivalent circuit and parameters, the LCC-C(CL) is constructed. 2 The efficiency formula and the efficiency intersection expression of the LCC-S topology;

[0038] The optimal parameter module is used to obtain the optimal parameters based on the efficiency intersection expression.

[0039] The beneficial effects of this invention are as follows:

[0040] This invention discloses a constant-voltage LCC-C(CL) based method. 2 The topology parameter design method involves constructing a constant-voltage LCC-C (CL) type. 2 The topological equivalent circuit is obtained by introducing a parameter representing the ratio of inductance to capacitance, and constructing an LCC-C (CL) circuit. 2 The efficiency formulas for the LCC-S topology and the efficiency formula for the LCC-S topology are used to find the intersection expression of the efficiency and obtain the optimal parameters. The method proposed in this invention solves the problem that existing technologies are not applicable to LCC-C (CL). 2 It addresses the problem by having strong resistance to offset and maintaining efficiency under variable load conditions. Attached Figure Description

[0041] Figure 1 This invention relates to a constant-voltage LCC-C(CL) type... 2 A flowchart illustrating the topology parameter design method.

[0042] Figure 2 It is LCC-C(CL)n Equivalent circuit diagram.

[0043] Figure 3 It is LCC-C(CL) n Schematic diagram of the equivalent load of the secondary circuit.

[0044] Figure 4 It is LCC-C(CL) 2 The equivalent circuit diagram is shown.

[0045] Figure 5 This invention relates to a constant-voltage LCC-C(CL) type... 2 A schematic diagram of the efficiency curves for the topology parameter design method when 0 < λ < 1.

[0046] Figure 6 This invention relates to a constant-voltage LCC-C(CL) type... 2 A schematic diagram of the efficiency curve of the topology parameter design method when λ > 1.

[0047] Figure 7 This invention relates to a constant-voltage LCC-C(CL) type... 2 A schematic diagram of the parameter design process for the topology parameter design method.

[0048] Figure 8 In Example 3, the present invention provides a constant-voltage LCC-C(CL) based method. 2 A schematic diagram of the efficiency curves for the topology parameter design method in the case of 0 < λ < 1.

[0049] Figure 9 In Example 3, the present invention provides a constant-voltage LCC-C(CL) based method. 2 A schematic diagram of the efficiency curve of the topology parameter design method when λ > 1.

[0050] Figure 10 In Example 3, the present invention provides a constant-voltage LCC-C(CL) based method. 2 A schematic diagram of the efficiency curve of the topology parameter design method during horizontal offset.

[0051] Figure 11 In Example 3, the present invention provides a constant-voltage LCC-C(CL) based method. 2 A schematic diagram of the efficiency curve of the topology parameter design method during vertical offset. Detailed Implementation

[0052] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0053] Example 1

[0054] like Figure 1As shown, a constant-voltage LCC-C(CL) based 2 The topology parameter design method includes the following specific steps:

[0055] S1: Constructing a constant-voltage LCC-C(CL) 2 The topological equivalent circuit;

[0056] S2: Introduce a parameter representing the ratio of inductance to capacitance; construct LCC-C(CL) based on the topological equivalent circuit and parameters. 2 The efficiency formula and the efficiency intersection expression of the LCC-S topology;

[0057] S3: Obtain the optimal parameters based on the efficiency intersection expression.

[0058] Example 2

[0059] More specifically, LCC-C(CL) n The equivalent circuit is as follows Figure 2 As shown, the secondary side of the equivalent circuit consists of several inductors and capacitors. However, in the case of perfect resonance, the nth-order equivalent circuit of the secondary side is as follows: Figure 3 As shown, the specific value of the equivalent load R is:

[0060]

[0061] Where L Cn satisfy L is a fictitious inductance used to simplify calculations. In reality, it is derived from several secondary inductors and capacitors, and therefore may not be equal to any single inductance or capacitance equivalent. When n = 1, 3, 5… (when n = 1, i.e., LCC-LCC topology), the load R… L Located in the denominator of the fraction, where n = 0 (i.e., LCC-S topology) and n = 2, 4, 6… (when n = 2, it is LCC-C (CL)). 2 When the topology is (R), L It is located in the numerator of the fraction.

[0062] When n = 2, 4, 6..., the equivalent load R is equal to the load R. L Multiply by a fraction. This fraction consists of several ratios of secondary inductance to capacitance. Consider this fraction as R. L Let the coefficient be λ. Then the equivalent load R = λR. L This means that, compared to the traditional LCC-S circuit, the secondary-side equivalent load introduces a coefficient, allowing for adjustment of the equivalent load size, thus increasing the freedom of parameter design and the circuit's ability to adapt to different situations. The choice of n=2 for analysis here is a comprehensive consideration of system complexity and production cost.

[0063] like Figure 4 As shown, the constant voltage type LCC-C(CL) 2 The topological equivalent circuit includes the power supply U in Inductor Lp, Capacitor C p Inductor L T Capacitor C T Resistor R2, Inductor L R Capacitor C R Resistor R3, first equivalent voltage I R Z M The second equivalent voltage I T Z M The first secondary circuit and the second secondary circuit; in the topological equivalent circuit, U in One end of Lp is connected to one end of C, and the other end of Lp is connected to C. p C T One end is connected; C T The other end and L T One end is electrically connected; L T The other end and I R Z M One end is connected; I R Z M The other end is connected to one end of R2; the other end of R2 is connected to C. p and U in The other end is connected; I T Z M One end and L R One end is connected, L R The other end and C R One end is connected, C R The other end is connected to the first secondary circuit, the first secondary circuit is connected to the second secondary circuit, one end of R3 is connected to the first secondary circuit, and the other end of R3 is connected to I. T Z M connect.

[0064] In one specific embodiment, the first secondary circuit includes the first secondary circuit equivalent inductance L. C1 Capacitor C1; The second secondary circuit includes the equivalent inductance L of the second secondary circuit. C2 Capacitor C2, Inductor internal resistance R L L C1 One end is respectively connected to C R The other end is connected to C1; L C2 One end is connected to one end of C2 and R respectively. L One end of C1 is connected; the other end of C1 is connected to the other end of C2 and R respectively. L The other end is connected.

[0065] In one specific embodiment, LCC-C(CL)2 The equivalent load R of the secondary circuit of the topological equivalent circuit is:

[0066]

[0067] In one specific embodiment, after introducing the parameter λ representing the ratio of inductance to capacitance, C2 = λC1, R = λ 2 R L .

[0068] In one specific embodiment, in step S2, the LCC-C(CL) is constructed based on the topological equivalent circuit and parameter λ. 2 The efficiency formulas for the equivalent circuit and the LCC-S topology, and the expression for the efficiency intersection point; specifically:

[0069] S201: Considering R2, R3, and the equivalent load R, we obtain LCC-C(CL). 2 The efficiency formula for the topology is η1:

[0070]

[0071] After simplification, we get:

[0072]

[0073] Where M is the mutual inductance value and ω is the frequency;

[0074] S202: Obtain the efficiency formula η2 for the LCC-S topology:

[0075]

[0076] S203: Make LCC-C(CL) 2 The efficiency formula for the topology is equal to that for the LCC-S topology, thus yielding the expression for the intersection of the efficiencies of the two topologies:

[0077]

[0078] In one specific embodiment, in step S2, R is further evaluated based on the efficiency intersection expression. L Taking the derivative, we obtain the expression for the optimal load value:

[0079]

[0080] From the expression for the optimal load value, we know that:

[0081] like Figure 5 As shown, 0 < λ < 1, the slower the efficiency decreases with increasing load, which means enhanced robustness to load. As λ decreases, the rate at which efficiency rises to its maximum value slows down, corresponding to an increase in impedance. The position shifts to the right. The load is... In the interval, λ = 1 has a higher efficiency than 0 < λ < 1; the load is in In the interval 0 < λ < 1, the efficiency is higher than that of λ = 1; this phenomenon is more pronounced when the coupling coefficient is small, because according to equation (5) The position will shift to the left. In this case, the LCC-S circuit reaches its maximum value faster when the load changes, and after reaching the maximum value, the rate of decrease is even faster when the load continues to increase. Therefore, a coefficient 0 < λ < 1 is introduced to reduce the rate of decrease as the load increases, i.e., in It is more efficient within the interval.

[0082] like Figure 6 As shown, λ>1, and as λ increases, the efficiency rises to its maximum value faster, and the corresponding impedance decreases. The position shifts to the left. The load is... In the interval, the efficiency of λ>1 is higher than that of λ=1; the load is in In the interval, the efficiency is higher when λ = 1 than when λ > 1. This phenomenon is more pronounced when the coupling coefficient is large. The position will shift to the right. In this case, the LCC-S changes slowly with the load, and the load corresponding to the peak efficiency is relatively large. Therefore, a coefficient λ>1 is introduced to increase the sensitivity of efficiency to the load, making its rate of increase faster. It is more efficient within the interval.

[0083] From the above two cases, it can be seen that when the load is in different value ranges, the value of λ can be adjusted to make LCC-C(CL). 2 The output efficiency of this topology is higher than that of the traditional LCC-S topology.

[0084] In one specific embodiment, such as Figure 7 As shown, when designing the optimal parameters, the operating conditions of the product are first roughly determined: if it operates under strong coupling and small load conditions, λ>1 is selected; if it operates under weak coupling and large load conditions, 0<λ<1 is selected. After determining the approximate range of λ, the specific λ value is calculated according to the range of the product's working load and equation (5): if λ>1, the maximum value of the load range is substituted into equation (5) to calculate λ; if 0<λ<1, the minimum value of the load range is substituted into equation (5) to calculate λ. At this time, the values ​​of capacitors C1 and C2 are determined. Finally, according to the principle that the reactance of each mesh on the secondary side is zero, the parameters of the remaining components are determined.

[0085] When the optimal parameters are obtained,

[0086] Specifically, in step S3, the optimal parameters are obtained based on the expression for the optimal load value. The specific steps are as follows:

[0087] S301: Confirmation of constant voltage type LCC-C(CL) 2 If the operating condition is a strongly coupled environment, proceed to step S302; if the load range of the operating condition is a weakly coupled environment, proceed to step S303.

[0088] S302: Assume λ>1, substitute the maximum value of the load range, ω, and M into the efficiency intersection expression to obtain the optimal parameter λ;

[0089] S303: Assume 0 < λ < 1, substitute the minimum value of the load range, ω, and M into the efficiency intersection expression to obtain the optimal parameter λ.

[0090] In one specific embodiment, in step S3, after obtaining the optimal parameter λ, the optimal L that makes the secondary circuit fully resonant is calculated based on the optimal parameter λ. C1 C1, L C2 C2.

[0091] This invention proposes a method based on LCC-C(CL). 2 The topology parameter compensation method, by introducing a new parameter λ, allows designers to design the load intersection point at their desired load value according to the different workload ranges of different products, thereby achieving LCC-C(CL) within the product's operating range. 2 The efficiency of this topology is consistently higher than that of LCC-S. This undoubtedly makes LCC-C (CL) more efficient. 2 The parameter design process of the topology is made more intuitive, reducing the design difficulty and giving full play to the circuit characteristics of the topology, such as strong anti-offset capability and high degree of design freedom.

[0092] This invention also proposes a method for selecting the optimal parameters, such that LCC-C(CL) 2 The topology is more efficient than LCC-S under strongly coupled conditions, which improves the circuit characteristics of the topology to some extent.

[0093] Example 3

[0094] In this embodiment, a prototype wireless power transmission system with a maximum power of 300W is built. The input voltage Uin = 110V, the operating frequency f = 200kHz, the transmitting inductance Lp = 64μH, the receiving inductance Ls = 64μH, and the coil internal resistance R2 = R3 = 0.2Ω.

[0095] In this embodiment, we assume 0 < λ < 1, C1 = 40.64 nF, C2 = 17.26 nF. LCC-S and LCC-C(CL) 2 The efficiency curve is as follows Figure 8 As shown, LCC-C(CL) can be observed. 2The intersection of the topology and the LCC-S topology is located at load R. L = Approximately 40Ω. Within the set load range, LCC-C(CL) 2 Both topologies can achieve efficiencies of over 80%, while the efficiency of the traditional LCC-S topology drops rapidly to below 60% as the load increases. This means that if a product's operating load only varies above 40Ω, the efficiency of the LCC-C(CL)2 topology will always be higher than that of LCC-S. The intersection value can be automatically adjusted according to the product's operating load range; for example, by decreasing the λ value, the intersection value can be increased, thus making it suitable for products with larger loads.

[0096] In this embodiment, λ>1, C1=20.23nF, C2=53.00nF, at this time... The efficiency curves of LCC-S and LCC-C(CL)2 are as follows: Figure 9 As shown, it can be observed that the intersection of the LCC-C(CL)2 topology and the LCC-S topology is located at the load R. L = Approximately 22Ω. Within 20Ω, the LCC-C(CL)2 topology achieves efficiency exceeding 80%, while the traditional LCC-S topology is 7% less efficient. This indicates that if a product's workload only varies below 22Ω, the LCC-C(CL)2 topology will consistently be more efficient than the LCC-S. The intersection value can be adjusted automatically according to the product's operating load range; for example, by increasing the λ value, the intersection value can be reduced, making it suitable for products with smaller loads.

[0097] In this embodiment, Figure 10 and Figure 11 The efficiency curves for LCC-S and LCC-C(CL)2 under horizontal and vertical offset are shown respectively. It can be found that when the coil offset is small or even when the coil is aligned and there is almost no offset, the efficiency of the LCC-C(CL)2 topology is higher than that of the traditional LCC-S topology. This also verifies the effectiveness of the parameter selection method proposed in this invention: taking λ>1 in a strong coupling environment can make the LCC-C(CL)2 topology more efficient than the traditional LCC-S topology under small load conditions.

[0098] Example 4

[0099] A parameter design system based on constant voltage LCC-C(CL)2 topology includes an equivalent circuit module, an efficiency focus expression module, and an optimal parameter module;

[0100] The equivalent circuit module is used to construct the topological equivalent circuit of the constant voltage type LCC-C(CL)2;

[0101] The efficiency focus expression module is used to introduce parameters representing the ratio of inductance to capacitance; based on the topological equivalent circuit and parameters, the efficiency formulas of LCC-C(CL)2 and LCC-S topology are constructed, along with the efficiency intersection expression.

[0102] The optimal parameter module is used to obtain the optimal parameters based on the efficiency intersection expression.

[0103] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A parameter design method based on a constant-voltage LCC-C(CL)² topology, characterized in that: The specific steps include the following: S1: Construct the topological equivalent circuit of constant voltage type LCC-C(CL)²; The topological equivalent circuit of the constant voltage type LCC-C(CL)² includes the power supply. ,inductance Lp ,capacitance ,inductance ,capacitance ,resistance R 2. Inductance ,capacitance ,resistance R 3. First equivalent voltage Second equivalent voltage First secondary circuit, second secondary circuit; In the topological equivalent circuit, one end and Lp One end is connected, Lp The other end is respectively with , One end is connected; The other end and One end is electrically connected; The other end and One end is connected; The other end and R Connect one end of 2; R The other end of 2 is respectively with and The other end is connected; one end and One end is connected, The other end and One end is connected, The other end is connected to the first secondary circuit, and the first secondary circuit is connected to the second secondary circuit. R One end of 3 is connected to the first secondary circuit. R The other end of 3 and connect; The first secondary circuit includes the equivalent inductance of the first secondary circuit. L C1 ,capacitance The second secondary circuit includes the equivalent inductance of the second secondary circuit. L C2 ,capacitance Inductor internal resistance ; L C1 one end is respectively with The other end and connect; L C2 one end is respectively with one end and One end is connected; The other end is respectively with The other end and The other end is connected; S2: Introduce a parameter representing the ratio of inductance to capacitance; based on the topological equivalent circuit and parameters, construct the efficiency formula of LCC-C(CL)² and the efficiency intersection expression of the efficiency formula of LCC-S topology; In step S2, based on the topological equivalent circuit and parameter λ, the efficiency intersection expression of the efficiency formulas for the LCC-C(CL)² topological equivalent circuit and the LCC-S topological efficiency formula is constructed; specifically: S201: Consider R 2 and R 3. Based on the equivalent load R, we obtain the efficiency formula for the LCC-C(CL)² topology: Where M is the mutual inductance value, For frequency; S202: Obtain the efficiency formula for the LCC-S topology. : S203: Make the efficiency formula of the LCC-C(CL)² topology equal to the efficiency formula of the LCC-S topology, and obtain the expression for the intersection of the efficiencies of the two topologies: S3: Obtain the optimal parameters based on the efficiency intersection expression.

2. The parameter design method based on constant voltage LCC-C(CL)² topology according to claim 1, characterized in that: The equivalent load R of the secondary circuit of the LCC-C(CL)² topological equivalent circuit is: 。 3. The parameter design method based on constant voltage LCC-C(CL)² topology according to claim 2, characterized in that: After introducing the parameter λ, which represents the ratio of inductance to capacitance, , .

4. The parameter design method based on constant voltage LCC-C(CL)² topology according to claim 1, characterized in that: In step S2, the efficiency formula for the LCC-C(CL)² topology is related to R. L Taking the derivative, we obtain the expression for the optimal load value: From the expression for the optimal load value, we know that: When 0 < λ < 1, as the load increases, the rate at which efficiency reaches its maximum value slows down, and the corresponding impedance increases; when the load is in the range (0, λ < 1), In the interval (), λ=1 has a higher efficiency than 0<λ<1; the load is in the () In the interval (∞), 0 < λ < 1, the efficiency is higher than... ; When λ>1, the load increases, the efficiency rises to its maximum value faster, and the corresponding impedance decreases; when the load is between (0, ..., ...), the efficiency rises to its maximum value faster, and the corresponding impedance decreases. In the interval (), λ>1 has a higher efficiency than λ=1; the load in () In the interval (∞), λ=1 is more efficient than λ>

1.

5. The parameter design method based on the constant-voltage LCC-C(CL)² topology according to claim 4, characterized in that: In step S3, the optimal parameters are obtained based on the expression for the optimal load value. The specific steps are as follows: S301: Confirm the operating condition of the constant voltage type LCC-C(CL)²; if the operating condition is a strongly coupled environment, proceed to step S302; if the load range of the operating condition is a weakly coupled environment, proceed to step S303. S302: Assuming λ>1, set the maximum value of the load range, Substituting M into the efficiency intersection expression, we obtain the optimal parameter λ; S303: Assume 0 < λ < 1, set the minimum value of the load range, Substituting M into the efficiency intersection expression, we obtain the optimal parameter λ.

6. The parameter design method based on the constant voltage LCC-C(CL)² topology according to claim 5, characterized in that: In step S3, after obtaining the optimal parameter λ, the optimal parameters that enable the secondary circuit to fully resonate are calculated based on the optimal parameter λ. L C1 、L C2 , .

7. A parameter design system based on a constant-voltage LCC-C(CL)² topology, used to implement the parameter design method based on a constant-voltage LCC-C(CL)² topology as described in any one of claims 1-6, characterized in that: This includes an equivalent circuit module, an efficiency focus expression module, and an optimal parameter module; The equivalent circuit module is used to construct the topological equivalent circuit of the constant voltage type LCC-C(CL)²; The efficiency focus expression module is used to introduce parameters representing the ratio of inductance to capacitance; based on the topological equivalent circuit and parameters, the efficiency formula of LCC-C(CL)² and the efficiency formula of LCC-S topology are constructed, and the efficiency intersection expression is expressed. The optimal parameter module is used to obtain the optimal parameters based on the efficiency intersection expression.

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