A method for designing parameters of a relay wireless energy transmission system

Abstract

The application provides a relay type wireless energy transmission system parameter design method, which is used for solving the problem of complex parameter design of the existing relay type wireless power supply system. The method steps are as follows: dynamically adjusting the working frequency of the system transmitting end and the transmitting end capacitor; taking the initial working frequency as the center frequency, finding all frequencies in the set frequency range, which make the phase difference between the transmitting end current and the receiving end current be 0 or 180 degrees, and taking the initial transmitting end capacitor parameter as the center capacitor parameter, finding all capacitor parameters in the set capacitor parameter range, which make the phase of the transmitting end current be 0 degrees; recording all parameter combinations of the frequency and the capacitor parameter which meet the conditions; calculating the working efficiency of each parameter combination, and taking the parameter combination with the highest efficiency as the working parameter of the system. The application realizes the load-independent constant voltage output and zero phase angle current input of the relay type wireless energy transmission system by adjusting only the transmitting end parameter.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and in particular to a parameter design method for a relay wireless power transmission system. Background Technology

[0002] Wireless power transfer technology is based on the principle of magnetic coupling, using a high-frequency magnetic field as the transmission medium. It achieves wireless energy transfer through electromagnetic coupling between coils. A common two-coil wireless power transfer system mainly consists of two parts: a transmitting coil and a receiving coil. The transmitting coil is connected to an alternating power supply, converting the alternating electric field into an alternating magnetic field, which is then induced into the receiving coil and converted into electrical energy to power the load. Wireless power transfer has advantages such as electrical isolation and no wire contact.

[0003] In certain application scenarios, such as the power supply of online monitoring equipment for high-voltage transmission lines, the distance for wireless power transmission needs to reach tens of centimeters to several meters. At this transmission distance, the coupling coefficient of the two-coil wireless power transmission system is small. Multiple relay coils can be added to enhance the coupling between the coils, thereby improving the system's transmission power and efficiency.

[0004] However, achieving high-efficiency and stable energy transmission in a repeater-based wireless power transfer system presents greater challenges than traditional two-coil systems. The increased number of repeater coils leads to more complex system characteristics, a higher system order, and inconsistent input and output characteristics under different frequencies and load conditions, making it difficult to maintain a stable system state and posing challenges to the smooth operation of the repeater-based wireless power transfer system. Furthermore, the large number of adjustable parameters and the large solution space make system parameter design more difficult. Summary of the Invention

[0005] The purpose of this invention is to provide a parameter design method for a relay-type wireless power transmission system. This method addresses the technical problem that existing relay-type wireless power supply systems typically require the design of compensation capacitors for each coil stage to achieve constant voltage and zero phase angle, resulting in complex parameter design and high requirements for the accuracy of compensation capacitor configuration and mutual inductance measurement.

[0006] First, a parameter design method for a relay-type wireless power transmission system is provided. The relay-type wireless power transmission system includes a transmitter and a receiver, and at least one relay terminal disposed between the transmitter and the receiver. The specific steps of the parameter design method are as follows:

[0007] S1: Dynamically adjust the parameters of the system transmitter, including the operating frequency and transmitter capacitance;

[0008] S2: At the initial operating frequency Using the center frequency as the reference, search within the set frequency range for frequencies that allow the transmitter current to... and receiving end current All frequencies with a phase difference of 0 or 180 degrees ,in: , To meet the required number of frequency parameters;

[0009] S3: At frequency Below, using the initial transmitter capacitance parameters Using the center capacitor parameters, find a range of capacitor parameters that allows the transmitter current to... All capacitance parameters with a phase of 0 degrees , , In frequency The number of capacitor parameters that meet the requirements;

[0010] S4: Record all combinations of frequency and capacitance parameters that meet the conditions, forming the transmitter parameter set. ;

[0011] S5: Calculate the working efficiency of each parameter combination in the transmitter parameter set, and take the parameter combination with the highest efficiency as the system's working parameters.

[0012] Optionally, the specific steps of step S2 are as follows:

[0013] S2.1: At the initial operating frequency With the center frequency as the base frequency, within the set frequency range... The step size changes the system's operating frequency;

[0014] S2.2: The impedance matrix of the relay wireless power transfer system Decomposed into , and ;

[0015] S2.3: The emitter current is represented by the decomposed matrix. and receiving end current The phase relationship;

[0016] S2.4: Determine the transmitter current and receiving end current Check if the phase difference is 0 or 180 degrees; if so, record the corresponding value. If the condition is not met, return to step S2.1; otherwise, return directly to step S2.1.

[0017] S2.5: Repeat steps S2.1 to S2.4 until the frequency after step adjustment exceeds the set frequency range, then output all frequencies that meet the requirements. .

[0018] Optionally, the matrix described in step S2 All elements on the main diagonal are 1, and the elements in the upper half of the main diagonal are... The lower half of the main diagonal is an empty set;

[0019] The matrix All elements on the main diagonal are 1, the upper half of the main diagonal is an empty set, and the lower half of the main diagonal is... ;in: For the first The coil and the first The reverse transmission coefficient between coils and .

[0020] Optionally, the matrix described in step S2 The main diagonal elements are The main diagonal and lower half of the region are empty sets; where: For the first The total equivalent resistance generated by the stage circuit; .

[0021] Optionally, in step S2.3, the transmitter current and receiving end current The phase relationship is equal to ,in, For phase operation; It is an alternating series, where each term is the product of the reverse transmission coefficients between several different coils, and the positive and negative terms of the product terms alternate.

[0022] Optionally, the specific steps of step S3 are as follows:

[0023] S3.1: At frequency Below, using the initial transmitter capacitance parameters The center capacitance parameter is used, and within the set capacitance parameter range, it is used to... The step size is used to change the transmitter capacitance parameters;

[0024] S3.2: Calculate the transmitter current based on changing the transmitter capacitance parameters. The phase;

[0025] S3.3: Determine the transmitter current Check if the phase is 0 degrees; if so, record the corresponding capacitance parameters. If the condition is not met, return to step S3.1; otherwise, return directly to step S3.1.

[0026] S3.4: At frequency Then, repeat steps S3.1 to S3.3 until the transmitter capacitor parameters after step adjustment exceed the set capacitor parameter range.

[0027] Optionally, in step S3, at frequency Next, execute steps S3.1 to S3.4 respectively to find the transmitter current. All capacitance parameters with a phase of 0 degrees.

[0028] Optionally, in step S3.2, the phase of the transmitter current is equal to the transmitter voltage. and the total equivalent impedance of the transmitter The phase operation value of the quotient.

[0029] Optionally, the working efficiency and system efficiency of the parameter combination in step S5. equal ,in, For the system's equivalent AC load, Indicates the real part.

[0030] Because of the adoption of the above technical solution, the present invention has the following advantages:

[0031] 1. This application enables a relay wireless power transmission system to achieve constant voltage output and zero phase angle current input independent of the load by adjusting only the parameters of the transmitting end.

[0032] 2. The parameter adjustment method of this application is simple and solves the problem that existing repeater wireless power supply systems require the design of compensation capacitors for each stage coil when achieving constant voltage and zero phase angle. The parameter design is complicated and the requirements for the accuracy of compensation capacitor configuration and mutual inductance measurement are high.

[0033] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0034] The accompanying drawings of this invention are described below.

[0035] Figure 1 This is a schematic diagram of the relay-type wireless power transmission system of the present invention.

[0036] Figure 2 This is a flowchart of the parameter design method for the relay-type wireless power transmission system of the present invention.

[0037] Figure 3 The AC input voltage of this invention Emitter current and receiving end current The waveform diagram.

[0038] Figure 4The DC output voltage of this invention Transient waveform diagram when the load resistance changes. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" or "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0040] Example 1:

[0041] A relay-type wireless power transmission system includes a transmitter and a receiver, and at least one relay located between the transmitter and the receiver; the transmitter, the relay, and the receiver constitute... Relay wireless power transmission system;

[0042] The transmitting end includes a transmitting capacitor and a transmitting coil connected to each other, and the other end of the transmitting capacitor and the transmitting coil is connected to an AC input power supply. The receiving end includes a receiving capacitor and a receiving coil connected to each other, and the other end of the receiving capacitor and the receiving coil is connected to an AC load. Each relay end includes a relay coil and a relay capacitor connected in series to form a loop.

[0043] In this embodiment, as Figure 1 The five-level relay wireless power transmission system shown is as follows: Figure 1 middle: For the transmitting end capacitor, For transmitting coil, AC input power, For the receiving end capacitor, For receiving coil, For AC load resistance; For relay coil, For relay terminal capacitor, For coil The internal resistance, The current is for the five circuits.

[0044] Example 2:

[0045] like Figure 2 The parameter design method for a relay wireless power transfer system shown herein includes the following specific steps:

[0046] S1: Dynamically adjust the parameters of the system's transmitter, including the system's operating frequency and transmitter capacitance;

[0047] In this embodiment, the initial operating frequency is known at the initial time. Coil parameters and initial transmitter capacitance parameters .

[0048] S2: At the initial operating frequency Using the center frequency as the reference, search within the set frequency range for frequencies that allow the transmitter current to... and receiving end current All frequencies with a phase difference of 0 or 180 degrees ,in: , To meet the required number of frequency parameters, the specific steps are as follows:

[0049] S2.1: At the initial operating frequency With the center frequency as the base frequency, within the set frequency range... The step size changes the system's operating frequency;

[0050] S2.2: The impedance matrix of the relay wireless power transfer system Decomposed into , and ;

[0051] In this embodiment, , and Represented as:

[0052] , ,

[0053] in, For the first The coil and the first The reverse transmission coefficient between coils Let be the reverse total equivalent impedance of the inductance generated by the i-th stage. and .

[0054] When n=5, the voltage-current relationship of the system can be expressed as:

[0055]

[0056] The elements of the impedance matrix can be represented as follows:

[0057]

[0058] In the formula, For the first The internal resistance of the coil in the stage circuit, For the first The self-inductance of the coil in the primary circuit, For the first The capacitance value in the stage circuit, For the first Level 1 loop and the first Mutual inductance between coils in a stage circuit.

[0059] S2.3: The decomposed matrix represents the transmitter current. and receiving end current Phase relationship:

[0060]

[0061] in, This is for phase operations.

[0062] S2.4: Determine the transmitter current and receiving end current Check if the phase difference is 0 or 180 degrees; if so, record the corresponding value. If the condition is not met, return to step S2.1; otherwise, return directly to step S2.1.

[0063] S2.5: Repeat steps S2.1 to S2.4 until the frequency after step adjustment exceeds the set frequency range, then output all frequencies that meet the requirements. .

[0064] S3: At frequency Below, using the initial transmitter capacitance parameters Using the center capacitor parameters, find a range of capacitor parameters that allows the transmitter current to... All capacitance parameters with a phase of 0 degrees , , In frequency The required number of capacitor parameters must be determined; the specific steps are as follows:

[0065] S3.1: At frequency Below, using the initial transmitter capacitance parameters The center capacitance parameter is used, and within the set capacitance parameter range, it is used to... The step size is used to change the transmitter capacitance parameters;

[0066] S3.2: Calculate the transmitter current based on changing the transmitter capacitance parameters. The phase;

[0067]

[0068] S3.3: Determine the transmitter current Check if the phase is 0 degrees; if so, record the corresponding capacitance parameters. If the condition is not met, return to step S3.1; otherwise, return directly to step S3.1.

[0069] S3.4: At frequency Then, repeat steps S3.1 to S3.3 until the transmitter capacitor parameter after step adjustment exceeds the set capacitor parameter range;

[0070] S3.5: At frequency Next, execute steps S3.1 to S3.4 respectively to find the transmitter current. All capacitance parameters with a phase of 0 degrees.

[0071] S4: Record all combinations of frequency and capacitance parameters that meet the conditions, forming the transmitter parameter set. ;

[0072] S5: Calculate the working efficiency of each parameter combination in the transmitter parameter set, and take the parameter combination with the highest efficiency as the system's working parameters.

[0073] In this embodiment, system efficiency for:

[0074]

[0075] in, This is the equivalent AC load resistance of the system. Indicates the real part.

[0076] S6: Simulation Verification:

[0077] like Figure 1 The circuit parameters of the five-level relay wireless power transmission system are shown in Table 1.

[0078] Table 1 Circuit Parameters of Relay Wireless Power Transfer System

[0079]

[0080] Based on the design process of steps S1 to S5, the system operating frequency when the system efficiency is maximized is calculated. Transmitter capacitor .

[0081] When this parameter is used, the system's input voltage and current waveforms are as follows: Figure 3 .Depend on Figure 3 It can be seen that the current in the first-stage loop (transmitter) of the system is in phase with the input voltage, indicating that the system has achieved zero-phase input characteristics.

[0082] When the system load increases from 40Ω to 160Ω in increments of 20Ω, the transient waveform of the system's DC output voltage is as follows: Figure 4 As shown, by Figure 4 It can be seen that the output current increases with the increase of the load, but the DC output voltage remains almost unchanged throughout the load change process, indicating that the system achieves the characteristic of constant voltage output.

[0083] In summary, this application enables the repeater wireless power transmission system to achieve constant voltage output and zero phase angle current input independent of the load simply by adjusting the transmitter parameters. This solves the problem that existing repeater wireless power supply systems require the design of compensation capacitors for each stage coil to achieve constant voltage and zero phase angle, which involves complex parameter design and high requirements for the accuracy of compensation capacitor configuration and mutual inductance measurement.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A parameter design method for a relay-type wireless power transmission system, the relay-type wireless power transmission system comprising a transmitter and a receiver, and at least one relay terminal disposed between the transmitter and the receiver, characterized in that, The specific steps of the parameter design method are as follows: S1: Dynamically adjust the parameters of the system transmitter, including the operating frequency and transmitter capacitance; S2: At the initial operating frequency Using the center frequency as the reference, search within the set frequency range for frequencies that allow the transmitter current to... and receiving end current All frequencies with a phase difference of 0 or 180 degrees ,in: , To meet the required number of frequency parameters; S3: At frequency Below, using the initial transmitter capacitance parameters Using the center capacitor parameters, find a range of capacitor parameters that allows the transmitter current to... All capacitance parameters with a phase of 0 degrees , , In frequency The number of capacitor parameters that meet the requirements; S4: Record all combinations of frequency and capacitance parameters that meet the conditions, forming the transmitter parameter set. ; S5: Calculate the working efficiency of each parameter combination in the transmitter parameter set, and take the parameter combination with the highest efficiency as the system's working parameters.

2. The parameter design method for a relay-type wireless power transmission system according to claim 1, characterized in that, The specific steps of step S2 are as follows: S2.1: At the initial operating frequency With the center frequency as the base frequency, within the set frequency range... The step size changes the system's operating frequency; S2.2: The impedance matrix of the relay wireless power transfer system Decomposed into , and ; S2.3: The emitter current is represented by the decomposed matrix. and receiving end current The phase relationship; S2.4: Determine the transmitter current and receiving end current Check if the phase difference is 0 or 180 degrees; if so, record the corresponding value. If the condition is not met, return to step S2.1; otherwise, return directly to step S2.

1. S2.5: Repeat steps S2.1 to S2.4 until the frequency after step adjustment exceeds the set frequency range, then output all frequencies that meet the requirements. .

3. The parameter design method for a relay-type wireless power transmission system according to claim 2, characterized in that, The matrix mentioned in step S2 All elements on the main diagonal are 1, and the elements in the upper half of the main diagonal are... The lower half of the main diagonal is an empty set; The matrix All elements on the main diagonal are 1, the upper half of the main diagonal is an empty set, and the lower half of the main diagonal is... ;in: For the first The coil and the first The reverse transmission coefficient between coils and .

4. The parameter design method for a relay-type wireless power transmission system according to claim 2, characterized in that, The matrix mentioned in step S2 The main diagonal elements are The main diagonal and lower half of the region are empty sets; where: For the first The total equivalent resistance generated by the stage circuit; .

5. The parameter design method for a relay-type wireless power transfer system according to claim 3, characterized in that, In step S2.3, the transmitter current and receiving end current The phase relationship is equal to ,in, For phase operation; It is an alternating series, where each term is the product of the reverse transmission coefficients between several different coils, and the positive and negative terms of the product terms alternate.

6. The parameter design method for a relay-type wireless power transfer system according to claim 1, characterized in that, The specific steps of step S3 are as follows: S3.1: At frequency Below, using the initial transmitter capacitance parameters The center capacitance parameter is used, and within the set capacitance parameter range, it is used to... The step size is used to change the transmitter capacitance parameters; S3.2: Calculate the transmitter current based on changing the transmitter capacitance parameters. The phase; S3.3: Determine the transmitter current Check if the phase is 0 degrees; if so, record the corresponding capacitance parameters. If the condition is not met, return to step S3.1; otherwise, return directly to step S3.

1. S3.4: At frequency Then, repeat steps S3.1 to S3.3 until the transmitter capacitor parameters after step adjustment exceed the set capacitor parameter range.

7. The parameter design method for a relay-type wireless power transfer system according to claim 6, characterized in that, In step S3, at frequency Next, execute steps S3.1 to S3.4 respectively to find the transmitter current. All capacitance parameters with a phase of 0 degrees.

8. The parameter design method for a relay-type wireless power transmission system according to claim 6 or 7, characterized in that, In step S3.2, the phase of the transmitter current is equal to the transmitter voltage. and the total equivalent impedance of the transmitter The phase operation value of the quotient.

9. The parameter design method for a relay-type wireless power transmission system according to claim 5, characterized in that, The working efficiency and system efficiency of parameter combinations in step S5 equal ,in, For the system's equivalent AC load, Indicates the real part.

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