Dynamic wireless charging system optimal control method based on accurate output adjustment

Abstract

A dynamic wireless charging system optimal control method based on accurate output regulation comprises the following steps: constructing an external system capable of generating an interference signal and a reference signal by using an accurate output regulation theory and aiming at the interference and constant reference voltage suffered by an energy receiving end Boost type DC-DC converter in an electric vehicle dynamic wireless charging system; therefore, a system control problem is converted into an output adjustment problem; and designing a state feedback controller based on the constructed external system and the mathematical model of the DC-DC converter, optimizing a state feedback gain parameter by means of a linear quadratic regulator (LQR), and finally obtaining an optimal state feedback controller. According to the method, the influence of large-range energy disturbance caused by movement of the electric vehicle on the system can be effectively restrained, optimal adjustment of system output can be achieved, and the method has practical engineering application prospects.

Description

Technical Field

[0001] This invention belongs to the field of control technology for dynamic wireless charging systems for electric vehicles, and specifically relates to an optimal control method for dynamic wireless charging systems based on precise output adjustment. Background Technology

[0002] Dynamic wireless charging technology offers a revolutionary solution for the continuous power supply of electric vehicles, potentially overcoming the range anxiety and battery capacity limitations of traditional charging methods. The dynamic wireless charging system utilizes a receiving coil installed on the underside of the vehicle and a transmitting coil embedded in the road surface to transfer energy non-contactly via electromagnetic induction. However, when the electric vehicle is in motion, the relative position of the vehicle and the charging track constantly changes, causing large-scale and continuous fluctuations in the mutual inductance parameters between the receiver and transmitter. These fluctuations introduce significant unknown disturbances into the DC-DC converter at the system's energy receiver, resulting in drastic changes in output voltage and seriously threatening the safe and stable operation of the load equipment.

[0003] To address the aforementioned problems, traditional control strategies (such as conventional PID control) often exhibit slow dynamic response, poor steady-state accuracy, or even instability due to their fixed parameters' inability to adapt to such a wide range of disturbances. While some advanced control methods have been proposed to enhance system robustness, these methods typically struggle to achieve a balance between disturbance suppression and optimal performance. Therefore, there is an urgent need for a control strategy capable of systematically handling a wide range of disturbances while ensuring the system reaches its optimal performance under certain performance indicators, thereby guaranteeing a continuous, stable, and efficient power supply for electric vehicles during dynamic charging. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention proposes an optimal control method for dynamic wireless charging systems based on precise output regulation. This method can effectively suppress large-scale disturbances in the system output voltage while ensuring optimal control of the dynamic and steady-state performance of the dynamic wireless charging system.

[0005] The technical solution adopted in this invention is:

[0006] An optimal control method for a dynamic wireless charging system based on precise output regulation, the specific steps of which are as follows:

[0007] Step 1: Establish the state-space model of the Boost DC-DC converter at the energy receiver end in the dynamic wireless charging system for electric vehicles;

[0008] Step 2: Based on the interference signal and constant reference voltage received by the Boost DC-DC converter, construct an external system with the aforementioned interference signal and constant reference voltage signal as the output.

[0009] Step 3: After combining the external system constructed in Step 2 with the state-space model of the Boost DC-DC converter constructed in Step 1, a controlled object model for output regulation problem is obtained.

[0010] Step 4: Based on the controlled object model constructed in Step 3, establish a state feedback controller based on the precise output regulation theory;

[0011] Step 5: Based on the linear quadratic regulator, optimize the state feedback gain parameter in Step 4 to finally obtain the optimal state feedback controller based on the precise output regulation theory and the linear quadratic regulator.

[0012] Step 6: Use the optimal state feedback controller obtained in Step 5 to control the Boost DC-DC converter at the energy receiver of the electric vehicle dynamic wireless charging system, thereby realizing the voltage regulation control of the electric vehicle dynamic wireless charging system.

[0013] Furthermore, the establishment of the state-space model of the energy receiver-side Boost-type DC-DC converter in step 1 includes:

[0014] The mathematical model formula for the energy receiver-side Boost DC-DC converter is as follows:

[0015]

[0016] in, and These are the filter inductor and output capacitor of the Boost DC-DC converter at the energy receiving end. , , , , and These represent the transient filter inductor current, transient output capacitor voltage, transient input voltage, transient output current, transient output voltage, and transient duty cycle of the Boost DC-DC converter. , and These represent the steady-state output voltage, steady-state inductor current, and steady-state duty cycle of the Boost-type DC-DC converter at the receiver of an electric vehicle at a specific location. and These are the transient output capacitor voltages of the Boost DC-DC converter. and transient inductor current The derivative with respect to time t;

[0017] By defining the state variable as The controlled variable is The control variable is The disturbance variable is The mathematical model of the aforementioned Boost-type DC-DC converter at the energy receiver end can be written as a state-space model, as shown in the following formula:

[0018]

[0019]

[0020] in, State variables The derivative, This is the system state matrix of the Boost DC-DC converter at the energy receiver. This is the control input matrix for the Boost DC-DC converter at the energy receiving end. This is the perturbation input matrix for the Boost DC-DC converter at the energy receiver. The energy receiving end is the output matrix of a Boost-type DC-DC converter.

[0021] Furthermore, the mathematical model of the external system in step 2 is as follows:

[0022]

[0023] in, It is the state variable of the external system. External system state variables The derivative, For the system matrix of the external system, The external system state variables in time The initial value at that point, , and These represent the input voltage, output current, and target reference voltage values ​​of the Boost DC-DC converter. The first output variable of the external system The parameter matrix, The second output variable of the external system The parameter matrix, The third output variable of the external system The parameter matrix, It is the initial state variable of the external system.

[0024] Furthermore, the input voltage of the Boost-type DC-DC converter at the energy receiver in step 2 is obtained as follows:

[0025] The formula for establishing the mathematical model of the mutual inductance fluctuation curve is as follows:

[0026]

[0027] in, This represents the time-varying mutual inductance between the receiving coil and the transmitting coil in a dynamic wireless charging system. Indicates time, Indicates the static mutual inductance reference value. This represents the amplitude of mutual inductance fluctuation. and All of these can be obtained using finite element analysis tools. This represents the angular frequency value related to vehicle speed and coil arrangement. This represents the initial phase angle value related to the initial position of the receiving coil;

[0028] Based on the input voltage of the energy receiver of the dynamic wireless charging system Mutual inductance value The proportional relationship, that is Input voltage of the Boost DC-DC converter at the energy receiving end The mathematical model formula is as follows:

[0029]

[0030] in, This represents the input voltage of the Boost DC-DC converter at the energy receiver end of the dynamic wireless charging system. Indicates the static input voltage reference value. This indicates the magnitude of the input voltage fluctuation.

[0031] Furthermore, the mathematical model of the controlled object in step 3, which is oriented towards output regulation, is as follows:

[0032]

[0033] in, Let be the coefficient matrix of the external variables in the state equation of the controlled object. Output the external variable coefficient matrix of the equation for the controlled object. Indicates output voltage With the target reference voltage The error between them; in particular, superscript This represents the matrix transpose symbol.

[0034] Furthermore, the formula for the state feedback controller in step 4 is as follows:

[0035]

[0036] in, This represents the output of the state feedback controller. and These are the state variable parameter matrix and the external variable parameter matrix of the state feedback controller, respectively.

[0037] Furthermore, the optimization of the optimal state feedback controller based on precise output regulation and the linear quadratic regulator in step 5 includes the following steps:

[0038] S5.1, building upon The regulator equation for solving is given by the following regulator formula:

[0039]

[0040] in, This is the matrix solution to the regulator equation;

[0041] S5.2, combining the parameter matrices A, B, and C obtained in step 1, the parameter matrix S obtained in step 2, and the parameter matrices P and Q obtained in step 3, the above regulator equation can be solved, and finally, the matrix solution of the regulator equation can be obtained. ;

[0042] S5.3, the optimal state variable parameter matrix K is designed using the linear quadratic regulator method. By solving the algebraic Riccati equation, the optimal state variable parameter matrix K is finally obtained, as shown in the following formula:

[0043]

[0044] in, To control the weight matrix, To obtain a positive definite symmetric matrix by solving the algebraic Riccati equation, the superscript... Represents the matrix transpose symbol;

[0045] S5.4, the external variable parameter matrix L of the state feedback controller is obtained, as shown in the following formula:

[0046] .

[0047] The beneficial effects of this invention are as follows: By combining precise output regulation theory with linear quadratic optimal control, this invention can not only systematically suppress large-scale coupled fluctuation disturbances caused by vehicle movement and ensure the stability and reliability of the output voltage, but also theoretically guarantee that the system achieves comprehensive optimization in key performance indicators such as dynamic response speed, overshoot and steady-state accuracy. It overcomes the inherent defects of poor adaptability of traditional PID control and the difficulty of balancing robustness and optimal performance in existing advanced control algorithms, and has important theoretical value and engineering application prospects. Attached Figure Description

[0048] Figure 1This is a schematic diagram of the optimal control of a dynamic wireless charging system for electric vehicles.

[0049] Figure 2 It is a mutual inductance fluctuation curve obtained based on finite element analysis tools;

[0050] Figure 3 This is the equivalent circuit diagram of the Boost DC-DC converter at the energy receiving end;

[0051] Figure 4 This is a diagram illustrating the static charging voltage regulation effect of the Boost DC-DC converter at the energy receiving end.

[0052] Figure 5 This is a diagram illustrating the dynamic charging and voltage regulation control effect of the Boost-type DC-DC converter at the energy receiving end. Detailed Implementation

[0053] The present invention will be further described below with reference to specific embodiments, but the invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all alternatives, improvements and equivalents that may be included within the scope of the claims.

[0054] See Figure 1 This embodiment provides an optimal control method for a dynamic wireless charging system based on precise output regulation. By designing an optimal state feedback controller to adjust the duty cycle of the Boost DC-DC converter, the stable transmission of the output voltage is achieved. The dynamic wireless charging system of this invention is based on the optimal controller design of precise output regulation and a linear quadratic regulator.

[0055] The specific steps are as follows:

[0056] Step 1: Establish the state-space model of the Boost DC-DC converter at the energy receiver end of the dynamic wireless charging system for electric vehicles; the equivalent circuit diagram of the Boost DC-DC converter at the energy receiver end of the dynamic wireless charging system is shown below. Figure 3 As shown;

[0057] The establishment of the state-space model for the energy receiver-side Boost-type DC-DC converter includes:

[0058] The mathematical model formula for the energy receiver-side Boost DC-DC converter is as follows:

[0059]

[0060] in, and These are the filter inductor and output capacitor of the Boost DC-DC converter at the energy receiving end. , , , , and These represent the transient filter inductor current, transient output capacitor voltage, transient input voltage, transient output current, transient output voltage, and transient duty cycle of the Boost DC-DC converter. , and These represent the steady-state output voltage, steady-state inductor current, and steady-state duty cycle of the Boost-type DC-DC converter at the receiver of the electric vehicle at a specific location. and These are the transient output capacitor voltages of the Boost DC-DC converter. and transient inductor current The derivative with respect to time t;

[0061] By defining the state variable as The controlled variable is The control variable is The disturbance variable is The mathematical model of the aforementioned Boost-type DC-DC converter at the energy receiver end can be written as a state-space model, as shown in the following formula:

[0062]

[0063]

[0064] in, State variables The derivative, This is the system state matrix of the Boost DC-DC converter at the energy receiver. This is the control input matrix for the Boost DC-DC converter at the energy receiving end. This is the perturbation input matrix for the Boost DC-DC converter at the energy receiver. The energy receiving end is the output matrix of a Boost-type DC-DC converter.

[0065] Step 2: Based on the interference signal and constant reference voltage received by the Boost DC-DC converter, construct an external system with the aforementioned interference signal and constant reference voltage signal as the output.

[0066] The mathematical model of the external system is as follows:

[0067]

[0068] in, It is the state variable of the external system. External system state variables The derivative, For the system matrix of the external system, The external system state variables in time The initial value at that point, , and These represent the input voltage, output current, and target reference voltage values ​​of the Boost DC-DC converter. The first output variable of the external system The parameter matrix, The second output variable of the external system The parameter matrix, The third output variable of the external system The parameter matrix, It is the initial state variable of the external system.

[0069] The input voltage of the Boost DC-DC converter at the energy receiving end The following is how to obtain it:

[0070] Mathematical modeling of the mutual inductance fluctuation curve in a dynamic wireless charging system for electric vehicles is performed using finite element analysis (FEM) tools, resulting in a mathematical model of the input voltage of the Boost-type DC-DC converter at the energy receiver. The mutual inductance fluctuation curve obtained using FEM tools is shown below. Figure 2 As shown;

[0071] The mathematical model formula for the mutual inductance fluctuation curve is as follows:

[0072]

[0073] in, This represents the time-varying mutual inductance between the receiving coil and the transmitting coil in a dynamic wireless charging system. Indicates time, Indicates the static mutual inductance reference value. This represents the amplitude of mutual inductance fluctuation. and All of these can be obtained using finite element analysis tools. This represents the angular frequency value related to vehicle speed and coil arrangement. This represents the initial phase angle value related to the initial position of the receiving coil;

[0074] Based on the input voltage of the energy receiver of the dynamic wireless charging system Mutual inductance value The proportional relationship, that is Input voltage of the Boost DC-DC converter at the energy receiving end The mathematical model formula is as follows:

[0075]

[0076] in, This represents the input voltage of the Boost DC-DC converter at the energy receiver end of the dynamic wireless charging system. Indicates the static input voltage reference value. This indicates the magnitude of the input voltage fluctuation.

[0077] Step 3: After combining the external system constructed in Step 2 with the state-space model of the Boost DC-DC converter constructed in Step 1, a controlled object model for output regulation problem is obtained.

[0078] The mathematical model of the controlled object in the output regulation problem is as follows:

[0079]

[0080] in, Let be the coefficient matrix of the external variables in the state equation of the controlled object. Output the external variable coefficient matrix of the equation for the controlled object. Indicates output voltage With the target reference voltage The error between them; in particular, superscript This represents the matrix transpose symbol.

[0081] Step 4: Based on the controlled object model constructed in Step 3, establish a state feedback controller based on the precise output regulation theory;

[0082] The formula for the state feedback controller is as follows:

[0083]

[0084] in, This represents the output of the state feedback controller. and These are the state variable parameter matrix and the external variable parameter matrix of the state feedback controller, respectively.

[0085] Step 5: Based on the linear quadratic regulator, optimize the state feedback gain parameter in Step 4 to finally obtain the optimal state feedback controller based on the precise output regulation theory and the linear quadratic regulator.

[0086] The optimization of the optimal state feedback controller based on precise output regulation and a linear quadratic regulator includes the following steps:

[0087] S5.1, building upon The regulator equation for solving is given by the following regulator formula:

[0088]

[0089] in, This is the matrix solution to the regulator equation;

[0090] S5.2, combining the parameter matrices A, B, and C obtained in step 1, the parameter matrix S obtained in step 2, and the parameter matrices P and Q obtained in step 3, the above regulator equation can be solved, and finally, the matrix solution of the regulator equation can be obtained. ;

[0091] S5.3, the optimal state variable parameter matrix K is designed using the linear quadratic regulator method. By solving the algebraic Riccati equation, the optimal state variable parameter matrix K is finally obtained, as shown in the following formula:

[0092]

[0093] in, To control the weight matrix, To obtain a positive definite symmetric matrix by solving the algebraic Riccati equation, the superscript... Represents the matrix transpose symbol;

[0094] S5.4, the external variable parameter matrix L of the state feedback controller is obtained, as shown in the following formula:

[0095] .

[0096] Step 6: Use the optimal state feedback controller obtained in Step 5 to control the Boost DC-DC converter at the energy receiver of the electric vehicle dynamic wireless charging system, thereby realizing the voltage regulation control of the electric vehicle dynamic wireless charging system.

[0097] This invention utilizes precise output regulation theory to construct an external system that generates the aforementioned interference signals and reference signals for the Boost-type DC-DC converter at the energy receiver in a dynamic wireless charging system for electric vehicles. This transforms the system control problem into an output regulation problem. Secondly, based on the constructed external system and the mathematical model of the DC-DC converter, a state feedback controller is designed, and the state feedback gain parameters are optimized using a linear quadratic regulator (LQR) to obtain the optimal state feedback controller. This invention not only effectively suppresses the impact of large-scale energy disturbances caused by the movement of electric vehicles on the system but also achieves optimal regulation of the system output, demonstrating promising practical engineering applications.

[0098] The control parameters of the optimal state feedback controller based on precise output regulation that can be obtained in this embodiment are as follows:

[0099]

[0100] The static charging voltage regulation effect of the optimal state feedback controller is as follows: Figure 4 As shown, the system is in the static charging phase. When time t=0.1s, the target reference voltage is... When the voltage jumps from 100V to 125V, the output voltage of the proposed optimal state feedback controller can quickly stabilize at the target reference voltage.

[0101] The dynamic charging voltage regulation control effect of the optimal state feedback controller is as follows: Figure 5 As shown, the system is in the dynamic charging phase. When time t=0.1s, the target reference voltage is... When the voltage jumps from 100V to 125V, the output voltage of the proposed optimal state feedback controller can quickly track the target reference voltage.

[0102] Finally, it should be noted that the above embodiments and descriptions are only used to illustrate the technical solutions of the present invention and not to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the disclosure of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the protection scope of the claims of the present invention.

Claims

1. An optimal control method for a dynamic wireless charging system based on precise output regulation, the specific steps of which are as follows: Step 1: Establish the state-space model of the Boost DC-DC converter at the energy receiver end in the dynamic wireless charging system for electric vehicles; Step 2: Based on the interference signal and constant reference voltage received by the Boost DC-DC converter, construct an external system with the aforementioned interference signal and constant reference voltage signal as the output. Step 3: After combining the external system constructed in Step 2 with the state-space model of the Boost DC-DC converter constructed in Step 1, a controlled object model for output regulation problem is obtained. Step 4: Based on the controlled object model constructed in Step 3, establish a state feedback controller based on the precise output regulation theory; Step 5: Based on the linear quadratic regulator, optimize the state feedback gain parameter in Step 4 to finally obtain the optimal state feedback controller based on the precise output regulation theory and the linear quadratic regulator. Step 6: Use the optimal state feedback controller obtained in Step 5 to control the Boost DC-DC converter at the energy receiver of the electric vehicle dynamic wireless charging system, thereby realizing the voltage regulation control of the electric vehicle dynamic wireless charging system.

2. The optimal control method for a dynamic wireless charging system based on precise output regulation according to claim 1, characterized in that: The establishment of the state-space model of the energy receiver Boost DC-DC converter in step 1 includes: The mathematical model formula for the energy receiver-side Boost DC-DC converter is as follows: in, and These are the filter inductor and output capacitor of the Boost DC-DC converter at the energy receiving end. , , , , and These represent the transient filter inductor current, transient output capacitor voltage, transient input voltage, transient output current, transient output voltage, and transient duty cycle of the Boost DC-DC converter. , and These represent the steady-state output voltage, steady-state inductor current, and steady-state duty cycle of the Boost-type DC-DC converter at the receiver of an electric vehicle at a specific location. and These are the transient output capacitor voltages of the Boost DC-DC converter. and transient inductor current The derivative with respect to time t; By defining the state variable as The controlled variable is The control variable is The disturbance variable is The mathematical model of the aforementioned Boost-type DC-DC converter at the energy receiver end can be written as a state-space model, as shown in the following formula: in, State variables The derivative, This is the system state matrix of the Boost DC-DC converter at the energy receiver. This is the control input matrix for the Boost DC-DC converter at the energy receiving end. This is the perturbation input matrix for the Boost DC-DC converter at the energy receiver. The energy receiving end is the output matrix of a Boost-type DC-DC converter.

3. The optimal control method for a dynamic wireless charging system based on precise output regulation according to claim 2, characterized in that: The mathematical model of the external system in step 2 is as follows: in, It is the state variable of the external system. External system state variables The derivative, For the system matrix of the external system, The external system state variables in time The initial value at that location, , and These represent the input voltage, output current, and target reference voltage values ​​of the Boost DC-DC converter. The first output variable of the external system The parameter matrix, The second output variable of the external system The parameter matrix, The third output variable of the external system The parameter matrix, It is the initial state variable of the external system.

4. The optimal control method for a dynamic wireless charging system based on precise output regulation according to claim 3, characterized in that: The input voltage of the Boost DC-DC converter at the energy receiver in step 2 The following is how to obtain it: The formula for establishing the mathematical model of the mutual inductance fluctuation curve is as follows: in, This represents the time-varying mutual inductance between the receiving coil and the transmitting coil in a dynamic wireless charging system. Indicates time, Indicates the static mutual inductance reference value. This represents the amplitude of mutual inductance fluctuation. and All of these can be obtained using finite element analysis tools. This represents the angular frequency value related to vehicle speed and coil arrangement. This represents the initial phase angle value related to the initial position of the receiving coil; Based on the input voltage of the energy receiver of the dynamic wireless charging system Mutual inductance value The proportional relationship, that is Input voltage of the Boost DC-DC converter at the energy receiving end The mathematical model formula is as follows: in, This represents the input voltage of the Boost DC-DC converter at the energy receiver end of the dynamic wireless charging system. Indicates the static input voltage reference value. This indicates the magnitude of the input voltage fluctuation.

5. The optimal control method for a dynamic wireless charging system based on precise output regulation according to claim 4, characterized in that: The mathematical model of the controlled object in step 3, which is the output-oriented regulation problem, is as follows: in, Let be the coefficient matrix of the external variables in the state equation of the controlled object. Output the external variable coefficient matrix of the equation for the controlled object. Indicates output voltage With the target reference voltage The error between them; in particular, superscript This represents the matrix transpose symbol.

6. The optimal control method for a dynamic wireless charging system based on precise output regulation according to claim 5, characterized in that: The formula for the state feedback controller in step 4 is as follows: in, This represents the output of the state feedback controller. and These are the state variable parameter matrix and the external variable parameter matrix of the state feedback controller, respectively.

7. The optimal control method for a dynamic wireless charging system based on precise output regulation according to claim 6, characterized in that: Step 5, the optimization of the optimal state feedback controller based on precise output regulation and a linear quadratic regulator, includes the following steps: S5.1, building upon The regulator equation for solving is given by the following regulator formula: in, This is the matrix solution to the regulator equation; S5.2, combining the parameter matrices A, B, and C obtained in step 1, the parameter matrix S obtained in step 2, and the parameter matrices P and Q obtained in step 3, the above regulator equation can be solved, and finally, the matrix solution of the regulator equation can be obtained. ; S5.3, the optimal state variable parameter matrix K is designed using the linear quadratic regulator method. By solving the algebraic Riccati equation, the optimal state variable parameter matrix K is finally obtained, as shown in the following formula: in, To control the weight matrix, To obtain a positive definite symmetric matrix by solving the algebraic Riccati equation, the superscript... Represents the matrix transpose symbol; S5.4, the external variable parameter matrix L of the state feedback controller is obtained, as shown in the following formula: 。

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