Output voltage control method for dynamic wireless charging system of electric vehicle

Abstract

The invention discloses an output voltage control method for a dynamic wireless charging system of an electric vehicle. A DC-DC circuit of an energy transmission transmitting end is designed, a linear active-disturbance-rejection controller and a hybrid controller are introduced, the linear active-disturbance-rejection controller observes state variables of the DC-DC circuit and estimated values of disturbance through an extended state observer, a linear state feedback control law forms a first control quantity, a disturbance compensation link outputs a second control quantity, and the DC-DC circuit is connected with the hybrid controller. The constant input voltage of the full-bridge inverter circuit is ensured; the hybrid controller outputs the switching frequency and the phase shift angle to adjust the stability of the load output voltage and the wide adjustment range of the system voltage gain. According to the method, the constant-voltage regulation performance and the anti-interference performance of the system are remarkably improved, meanwhile, the implementation cost of adjusting system elements is reduced, the stability and robustness of the system are further enhanced, and an effective solution is provided for stable operation of the dynamic wireless charging system of the electric vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of dynamic wireless charging and relates to a dynamic wireless charging control method for an electric vehicle, and in particular to an output voltage control method and system for a dynamic wireless charging system for an electric vehicle. Background Art

[0002] The battery life of electric vehicles and the convenience of charging have always been the primary factors restricting their large-scale promotion. As a new charging method, dynamic wireless power transmission (DWPT) technology can achieve uninterrupted power replenishment during the driving of electric vehicles without direct plugging and unplugging, effectively alleviating the battery life anxiety of electric vehicles and improving the convenience of charging.

[0003] DWPT technology achieves power transmission of electrical equipment during movement by laying energy transmission transmitting devices along the moving line of energy transmission receiving devices. However, in actual working conditions, dynamic wireless charging systems face many challenges, such as position offset between the energy transmission transmitting end and the receiving end, load resistance changes, etc., or the need to ensure the stability of the system output voltage and high transmission efficiency in scenarios where the system voltage gain changes. The above factors will cause the system output voltage to be unstable, affecting the charging efficiency and charging quality of the system. Therefore, studying a dynamic wireless charging system with a constant voltage output characteristic that is resistant to load and voltage gain offset is of great significance for improving the endurance and user experience of electric vehicles.

[0004] For example, the Chinese patent document with publication number CN118971402A discloses a dual-frequency dynamic wireless charging system and a wireless charging method. First, the two adjacent transmitting coils at the transmitting end are configured with different resonant frequencies. Secondly, the receiving end is provided with two resonant frequency points through a clever topological design, corresponding to the two resonant frequencies of the transmitting end, so that any transmitting channel is in a high-impedance state to the coupled magnetic field of its adjacent transmitting channel, avoiding mutual crosstalk between the transmitting coils and improving the transmission efficiency of the system. However, when there is a jump interference in the system input voltage or load impedance, constant voltage or constant current output cannot be guaranteed.

[0005] At present, the dynamic wireless charging system has limited ability to quickly respond to various disturbance changes during vehicle driving, such as speed changes, lateral offsets, changes in system input voltage and load, etc., resulting in the system response speed may not be able to meet this demand, causing the charging power to fluctuate and become unstable. Some constant voltage control algorithms (such as PI control, etc.) cannot achieve precise control of the charging voltage, affecting the control accuracy of the equipment. At the same time, the dynamic wireless charging system requires the use of high-precision sensors, controllers, and actuators, so frequent replacement of hardware facilities increases the system cost, so it is more meaningful to study a faster and more effective control method. Summary of the invention

[0006] The purpose of the present invention is to overcome the problems existing in the prior art and provide a method for controlling the output voltage of a dynamic wireless charging system for electric vehicles. The present invention enhances the rapidity and stability of system control by introducing a linear anti-disturbance controller (LADRC), a frequency conversion controller and a phase shift controller at the energy transmission transmitting end, and at the same time utilizes a multi-transmitter-single-receiver magnetic coupling mechanism design and an LCC-S resonant conversion network to solve the output voltage fluctuation problem caused by the segmented transmitting device. The present invention significantly improves the constant voltage regulation performance and anti-interference performance of the system, while also reducing the implementation cost of adjusting system components, and further enhancing the stability and robustness of the system. The present invention improves the constant voltage output performance of ordinary wireless charging systems, provides an effective solution for the stable operation of dynamic wireless charging systems for electric vehicles, and has a great impact on the field of dynamic wireless charging technology.

[0007] The specific technical solutions adopted by the present invention are as follows:

[0008] 1. A method for controlling output voltage of a dynamic wireless charging system for electric vehicles

[0009] A DC-DC circuit is added between the full-bridge inverter circuit and the DC power supply of the electric vehicle dynamic wireless charging system. The electric vehicle dynamic wireless charging system is connected to the power grid. The LADRC controller controls the DC-DC circuit according to the system input voltage, thereby stably controlling the input voltage of the full-bridge inverter circuit.

[0010] The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage.

[0011] The DC-DC circuit is a Boost chopper circuit.

[0012] The LADRC controller includes a linear extended state observer and a linear state feedback control law. The linear state feedback control law converts the full-bridge inverter circuit input voltage reference value U d ' cref The full-bridge inverter circuit input voltage U output by the linear extended state observer d ' c The difference between the estimated value z1 and the control value u0 is used as the feedback control quantity and the first control quantity u0 is output;

[0013] According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the first control quantity u0 is subjected to disturbance compensation to obtain the second control quantity u, and the PWM drive signal of the switch tube in the DC-DC circuit is generated according to the second control quantity u to control the DC-DC circuit; the linear extended state observer obtains the actual input voltage U of the full-bridge inverter circuit according to the product of the second control quantity u and the control gain b of the full-bridge inverter circuit d ' c Estimate the system state of the DC-DC circuit and observe the disturbance, thereby outputting the full-bridge inverter circuit input voltage U d ' c The estimated value z1 of and the estimated value z2 of the total disturbance f are as follows:

[0014]

[0015] in, The input voltage U is the full-bridge inverter circuit d ' c The differential of the estimated value z1, is the differential of the estimated value z2 of the total disturbance f; β1, β2 are the two control coefficients of the linear extended state observer.

[0016] According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the second control quantity u is obtained after the first control quantity u0 is subjected to disturbance compensation, which specifically satisfies the following formula:

[0017]

[0018] The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage, specifically including:

[0019] First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the first PI controller is based on the voltage error U error Calculate the phase shift angle D; then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s ; According to the phase shift angle D and switching frequency f s Generate PWM drive signal for the corresponding switch tube, so as to stabilize the output voltage of the control system.

[0020] The control method further comprises:

[0021] The four parallel pairs of diodes and capacitors in the rectifier circuit in the wireless charging system are replaced with four controllable MOSFET switch tubes, and the second single hybrid controller is used to perform frequency conversion and phase shift control on the four controllable MOSFET switch tubes in the rectifier circuit according to the system output voltage, thereby stabilizing the system output voltage.

[0022] The second single hybrid controller is used to perform frequency conversion and phase shift control on four controllable MOSFET switches of the rectifier circuit according to the system output voltage, so as to stabilize the system output voltage, specifically including:

[0023] First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the second PI controller is based on the voltage error U error Calculate the phase shift angle D; then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s ; According to the phase shift angle D and switching frequency f s Generate PWM drive signal for the corresponding switch tube, so as to stabilize the output voltage of the control system.

[0024] 2. An output voltage control device for a dynamic wireless charging system of an electric vehicle

[0025] A DC-DC circuit is added between the full-bridge inverter circuit and the DC power supply of the dynamic wireless charging system for electric vehicles, and the dynamic wireless charging system for electric vehicles is connected to the power grid;

[0026] The LADRC controller is used to control the DC-DC circuit according to the system input voltage, thereby stabilizing the input voltage of the full-bridge inverter circuit;

[0027] The first single hybrid controller is used to perform frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, so as to stabilize the system output voltage.

[0028] 3. An output voltage control device for a dynamic wireless charging system of an electric vehicle

[0029] A DC-DC circuit is added between the full-bridge inverter circuit and the DC power supply of the dynamic wireless charging system of the electric vehicle, and the dynamic wireless charging system of the electric vehicle is connected to the power grid; and the four parallel pairs of diodes and capacitors in the rectifier circuit of the wireless charging system are replaced with four controllable MOSFET switch tubes;

[0030] The LADRC controller is used to control the DC-DC circuit according to the system input voltage, thereby stabilizing the input voltage of the full-bridge inverter circuit;

[0031] The first single hybrid controller is used to perform frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, so as to stabilize the system output voltage.

[0032] The second single hybrid controller is used to perform frequency conversion and phase shift control on four controllable MOSFET switch tubes of the rectifier circuit according to the system output voltage, so as to stabilize the system output voltage.

[0033] Compared with the prior art, the present invention brings the following beneficial effects:

[0034] The present invention determines the topology of constant voltage characteristics by introducing an LCC-S resonant conversion network. Secondly, the LADRC controller is introduced to adjust the input voltage of the full-bridge inverter circuit to maintain constant voltage when the input voltage jumps; a hybrid controller (including variable frequency control and phase shift control) is introduced to adjust the switching frequency and phase shift angle of the full-bridge inverter circuit at the energy transmission transmitting end to achieve the stability of load output voltage adjustment and wide range adjustment of system voltage gain, thereby improving the constant voltage regulation performance and anti-interference performance of the system, while also reducing the implementation cost of adjusting system components, and further enhancing the stability and robustness of the system.

[0035] Furthermore, when the DC input voltage of the dynamic wireless charging system for electric vehicles in the present invention undergoes a step increase or step decrease (similarly), the load output voltage can be quickly brought to an ideal voltage drop, thereby satisfying the rapidity of wireless power transmission.

[0036] Furthermore, the electric vehicle dynamic wireless charging system of the present invention can stably achieve constant voltage control and wide range variation of voltage gain under the LADRC controller combined with the hybrid controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a topology diagram of LADRC control combined with single hybrid control of the electric vehicle dynamic wireless charging system of the present invention;

[0038] Figure 2 This is a topology diagram of LADRC control combined with dual hybrid control of the electric vehicle dynamic wireless charging system of the present invention;

[0039] Figure 3 This is a simplified model diagram of the LCC resonant converter of the electric vehicle dynamic wireless charging system of the present invention;

[0040] Figure 4 This is a flowchart of the LADRC controller of the electric vehicle dynamic wireless charging system of the present invention;

[0041] Figure 5 is a relationship diagram between load output voltage and frequency ratio under different phase shift angles of the present invention;

[0042] Figure 6 It is a response effect diagram of DC input voltage and load output voltage when single hybrid, dual hybrid, LADRC control combined with single hybrid, and LADRC control combined with dual hybrid control of the present invention;

[0043] Figure 7 This is a diagram showing the voltage gain response effect of the system when single hybrid, dual hybrid, LADRC control combined with single hybrid, and LADRC control combined with dual hybrid control are used in the present invention. DETAILED DESCRIPTION

[0044] The present invention is further elaborated and illustrated below in conjunction with the accompanying drawings. It should be noted that the following embodiments are only used to help understand the present invention, and the resonant conversion network can be combined accordingly without conflict. The dynamic wireless charging system includes a power supply, a DC-DC circuit, an energy transmission transmitting device (including a high-frequency inverter circuit, an LCC resonant conversion network, and an energy transmitting coil), an energy transmission receiving device (including an energy receiving coil, an S resonant conversion network, a rectifier circuit, and a control circuit) and a load impedance.

[0045] Example 1

[0046] The present invention proposes a method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle, the control method comprising:

[0047] like Figure 1 As shown, a dynamic wireless charging system for electric vehicles is constructed, an LCC-S resonant conversion network is introduced, and a topology with constant voltage characteristics is determined. A DC-DC circuit is added between the full-bridge inverter circuit (DWCS) and the DC power supply, and the DC-DC circuit is a Boost boost chopper circuit. The dynamic wireless charging system for electric vehicles is connected to the power grid, and the LADRC controller controls the DC-DC circuit according to the system input voltage, that is, stably controls the output voltage of the DC-DC circuit, thereby stably controlling the input voltage of the full-bridge inverter circuit;

[0048] Among them, the mesh current matrix equation of the simplified circuit model of the dynamic wireless charging system topology based on the LCC-S resonant conversion network is as follows:

[0049]

[0050] Among them, ω is the system operating angular frequency, M is the mutual inductance of the two resonant inductors, L p and L s is the resonant inductance between the energy transmission transmitting end and the energy transmission receiving end, C p and C s is the resonant capacitance between the energy transmission transmitting end and the energy transmission receiving end, L c1 is the compensation inductance at the energy transmission transmitting end, Ip and I s is the resonant inductor current between the energy transmission transmitting end and the energy transmission receiving end, I c1 is the compensation inductor current at the energy transfer transmitting end, U ab is the input current of the energy transmission transmitter, U cd is the output current of the energy transmission receiving device, R eq is the system load impedance.

[0051] like Figure 4 As shown, the LADRC controller includes a linear extended state observer (LESO) and a linear state feedback control law (LSEF). The linear state feedback control law converts the full-bridge inverter circuit input voltage reference value U d ' cref The full-bridge inverter circuit input voltage U output by the linear extended state observer d ' c The difference between the estimated value z1 and the control value u0 is used as the feedback control quantity and the first control quantity u0 is output. The control quantity u0 formed by the linear proportional controller LESF can be expressed as:

[0052] u0=k p (U d ' cref -z1)

[0053] In the above formula, k p represents the proportional coefficient of the proportional controller, U d ' cref Represents the input voltage reference value of the full-bridge inverter circuit.

[0054] According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the first control quantity u0 is subjected to disturbance compensation to obtain the second control quantity u, and the PWM drive signal of the switch tube in the DC-DC circuit is generated according to the second control quantity u to control the DC-DC circuit;

[0055] The linear extended state observer is based on the product of the second control quantity u and the control gain b of the full-bridge inverter circuit, the actual input voltage U d ' c (i.e., the output voltage of the DC-DC circuit) estimates the system state of the DC-DC circuit and observes the disturbance, thereby outputting the input voltage U of the full-bridge inverter circuit d ' c The estimated value z1 of and the estimated value z2 of the total disturbance f are as follows:

[0056]

[0057] in, The input voltage U is the full-bridge inverter circuit d' c The differential of the estimated value z1, is the differential of the estimated value z2 of the total disturbance f; β1 and β2 are the two control coefficients of the linear extended state observer, both of which are adjustable parameters.

[0058] According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the second control quantity u is obtained after the first control quantity u0 is subjected to disturbance compensation, which specifically satisfies the following formula:

[0059]

[0060] The LADRC controller converts the uncertainty of the system (including external disturbances and internal disturbances) into an observable state, estimates the state information of these disturbances in real time through the linear extended state observer (LESO), and compensates in real time using the linear state feedback control law (LSEF), so that when the DC-DC circuit module faces complex disturbances and nonlinear characteristics, the LADRC can also achieve stable control of the input voltage of the full-bridge inverter circuit.

[0061] Among them, the linear extended state observer (LESO) expands the total disturbance into a new state variable of the system and estimates it, and on this basis further completes the system's feedback control and disturbance compensation operations. In LADRC, the ESO can be converted into a linear extended state observer (LESO) by linearizing a nonlinear function with complex parameters, and its parameters are linked to the observer bandwidth, which can also play the role of estimating the system state and observing disturbances.

[0062] The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage.

[0063] The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage, specifically including:

[0064] First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the first PI controller is based on the voltage error U error The phase shift angle D is calculated; the proportional coefficient of the first PI controller is set to 0.001, and the integral coefficient is set to 0.8. Then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s , the phase shift angle D and the switching frequency f s Loaded into the phase shift register and the period register respectively; according to the phase shift angle D and the switching frequency f sGenerate a PWM drive signal for the corresponding switch tube to stabilize the output voltage of the control system, that is, a single hybrid control method. When the input voltage jumps, the load output voltage has an overshoot value and then tends to be constant.

[0065] like Figure 3 As shown, only the LCC resonant converter in the resonant conversion network is considered. ab is the equivalent input voltage of the LCC resonant converter, nU sec is the equivalent output voltage of the LCC resonant converter, R ac is the equivalent resistance.

[0066] When the controller adopts variable frequency control and phase shift control, the switching frequency and phase shift angle of the high-frequency inverter circuit jointly affect the voltage gain of the dynamic wireless charging system. Indicates the magnitude of the phase shift angle, where T on Represents half a switching cycle The time when the diagonal MOSFET switches are turned on simultaneously. Assuming the system voltage gain The output voltage U of the energy transmission receiving end out The energy transmission transmitting end input voltage U dc According to the fundamental component approximation method and Fourier series expansion, the effective value of the fundamental component of the input signal of the LCC-S resonant conversion network under variable frequency control and phase shift control can be obtained: Similarly, the output voltage U at the receiving end of energy transmission cd The effective value of the fundamental component under frequency conversion control and phase shift control Then the voltage U on the transformer at the energy transmission transmitting end is sec for:

[0067]

[0068] Then the following formula is derived:

[0069]

[0070] The AC equivalent resistance before the rectifier circuit Under frequency conversion control and phase shift control, it is converted to the AC equivalent resistance R of the LCC resonant converter ac for Where R L is the system load impedance. And the system voltage gain is Therefore, the transfer function of the system voltage gain G(jω) can be obtained. s ):

[0071]

[0072] Among them, ω sis the switching angular frequency. The formula derived from the resonant angular frequency is: ω0 is the resonant angular frequency. Substituting the above formula into the transfer function of the system voltage gain G(jω s ), then we have the following formula:

[0073]

[0074] definition is the ratio of the resonant capacitance to the compensation capacitance, is the quality factor of the resonant circuit, then the combined quality factor formula is The following formula is obtained:

[0075]

[0076] Therefore, the system voltage gain transfer function G(jω s ) can be simplified to the following formula:

[0077]

[0078] definition is the ratio of the switching frequency to the resonant frequency, where f s is the switching frequency, f0 is the resonant frequency, ω s is the switching angular frequency, and ω0 is the resonant angular frequency. Figure 3 Topologically write the mesh current equation and get the following formula:

[0079]

[0080] According to the formula The resonant frequency derivation formula and formula (8) give the system voltage gain and output voltage formula under the hybrid controller, which are:

[0081]

[0082] The hybrid controller adjusts the switching frequency and phase shift angle of the full-bridge inverter circuit at the energy transmission transmitter to adjust the stability of the load output voltage and the wide range of voltage gain. Among them, G is the system voltage gain, U out is the load output voltage, n is the linear transformer coil winding ratio, U dc is the system DC input voltage, Q is the quality factor of the resonant circuit, λ=C p / C c1 is the ratio of the resonant capacitance to the compensation capacitance, C c1 is the compensation capacitor at the transmitting end of energy transfer, f N is the switching frequency f s With the resonant frequency f r ratio, D is the size of the phase shift angle, Io is the current flowing through the system load impedance.

[0083] Let λ=4,Q=0.4,n=1, and plot to get 0<f N <1 and 1<f N <2, the system output voltage U under the hybrid control method out Curves, such as Figure 5 As shown. When the ratio of resonant capacitor to compensation capacitor λ, quality factor Q, linear transformer coil winding ratio n, and the ratio of switching frequency to resonant frequency f are maintained N Certainly, under the hybrid control method, the load output voltage can be adjusted by adjusting the phase shift angle D. According to the above analysis, for single frequency conversion control or phase shift control, the hybrid control method is more flexible in adjusting the load output voltage.

[0084] Example 2

[0085] The present invention proposes a method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle, the control method comprising:

[0086] like Figure 1 As shown, a dynamic wireless charging system for electric vehicles is constructed, an LCC-S resonant conversion network is introduced, and a topology with constant voltage characteristics is determined. A DC-DC circuit is added between the full-bridge inverter circuit (DWCS) and the DC power supply, and the DC-DC circuit is a Boost boost chopper circuit. The dynamic wireless charging system for electric vehicles is connected to the power grid, and the LADRC controller controls the DC-DC circuit according to the system input voltage, that is, stably controls the output voltage of the DC-DC circuit, thereby stably controlling the input voltage of the full-bridge inverter circuit;

[0087] like Figure 4 As shown, the LADRC controller includes a linear extended state observer (LESO) and a linear state feedback control law (LSEF). The linear state feedback control law converts the full-bridge inverter circuit input voltage reference value U d ' cref The full-bridge inverter circuit input voltage U output by the linear extended state observer d ' c The difference between the estimated value z1 and the control value u0 is used as the feedback control quantity and the first control quantity u0 is output. The control quantity u0 formed by the linear proportional controller LESF can be expressed as:

[0088] u0=k p (U d ' cref -z1)

[0089] In the above formula, k p represents the proportional coefficient of the proportional controller, U d ' crefRepresents the input voltage reference value of the full-bridge inverter circuit.

[0090] According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the first control quantity u0 is subjected to disturbance compensation to obtain the second control quantity u, and the PWM drive signal of the switch tube in the DC-DC circuit is generated according to the second control quantity u to control the DC-DC circuit;

[0091] The linear extended state observer is based on the product of the second control quantity u and the control gain b of the full-bridge inverter circuit, the actual input voltage U d ' c (i.e., the output voltage of the DC-DC circuit) estimates the system state of the DC-DC circuit and observes the disturbance, thereby outputting the input voltage U of the full-bridge inverter circuit d ' c The estimated value z1 of and the estimated value z2 of the total disturbance f are as follows:

[0092]

[0093] in, The input voltage U is the full-bridge inverter circuit d ' c The differential of the estimated value z1, is the differential of the estimated value z2 of the total disturbance f; β1 and β2 are the two control coefficients of the linear extended state observer, both of which are adjustable parameters.

[0094] According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the second control quantity u is obtained after the first control quantity u0 is subjected to disturbance compensation, which specifically satisfies the following formula:

[0095]

[0096] The LADRC controller converts the uncertainty of the system (including external disturbances and internal disturbances) into an observable state, estimates the state information of these disturbances in real time through the linear extended state observer (LESO), and compensates in real time using the linear state feedback control law (LSEF), so that when the DC-DC circuit module faces complex disturbances and nonlinear characteristics, the LADRC can also achieve stable control of the input voltage of the full-bridge inverter circuit.

[0097] Among them, the linear extended state observer (LESO) expands the total disturbance into a new state variable of the system and estimates it, and on this basis further completes the system's feedback control and disturbance compensation operations. In LADRC, the ESO can be converted into a linear extended state observer (LESO) by linearizing a nonlinear function with complex parameters, and its parameters are linked to the observer bandwidth, which can also play the role of estimating the system state and observing disturbances.

[0098] The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage.

[0099] The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage, specifically including:

[0100] First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the first PI controller is based on the voltage error U error The phase shift angle D is calculated; the proportional coefficient of the first PI controller is set to 0.001, and the integral coefficient is set to 0.8. Then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s , the phase shift angle D and the switching frequency f s Loaded into the phase shift register and the period register respectively; according to the phase shift angle D and the switching frequency f s Generate a PWM drive signal for the corresponding switch tube to stabilize the output voltage of the control system, that is, a single hybrid control method. When the input voltage jumps, the load output voltage has an overshoot value and then tends to be constant.

[0101] like Figure 2 As shown, the four parallel pairs of diodes and capacitors in the rectifier circuit in the wireless charging system are replaced with four controllable MOSFET switches, and the second single hybrid controller is used to perform frequency conversion and phase shift control on the four controllable MOSFET switches in the rectifier circuit according to the system output voltage, thereby stabilizing the system output voltage.

[0102] The second single hybrid controller is used to perform frequency conversion and phase shift control on four controllable MOSFET switches of the rectifier circuit according to the system output voltage, so as to stabilize the system output voltage, specifically including:

[0103] First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the second PI controller is based on the voltage error U errorThe phase shift angle D is calculated; the proportional coefficient of the second PI controller is set to 0.001, and the integral coefficient is set to 0.8. Then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s , the phase shift angle D and the switching frequency f s Loaded into the phase shift register and the period register respectively; according to the phase shift angle D and the switching frequency f s Generate a PWM drive signal for the corresponding switch tube, thereby stabilizing the output voltage of the control system. When the input voltage jumps stepwise, the load output voltage gradually tends to be constant after fluctuations. In this way, there is hybrid control at both the front and back ends of the dynamic wireless charging system, that is, a dual hybrid control method.

[0104] The present invention introduces LADRC controller and hybrid controller, wherein the hybrid controller (including frequency conversion control and phase shift control) adjusts the driving signal of the DC-DC circuit switch tube at the energy transmission transmitting end, so that the input voltage of the full-bridge inverter circuit remains constant when the DC input voltage jumps stepwise; and adjusts the switching frequency and phase shift angle of the full-bridge inverter circuit to achieve the stability of the load output voltage and the wide range adjustment of the system voltage gain. Finally, the stability and simulation experimental analysis are used to verify and observe the effective performance of the method.

[0105] The simulation results are shown in Figure 6 , Figure 7 middle, Figure 6 (a) shows the response effect diagram of DC input voltage and load output voltage under single hybrid control. When the ideal output voltage is 100V and a step impulse occurs at 25ms, the load output voltage first slowly rises to the ideal value before the step point, and there is a large overshoot value at the step point. After reaching the overshoot peak, it slowly drops to and remains at the ideal value. At the same time, Figure 6 (b) is the response effect diagram of DC input voltage and load output voltage under dual hybrid control. Under dual hybrid control, the load output voltage has a spike before the step point, and then slowly rises to 100 volts. There is also a large overshoot value at the step point. After reaching the overshoot peak, it oscillates and fluctuates down to and remains at the ideal value. Compared with the uncontrolled method, the dynamic wireless charging system under single hybrid control and the dynamic wireless charging system under dual hybrid control have general constant voltage regulation performance, higher overshoot, longer regulation time, and the overshoot under single hybrid control is slightly higher than that under dual hybrid control. Figure 6 (c) is the response effect diagram of DC input voltage and load output voltage when LADRC controller is combined with single hybrid control. The adjustment time of load output voltage before the step point is shorter than that of single hybrid control. At the same time, there is a very small fluctuation (negligible) after the step point, and then it drops rapidly to and remains at the ideal value. Figure 6(d) is the response effect diagram of DC input voltage and load output voltage when LADRC controller is combined with dual hybrid control. The load output voltage has a spike before the step point, and then slowly rises to 100 volts, but an oscillation wave appears again until the step point. There is also a slightly larger overshoot value. After reaching the overshoot peak, it oscillates and fluctuates down to and remains at the ideal value, and the adjustment time is lower than that of a single dual hybrid control method. Compared with traditional PI control (single phase shift control, single frequency conversion control, hybrid control), the system output voltage control performance is the best when LADRC controller is combined with a single hybrid controller, and the system output voltage control performance is poor when single hybrid control and dual hybrid control methods are used.

[0106] Figure 7 (a) and Figure 7 (b) shows the effect diagram of system voltage gain under single hybrid control and dual hybrid control. It can be observed that under hybrid control, the system voltage gain can be controlled in the range of greater than 1 and less than 1, with a wide adjustment range. Figure 7 (c) and Figure 7 (d) presents the LADRC controller combined with single hybrid control and dual hybrid control respectively. It can be observed that the voltage gain fluctuation value after the step jump point is lower than that of the single hybrid control and dual hybrid control methods. These simulation results strongly support the performance effectiveness and stability of the present invention, and further prove the application potential of the proposed LADRC controller combined with a single hybrid controller in the dynamic wireless charging system of electric vehicles.

[0107] Finally, it should be noted that the above embodiments and explanations are only used to illustrate the technical solution of the present invention rather than to limit it. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope disclosed in the technical solution of the present invention, which should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle, characterized in that: include: A DC-DC circuit is added between the full-bridge inverter circuit and the DC power supply of the electric vehicle dynamic wireless charging system. The electric vehicle dynamic wireless charging system is connected to the power grid. The LADRC controller controls the DC-DC circuit according to the system input voltage, thereby stably controlling the input voltage of the full-bridge inverter circuit. The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage.

2. The method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle according to claim 1, characterized in that: The DC-DC circuit is a Boost chopper circuit.

3. The method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle according to claim 1, characterized in that: The LADRC controller includes a linear extended state observer and a linear state feedback control law. The linear state feedback control law converts the full-bridge inverter circuit input voltage reference value U d ' cref The full-bridge inverter circuit input voltage U output by the linear extended state observer d ' c The difference between the estimated value z1 and the control value u0 is used as the feedback control quantity and the first control quantity u0 is output; According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the first control quantity u0 is subjected to disturbance compensation to obtain the second control quantity u, and the PWM drive signal of the switch tube in the DC-DC circuit is generated according to the second control quantity u to control the DC-DC circuit; The linear extended state observer is based on the product of the second control quantity u and the control gain b of the full-bridge inverter circuit, the actual input voltage U d ' c Estimate the system state of the DC-DC circuit and observe the disturbance, thereby outputting the full-bridge inverter circuit input voltage U d ' c The estimated value z1 of and the estimated value z2 of the total disturbance f are as follows: in, The input voltage U is the full-bridge inverter circuit d ' c The differential of the estimated value z1, is the differential of the estimated value z2 of the total disturbance f; β1, β2 are the two control coefficients of the linear extended state observer.

4. The method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle according to claim 3, characterized in that: According to the estimated value z2 of the total disturbance f output by the linear extended state observer, the second control quantity u is obtained after the first control quantity u0 is subjected to disturbance compensation, which specifically satisfies the following formula:

5. The method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle according to claim 1, characterized in that: The first single hybrid controller performs frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, thereby stabilizing the system output voltage, specifically including: First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the first PI controller is based on the voltage error U error Calculate the phase shift angle D; then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s ; According to the phase shift angle D and switching frequency f s Generate PWM drive signal for the corresponding switch tube, so as to stabilize the output voltage of the control system.

6. The method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle according to claim 1, characterized in that: The control method further comprises: The four parallel pairs of diodes and capacitors in the rectifier circuit in the wireless charging system are replaced with four controllable MOSFET switch tubes, and the second single hybrid controller is used to perform frequency conversion and phase shift control on the four controllable MOSFET switch tubes in the rectifier circuit according to the system output voltage, thereby stabilizing the system output voltage.

7. The method for controlling the output voltage of a dynamic wireless charging system for an electric vehicle according to claim 6, characterized in that: The second single hybrid controller is used to perform frequency conversion and phase shift control on four controllable MOSFET switches of the rectifier circuit according to the system output voltage, so as to stabilize the system output voltage, specifically including: First, calculate the voltage error U between the actual output voltage of the system and the given output voltage error Then the second PI controller is based on the voltage error U error Calculate the phase shift angle D; then, according to the voltage error U error The switching frequency f is calculated by using the phase shift angle D s ; According to the phase shift angle D and switching frequency f s Generate PWM drive signal for the corresponding switch tube, so as to stabilize the output voltage of the control system.

8. An output voltage control device for a dynamic wireless charging system of an electric vehicle, characterized in that: include: A DC-DC circuit is added between the full-bridge inverter circuit and the DC power supply of the dynamic wireless charging system for electric vehicles, and the dynamic wireless charging system for electric vehicles is connected to the power grid; The LADRC controller is used to control the DC-DC circuit according to the system input voltage, thereby stabilizing the input voltage of the full-bridge inverter circuit; The first single hybrid controller is used to perform frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, so as to stabilize the system output voltage.

9. An output voltage control device for a dynamic wireless charging system of an electric vehicle, characterized in that: include: A DC-DC circuit is added between the full-bridge inverter circuit and the DC power supply of the dynamic wireless charging system of the electric vehicle, and the dynamic wireless charging system of the electric vehicle is connected to the power grid; and the four parallel pairs of diodes and capacitors in the rectifier circuit of the wireless charging system are replaced with four controllable MOSFET switch tubes; The LADRC controller is used to control the DC-DC circuit according to the system input voltage, thereby stabilizing the input voltage of the full-bridge inverter circuit; The first single hybrid controller is used to perform frequency conversion and phase shift control on the full-bridge inverter circuit according to the system output voltage, so as to stabilize the system output voltage. The second single hybrid controller is used to perform frequency conversion and phase shift control on four controllable MOSFET switch tubes of the rectifier circuit according to the system output voltage, so as to stabilize the system output voltage.

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