EV-DWPT system output power control method and device based on primary side control

Abstract

The invention relates to an EV-DWPT system output power control method and device based on primary side control, and belongs to the wireless power transmission technology, and the method comprises the steps: determining a power fluctuation influence factor according to the output characteristics of an LCC-S topological structure; on the basis of an LCC-S compensation EV-DWPT system with double electric energy transmitting ends and a single electric energy receiving end, parameter information of the double electric energy transmitting ends is collected, and a system equivalent mutual inductance model about the power fluctuation influence factors is established; wherein the double-electric-energy transmitting end comprises a first electric-energy transmitting end and a second electric-energy transmitting end, the first electric-energy transmitting end at least comprises a first high-frequency inversion module, and the second electric-energy transmitting end at least comprises a second high-frequency inversion module; and performing synchronous phase shift control on the first high-frequency inversion module and the second high-frequency inversion module through a synchronous control structure according to the system equivalent mutual inductance model, so that the output voltage and the output power of the electric energy receiving end are kept stable.

Description

Technical Field

[0001] The present application relates to wireless power transmission technology, and in particular to a method and device for controlling output power of a dynamic wireless charging system for an electric vehicle. Background Art

[0002] Wireless power transmission technology has changed the way that wired power transmission requires electrical contact, making power supply more flexible. It is of great value in the field of electric vehicle charging, especially dynamic wireless charging. Dynamic wireless charging of electric vehicles can realize charging while driving. It charges the on-board battery of electric vehicles through the energy emitted by the power rails laid under the road, effectively solving the problem of insufficient battery life. At the same time, it can reduce the capacity of the on-board battery pack of electric vehicles and reduce the cost of electric vehicles. Therefore, the Electric Vehicle Dynamic Wireless Power Transfer (EV-DWPT) technology is a very important branch of electric vehicle wireless charging / power supply technology.

[0003] In the electric vehicle dynamic wireless charging system, according to the different structures of the road-side energy transmitter, it can be divided into two types: dynamic wireless charging based on long rails and dynamic wireless charging based on short rails. Figure 1 As shown in the figure, it has the advantages of flexibility, low electromagnetic pollution, and low loss, and has become the current mainstream solution. However, when the electric vehicle is driving at the switch point of the rail, the mutual inductance between the transmitting coil and the pickup coil will change significantly, resulting in unstable output power of the system. Unstable power pulsation will affect the charging life of the on-board battery. Therefore, stable control of the output power of the EV-DWPT system is crucial.

[0004] The output power of the EV-DWPT system based on magnetic coupling is very sensitive to changes in the coil coupling coefficient. In order to adjust the output power according to the change in coupling mutual inductance, there are generally power control methods for primary side control and secondary side control. For secondary side control, it is necessary to add a DCDC link on the secondary side for power regulation. Since the power level of the dynamic wireless charging system of electric vehicles is generally high, the electrical stress requirements of the DCDC link are high, and the heat dissipation requirements are also relatively high.

[0005] Therefore, it is necessary to provide a method to solve the above problems and solve the output power fluctuation problem caused by the change of coupling coefficient in the EV-DWPT system based on LCC-S compensation by primary-side control. Summary of the invention

[0006] The present application provides an EV-DWPT system output power control method and device based on primary side control, which solves the output power fluctuation problem caused by the change of coupling coefficient in the EV-DWPT system based on LCC-S compensation by means of primary side control.

[0007] The technical solution of this application is as follows:

[0008] According to a first aspect of an embodiment of the present application, a method for controlling output power of an EV-DWPT system based on primary side control is provided, comprising:

[0009] S1: Determine the power fluctuation influencing factor according to the output characteristics of the LCC-S topology;

[0010] S2: Based on the LCC-S compensation EV-DWPT system with dual power transmitters and single power receivers, parameter information of the dual power transmitters is collected to establish a system equivalent mutual inductance model of the power fluctuation influencing factors; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module;

[0011] S3: According to the system equivalent mutual inductance model, the first high-frequency inverter module and the second high-frequency inverter module are synchronously phase-shifted controlled through a synchronous control structure to keep the output voltage and output power of the power receiving end stable.

[0012] Optionally, the LCC-S topology structure includes:

[0013] DC power supply, high frequency inverter circuit, primary compensation circuit, transmitting coil, receiving coil, secondary compensation circuit, rectifier filter circuit and power load; wherein,

[0014] The primary compensation circuit includes a compensation coil L f , the first compensation capacitor C f and the second compensation capacitor C P , compensation coil L f One end of the high-frequency inverter circuit is connected to the compensation coil L f The other end is connected to the first compensation capacitor C f One end and the transmitting coil L p One end of the transmitting coil L p The other end is connected to the second compensation capacitor C P The other end of the high frequency inverter circuit is connected to the first compensation capacitor C f The other end of the second compensation capacitor C P The other end of

[0015] The secondary side compensation circuit includes a third compensation capacitor C S , the third compensation capacitor C S One end of the rectifier filter circuit is connected to the third compensation capacitor C S The other end is connected to the receiving coil L s The other end of the rectifier filter circuit is connected to the receiving coil L s the other end.

[0016] Optionally, according to the output characteristics of the LCC-S topology structure, a power fluctuation influencing factor is determined, specifically including:

[0017] S101: Under the condition that the LCC-S topology structure is in a resonant state, establishing a secondary side reactance model and a secondary side output current model;

[0018] S102: Determine the power fluctuation influence factor according to the secondary side reactance model and the secondary side output current model when the secondary side output current remains stable.

[0019] Optionally, under the condition that the LCC-S topology structure is in a resonant state, a secondary side reactance model and a secondary side output current model are established, specifically including:

[0020] In the LCC-S topology, when the system is in resonance:

[0021]

[0022] The equivalent load on the secondary side is Then we have:

[0023]

[0024] Among them, Z s Represents the secondary reactance, Z ref Represents the primary side emission impedance; Z p Represents the primary reactance;

[0025]

[0026] Among them, I T Represents the primary input current, I p Represents the primary resonant cavity current, I s Indicates the secondary output current;

[0027] U dc Indicates the DC input voltage, U in Indicates the AC input voltage, U L and I L Respectively represent the DC output voltage and current of the power receiving end, L P , L S and Lf Respectively represent the inductance of the transmitting coil, receiving coil and compensation coil; M represents the mutual inductance between the transmitting coil and the receiving coil; ω represents the operating frequency, R eq Indicates the equivalent load on the secondary side.

[0028] Optionally, according to the secondary side reactance model and the secondary side output current model, when the secondary side output current remains stable, determining the power fluctuation influence factor specifically includes:

[0029] Based on formula (2) and formula (3), the power control of the primary side is carried out, and the power fluctuation influencing factor is determined as the primary side resonant cavity current I p And the mutual inductance M between the energy coils.

[0030] Optionally, in the LCC-S compensation EV-DWPT system with dual power transmitting ends and a single power receiving end, the first power transmitting end and the second power transmitting end are adjacently laid on the road, and the transmitting coil L of the first power transmitting end p1 and the transmitting coil L of the second electric energy transmitting end p2 The receiving coil L of the electric energy receiving end arranged on the electric vehicle s Form an energy coil;

[0031] Wherein, M1 represents the transmitting coil L of the first power transmitting end p1 and receiving coil L s The mutual inductance between them, M2 represents the transmitting coil L of the second power transmitting end p2 and receiving coil L s The mutual inductance between them, M3 represents the transmitting coil L of the first electric energy p1 and the second electric energy transmitting coil L p2 The mutual inductance of M1 and M2 will change as the electronic car moves; M3 remains unchanged when the coil spacing is determined.

[0032] Optionally, the LCC-S compensation EV-DWPT system based on dual power transmitters and single power receivers collects parameter information of the dual power transmitters and establishes a system equivalent mutual inductance model of the power fluctuation influencing factors, specifically including:

[0033] S201, determine the receiving coil L s For the transmitting coil L p1 and the transmitting coil L p2 The resulting reflected impedances are:

[0034]

[0035] Among them, the parameter value is set to L f1 =L f2 =L f , Cf1 =C f2 =C f , C p1 =C p2 =C p , L p1 =L p2 =L p , and the resonant cavity current is the same I p1 =I p2 =I p , then the receiving coil L s For the transmitting coil L p1 and the transmitting coil L p2 The resulting reflected impedance is converted to:

[0036]

[0037] S202: Set the constraint condition as follows: when the high-frequency inverter module loss and the compensation network loss are ignored, the DC input power is equal to the active power consumed by the transmitting coil, then:

[0038]

[0039] S203: When I p1 and I p2 When the frequency, phase and magnitude are the same, the system equivalent mutual inductance model is:

[0040]

[0041] Among them, P dc1 represents the DC input power of the first electric energy transmission field, P dc2 Indicates the DC input power of the second electric energy transmission field, U dc1 Represents the DC input voltage of the first power transmission field, I dc1 Represents the DC input current of the first power transmission field, I p1_rms Represents the resonant cavity current I p1 The effective value of I p2_rms Represents the resonant cavity current I p2 The effective value, R p1 Indicates the transmitting coil L p1 The equivalent resistance, Re{Z r1} and Re{Z r2} represents the equivalent resistance of the two reflected impedances, Re{Z s} represents the secondary side reactance Z s The equivalent resistance of.

[0042] On the other hand, an output power control device of an EV-DWPT system based on primary side control is provided, comprising:

[0043] An impact factor determination module, used to determine the power fluctuation impact factor according to the output characteristics of the LCC-S topology structure;

[0044] A model building module, based on an LCC-S compensation EV-DWPT system with dual power transmitters and a single power receiver, collects parameter information of the dual power transmitters and establishes a system equivalent mutual inductance model of the power fluctuation influencing factor; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module;

[0045] The synchronous phase shift control module performs synchronous phase shift control on the first high-frequency inverter module and the second high-frequency inverter module through a synchronous control structure according to the system equivalent mutual inductance model, so that the output voltage and output power of the power receiving end remain stable.

[0046] Beneficial effects:

[0047] The present application provides an output power control method and device for an EV-DWPT system based on primary-side control, wherein a power fluctuation influencing factor is determined according to the output characteristics of an LCC-S topological structure; an LCC-S compensated EV-DWPT system with dual power transmitters and a single power receiver is used to collect parameter information of the dual power transmitters and establish a system equivalent mutual inductance model for the power fluctuation influencing factor; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module; according to the system equivalent mutual inductance model, the first high-frequency inverter module and the second high-frequency inverter module are synchronously phase-shifted controlled by a synchronous control structure, and the output power fluctuation problem caused by the change of the coupling coefficient in the EV-DWPT system based on LCC-S compensation is solved by primary-side control, thereby realizing stable control of the output power of the electric vehicle during dynamic driving of the electric vehicle, and stabilizing the output voltage and power.

[0048] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0050] Figure 1 A dynamic wireless charging solution for electric vehicles based on short guide rails is shown according to an exemplary embodiment;

[0051] Figure 2 is a flow chart of an output power control method of an EV-DWPT system based on primary side control according to an exemplary embodiment;

[0052] Figure 3 is a schematic diagram of an LCC-S topology circuit according to an exemplary embodiment;

[0053] Figure 4 is a schematic diagram of a system circuit in a dual-transmitting and single-receiving situation according to an exemplary embodiment;

[0054] Figure 5 is a schematic diagram of an equivalent circuit of a coupling mechanism in a dual-transmitting and single-receiving situation according to an exemplary embodiment;

[0055] Figure 6 is a schematic diagram of a synchronous control structure of an EV-DWPT system according to an exemplary embodiment;

[0056] Figure 7 is a schematic diagram of switching of a transmitting coil of an EV-DWPT system according to an exemplary embodiment;

[0057] Figure 8 is a schematic diagram of a coupling mechanism according to an exemplary embodiment;

[0058] Fig. 9 is a schematic diagram showing a change in mutual inductance of a coupling mechanism according to an exemplary embodiment;

[0059] Fig.10 is a schematic diagram of mutual inductance estimation and voltage output curve according to an exemplary embodiment;

[0060] Fig.11 is a schematic diagram of a control process parameter variation curve according to an exemplary embodiment; DETAILED DESCRIPTION

[0061] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0062] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0063] The dynamic wireless charging system of electric vehicles generally adopts the LCC-S topology, which has significant advantages in charging efficiency, stability, safety, compatibility and cost optimization. Specifically, the LCC-S topology has efficient energy transmission characteristics, which helps to achieve higher charging efficiency during wireless charging. At the same time, the structure can also provide stable charging power to ensure that electric vehicles can continuously and stably receive electrical energy during driving. The LCC-S topology can effectively reduce electromagnetic radiation and electromagnetic interference, thereby reducing potential harm to the surrounding environment and human body. In addition, the structure also has strong anti-interference ability, which can ensure the stable operation of the wireless charging system. The LCC-S topology also has good compatibility and can match various types of electric vehicle wireless charging systems. This means that in practical applications, the structure can support a wider range of vehicle models and charging scenarios, and increase the popularity and application scope of wireless charging technology. These advantages make the LCC-S topology an ideal choice for dynamic wireless charging systems for electric vehicles.

[0064] like Figure 2 As shown, the present application provides an EV-DWPT system output power control method based on primary side control, which specifically includes:

[0065] S1, determine the power fluctuation influencing factor based on the output characteristics of the LCC-S topology.

[0066] The LCC-S topology structure adopted by the dynamic wireless charging system for electric vehicles in this application is as follows Figure 3 As shown. The power transmitter is laid on the road, including a DC power supply, a high-frequency inverter circuit, a primary compensation circuit, and a transmitting coil; the power receiver is set on the electric vehicle, including a receiving coil, a secondary compensation circuit, a rectifier filter circuit, and an electrical load; the transmitting coil and the receiving coil form a coupling mechanism to achieve wireless power transmission. When the electric vehicle is driving on the road where the power transmitter is set, the receiving coil is moved close to the transmitting coil.

[0067] In some embodiments, the high-frequency inverter module at the power transmitting end includes a first switch tube Q1, a second switch tube Q2, a third switch tube Q3 and a fourth switch tube Q4, one end of the DC power supply is connected to the first switch tube Q1 and the third switch tube Q3 respectively, the other end of the DC power supply is connected to the second switch tube Q2 and the fourth switch tube Q4 respectively, the first switch tube Q1 is connected to the second switch tube Q2, and the third switch tube Q3 is connected to the fourth switch tube S4. The primary compensation circuit includes a compensation coil L f , the first compensation capacitor C f and the second compensation capacitor C P , compensation coil L f One end of the high-frequency inverter circuit is connected to the compensation coil L f The other end is connected to the first compensation capacitor C f One end and the transmitting coil L p One end of the transmitting coil L p The other end is connected to the second compensation capacitor C P The other end of the high frequency inverter circuit is connected to the first compensation capacitor C f The other end of the second compensation capacitor C P the other end.

[0068] In some embodiments, the secondary side compensation circuit provided on the power receiving end of the electric vehicle includes a third compensation capacitor C S , the third compensation capacitor C S One end of the rectifier filter circuit is connected to the third compensation capacitor C S The other end is connected to the receiving coil L s The other end of the rectifier filter circuit is connected to the receiving coil L s The rectifier filter circuit includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a rectifier capacitor C d . Electrical load R L Respectively with the rectifier capacitor C d The series branch consisting of the first diode D1 and the second diode D2, and the series branch consisting of the third diode D3 and the fourth diode D4 are connected in parallel, and the transmitting coil L p and receiving coil L s Form an energy coil.

[0069] In some embodiments, the DC input is inverted into the high-frequency voltage required by the system through a high-frequency inverter module, injected into the compensation network, and obtained as high-frequency and high-voltage AC through the primary LC compensation circuit at the transmitting end. Under its action, an interactive electric field is formed between the two pairs of plates of the coupling mechanism. Under the action of the interactive electric field, a displacement current is generated that "flows through" the plates, and then converted into DC on the load after passing through the secondary LC compensation network and the rectifier and filter circuit at the receiving end, thereby finally realizing the wireless transmission of electric energy.

[0070] exist Figure 3 In the example, the DC input voltage is represented by U dc Indicates that the AC input voltage is represented by U in The DC output voltage and current of the power receiving end are represented by U L and I L Indicated by L, the inductance of the transmitting coil, receiving coil and compensation coil are P , L S and L f The mutual inductance between the transmitting coil and the receiving coil is represented by M. In addition, in this application, ω represents the operating frequency, R eq Indicates the equivalent load on the secondary side.

[0071] In some embodiments, according to the output characteristics of the LCC-S topology structure, determining the power fluctuation influencing factor specifically includes:

[0072] S101: Under the condition that the LCC-S topology structure is in a resonant state, a secondary side reactance model is established.

[0073] In the LCC-S topology, when the system is in resonance:

[0074]

[0075] The equivalent load on the secondary side is Then we have:

[0076]

[0077] Among them, Z s Represents the secondary reactance, Z ref Represents the primary side emission impedance; Z p Represents the primary reactance.

[0078]

[0079] Among them, I T Represents the primary input current, I p Represents the primary resonant cavity current, I s Represents the secondary output current.

[0080] S102: determining a power fluctuation influence factor according to the secondary side reactance model and the secondary side output current model when the secondary side output current remains stable.

[0081] This application is based on the fact that the LCC resonant network has a constant current characteristic. When the input voltage remains unchanged, the primary resonant cavity current I p is a constant current. At this time, the secondary output current I s It changes with the fluctuation of mutual inductance M, and the load output voltage also fluctuates. So, when the mutual inductance M changes, if we control the primary resonant cavity current I p Following the change of the mutual inductance M, the secondary output current remains stable, while the primary resonant cavity current I p The control is achieved by controlling the AC input voltage U in The present application performs primary power control based on the above formula (2) and formula (3) to determine the power fluctuation influencing factor as the primary resonant cavity current I p And the mutual inductance M between the energy coils.

[0082] S2, based on the LCC-S compensation EV-DWPT system with dual power transmitters and single power receivers, collects parameter information of the dual power transmitters and establishes a system equivalent mutual inductance model of the power fluctuation influencing factors; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes a first high-frequency inverter module, and the second power transmitter includes a second high-frequency inverter module.

[0083] In some embodiments, the actual dynamic electric vehicle wireless charging system usually works on a road with continuous power transmitters, multiple primary circuits are laid adjacent to each other on the road, and the components of the multiple primary circuits are the same. When the electric vehicle passes through the road, the secondary circuit of the electric vehicle is coupled with two adjacent primary circuits on the road to form an LCC-S compensation EV-DWPT system with dual power transmitters and single power receivers (abbreviated as: dual transmitters and single receivers). The circuit structure is simplified as follows: Figure 4 shown.

[0084] For example, the first power transmitting end and the second power transmitting end are adjacently laid on a road, and the transmitting coil L of the first power transmitting end p1 and the transmitting coil L of the second electric energy transmitting end p2 The receiving coil L of the electric energy receiving end arranged on the electric vehicle s Form an energy coil.

[0085] In some embodiments, M1 represents the transmitting coil L of the first power transmitting end. p1 and receiving coil L sThe mutual inductance between them, M2 represents the transmitting coil L of the second power transmitting end p2 and receiving coil L s The mutual inductance between them, where the movement of the electronic car causes the transmitting coil L of the first power transmitting end p1 and the transmitting coil L of the second electric energy transmitting end p2 With receiving coil L s The relative position of M1 and M2 will change with the movement of the electronic car. M3 represents the distance between two adjacent primary coils, that is, the transmitting coil L of the first electric energy. p1 and the second electric energy transmitting coil L p2 The mutual inductance is usually constant after the coil spacing is determined. Therefore, after estimating the mutual inductances M1 and M2, the primary resonant cavity current I p1 and the primary resonant cavity current I p2 By controlling the secondary output current I s Stay steady.

[0086] In some embodiments, the parameters such as mutual inductance are estimated by collecting the primary side parameter information, without the need for communication, so that control can be achieved only on the primary side. Figure 5 1 is a schematic diagram of an equivalent circuit of a coupling mechanism in a dual-transmitter and single-receiver situation according to an exemplary embodiment. It can be seen from the equivalent circuit that when other parameters are known, the mutual inductance parameter can be estimated by measuring the reflected impedance.

[0087] In some embodiments, step S2 specifically includes:

[0088] S201, determine the receiving coil L s For the transmitting coil L p1 and the transmitting coil L p2 The resulting reflected impedances are:

[0089]

[0090] Since the original sides in the system are the same, the parameter value is set to L f1 =L f2 =L f , C f1 =C f2 =C f , C p1 =C p2 =C p , L p1 =L p2 =L p Since the parameters of the two primary circuits are the same, the DC input voltage and the inverter drive signal are the same, the resonant cavity current is the same I p1 =Ip2 =I p , at this time the reflected impedance of the primary side is:

[0091]

[0092] S202: Setting a constraint condition as follows: when the high-frequency inverter module loss and the compensation network loss are ignored, the DC input power is equal to the active power consumed by the transmitting coil.

[0093] In some embodiments, to avoid measuring too many high-frequency parameters, the present application sets the constraint condition when doing the estimation calculation: when ignoring the high-frequency inverter module loss and the compensation network loss, the DC input power is equal to the active power consumed by the transmitting coil. The DC voltage and DC current are low-frequency quantities and are easier to measure. Therefore, the high-frequency parameters only need to measure the resonant cavity current I p Then we have:

[0094]

[0095] Where P dc1 represents the DC input power of the first electric energy transmission field, P dc2 Indicates the DC input power of the second electric energy transmission field, U dc1 Represents the DC input voltage of the first power transmission field, I dc1 Represents the DC input current of the first power transmission field, I p1_rms Represents the resonant cavity current I p1 The effective value of I p2_rms Represents the resonant cavity current I p2 The effective value, R p1 Indicates the transmitting coil L p1 The equivalent resistance, Re{Z r1} and Re{Z r2} represents the equivalent resistance of the two reflected impedances, Re{Z s} represents the secondary side reactance Z s The equivalent resistance of.

[0096] For a set of transmitting coils, the mutual inductance between the receiving coil and the receiving coil cannot be calculated separately, because the receiving coil and other transmitting coils also have coupled mutual inductance. Especially in the transition region, the coupling between the receiving coil and the two sets of transmitting coils is relatively strong and cannot be ignored.

[0097] S203: When I p1 and I p2 When the frequency, phase and magnitude are the same, the system equivalent mutual inductance model is:

[0098]

[0099] Therefore, the DC input power P can be measured dc1 and P dc2 , calculate the total equivalent mutual inductance M under dual transmitter and single receiver total .

[0100] S3, according to the system equivalent mutual inductance model, synchronously phase-shift control is performed on the first high-frequency inverter module and the second high-frequency inverter module through a synchronous control structure, so that the output voltage and output power of the power receiving end remain stable.

[0101] When dual transmitter and single receiver, the secondary current I s for:

[0102]

[0103] After estimating the total equivalent mutual inductance M total After that, the primary resonant cavity current I can be controlled p Achieve secondary side output current I s From the LCC network characteristics and formula (3), we can know that the primary resonant cavity current I p With AC input voltage U in It is a linear relationship. By controlling U in The size of the primary resonant cavity current I can be controlled p . The AC input voltage U in It is the output voltage of the high-frequency inverter module, and its size can be controlled by phase shifting within the high-frequency inverter module.

[0104] Based on the above mutual inductance estimation algorithm, since a single group of transmitting ends cannot calculate the mutual inductance with the receiving end, it is necessary to control both groups of transmitting ends at the same time. The present application illustrates an EV-DWPT system synchronous control structure design as follows: Figure 6 shown.

[0105] The first power transmitting end includes a first high-frequency inverter module, the second power transmitting end includes a second high-frequency inverter module, and the driving signals of the first high-frequency inverter module and the second high-frequency inverter module are controlled by the same control structure. When the vehicle end moves to face the i-th group of power transmitting ends, the i+1 group of power transmitting ends is turned on in advance, and the i-1 group of power transmitting ends is turned off at the same time, so that only two groups of transmitting ends are turned on at the same time, and the total coupling mutual inductance of the current two groups of transmitting ends and the vehicle end is estimated for control to maintain output stability.

[0106] The position of the electric vehicle is detected by estimating the mutual inductance parameters. When the vehicle enters the wireless charging road surface, the charging start signal is triggered, and then the first transmitting coil is turned on in advance to start charging. When the estimated mutual inductance reaches the peak during the driving process, it can be determined that it is facing the current transmitting coil. The control algorithm counts the transmitting coils to determine the position of the electric vehicle, and turns on and off a group of transmitting coils at the same time. For example, the power transmitting end switches as follows Figure 7 shown.

[0107] The present application exemplifies an output power control method and device for an EV-DWPT system based on primary-side control, which determines a power fluctuation influencing factor according to the output characteristics of an LCC-S topological structure; based on an LCC-S compensation EV-DWPT system with dual power transmitters and a single power receiver, collects parameter information of the dual power transmitters, and establishes a system equivalent mutual inductance model for the power fluctuation influencing factor; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module; according to the system equivalent mutual inductance model, synchronous phase shift control is performed on the first high-frequency inverter module and the second high-frequency inverter module through a synchronous control structure, and the output power fluctuation problem caused by the change of the coupling coefficient in the EV-DWPT system based on LCC-S compensation is solved through primary-side control, thereby realizing stable control of the output power of the electric vehicle during dynamic driving of the electric vehicle, so as to stabilize the output voltage and power.

[0108] In some embodiments, in order to verify the total coupling mutual inductance of the two sets of transmitters and vehicle terminals and the AC input voltage U in The control can make the secondary current I s The correctness of the parameter design method tends to be stable. This application uses COMSOL finite element simulation software to exemplify the following Figure 8 The coupling mechanism shown in the figure has parameters designed as shown in Table 1. Through parametric sweep simulation, the mutual inductance curves M1 and M2 between each transmitting coil and the receiving coil during the movement and the total mutual inductance curve M between the receiving coil and the two transmitting coils are obtained. total like Fig. 9 As shown, data input for the simulation model.

[0109] Table 1 Coupling mechanism parameters

[0110]

[0111] This application uses SIMULINK simulation software to build a dual-transmitter, single-receiver LCC-S topology electric vehicle dynamic wireless charging simulation model, introducing Fig. 9 The obtained transmitting coil L p1and the transmitting coil L p2 The mutual inductance data is then transferred to the simulation.

[0112] The simulation results of mutual inductance estimation and output voltage are as follows: Fig.10 As shown in the figure, the estimated mutual inductance can track the actual mutual inductance changes more accurately. Using the estimated mutual inductance, the inverter voltage is controlled by shifting the primary side phase, and then the primary resonant cavity current is controlled to keep the output voltage stable, and the fluctuation range of the transition zone is 5%. During the control process, the primary resonant cavity current I p Parameter changes such as Fig.11 shown.

[0113] The present application provides an EV-DWPT system output power control device based on primary side control, which is characterized by comprising:

[0114] An impact factor determination module, used to determine the power fluctuation impact factor according to the output characteristics of the LCC-S topology structure;

[0115] A model building module, based on an LCC-S compensation EV-DWPT system with dual power transmitters and a single power receiver, collects parameter information of the dual power transmitters and establishes a system equivalent mutual inductance model of the power fluctuation influencing factor; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module;

[0116] The synchronous phase shift control module performs synchronous phase shift control on the first high-frequency inverter module and the second high-frequency inverter module through a synchronous control structure according to the system equivalent mutual inductance model, so that the output voltage and output power of the power receiving end remain stable.

[0117] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0118] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for controlling output power of an EV-DWPT system based on primary side control, characterized in that: include: S1: Determine the power fluctuation influencing factor according to the output characteristics of the LCC-S topology; S2: Based on the LCC-S compensation EV-DWPT system with dual power transmitters and single power receivers, parameter information of the dual power transmitters is collected to establish a system equivalent mutual inductance model of the power fluctuation influencing factors; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module; S3: According to the system equivalent mutual inductance model, the first high-frequency inverter module and the second high-frequency inverter module are synchronously phase-shifted controlled through a synchronous control structure to keep the output voltage and output power of the power receiving end stable.

2. The output power control method according to claim 1, characterized in that: The LCC-S topology includes: DC power supply, high frequency inverter circuit, primary compensation circuit, transmitting coil, receiving coil, secondary compensation circuit, rectifier filter circuit and power load; wherein, The primary compensation circuit includes a compensation coil L f , the first compensation capacitor C f and the second compensation capacitor C P , compensation coil L f One end of the high-frequency inverter circuit is connected to the compensation coil L f The other end is connected to the first compensation capacitor C f One end and the transmitting coil L p One end of the transmitting coil L p The other end is connected to the second compensation capacitor C P The other end of the high frequency inverter circuit is connected to the first compensation capacitor C f The other end of the second compensation capacitor C P The other end of The secondary side compensation circuit includes a third compensation capacitor C S , the third compensation capacitor C S One end of the rectifier filter circuit is connected to the third compensation capacitor C S The other end is connected to the receiving coil L s The other end of the rectifier filter circuit is connected to the receiving coil L s the other end.

3. The output power control method according to claim 2, characterized in that: According to the output characteristics of the LCC-S topology, the power fluctuation influencing factors are determined, including: S101: Under the condition that the LCC-S topology structure is in a resonant state, establishing a secondary side reactance model and a secondary side output current model; S102: Determine the power fluctuation influence factor according to the secondary side reactance model and the secondary side output current model when the secondary side output current remains stable.

4. The output power control method according to claim 3, characterized in that: Under the condition that the LCC-S topology structure is in a resonant state, a secondary side reactance model and a secondary side output current model are established, specifically including: In the LCC-S topology, when the system is in resonance: The equivalent load on the secondary side is Then we have: Among them, Z s Represents the secondary reactance, Z ref Represents the primary side emission impedance; Z p Represents the primary reactance; Among them, I T Represents the primary input current, I p Represents the primary resonant cavity current, I s Indicates the secondary output current; U dc Indicates the DC input voltage, U in Indicates the AC input voltage, U L and I L Respectively represent the DC output voltage and current of the power receiving end, L P , L S and L f Respectively represent the inductance of the transmitting coil, receiving coil and compensation coil; M represents the mutual inductance between the transmitting coil and the receiving coil; ω represents the operating frequency, R eq Indicates the equivalent load on the secondary side.

5. The output power control method according to claim 4, characterized in that: According to the secondary side reactance model and the secondary side output current model, when the secondary side output current remains stable, determining the power fluctuation influence factor specifically includes: Based on formula (2) and formula (3), the power control of the primary side is carried out, and the power fluctuation influencing factor is determined as the primary side resonant cavity current I p And the mutual inductance M between the energy coils.

6. The output power control method according to claim 5, characterized in that: In the LCC-S compensation EV-DWPT system with dual power transmitters and a single power receiver, the first power transmitter and the second power transmitter are adjacently laid on the road. The transmitting coil L of the first power transmitter p1 and the transmitting coil L of the second electric energy transmitting end p2 The receiving coil L of the electric energy receiving end arranged on the electric vehicle s Form an energy coil; Wherein, M1 represents the transmitting coil L of the first power transmitting end p1 and receiving coil L s The mutual inductance between them, M2 represents the transmitting coil L of the second power transmitting end p2 and receiving coil L s The mutual inductance between them, M3 represents the transmitting coil L of the first electric energy p1 and the second electric energy transmitting coil L p2 The mutual inductance of M1 and M2 will change as the electronic car moves; M3 remains unchanged when the coil spacing is determined.

7. The output power control method according to claim 6, characterized in that: The LCC-S compensation EV-DWPT system based on dual power transmitters and single power receivers collects parameter information of the dual power transmitters and establishes a system equivalent mutual inductance model of the power fluctuation influencing factors, specifically including: S201, determine the receiving coil L s For the transmitting coil L p1 and the transmitting coil L p2 The resulting reflected impedances are: Among them, the parameter value is set to L f1 =L f2 =L f , C f1 =C f2 =C f , C p1 =C p2 =C p , L p1 =L p2 =L p , and the resonant cavity current is the same I p1 =I p2 =I p , then the receiving coil L s For the transmitting coil L p1 and the transmitting coil L p2 The resulting reflected impedance is converted to: S202: Set the constraint condition as follows: when the high-frequency inverter module loss and the compensation network loss are ignored, the DC input power is equal to the active power consumed by the transmitting coil, then: Q dc1 =U dc1 I dc1 =I p1_rms 2 (R p1 +Re{Z r1 }) (8) S203: When I p1 and I p2 When the frequency, phase and magnitude are the same, the system equivalent mutual inductance model is: Among them, P dc1 represents the DC input power of the first electric energy transmission field, P dc2 represents the DC input power of the second electric energy transmission field, U dc1 Represents the DC input voltage of the first power transmission field, I dc1 Represents the DC input current of the first power transmission field, I p1_rms Represents the resonant cavity current I p1 The effective value of I p2_rms Represents the resonant cavity current I p2 The effective value, R p1 Indicates the transmitting coil L p1 The equivalent resistance, Re{Z r1 } and Re{Z r2 } represents the equivalent resistance of the two reflected impedances, Re{Z s } represents the secondary side reactance Z s The equivalent resistance of 8. An output power control device for an EV-DWPT system based on primary side control, characterized in that: include: An impact factor determination module, used to determine the power fluctuation impact factor according to the output characteristics of the LCC-S topology structure; A model building module, based on an LCC-S compensation EV-DWPT system with dual power transmitters and a single power receiver, collects parameter information of the dual power transmitters and establishes a system equivalent mutual inductance model of the power fluctuation influencing factor; wherein the dual power transmitters include a first power transmitter and a second power transmitter, the first power transmitter includes at least a first high-frequency inverter module, and the second power transmitter includes at least a second high-frequency inverter module; The synchronous phase shift control module performs synchronous phase shift control on the first high-frequency inverter module and the second high-frequency inverter module through a synchronous control structure according to the system equivalent mutual inductance model, so that the output voltage and output power of the power receiving end remain stable.

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