Dynamic wireless power supply system receiving coil motion speed estimation method

Abstract

The application provides a dynamic wireless power supply system receiving coil motion speed estimation method, which comprises the following steps: S1: measuring the direct current input current of an inverter corresponding to a current transmitting coil at a period Ts; S2: performing sliding average filtering on the direct current input current obtained in step S1; S3: determining the mutual inductance value between the current transmitting coil and the receiving coil according to the direct current input current after the filtering processing in step S2; S4: determining the position of the receiving coil at the current moment according to the mutual inductance value obtained in step S3 and the mutual inductance-displacement relationship; and S5: determining the moving speed of the receiving coil according to the positions of the receiving coil obtained at two moments and the time difference. The method can estimate the mutual inductance between the receiving coil and the transmitting coil of the dynamic wireless power supply system, the position of the receiving coil and the motion speed, and provides more reference information for the control of the dynamic wireless power supply system.

Description

TECHNICAL FIELD

[0001] The present application relates to wireless power supply technology, in particular to a dynamic wireless power supply system receiving coil movement speed estimation method. BACKGROUND

[0002] The wireless power supply system uses the high-frequency electromagnetic field near-field coupling principle, uses the high-frequency magnetic field as the transmission medium, realizes the wireless transmission of electric energy through the magnetic field coupling between the transmitting coil and the receiving coil. The common two-coil wireless power supply system mainly consists of two parts, one part is the transmitting end connected on the power supply side, and the other part is the receiving end located on the load side. Energy is transmitted from the transmitting end to the receiving end by electromagnetic induction. The dynamic wireless power supply system can be used for dynamic charging of electrified transportation vehicles, thereby reducing the parking charging time of the transportation vehicles and improving the carrying efficiency.

[0003] Under normal circumstances, in order to reduce the loss of the energized transmitting coil of the dynamic wireless power supply system, the transmitting coil needs to be segmented, and only when the receiving coil moves to the vicinity of a certain segment of the transmitting coil, the segment of the transmitting coil starts to work. Therefore, the segmentation switching process and control mode of the transmitting coil are closely related to the position and motion state of the receiving coil.

[0004] However, the existing method mainly estimates the position of the receiving coil, and cannot obtain the motion speed information of the receiving coil, resulting in a lag in the segmentation switching control process when the receiving coil moves at a high speed, which significantly affects the segmentation switching response speed and control effect of the dynamic wireless power supply system. SUMMARY

[0005] Therefore, the present application provides a dynamic wireless power supply system receiving coil movement speed estimation method, which solves the problem that it is difficult for the ground end to estimate the motion speed of the receiving coil in the dynamic wireless power supply system and to evaluate the motion state of the receiving coil, thereby providing more detailed information for the segmentation switching of the transmitting coil.

[0006] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0007] A dynamic wireless power supply system receiving coil movement speed estimation method, comprising the following steps:

[0008] S1: measuring the direct current input current of the inverter corresponding to the current transmitting coil with a period Ts;

[0009] S2: performing sliding average filtering on the direct current input current obtained in step S1;

[0010] S3: determining the mutual inductance value between the current transmitting coil and the receiving coil according to the direct current input current after filtering in step S2;

[0011] S4: determining the position of the receiving coil at the current time according to the mutual inductance value obtained in step S3 and the mutual inductance-displacement relationship;

[0012] S5: determining the moving speed of the receiving coil according to the positions of the receiving coil at two times and the time difference.

[0013] Optionally, in step S3, the mutual inductance value between the current transmitting coil and the receiving coil is determined according to V P is the output voltage of the inverter of the system transmitting end, R P and R S are the internal resistances of the transmitting coil and the receiving coil respectively, ω is the working angular frequency of the system, I P is the effective value of the transmitting coil current, and α is the conduction angle of the inverter, I in is the DC input current after filtering.

[0014] Optionally, the system establishes a mutual inductance-displacement relationship table according to empirical data, and in step S4, the position of the receiving coil corresponding to the mutual inductance value at the current time is determined by table lookup.

[0015] Optionally, in step S4, the position of the receiving coil corresponding to the mutual inductance value at the current time is determined by interpolation, and the specific steps include:

[0016] S401: according to the mutual inductance value M PS between the current transmitting coil and the receiving coil, finding out the adjacent larger value M L and the smaller value M S from the mutual inductance-displacement relationship table, and recording the positions S L and S S corresponding to the larger value M L and the smaller value M S ;

[0017] S402: calculating the position corresponding to the mutual inductance value M PS according to .

[0018] Optionally, in step S5, the moving speed of the receiving coil is determined according to , wherein S PS is the position of the receiving coil at the current period, and S PS0 is the position of the receiving coil at the last period.

[0019] Optionally, the transmitting coils in the system are arranged in segments along the movement path of the receiving coil, and the starting position information of each segment of the transmitting coil is predetermined, when the receiving coil reaches the starting position of the transmitting coil, the controller corresponding to the transmitting coil executes steps S1-S5 to estimate the movement speed of the receiving coil.

[0020] Effects of the present application are:

[0021] (1) The present application can estimate the mutual inductance between the receiving coil and the transmitting coil of the dynamic wireless power supply system;

[0022] (2) The present application can be used to estimate the position of the receiving coil of the dynamic wireless power supply system;

[0023] (3) The present application can be used to estimate the movement speed of the receiving coil of the dynamic wireless power supply system. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below, and obviously, the drawings in the following description can only be some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The circuit diagram of the dynamic wireless power supply system in the specific embodiment of the present application.

[0026] Figure 2 The flow chart of the receiving coil movement speed estimation method in the specific embodiment of the present application.

[0027] Figure 3 The curve drawn for the mutual inductance-displacement relationship table data in the specific embodiment of the present application. DETAILED DESCRIPTION

[0028] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present application, and therefore only serve as examples, and cannot limit the protection scope of the present application.

[0029] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present application should be understood as the usual meaning understood by those skilled in the art to which the present application belongs.

[0030] As shown in the dynamic wireless power supply system, Figure 1 with two transmitting coils at the transmitting end and a single receiving coil at the receiving end, for example, the inverter 1 of the transmitting end and its transmitting end circuit C p1 and L p1When in operation, inverter 2 is in the off state, and the receiving coil can move along the arrangement path of the two transmitting coils. Using coil Lp1 as the current transmitting coil, the speed of the receiving coil is estimated by measuring the current of inverter 1. This leads to the conclusion of a method for estimating the speed of the receiving coil in a dynamic wireless power supply system provided in this embodiment. The specific process is as follows: Figure 2 As shown, it includes the following steps:

[0031] S1: Measure the inverter DC input current corresponding to the current transmitting coil with a period of Ts;

[0032] S2: Perform a moving average filter on the DC input current obtained in step S1;

[0033] S3: Determine the mutual inductance value between the current transmitting coil and receiving coil based on the DC input current after filtering in step S2. In specific implementation, this can be done by first determining the mutual inductance value between the current transmitting coil and receiving coil based on the DC input current after filtering. in1 The effective value I of the current in transmitting coil 1 is obtained by conversion. P1 for: α1 is the conduction angle of inverter 1, and then according to The mutual inductance M between transmitting coil 1 and receiving coil can then be calculated. 1S V P1 This is the output voltage of inverter 1 at the transmitting end;

[0034] S4: Based on the mutual inductance value and mutual inductance-displacement relationship obtained in step S3, determine the position of the receiving coil at the current moment; the mutual inductance-displacement relationship in the system can be referenced. Figure 3 As shown, when the obtained mutual inductance value can be directly obtained from the mutual inductance-displacement relationship table, the corresponding position information can be directly read using the table lookup method. If the obtained mutual inductance value cannot be directly obtained from the mutual inductance-displacement relationship table, the interpolation method can be used. The specific steps include:

[0035] S401: Based on the current mutual inductance value M between the transmitting coil and the receiving coil 1S Find the match with M 1S Adjacent larger value M L1 and smaller value M S1 And record M L1 and M S1 Corresponding position S L1 and S S1 ;

[0036] S402: According to Calculate the mutual inductance value M 1S The corresponding position S 1S ;

[0037] S5: determining the moving speed of the receiving coil according to the position of the receiving coil and the time difference obtained at two time points, taking a single period as the time difference, the moving speed of the receiving coil can be determined according to Calculate the moving speed v of the receiving coil, S 1S0 is the position of the receiving coil in the last period.

[0038] For example, the motion speed estimation of the receiving coil in the whole charging process can be realized by using multiple transmitting coils respectively, in the specific implementation, the transmitting coils in the system are arranged in sections along the moving path of the receiving coil, and the starting position information of each section of the transmitting coil is determined in advance, when the receiving coil reaches the starting position of the transmitting coil, the controller corresponding to the transmitting coil executes steps S1-S5 to estimate the motion speed of the receiving coil.

[0039] As can be seen from the above, the motion speed estimation method of the receiving coil of the dynamic wireless power supply system provided by the present application can calculate the mutual inductance between the receiving coil and the transmitting coil of the dynamic wireless power supply system, and can estimate the position and motion speed of the receiving coil, thereby providing more reference information for the control of the dynamic wireless power supply system, and providing more accurate control for the segmented switching of the transmitting coil.

[0040] Finally, it should be noted that the above disclosure is only one preferred embodiment of the present application, and of course cannot limit the scope of the rights of the present application, and those skilled in the art can understand that all or part of the above-mentioned embodiments can be implemented, and equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A method for estimating the speed of motion of a receiver coil of a dynamic wireless power supply system, characterized in that, The method comprises the following steps: S1: measuring the DC input current of the inverter corresponding to the current transmitting coil with a period Ts; S2: performing a sliding average filtering on the DC input current obtained in step S1; S3: determining the mutual inductance value between the current transmitting coil and the receiving coil according to the DC input current after the filtering in step S2; S4: determining the position of the receiving coil at the current time according to the mutual inductance value obtained in step S3 and the mutual inductance-displacement relationship; S5: determining the moving speed of the receiving coil according to the positions of the receiving coil obtained at two times and the time difference; In step S4, the system establishes a mutual inductance-displacement relationship table according to empirical data, when the obtained mutual inductance value can be directly obtained from the mutual inductance-displacement relationship table, the position of the receiving coil corresponding to the mutual inductance value at the current time is determined by the table lookup method, if the obtained mutual inductance value cannot be directly obtained from the mutual inductance-displacement relationship table, the position of the receiving coil is obtained by the interpolation method, and the specific steps comprise: S401: Find the mutual inductance value M between the current transmitting coil and the receiving coil PS Find the adjacent larger value M and smaller value M from the mutual inductance-displacement relationship table L , S Record the larger value M and the smaller value M L , S The corresponding positions S and S L , S ; S402: According to Computing mutual inductance value M PS The corresponding position.

2. The dynamic wireless power system receiver coil motion speed estimation method of claim 1, wherein: In step S3, the mutual inductance value between the current transmitting coil and the receiving coil is determined according to V = M * I P R is the output voltage of the system transmitting end inverter, R P and R S are the transmitting end coil internal resistance and the receiving end coil internal resistance respectively, ω is the system working angular frequency, I P is the effective value of the transmitting coil current, and α is the inverter conduction angle, I in is the filtered direct current input current.

3. The dynamic wireless power system receiver coil motion speed estimation method of claim 1, wherein: In step S5, the position of the receiving coil is determined in accordance with the movement speed of the receiving coil is determined, wherein the position of the receiving coil for the current cycle is determined, S PS0 the position of the receiving coil for the previous cycle is determined.

4. The dynamic wireless power supply system reception coil motion speed estimation method according to claim 3, characterized by: The transmitting coil in the system is segmented along the moving path of the receiving coil, and the starting position information of each segment of the transmitting coil is determined in advance, when the receiving coil reaches the starting position of the transmitting coil, the controller corresponding to the transmitting coil performs steps S1-S5 to estimate the moving speed of the receiving coil.

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