Charging control method, device and circuit of three-phase motor and electric vehicle

Abstract

This application provides a charging control method, device, circuit, and electric vehicle for a three-phase motor. First, the current position of the rotor in the three-phase motor is obtained. Then, based on the mapping relationship between the rotor's position and the duty cycle of the bridge arm in the corresponding converter of the three-phase motor, the duty cycle of the bridge arm corresponding to the rotor's current position is determined. Finally, based on the duty cycle of the bridge arm corresponding to the rotor's current position, the angle between the total current vector of the stator windings in the three-phase motor and the position of the permanent magnet flux linkage of the rotor is adjusted. By adjusting the angle between the total current vector of the stator windings and the position of the permanent magnet flux linkage of the rotor according to the current position of the motor rotor, the electromagnetic torque experienced by the motor rotor in charging mode is reduced, thereby improving the stability of the charging process and reducing losses and safety hazards.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, and in particular to a charging control method, device, circuit, and electric vehicle for a three-phase motor. Background Technology

[0002] A typical electric vehicle generally includes components such as a power battery, an electric motor drive system, an on-board charging system, and a battery management system. Among these, the power battery is the primary energy storage device; during vehicle operation, the electrical energy in the power battery is converted into traction force by the electric motor drive system. However, the driving range of the power battery is limited, necessitating charging via an on-board charging system.

[0003] Due to limitations in space and weight, integrated motor drive and on-board charging systems have attracted widespread attention in the industry. The implementation idea of ​​such systems is to reuse the motor stator winding and inverter in the motor drive system as the charging filter inductor and rectifier in the on-board charging system, thereby constructing an integrated drive and charging circuit, which significantly reduces the size and weight of the on-board charging system.

[0004] However, when reused as a charging filter inductor, the current flowing through the motor stator windings inevitably generates a magnetic field in the motor air gap. The motor rotor experiences a continuous tangential torque within this magnetic field, causing motor vibration or rotation. Existing integrated drive and charging circuits cannot effectively control the electromagnetic torque experienced by the motor rotor during charging, potentially affecting the vehicle's stationary state, thus reducing the stability of the charging process and increasing losses and safety hazards. Summary of the Invention

[0005] This application provides a charging control method, device, circuit, and electric vehicle for a three-phase motor, in order to solve the technical problem in the prior art that the electromagnetic torque experienced by the motor rotor in the charging mode cannot be effectively controlled.

[0006] In a first aspect, this application provides a charging control method for a three-phase motor, the method comprising:

[0007] Obtain the current position of the rotor in the three-phase motor;

[0008] Based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor, the duty cycle of the bridge arm corresponding to the current position of the rotor is determined.

[0009] Based on the duty cycle of the bridge arm corresponding to the current position of the rotor, adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor.

[0010] In one optional implementation, determining the duty cycle of the bridge arm corresponding to the current position of the rotor includes:

[0011] The duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor are determined. The first bridge arm is the bridge arm corresponding to the first stator winding in the three-phase motor, and the second bridge arm is the bridge arm corresponding to the second stator winding in the three-phase motor. The first stator winding is used to output the first current vector, and the second stator winding is used to output the second current vector.

[0012] In one optional implementation, the sum of the duty cycles of the first bridge arm and the second bridge arm is 1.

[0013] In one optional implementation, adjusting the angle between the total current vector of the stator windings in the three-phase motor and the position of the permanent magnet flux linkage of the rotor includes:

[0014] Within a preset angle adjustment range, adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor.

[0015] In one alternative implementation, the converter includes a DC-DC converter and / or an AC-DC converter.

[0016] Secondly, this application provides a charging control device for a three-phase motor, the device comprising:

[0017] The acquisition module is used to acquire the current position of the rotor in the three-phase motor;

[0018] The control module is used to determine the duty cycle of the bridge arm corresponding to the current position of the rotor based on the mapping relationship between the position of the rotor and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor; and to adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor based on the duty cycle of the bridge arm corresponding to the current position of the rotor.

[0019] In one optional implementation, the control module is specifically used to determine the duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor. The first bridge arm is the bridge arm corresponding to the first stator winding in the three-phase motor, and the second bridge arm is the bridge arm corresponding to the second stator winding in the three-phase motor. The first stator winding is used to output a first current vector, and the second stator winding is used to output a second current vector.

[0020] In one optional implementation, the sum of the duty cycles of the first bridge arm and the second bridge arm is 1.

[0021] In one optional implementation, the control module is specifically used to adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor within a preset angle adjustment range.

[0022] In one alternative implementation, the converter includes a DC-DC converter and / or an AC-DC converter.

[0023] Thirdly, this application provides a charging control circuit for a three-phase motor, comprising: a controller, a three-phase motor, and a converter; the controller is connected to the three-phase motor and the converter respectively, and the three-phase motor is connected to the converter; wherein, the controller is configured to: acquire the current position of the rotor in the three-phase motor; determine the duty cycle of the bridge arm corresponding to the current position of the rotor according to the mapping relationship between the position of the rotor and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor; and adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor according to the duty cycle of the bridge arm corresponding to the current position of the rotor.

[0024] Fourthly, this application provides an electric vehicle, including: a battery and a charging control circuit; the charging control circuit is connected to the battery, and a controller in the charging control circuit is used to perform the method as described in any one of the first aspects.

[0025] This application provides a charging control method, device, circuit, and electric vehicle for a three-phase motor. First, the current position of the rotor in the three-phase motor is obtained. Then, based on the mapping relationship between the rotor's position and the duty cycle of the bridge arm in the corresponding converter of the three-phase motor, the duty cycle of the bridge arm corresponding to the rotor's current position is determined. Finally, based on the duty cycle of the bridge arm corresponding to the rotor's current position, the angle between the total current vector of the stator windings in the three-phase motor and the position of the permanent magnet flux linkage of the rotor is adjusted. By adjusting the angle between the total current vector of the stator windings and the position of the permanent magnet flux linkage of the rotor according to the current position of the motor rotor, the electromagnetic torque experienced by the motor rotor in charging mode is reduced, thereby improving the stability of the charging process and reducing losses and safety hazards. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1A schematic diagram of the circuit structure of a charging control circuit for a three-phase motor provided in an embodiment of this application;

[0028] Figure 2 A flowchart illustrating a charging control method for a three-phase motor provided in an embodiment of this application;

[0029] Figure 3 This embodiment provides a schematic diagram of the current vector of the stator winding in a three-phase motor.

[0030] Figure 4 An electromagnetic torque T provided in the embodiments of this application e Correspondence diagram between the included angle β;

[0031] Figure 5 A diagram showing the correspondence between duty cycle k and included angle θ provided in this application embodiment;

[0032] Figure 6 An electromagnetic torque T provided in the embodiments of this application e A comparison diagram showing the before and after adjustments;

[0033] Figure 7 A flowchart illustrating another charging control method for a three-phase motor provided in an embodiment of this application;

[0034] Figure 8 This is a schematic diagram of the structure of a charging control device for a three-phase motor provided in an embodiment of this application. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] A typical electric vehicle generally includes components such as a power battery, an electric motor drive system, an on-board charging system, and a battery management system. Among these, the power battery is the primary energy storage device; during vehicle operation, the electrical energy in the power battery is converted into traction force by the electric motor drive system. However, the driving range of the power battery is limited, necessitating charging via an on-board charging system.

[0037] Due to limitations in space and weight, integrated motor drive and on-board charging systems have attracted widespread attention in the industry. The implementation idea of ​​such systems is to reuse the motor stator winding and inverter in the motor drive system as the charging filter inductor and rectifier in the on-board charging system, thereby constructing an integrated drive and charging circuit, which significantly reduces the size and weight of the on-board charging system.

[0038] However, when reused as a charging filter inductor, the current flowing through the motor stator windings inevitably generates a magnetic field in the motor air gap. The motor rotor experiences a continuous tangential torque within this magnetic field, causing motor vibration or rotation. Existing integrated drive and charging circuits cannot effectively control the electromagnetic torque experienced by the motor rotor during charging, potentially affecting the vehicle's stationary state, thus reducing the stability of the charging process and increasing losses and safety hazards.

[0039] To address the aforementioned technical problems, this application provides a charging control method, device, circuit, and electric vehicle for a three-phase motor. By adjusting the angle between the total current vector of the motor stator winding and the position of the permanent magnet flux linkage of the motor rotor according to the current position of the motor rotor, the electromagnetic torque experienced by the motor rotor in charging mode is reduced, thereby improving the stability of the charging process and reducing losses and safety hazards.

[0040] The circuit structure of a charging control circuit for a three-phase motor, as described in this application, will be explained below.

[0041] Figure 1 This is a schematic diagram of the circuit structure of a charging control circuit for a three-phase motor provided in an embodiment of this application. Figure 1 As shown, it includes a controller 101 and a drive and charging integrated circuit 102. The drive and charging integrated circuit 102 includes a first interface 1021, a capacitor 1022, a relay switch 1023, a three-phase motor 1024, a DC-DC converter 1025, a capacitor 1026, a second interface 1027, and a relay switch 1028.

[0042] The connection relationships between the parts are as follows: Figure 1 As shown in the diagram. Furthermore, the first interface 1021 can be connected to an external charging power source, and the second interface 1027 can be connected to the vehicle's battery pack. In charging mode, the charging current can flow in from a single phase of the three-phase motor and flow out in parallel from the other two phases.

[0043] It is understood that the controller 101 can be used to control the driving and / or charging process of the integrated drive and charging circuit 102. It should be noted that this charging control circuit is applicable to DC charging of electric vehicles, meaning the first interface 1021 can be connected to a DC charging station. In other embodiments, by adjusting the circuit structure, such as by adding an AC-DC converter, the charging control circuit can also be applied to AC charging of electric vehicles; this application does not impose any limitations on this.

[0044] It should be understood that the circuit structure of the charging control circuit in this application can be... Figure 1 The circuit structure of the charging control circuit for a three-phase motor is shown in the figure, but it is not limited to this. It can also be used for other circuit structures that require charging control of a three-phase motor.

[0045] The following uses a controller integrated with or installed with relevant execution code as an example to illustrate the technical solutions of the embodiments of this application in detail. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0046] Figure 2 This is a flowchart illustrating a charging control method for a three-phase motor provided in an embodiment of this application. This embodiment relates to the process of charging control for a three-phase motor. Figure 2 As shown, the method includes:

[0047] S201. Obtain the current position of the rotor in the three-phase motor.

[0048] In this embodiment of the application, the controller can first obtain the current position of the three-phase motor rotor, and then adjust the angle between the total current vector of the stator winding and the position of the permanent magnet flux linkage of the rotor according to the current position of the rotor.

[0049] This application does not limit how the current position of the rotor is obtained. In some embodiments, the controller can obtain the rotor position through a position sensor corresponding to the three-phase motor. For example, the current position of the rotor is obtained in real time through a rotary encoder at the shaft end of the three-phase motor. This application also does not limit the type of three-phase motor.

[0050] The following explains the total current vector of the stator windings in a three-phase motor. For example, Figure 3 This is a schematic diagram of the current vector of the stator winding in a three-phase motor provided in this embodiment. Figure 3 As shown, the three-phase motor includes stator windings of phase A, phase B, and phase C. The current vectors corresponding to the stator windings of phase A, phase B, and phase C are respectively i a i b i cAmong them, i a i b i c The directions are respectively as follows Figure 3 As shown by the arrow in the image, i can be... a i b i c The vector sum is defined as the total current vector i of the stator winding. s and i a i b i c i s The magnitudes of the current vectors are denoted as I. a I b I c I s In the integrated drive and charging circuit, in charging mode, current can flow into the A-phase stator winding and flow out in parallel from the B-phase and C-phase stator windings, i.e., I... b =I c =-0.5I a .

[0051] The angle β between the total current vector of the stator windings and the position of the permanent magnet flux linkage in the rotor of a three-phase motor is explained below. For example, if the direction of the permanent magnet flux linkage in the rotor is taken as the d-axis, a common dq coordinate system can be established on the rotor of the three-phase motor, and this coordinate system rotates synchronously with the rotor. At this time, the total current vector i s The angle β between the rotor's permanent magnet flux linkage and the position of the rotor's permanent magnet flux linkage is the total current vector i. s The angle between I and the d-axis. It is understandable that, due to I... a It is basically fixed during a certain charging process, and I b =I c =-0.5I a Therefore, the total current vector i s The magnitude and direction of the d-axis are fixed, while the d-axis changes with the position of the rotor. Therefore, the included angle β can be determined by the position of the rotor.

[0052] The electromagnetic torque experienced by the rotor in a three-phase motor is explained below. For example, formula (1) is the electromagnetic torque formula for a three-phase motor.

[0053]

[0054] Among them, T e Let p be the magnitude of the electromagnetic torque acting on the rotor, and p be the number of pole pairs of the three-phase motor. L represents the magnitude of the magnetic flux linkage in the permanent magnets of the rotor. d L q These are the inductance components of the motor's d-axis and q-axis, respectively. sLet I be the magnitude of the total current vector in the stator winding, and β be the angle between the total current vector and the direction of the magnetic flux linkage of the permanent magnet in the rotor. From formula (1), it can be seen that when the charging current I... a Given a fixed magnitude, the electromagnetic torque T corresponding to a certain three-phase motor e The value of is determined by the included angle β.

[0055] Due to the total current vector i s The size is fixed and the direction coincides with the straight line of phase A of the stator winding. If the position where phase A of the stator winding coincides with the d-axis of the rotor is taken as the starting position, and the counterclockwise direction is taken as the positive direction of the change of the included angle β when rotating along the d-axis, then the range of the included angle β can be recorded as [0°, 360°). For example, Figure 4 An electromagnetic torque T provided in the embodiments of this application e A diagram showing the correspondence between the angle β and the angle β. If Figure 4 As shown, the horizontal axis of the coordinate system represents the value of the included angle β, and the vertical axis represents the electromagnetic torque T. e The possible values. From Figure 4 As can be seen, during the static charging process of a car, the electromagnetic torque T varies depending on the rotor's position. e The value of can be extremely large, which could lead to unintended movement of the electric vehicle.

[0056] S202. Based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor, determine the duty cycle of the bridge arm corresponding to the current position of the rotor.

[0057] In this step, after obtaining the current position of the rotor, the controller can determine the duty cycle of the bridge arm corresponding to the current position of the rotor based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor.

[0058] This application does not limit how the duty cycle of the bridge arm corresponding to the current position of the rotor is determined. In some embodiments, the controller can determine the duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor based on the mapping relationship. The first bridge arm is the bridge arm corresponding to the first stator winding in the three-phase motor, and the second bridge arm is the bridge arm corresponding to the second stator winding in the three-phase motor. The first stator winding is used to output a first current vector, and the second stator winding is used to output a second current vector. For example, the charging current can flow into the A-phase stator winding of the three-phase motor and flow out in parallel from the B-phase and C-phase stator windings. The B-phase and C-phase stator windings of the three-phase motor are respectively connected to the first and second bridge arms in the DC / DC converter.

[0059] This application does not limit the relationship between the duty cycles of the first and second bridge arms. In some embodiments, the sum of the duty cycles of the first and second bridge arms is 1. For example, if the duty cycle of the bridge arm corresponding to the B-phase stator winding is denoted as k, and the duty cycle of the bridge arm corresponding to the C-phase stator winding is defined as 1-k, where the value of k ranges from [0,1], then the proportional distribution of charging current between the B-phase and C-phase can be achieved.

[0060] Furthermore, by adjusting the duty cycle of the bridge arms corresponding to the B-phase and C-phase stator windings, I can be changed. b I c The magnitude of i is then adjusted to control the total current vector i. s The angle θ between phase A and its location. The correspondence between duty cycle k and angle θ is explained below. For example, Figure 5 This is a diagram illustrating the correspondence between duty cycle k and included angle θ, provided for embodiments of this application. Figure 5 As shown, when k=1, I b =-I a I c =0, then the included angle θ is 30°; when k = 0.5, I b =I c =-0.5I a Then the included angle θ is 0°; when k = 1, I b =0, I c =-I a If the position of phase A is taken as the starting position of the angle θ, and the counterclockwise direction is taken as the positive direction of the angle, then the range of values ​​of the angle θ as it changes with the duty cycle k can be recorded as [-30°, 30°].

[0061] In this application embodiment, there are no restrictions on how to determine the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor. In some embodiments, the above mapping relationship can be determined according to the electromagnetic torque formula of the three-phase motor, so as to adjust the included angle β by adjusting k, thereby reducing the electromagnetic torque on the rotor during charging. For example, the current position of the d-axis can be determined according to the current position of the rotor fed back when the car stops; if the included angle α is denoted as the included angle between the current position of the d-axis and the position of phase A, since the adjustment range of the included angle θ can be [-30°, 30°], the adjustment range of the included angle β with the duty cycle k can be [α-30°, α+30°]; according to the electromagnetic torque formula, the included angle β and included angle θ corresponding to the minimum value of the electromagnetic torque can be determined within the adjustment range of included angle β, and then the duty cycle k corresponding to the minimum value of the electromagnetic torque can be determined according to the relationship between included angle θ and duty cycle k, thereby establishing a mapping relationship between the current position of the rotor and the duty cycle k.

[0062] For example, Table 1 is a list of mapping relationships between included angle α and duty cycle k provided in an embodiment of this application. In the original scheme, since the value of k is fixed at 0.5, the included angle α and included angle β are equal in size. In this embodiment, since the value of k can be adjusted, the included angle β can be obtained as included angle α - included angle θ. As shown in the data in Table 1, the electromagnetic torque T on the rotor before the value of k is adjusted... e In comparison, the electromagnetic torque T on the rotor after adjusting the value of k e It has decreased significantly.

[0063] Table 1

[0064] 10 0.35 9.8 0.1 5.242474009 20 0.20 19.1 0.4 10.95945554 30 0.00 30.0 0.0 17.53458912 40 0.00 30.0 4.8 25.18177455 160 0.80 -19.1 1.9 37.3618953 170 0.65 -9.8 0.3 19.29091877 180 0.50 0.0 0.0 1.37E-14

[0065] For example, Figure 6 An electromagnetic torque T provided in the embodiments of this application e A comparison diagram showing the before and after adjustments. (e.g.) Figure 6 As shown, the horizontal axis represents the value of the included angle α, and curve A represents the electromagnetic torque T before k adjustment. e Curve showing the change in angle α; Curve B represents the electromagnetic torque T after k adjustment. e The curve showing the change of angle α. From... Figure 6 It can be clearly seen from the image that the electromagnetic torque T on the rotor after k is adjusted... e Significantly reduced.

[0066] S203. Based on the duty cycle of the bridge arm corresponding to the current position of the rotor, adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor.

[0067] In this step, after determining the duty cycle of the bridge arm corresponding to the current position of the rotor, the controller can adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor according to the duty cycle of the bridge arm corresponding to the current position of the rotor.

[0068] This application does not limit how the aforementioned included angle β is adjusted. In some embodiments, the controller can adjust the angle between the total current vector of the stator windings and the position of the permanent magnet flux linkage of the rotor within a preset included angle adjustment range.

[0069] It should be noted that when the charging current flows in from the center tap of the three-phase motor and outputs from the parallel connection of phases A, B, and C, the electromagnetic torque on the rotor of the three-phase motor is relatively small. However, this scheme has a high current ripple frequency, leading to severe motor heating; secondly, the charging inductor is small, requiring additional hardware to increase the inductance value. The charging control method for a three-phase motor provided in this application, when the charging current flows in from a single phase of the three-phase motor and outputs from the parallel connection of the other two phases, increases the Boost inductance value due to the series connection of the motor phase inductors, thereby reducing the current ripple during the charging process and reducing the use of external charging inductors.

[0070] This application provides a charging control method for a three-phase motor. First, the current position of the rotor in the three-phase motor is obtained. Then, based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the corresponding converter of the three-phase motor, the duty cycle of the bridge arm corresponding to the current rotor position is determined. Finally, based on the duty cycle of the bridge arm corresponding to the current rotor position, the angle between the total current vector of the stator windings and the position of the permanent magnet flux linkage of the rotor is adjusted. By adjusting the angle between the total current vector of the stator windings and the position of the permanent magnet flux linkage of the rotor according to the current rotor position, the electromagnetic torque experienced by the rotor in charging mode is reduced, thereby improving the stability of the charging process and reducing losses and safety hazards.

[0071] Based on the above embodiments, the following explains how the controller determines the duty cycle of the bridge arm corresponding to the current position of the rotor. Figure 7 A flowchart illustrating another charging control method for a three-phase motor provided in this application embodiment is shown below. Figure 7 As shown, the method includes:

[0072] S701. Obtain the current position of the rotor in the three-phase motor.

[0073] S701. Determine the duty cycle of the first bridge arm corresponding to the current position of the rotor based on the mapping relationship between the rotor position and the duty cycle of the first bridge arm.

[0074] S703. Determine the duty cycle of the second bridge arm corresponding to the current position of the rotor based on the relationship between the duty cycles of the first bridge arm and the second bridge arm.

[0075] S704. Based on the duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor, adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor.

[0076] The technical terms, technical effects, technical features, and optional implementation methods of S701-S704 can be found in [reference]. Figure 2The explanations of S201-S203 shown are redundant and will not be repeated here.

[0077] This application provides a charging control method for a three-phase motor. First, the current position of the rotor in the three-phase motor is obtained. Then, based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the corresponding converter of the three-phase motor, the duty cycle of the bridge arm corresponding to the current rotor position is determined. Finally, based on the duty cycle of the bridge arm corresponding to the current rotor position, the angle between the total current vector of the stator windings and the position of the permanent magnet flux linkage of the rotor is adjusted. This method reduces the electromagnetic torque experienced by the motor rotor in the charging mode within the integrated drive and charging circuit of an electric vehicle, thereby improving the stability of the charging process and reducing losses and safety hazards.

[0078] Figure 8 This is a schematic diagram of a charging control device for a three-phase motor provided in an embodiment of this application. This charging control device for the three-phase motor can be implemented through software, hardware, or a combination of both, and can be, for example, the controller in the above embodiment, to execute the charging control method for the three-phase motor in the above embodiment. Figure 8 As shown, the charging control device 800 for the three-phase motor includes:

[0079] The acquisition module 801 is used to acquire the current position of the rotor in the three-phase motor;

[0080] The control module 802 is used to determine the duty cycle of the bridge arm corresponding to the current position of the rotor based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor; and to adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor based on the duty cycle of the bridge arm corresponding to the current position of the rotor.

[0081] In one optional implementation, the control module 802 is specifically used to determine the duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor. The first bridge arm is the bridge arm corresponding to the first stator winding in the three-phase motor, and the second bridge arm is the bridge arm corresponding to the second stator winding in the three-phase motor. The first stator winding is used to output a first current vector, and the second stator winding is used to output a second current vector.

[0082] In one alternative implementation, the sum of the duty cycles of the first bridge arm and the second bridge arm is 1.

[0083] In one optional implementation, the control module 802 is specifically used to adjust the angle between the total current vector of the stator winding and the position of the permanent magnet flux linkage of the rotor in a three-phase motor within a preset angle adjustment range.

[0084] In one alternative implementation, the converter includes a DC-DC converter and / or an AC-DC converter.

[0085] It needs to be explained that, Figure 8 The charging control device for a three-phase motor provided in the illustrated embodiment can be used to execute the charging control method for a three-phase motor provided in any of the above embodiments. The specific implementation and technical effects are similar, and will not be described in detail here.

[0086] This application also provides an electric vehicle, including: a battery and a charging control circuit; the charging control circuit is connected to the battery, and the controller in the charging control circuit is used to execute the charging control method for a three-phase motor provided in the above method embodiments.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A charging control method for a three-phase motor, characterized in that, The charging current flows into one phase of the stator winding in a three-phase motor and flows out in parallel from the other two phase stator windings. The method includes: Obtain the current position of the rotor in the three-phase motor; Based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor, the duty cycle of the bridge arm corresponding to the current position of the rotor is determined. Based on the duty cycle of the bridge arm corresponding to the current position of the rotor, adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor.

2. The method according to claim 1, characterized in that, Determining the duty cycle of the bridge arm corresponding to the current position of the rotor includes: The duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor are determined. The first bridge arm is the bridge arm corresponding to the first stator winding in the three-phase motor, and the second bridge arm is the bridge arm corresponding to the second stator winding in the three-phase motor. The first stator winding is used to output the first current vector, and the second stator winding is used to output the second current vector.

3. The method according to claim 2, characterized in that, The sum of the duty cycle of the first bridge arm and the duty cycle of the second bridge arm is 1.

4. The method according to claim 1, characterized in that, Adjusting the angle between the total current vector of the stator windings in the three-phase motor and the position of the permanent magnet flux linkage of the rotor includes: Within a preset angle adjustment range, adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor.

5. The method according to any one of claims 1-4, characterized in that, The converter includes a DC-DC converter and / or an AC-DC converter.

6. A charging control device for a three-phase motor, characterized in that, The charging current flows into one phase of the stator winding of the three-phase motor and flows out in parallel from the other two phase stator windings. The device includes: The acquisition module is used to acquire the current position of the rotor in the three-phase motor; The control module is used to determine the duty cycle of the bridge arm corresponding to the current position of the rotor based on the mapping relationship between the position of the rotor and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor; and to adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor based on the duty cycle of the bridge arm corresponding to the current position of the rotor.

7. The apparatus according to claim 6, characterized in that, The control module is specifically used to determine the duty cycle of the first bridge arm and the duty cycle of the second bridge arm corresponding to the current position of the rotor. The first bridge arm is the bridge arm corresponding to the first stator winding in the three-phase motor, and the second bridge arm is the bridge arm corresponding to the second stator winding in the three-phase motor. The first stator winding is used to output a first current vector, and the second stator winding is used to output a second current vector.

8. The apparatus according to claim 7, characterized in that, The sum of the duty cycle of the first bridge arm and the duty cycle of the second bridge arm is 1.

9. The apparatus according to claim 6, characterized in that, The control module is specifically used to adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor within a preset angle adjustment range.

10. The apparatus according to any one of claims 6-9, characterized in that, The converter includes a DC-DC converter and / or an AC-DC converter.

11. A charging control circuit for a three-phase motor, characterized in that, The charging current flows into one phase of the stator winding in the three-phase motor and flows out in parallel from the other two phase stator windings. The circuit includes: Controller, three-phase motor and converter; The controller is connected to the three-phase motor and the converter respectively, and the three-phase motor is connected to the converter; The controller is configured to: acquire the current position of the rotor in the three-phase motor; determine the duty cycle of the bridge arm corresponding to the current position of the rotor based on the mapping relationship between the rotor position and the duty cycle of the bridge arm in the converter corresponding to the three-phase motor; and adjust the angle between the total current vector of the stator winding in the three-phase motor and the position of the permanent magnet flux linkage of the rotor based on the duty cycle of the bridge arm corresponding to the current position of the rotor.

12. An electric vehicle, characterized in that, include: A battery and a charging control circuit; the charging control circuit is connected to the battery, and a controller in the charging control circuit is used to perform the method as described in any one of claims 1 to 5.

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