Control method for motor system, motor control device, and motor system

Abstract

A control method of a motor system includes detecting a battery temperature of a battery, determining whether the battery temperature is less than a threshold temperature, and generating a heating request signal to control the motor system to execute a battery heating procedure when it is determined that the battery temperature is less than the threshold temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to a control method of a motor system, a motor control device and a motor system, in particular to a control method of an active heating function of an asynchronous motor system based on an electric vehicle, a motor control device and a motor system. BACKGROUND

[0002] The technology of electric vehicles is increasingly mature. Due to the characteristics of the battery, the battery needs to be heated to a suitable use temperature to achieve the best use condition when the electric vehicle is used in a cold charging environment. At present, most electric vehicles use the method of adding positive temperature coefficient (PTC) heating resistance wire to heat the battery, which further generates additional costs and parts procurement requirements. Therefore, how to achieve the purpose of heating the battery without increasing the original manufacturing cost has become one of the topics of concern in the industry. SUMMARY

[0003] (I) Invention purposes

[0004] The purpose of the present application is to provide a control method of a motor system, a motor control device and a motor system to solve the above problems.

[0005] (II) Technical solutions

[0006] In order to solve the above problems, according to one aspect of the present application, the present application provides a control method of a motor system, comprising: detecting a battery temperature of a battery; determining whether the battery temperature is less than a threshold temperature; and generating a heating request signal to control the motor system to execute a battery heating program when it is determined that the battery temperature is less than the threshold temperature.

[0007] According to another aspect of the present application, the present application provides a motor control device for use in a motor system, comprising: a temperature detector for detecting a battery temperature of a battery; a processing circuit for generating a heating request signal according to the battery temperature and a threshold temperature; a motor controller for outputting a D-axis sinusoidal current according to the heating request signal; and a coordinate conversion device for converting the D-axis sinusoidal current into a three-phase current to control the motor system to execute a battery heating program.

[0008] According to another aspect of the present application, the present application provides a motor electronic system, comprising: a high-voltage battery; a motor; a motor control device for controlling the motor to actively generate heat to produce heat energy when the high-voltage battery has a heating demand; and a heat conduction assembly cooling device for conducting the heat energy generated by the motor to the high-voltage battery. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The schematic diagram of the motor system of the embodiment of the present application;

[0010] Figure 2 Flowchart of an embodiment of the present application;

[0011] Figure 3 Schematic diagram of an embodiment of the present application coordinate conversion device utilizing inverse Park conversion to convert D-axis sinusoidal current to three-phase current;

[0012] Figures 4 to 6 Schematic diagram of an embodiment of the present application motor control device and motor operation when the temperature of the high-voltage battery is too low.

[0013] Figure 7 Schematic diagram of another embodiment of the present application motor system with active battery heating.

[0014] Reference signs:

[0015] 1, 7: motor system

[0016] 10: motor control device

[0017] 102: temperature probe

[0018] 104: processing circuit

[0019] 1042: receiving module

[0020] 1044: comparison module

[0021] 106: motor controller

[0022] 108: coordinate conversion device

[0023] 110: power switch circuit

[0024] 2: flowchart

[0025] 20: motor

[0026] 202: stator winding

[0027] 30: high-voltage battery

[0028] 40: heat conduction assembly

[0029] S200, S202, S204, S206, S208: steps DETAILED DESCRIPTION

[0030] Certain terms are used throughout the present description and claims to refer to particular components. As one skilled in the art will appreciate, manufacturers can refer to a component by different names. This document does not intend to distinguish between components that differ in name but not in function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to." Also, the term "couple" or "coupled" as used herein is intended to mean either an indirect or direct electrical connection. Thus, if a first device couples to a second device, that connection can be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.

[0031] Reference is made to Figure 1 , Figure 1 is a schematic diagram of a motor system 1 according to an embodiment of the present application. The motor system 1 includes a motor control device 10, a motor 20, and a high-voltage battery 30. The motor 20 can be an asynchronous motor, for example, but is not limited thereto. The motor system 1 can be an asynchronous motor system of an electric vehicle. The high-voltage battery 30 can supply electric energy to the motor control device 10. The motor control device 10 is configured to control the motor 20 to generate thermal energy for a battery heating procedure when a temperature of the high-voltage battery 30 is too low, and to provide the generated thermal energy to the high-voltage battery 30 so that the high-voltage battery 30 is warmed up to implement the battery heating procedure. The motor 20 can provide the generated thermal energy to the high-voltage battery 30 through a thermal conduction component to implement the battery heating procedure. The motor control device 10 includes a temperature detector 102, a processing circuit 104, a motor controller 106, and a coordinate conversion device 108. The temperature detector 102 is configured to detect a battery temperature of the high-voltage battery 30. The processing circuit 104 is configured to generate a heating request signal according to the battery temperature and a threshold temperature. The motor controller 106 is configured to output a D-axis sinusoidal current according to the heating request signal. The coordinate conversion device 108 is configured to convert the D-axis sinusoidal current into a three-phase current to control the motor system 1 to implement the battery heating procedure.

[0032] Reference is made to Figure 2 , with respect to a method of operating the motor system 1, which can be summarized as flow 2, reference is made to Figure 2 , Figure 2 is a schematic diagram of flow 2 according to an embodiment of the present application. Flow 2 includes the following steps:

[0033] Step S200: Start.

[0034] Step S202: Detect a battery temperature of a high-voltage battery.

[0035] Step S204: Determine whether the battery temperature is less than a threshold temperature.

[0036] Step S206: A heating request signal is generated to control the motor system to perform a battery heating procedure when the battery temperature is determined to be less than the threshold temperature.

[0037] Step S208: End.

[0038] According to flow 2, in step S202, the high voltage battery 30 can provide electric energy for the electric vehicle to operate, for example, the motor system 1 is applied in an electric vehicle. After the electric vehicle is started, the temperature detector 102 detects the battery temperature of the high voltage battery 30. In step S204, the processing circuit 104 determines whether the battery temperature is less than the threshold temperature. For example, the processing circuit 104 includes a receiving module 1042 and a comparison module 1044. The receiving module 1042 is used to receive the battery temperature. The comparison module 1044 is used to compare the battery temperature with the threshold temperature.

[0039] In step S206, when the battery temperature is determined to be less than the threshold temperature, the comparison module 1044 of the processing circuit 104 generates a heating request signal. Then, the motor control device 10 generates three-phase current according to the heating request signal to control the motor 20 to operate to generate heat energy, and the motor 20 provides the generated heat energy to the battery 30, thereby heating the battery to achieve a battery heating procedure. The electrical angle of the three-phase current output by the motor control device 10 is sequentially increased from an initial angle. For example, the initial angle can be 30 degrees or other angles. The electrical angle of the three-phase current output by the control device 10 can be sequentially increased from the initial angle and the electrical angle is sequentially increased by a first angle.

[0040] In an embodiment, the electrical angle is increased by the first angle every predetermined time. For example, the first angle is 60 degrees, and the electrical angle can be sequentially increased by 60 degrees every predetermined time from the initial angle.

[0041] In another embodiment, the electrical angle is increased by a first angle each time the D-axis sinusoidal current crosses zero. For example, the first angle is 60 degrees, and the electrical angle can be increased by 60 degrees each time the D-axis sinusoidal current crosses zero, starting from an initial angle. In other words, after the processing circuit 104 generates the heating request signal, the motor controller 106 outputs the D-axis sinusoidal current according to the heating request signal. The coordinate conversion device 108 is configured to convert the D-axis sinusoidal current into three-phase currents to control the motor system 1 to perform the battery heating procedure. For example, the coordinate conversion device 108 converts the D-axis sinusoidal current into three-phase currents using an inverse Clark transformation method or an inverse Park transformation method to control the motor system 1 to perform the battery heating procedure. More specifically, the coordinate conversion device 108 converts the three-phase currents and outputs the three-phase currents to the motor 20, so that the motor 20 operates to generate heat energy. The heat energy generated by the operation of the motor 20 can be provided to the high-voltage battery 30, so that the high-voltage battery 30 is warmed up to achieve the purpose of the battery heating procedure. At the same time, since the electrical angle of the three-phase currents output by the motor control device 10 is sequentially increased from an initial angle and the electrical angle is increased by a first angle each time, the motor 20 can be evenly heated to achieve the purpose of the battery heating.

[0042] Please refer to Figure 3 , Figure 3 is a schematic diagram of the coordinate conversion device 108 of an embodiment of the application converting the D-axis sinusoidal current into three-phase currents using an inverse Park transformation method. When the battery temperature is less than the threshold temperature, the processing circuit 104 generates a heating request signal, and the motor controller 106 outputs a D-axis sinusoidal current, a Q-axis current, and a zero-axis current according to the heating request signal, wherein the amplitude of the D-axis sinusoidal current is related to a heating power of the motor system 1, and the Q-axis current and the zero-axis current are assumed to be zero. As shown in equation (1).

[0043] I D = A * sin(2πf)

[0044] I Q = 0 I0= 0 (1)

[0045] wherein I D is the D-axis sinusoidal current, A is the amplitude of the D-axis sinusoidal current, I Q is the Q-axis current, and I0is the zero-axis current.

[0046] The coordinate conversion device 108 converts the D-axis sinusoidal current output by the motor controller 106 according to the heating request signal into three-phase currents I U , I V , and I Wto control the motor system 1 to execute a battery heating program. The inverse Park conversion is shown in equation (2).

[0047]

[0048] where I U , I V , I W are three-phase currents, θ is an electrical angle for the inverse Park conversion, I D is a D-axis sinusoidal current, I Q is a Q-axis current, and I0is a zero-axis current.

[0049] For example, the coordinate conversion device 108 converts the D-axis sinusoidal current, the Q-axis current, and the zero-axis current outputted from the motor controller 106 according to the heating request signal into the three-phase currents I U , I V , I W using the inverse Park conversion, the electrical angles of the three-phase currents I U , I V , I W are different by 120°, respectively, as shown in equation (3).I u = cos θ * A * sin (2πf)

[0050] I u = cos (θ - 120°) * A * sin (2πf)

[0051] I u = cos (θ + 120°) * A * sin (2πf) (3)

[0052] where I U , I V , I W are three-phase currents, and θ is an electrical angle of the three-phase currents (i.e., an electrical angle for the inverse Park conversion).

[0053] In a variant embodiment, the electrical angle θ of the inverse Park conversion is sequentially increased from an initial angle, and the electrical angle θ is increased by a first angle in turn. For example, the initial angle is 30 degrees and the first angle is 60 degrees, the electrical angle is increased by 60 degrees every predetermined time or the electrical angle is increased by 60 degrees every time the D-axis sinusoidal current passes through zero.

[0054] For example, if the first angle is 60°, the electrical angle is increased by 60° every predetermined time. Assuming that the initial angle is 30° at a first time T1, that is, the electrical angle θ = 30°, cos (θ - 120°) = 0, the three-phase currents I U , I V , I WAs shown in equation (4).

[0055]

[0056] I v = 0 * A * sin(2πf)

[0057]

[0058] When at the second time T2, the electrical angle θ is increased from 30° to 90°, the electrical angle θ = 90°, cos θ = 0, three-phase current I U , I V , I W As shown in equation (5).

[0059] I u = 0 * A * sin(2πf)

[0060]

[0061]

[0062] When at the third time T3, the electrical angle θ is increased from 90° to 150°, the electrical angle θ = 150°, cos(θ + 120°) = 0, three-phase current I U , I V , I W As shown in equation (6).

[0063]

[0064]

[0065] I w = 0 * A * sin(2πf) (6)

[0066] When at the fourth time T4, the electrical angle θ is increased from 150° to 210°, the electrical angle θ = 210°, cos(θ - 120°) = 0, three-phase current I U , I V , I W As shown in equation (7).

[0067]

[0068] I v = 0 * A * sin(2πf)

[0069]

[0070] When the electric angle θ is increased from 210° to 270° at the fifth time T5, and the electric angle θ = 270°, cos θ = 0, The three-phase current I U , I V , I W is shown as formula (8).

[0071] The three-phase current I u = 0 * A * sin (2πf)

[0072]

[0073]

[0074] When the electric angle θ is increased from 270° to 330° at the sixth time T6, and so on. When the electric angle θ = 330°, cos (θ + 120°) = 0, the three-phase current I U , I V , I W is shown as formula (9).

[0075]

[0076]

[0077] The three-phase current I w = 0 * A * sin (2πf) (9)

[0078] Please refer to Figure 4 , Figures 4 to 6 is the operation schematic diagram of the motor control device 10 and the motor 20 of the embodiment of the application for balancing heat generation when the temperature of the high-voltage battery 30 is too low, as shown in Figure 4 The motor control device 10 further includes a power switch circuit 110. The motor controller 106 generates a D-axis sinusoidal current according to the heating request signal, and the coordinate conversion device 108 converts the D-axis sinusoidal current into the three-phase current I U , I V , I W . The power switch circuit 110 is used to control the output of the three-phase current I U , I V , I W . The three-phase current I U , I V , I W is output to drive the operation of the motor 20 and generate heat energy. The motor 20 includes a stator winding 202. The stator winding 202 includes a first resistor R U , a second resistor R V , and a third resistor R WWhen three-phase current flows through stator winding 202, heat energy can be generated. For example, three-phase current I U Through the first resistor R U Three-phase current I V Through the second resistor R V and three-phase current I W Through the third resistor R W This makes the first resistance R of stator winding 202 U Second resistor R V and the third resistor R W Heat is generated. The heat generated by the motor 20 can be supplied to the high-voltage battery 30 to raise the temperature of the high-voltage battery 30 and achieve the purpose of the battery heating program.

[0079] In one embodiment, please continue to refer to Figures 4-6 At the first time T1, the three-phase current I is as shown in equation (4). U I V I W Drive stator winding 202, where three-phase current I V It is zero, therefore, as Figure 4 As shown, the three-phase current I is controlled by the power switching circuit 110. U Through the first resistor R U and three-phase current I W Through the third resistor R W This makes the first resistance R of stator winding 202 U and the third resistor R W Heat is generated because of the three-phase current I. V The value is zero, therefore the second resistance R V No current flows and therefore no heat is generated. At the second time T2, the three-phase current I is as shown in equation (5). U I V I W Drive stator winding 202, where three-phase current I U It is zero, therefore, as Figure 5 As shown, the three-phase current I is controlled by the power switching circuit 110. V Through the second resistor R V and three-phase current I W Through the third resistor R W This makes the second resistance R of stator winding 202 V and the third resistor R W Heat is generated because of the three-phase current I. U The first resistance R is zero. U No current flows and therefore no heat is generated. At the third time T3, the three-phase current I is as shown in equation (6). U I V IW The stator winding 202 is driven, and as shown by the control of the power switching circuit 110, the three-phase current I Figure 6 U passes through the first resistor R U and the three-phase current I V passes through the second resistor R V The first resistor R U and the second resistor R V of the stator winding 202 generate heat energy, and because the three-phase current I W is zero, the third resistor R W has no current passing therethrough and does not generate heat energy. At the fourth time T4, the three-phase current I U , I V , I W drives the stator winding 202, and as shown by the control of the power switching circuit 110, the three-phase current I Figure 4 U passes through the first resistor R U and the three-phase current I W passes through the third resistor R W The first resistor R U and the third resistor R W of the stator winding 202 generate heat energy, and because the three-phase current I V is zero, the second resistor R V has no current passing therethrough and does not generate heat energy. At the fifth time T5, the three-phase current I U , I V , I W drives the stator winding 202, and as shown by the control of the power switching circuit 110, the three-phase current I Figure 5 V passes through the second resistor R V and the three-phase current I W passes through the third resistor R W The second resistor R V and the third resistor R W of the stator winding 202 generate heat energy, and because the three-phase current I U is zero, the first resistor R U has no current passing therethrough and does not generate heat energy. At the sixth time T6, the three-phase current I U , I V , I W drives the stator winding 202, and as shown by the control of the power switching circuit 110, the three-phase current I Figure 6 U passes through the first resistor R U and the three-phase current I V ​​​​through the second resistor R V The first resistor R U of the stator winding 202 is made to generate heat energy, and because the three-phase current I V is zero, the third resistor R W has no current passing through and generates no heat energy. W

[0080] In other words, the coordinate conversion device 108 converts the D-axis sinusoidal current outputted by the motor controller 106 according to the heating request signal into the three-phase current I U , I V , I W using the inverse Park conversion, and sequentially increases the electrical angle of the inverse Park conversion by 60 degrees every predetermined time starting from the initial angle of 30 degrees to achieve the alternating balanced output of the three-phase current, so that the heat energy generated by the stator winding is kept balanced in a long time range, thereby achieving the function of active balanced heating.

[0081] When the embodiment of the present application is applied to an electric vehicle, no additional components are needed, and the battery heating purpose can be achieved directly by using the motor system 1 on the electric vehicle. At the same time, the active balanced heating function of the motor system 1 of the embodiment of the present application can meet the demand of the whole vehicle heating function, and ensure the reliability and stability of the system.

[0082] Please refer to Figure 7 , Figure 7 is a schematic diagram of the motor system 7 with active battery heating according to the embodiment of the present application. The motor system 7 includes a motor control device 10, a motor 20, a high-voltage battery 30, and a heat conduction component 40. The motor control device 10 outputs a three-phase current to drive the motor 20 to operate when there is a heating demand for the high-voltage battery 30, so that the motor 20 operates to actively and balancedly generate heat to provide heat energy for the high-voltage battery 30. The heat conduction component 40 is used to transfer the heat energy generated by the motor 20 to the high-voltage battery 30. The heat conduction component 40 can be the original cooling device and cooling loop of the motor system 7. When there is a heating demand for the heat energy generated by the motor 20, the original cooling device and cooling loop of the motor system 7 can be used to transfer the heat energy generated by the motor 20 to the high-voltage battery 30 to achieve the purpose of battery heating. The heat conduction component 40 can also be any device that can conduct heat energy, such as a heat conduction sheet, a heat conduction fin, or a device made of a material with good heat conduction coefficient, but is not limited thereto.

[0083] ​The above-described embodiments can be combined, modified, or varied by those skilled in the art in accordance with the spirit of the present application without being limited thereto. All of the above-described statements, steps, and / or processes (including suggested steps) can be implemented by hardware, software, firmware (i.e., a combination of hardware devices and computer instructions, data in the hardware devices being read-only software data), electronic systems, or a combination of the above devices, etc. The hardware can include analog, digital, and hybrid circuits (i.e., microcircuits, microchips, or silicon chips). The electronic systems can include system on chip (SoC), system in package (SiP), computer on module (CoM), and motor system 1. The process steps and embodiments of the present application can exist in the form of program codes or instructions and be stored in a computer-readable recording medium. The computer-readable recording medium can include read-only memory (ROM), Flash Memory, random-access memory (RAM), Subscriber Identity Module (SIM), hard disk, floppy disk, or compact disc read-only memory (CD-ROM / DVD-ROM / BD-ROM), but is not limited thereto. A processor can be used to read and execute the program codes or instructions stored in the computer-readable medium to implement all of the above-described steps and functions.

[0084] In summary, the motor system of the embodiment of the present application performs a battery heating program when the battery temperature of the high-voltage battery 30 is less than the threshold temperature, so that the alternating balanced output of three-phase current is achieved, and the heat energy generated by the motor stator winding is kept balanced in a long time range, thereby achieving the function of active balanced heating. When applied to an electric vehicle, no additional components are needed, and the battery heating purpose can be achieved by directly using the motor system on the electric vehicle. Therefore, the active balanced heating function of the motor system 1 of the embodiment of the present application can meet the demand of the whole vehicle heating function, while ensuring the reliability and stability of the system.

[0085] The above-described embodiments are merely preferred embodiments of the present application and are not intended to limit the present application. Various modifications and changes can be made by those skilled in the art without departing from the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A control method of an electric motor system, characterized by, comprising: detecting a battery temperature of a battery; determining whether the battery temperature is less than a threshold temperature; generating a heating request signal when it is determined that the battery temperature is less than the threshold temperature; outputting, by a motor controller of the motor system, a D-axis sinusoidal current according to the heating request signal, and outputting a Q-axis current and a zero-axis current as zero; and converting the D-axis sinusoidal current into a three-phase current by performing an inverse Park's transformation to control the motor to operate to generate heat energy and to provide the generated heat energy to the battery to warm up the battery to implement a battery heating procedure; wherein an electrical angle for performing the inverse Park's transformation is sequentially increased from an initial angle, and the electrical angle is sequentially increased by a first angle, the initial angle being 30 degrees and the first angle being 60 degrees, such that in the battery heating procedure, a current of each phase of the three-phase current is sequentially and alternately zero, and at the same time, currents of the other two phases are not zero.

2. The control method of claim 1, wherein the electrical angle is increased by the first angle every predetermined time.

3. The control method of claim 1, wherein the electrical angle is increased by the first angle every time the D-axis sinusoidal current passes zero.

4. The control method of claim 1, wherein an amplitude of the D-axis sinusoidal current is related to a heat generation power of the motor system.

5. The control method of claim 1, wherein the battery is a high-voltage battery. comprising:

6. An electric motor control device for use in an electric motor system, characterized by comprising: a temperature detector for detecting a battery temperature of a battery; a processing circuit for generating a heating request signal according to the battery temperature and a threshold temperature; a motor controller for outputting a D-axis sinusoidal current according to the heating request signal, and outputting a Q-axis current and a zero-axis current as zero; a coordinate conversion device for converting the D-axis sinusoidal current into a three-phase current to control the motor system to implement a battery heating procedure, wherein the coordinate conversion device converts the D-axis sinusoidal current into the three-phase current by using an inverse Clark's transformation or an inverse Park's transformation, and an electrical angle for performing the inverse Park's transformation is sequentially increased from an initial angle, and the electrical angle is sequentially increased by a first angle, the initial angle being 30 degrees and the first angle being 60 degrees, such that in the battery heating procedure, a current of each phase of the three-phase current is sequentially and alternately zero, and at the same time, currents of the other two phases are not zero. the processing circuit further comprises:

7. The motor control device of claim 6, wherein a receiving module for receiving the battery temperature; and a comparing module for comparing the battery temperature with the threshold temperature and generating the heating request signal when the battery temperature is lower than the threshold temperature.

8. The motor control device of claim 6, wherein the motor is an asynchronous motor.

9. The motor control device of claim 8, wherein the asynchronous motor further comprises: a stator winding through which the three-phase current passes to generate heat energy.

10. The motor control device of claim 6, wherein the electrical angle is increased by the first angle every predetermined time; or ​ The electrical angle is increased by the first angle each time the D-axis sinusoidal current crosses zero.

11. The motor control device of claim 6, wherein, The D-axis sinusoidal current is related to a heating power of the motor system.

12. The motor control device of claim 6, wherein, The battery is a high-voltage battery.

13. An electric machine system characterized by Comprising: a high-voltage battery; a motor; The motor control device of claim 6, for controlling the motor to actively generate heat energy when the high-voltage battery has a heating demand; and a heat conduction assembly for conducting the heat energy generated by the motor to the high-voltage battery.

14. The motor system of claim 13, wherein, The heat conduction assembly is a cooling device of the motor system.

Images