Current zero position determination method, device and storage medium

Abstract

The present application discloses a method, device and storage medium for determining current zero position, which belongs to the field of motor control technology. The method includes: at the startup moment of the controller, obtaining the bus current value of the bus input to the inverter as the first bus current value, and obtaining the three-phase current value output by the inverter to the motor; during the operation of the controller, if the mechanical power of the motor is zero, obtaining the bus current value of the bus input to the inverter as the second bus current value; taking the difference between the second bus current value and the first bus current value as the current zero position drift value; and determining the three-phase current zero position based on the current zero position drift value and the three-phase current value. The present application can accurately determine the three-phase current zero position of the motor, thereby facilitating the controller to accurately control the motor accordingly.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a current zero position determination method, device, and storage medium. Background Art

[0002] A motor system typically consists of a busbar, a motor, an inverter connected between the busbar and the motor, and a controller connected to the inverter. Accurate control of the three-phase current input to the motor by the controller is crucial in a motor system. To ensure the accuracy of the three-phase current, it is necessary to determine the zero position of the three-phase current.

[0003] In the related art, the zero position of the three-phase current is not accurate enough, which affects the accurate control of the motor by the controller. Summary of the Invention

[0004] This application provides a current zero position determination method, device, and storage medium that can accurately determine the three-phase current zero position of a motor, thereby facilitating a controller to accurately control the motor. The technical solution is as follows:

[0005] In a first aspect, a current zero position determination method is provided, which is applied to a controller in a motor system, wherein the motor system includes a bus, an inverter, a motor, and the controller, wherein the inverter is connected between the bus and the motor, and the controller is connected to the inverter, and the method includes:

[0006] At the start-up moment of the controller, a bus current value input from the bus to the inverter is obtained as a first bus current value, and a three-phase current value output from the inverter to the motor is obtained;

[0007] During operation of the controller, if the mechanical power of the motor is zero, obtaining a bus current value input from the bus to the inverter as a second bus current value;

[0008] Taking the difference between the second bus current value and the first bus current value as the current zero drift value;

[0009] The three-phase current zero point is determined according to the current zero point drift value and the three-phase current values.

[0010] In the present application, at the startup moment of the controller, the mechanical power of the motor is zero. At this time, the first bus current value and the three-phase current value of the motor are obtained, and the obtained three-phase current value is the initial zero position of the three-phase current. During the operation of the controller, the temperature of the motor system increases. During this operation, if the mechanical power of the motor is still zero, the mechanical power of the bus is also close to zero. At this time, the second bus current value can be obtained, and the difference between the second bus current value and the first bus current value is the current zero drift value caused by the increase in the temperature of the motor system. Therefore, according to the current zero drift value and the initial zero position of the three-phase current, the three-phase current zero position during the operation of the controller can be determined, so that the controller can accurately control the motor accordingly.

[0011] Optionally, the method further includes:

[0012] Obtaining the speed and torque of the motor;

[0013] If the rotation speed of the motor is less than or equal to the rotation speed threshold and the torque of the motor is zero, it is determined that the mechanical power of the motor is zero.

[0014] Optionally, the rotation speed threshold is less than or equal to one third of the rated rotation speed of the motor.

[0015] Optionally, the three-phase current values include an A-phase current value, a B-phase current value, and a C-phase current value, and determining the three-phase current zero position according to the current zero position drift value and the three-phase current values includes:

[0016] The sum of the A-phase current value and the current zero drift value is used as the A-phase current zero position;

[0017] The sum of the B-phase current value and the current zero drift value is used as the B-phase current zero position;

[0018] The sum of the C-phase current value and the current zero drift value is taken as the C-phase current zero point.

[0019] Optionally, at the startup moment of the controller, obtaining a bus current value input from the bus to the inverter as a first bus current value, and obtaining a three-phase current value output from the inverter to the motor, includes:

[0020] At the startup moment of the controller, the bus current value of the bus input to the inverter is obtained as the first bus current value through the first Hall current sensor, and the three-phase current value of the inverter output to the motor is obtained through the second Hall current sensor.

[0021] Optionally, after determining the three-phase current zero position according to the current zero position drift value and the three-phase current value, the method further includes:

[0022] According to the three-phase current zero position, the magnitude of the three-phase current output by the inverter to the motor is controlled.

[0023] In a second aspect, a current zero position determination device is provided. The device is applied to a controller in a motor system. The motor system includes a bus, an inverter, a motor, and the controller. The inverter is connected between the bus and the motor, and the controller is connected to the inverter. The device includes:

[0024] a current acquisition module, configured to acquire, at the startup moment of the controller, a bus current value input from the bus to the inverter as a first bus current value, and to acquire a three-phase current value output from the inverter to the motor;

[0025] The current acquisition module is further configured to, during operation of the controller, if the mechanical power of the motor is zero, acquire a bus current value input from the bus to the inverter as a second bus current value;

[0026] a difference determination module, configured to use the difference between the second bus current value and the first bus current value as a current zero drift value;

[0027] The current zero position determination module is used to determine the three-phase current zero position according to the current zero position drift value and the three-phase current value.

[0028] Optionally, the device further comprises:

[0029] A motor data acquisition module, used to obtain the speed and torque of the motor;

[0030] The judgment module is configured to determine that the mechanical power of the motor is zero if the rotational speed of the motor is less than or equal to a rotational speed threshold and the torque of the motor is zero.

[0031] Optionally, the rotation speed threshold is less than or equal to one third of the rated rotation speed of the motor.

[0032] Optionally, the three-phase current value includes an A-phase current value, a B-phase current value, and a C-phase current value, and the current zero position determination module is configured to:

[0033] The sum of the A-phase current value and the current zero drift value is used as the A-phase current zero position;

[0034] The sum of the B-phase current value and the current zero drift value is used as the B-phase current zero position;

[0035] The sum of the C-phase current value and the current zero drift value is taken as the C-phase current zero point.

[0036] Optionally, the current acquisition module is used to:

[0037] At the startup moment of the controller, the bus current value of the bus input to the inverter is obtained as the first bus current value through the first Hall current sensor, and the three-phase current value of the inverter output to the motor is obtained through the second Hall current sensor.

[0038] Optionally, the device further comprises:

[0039] A control module is used to control the magnitude of the three-phase current output by the inverter to the motor according to the zero position of the three-phase current.

[0040] In a third aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the method described in the first aspect when executed by the processor.

[0041] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method described in the first aspect is implemented.

[0042] It can be understood that the beneficial effects of the second, third and fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] Figure 1 It is a structural diagram of a motor system in the related art;

[0045] Figure 2 This is a flow chart of a first current zero position determination method provided in an embodiment of the present application;

[0046] Figure 3 1 is a schematic structural diagram of a motor system provided in an embodiment of the present application;

[0047] Figure 4 This is a flow chart of a second current zero position determination method provided in an embodiment of the present application;

[0048] Figure 5 This is a flowchart of an operation for determining whether the mechanical power of a motor is 0, provided by an embodiment of the present application;

[0049] Figure 6 This is a flow chart of a third current zero position determination method provided in an embodiment of the present application;

[0050] Figure 7 This is a flow chart of a current zero position determination device provided by an embodiment of the present application;

[0051] Figure 8 It is a structural diagram of a computer device provided in an embodiment of the present application.

[0052] The meanings of the figures are as follows:

[0053] 10. Motor system;

[0054] 102. A first Hall current sensor;

[0055] 104. A second Hall current sensor;

[0056] 110, busbar;

[0057] 120. Inverter;

[0058] 130. Motor;

[0059] 140. Controller;

[0060] 150, power supply;

[0061] 20. Current zero position determination device;

[0062] 201. Current acquisition module;

[0063] 202. Difference determination module;

[0064] 203. Current zero position determination module;

[0065] 30. Computer equipment;

[0066] 31. Memory;

[0067] 32. Computer programs;

[0068] 33. Processor. DETAILED DESCRIPTION

[0069] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0070] It should be understood that the “multiple” mentioned in this application refers to two or more. In the description of this application, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate the clear description of the technical solution of this application, words such as “first” and “second” are used to distinguish between identical or similar items with basically the same functions and effects. Those skilled in the art can understand that words such as “first” and “second” do not limit the quantity and execution order, and words such as “first” and “second” do not necessarily limit them to be different.

[0071] Before explaining the embodiments of the present application in detail, the application scenarios of the embodiments of the present application are first explained.

[0072] Figure 1 1 is a schematic diagram of the structure of a motor system 10 in the related art. The motor system 10 can be applied to electric vehicles and other equipment. Figure 1 The motor system 10 generally includes a busbar 110, a motor 130, an inverter 120 connected between the busbar 110 and the motor 130, and a controller 140. The busbar 110 is connected between the power supply 150 and the inverter 120, and is used to transmit the direct current in the power supply 150 to the inverter 120. The inverter 120 is used to convert the direct current into three-phase current (i.e., three-phase alternating current) and transmit the three-phase current to the motor 130, so that the motor 130 is powered and works. The controller 140 is connected to the inverter 120, and the controller 140 can control the magnitude and frequency of the three-phase current output by the inverter 120 to the motor 130. In the motor system 10, if the controller 140 wants to accurately control the speed of the motor 130, it needs to accurately control the magnitude of the three-phase current input to the motor 130. In order to accurately control the magnitude of the three-phase current input to the motor 130, it needs to accurately locate the zero position of the three-phase current.

[0073] In the related art, the three-phase current output from the inverter 120 to the motor 130 at the start-up time of the controller 140 is generally used as the zero position of the three-phase current. However, during the operation of the motor system 10, the temperature increases, causing the zero position of the three-phase current to drift.

[0074] To this end, an embodiment of the present application provides a current zero position determination method, which can accurately determine the zero position of the three-phase current in the motor system 10, thereby improving the control accuracy of the motor 130.

[0075] The current zero position determination method provided in the embodiment of the present application is explained in detail below.

[0076] The current zero position determination method provided in the embodiment of the present application is applied to the controller 140 in the motor system 10. Figure 1 The motor system 10 includes a busbar 110, an inverter 120, a motor 130, and a controller 140. The busbar 110 is used to output DC power to the inverter 120. The inverter 120 is connected between the busbar 110 and the motor 130 and is used to convert the DC power into three-phase current and output it to the motor 130, thereby energizing the motor 130. The controller 140 is connected to the inverter 120 and can control the magnitude and frequency of the three-phase current output by the inverter 120 to the motor 130.

[0077] Figure 2 This is a flow chart of a method for determining current zero position provided by an embodiment of the present application. Figure 2 , the method includes the following steps.

[0078] S100 , when the controller 140 is started, a bus current value input from the bus 110 to the inverter 120 is obtained as a first bus current value, and three-phase current values output from the inverter 120 to the motor 130 are obtained.

[0079] The startup moment of the controller 140 refers to the moment when the controller 140 switches from the power-off state to the power-on state, is powered on and starts working. In the motor system 10, at the startup moment of the controller 140, the mechanical power of the motor 130 is zero. At this time, the bus current value input from the bus 110 to the inverter 120 is obtained and recorded as the first bus current value. In other words, the first bus current value is the magnitude of the current in the bus 110 at the startup moment of the controller 140. At the same time, at the startup moment of the controller 140, the magnitude of the three-phase current output by the inverter 120 to the motor 130 is also obtained, that is, the three-phase current value output by the inverter 120 to the motor 130.

[0080] In some embodiments, the operation of the controller 140 acquiring the first bus current value and the three-phase current values in step S100 can be implemented using a Hall effect current sensor. That is, the controller 140 can acquire the first bus current value and the three-phase current values using a Hall effect current sensor. A Hall effect current sensor is a current sensor that detects the magnitude of the current in a conductor based on the Hall effect.

[0081] Figure 3 Schematic diagram of the structure of a motor system 10 provided in an embodiment of the present application. Figure 3The motor system 10 is provided with a first Hall-effect current sensor 102 and a second Hall-effect current sensor 104. The first Hall-effect current sensor 102 is provided on the busbar 110 side and is used to obtain the busbar current value input from the busbar 110 to the inverter 120. The second Hall-effect current sensor 104 is provided on the conductor side of the three-phase current and is used to obtain the three-phase current value output from the inverter 120 to the motor 130.

[0082] It should be understood that the three-phase current includes A-phase current, B-phase current and C-phase current, the conductors used to transmit the three-phase current also include A-phase line, B-phase line and C-phase line, and the three-phase current values also include A-phase current value, B-phase current value and C-phase current value. Among them, the A-phase line is used to transmit the A-phase current, and the magnitude of the A-phase current is the A-phase current value. The B-phase line is used to transmit the B-phase current, and the magnitude of the B-phase current is the B-phase current value. The C-phase line is used to transmit the C-phase current, and the magnitude of the C-phase current is the C-phase current value. Therefore, in an embodiment of the present application, three second Hall current sensors 104 can be set. The three second Hall current sensors 104 are respectively used to detect the A-phase current value, the B-phase current value and the C-phase current value output by the inverter 120 to the motor 130.

[0083] Therefore, see Figure 4 , step S100 may specifically include: at the startup moment of the controller 140, obtaining the bus current value input from the bus 110 to the inverter 120 as the first bus current value through the first Hall current sensor 102, and obtaining the three-phase current value output from the inverter 120 to the motor 130 through the second Hall current sensor 104, that is, obtaining the A-phase current value, the B-phase current value and the C-phase current value output from the inverter 120 to the motor 130 through the second Hall current sensor 104.

[0084] S200 , during the operation of the controller 140 , if the mechanical power of the motor 130 is zero, a bus current value input from the bus 110 to the inverter 120 is obtained as a second bus current value.

[0085] The operating process of controller 140 refers to the period after controller 140 is started, powered on, and in operation. During this operating process, if the mechanical power of motor 130 is zero, the mechanical power of bus 110 is also approximately zero. At this point, the bus current value input from bus 110 to inverter 120 is again obtained and recorded as the second bus current value. In other words, the second bus current value is the magnitude of the current in bus 110 when the mechanical power of bus 110 is approximately zero during the operating process of controller 140.

[0086] In some embodiments, the operation of the controller 140 acquiring the second bus current value in step S200 may be implemented by a Hall current sensor, that is, the controller 140 may acquire the second bus current value by using the Hall current sensor.

[0087] like Figure 3 As shown, the motor system 10 is provided with a first Hall current sensor 102 . The first Hall current sensor 102 is provided on the bus 110 side and is used to obtain the bus current value input from the bus 110 to the inverter 120 .

[0088] Specifically, see Figure 4 , step S200 may specifically include: during the operation of the controller 140 , if the mechanical power of the motor 130 is zero, obtaining the bus current value input from the bus 110 to the inverter 120 as the second bus current value through the first Hall current sensor 102 .

[0089] Further, see Figure 5 During the operation of the controller 140, the operation of determining whether the mechanical power of the motor 130 is zero may include the following steps S001 and S002. Of course, other methods may be used to determine whether the mechanical power of the motor 130 is zero, which is not limited in this embodiment of the present application.

[0090] S001 , obtaining the rotation speed and torque of the motor 130 .

[0091] Generally speaking, the mechanical power of the motor 130 is related to the rotational speed and torque of the motor 130. Therefore, after the controller 140 is started, the rotational speed and torque of the motor 130 can be obtained in real time.

[0092] S002 : If the rotation speed of the motor 130 is less than or equal to the rotation speed threshold and the torque of the motor 130 is zero, it is determined that the mechanical power of the motor 130 is zero.

[0093] If the rotation speed of the motor 130 is greater than the rotation speed threshold, and / or the torque of the motor 130 is not zero, it is determined that the mechanical power of the motor 130 is not zero.

[0094] Controller 140 may pre-store a speed threshold. This speed threshold is used to compare the speed of motor 130, as measured in real time by controller 140 in step S001. In this embodiment of the present application, if the speed of motor 130 is less than or equal to the speed threshold and the torque of motor 130 is zero, the mechanical power of motor 130 is zero. At this point, step S200 can be executed.

[0095] In the embodiment of the present application, the speed threshold preset in the controller 140 can be much lower than the rated speed of the motor 130. For example, the speed threshold can be less than one-third or one-quarter of the rated speed of the motor 130, and the embodiment of the present application is not limited thereto. For example, when the rated speed of the motor 130 is 1500 rpm, the speed threshold can be set to 500 rpm, 400 rpm, or 300 rpm, etc.

[0096] When the speed threshold is set to 300 rpm, if the real-time speed of motor 130 is 200 rpm and the torque of motor 130 is zero, controller 140 can determine that the mechanical power of motor 130 is zero and then execute the above step S200. Conversely, if the real-time speed of motor 130 is 400 rpm and / or the torque of motor 130 is not zero, controller 140 can determine that the mechanical power of motor 130 is not zero and then skip step S200.

[0097] S300: Taking the difference between the second bus current value and the first bus current value as the current zero drift value.

[0098] After respectively obtaining the first bus current value and the second bus current value, the first bus current value is subtracted from the second bus current value to obtain a difference between the second bus current value and the first bus current value.

[0099] At the startup moment of the controller 140, the motor system 10 has not yet generated heat due to operation. At this time, the three-phase current value output by the inverter 120 to the motor 130 can be referred to as the initial zero position of the three-phase current. The initial zero position of the three-phase current is the zero position of the three-phase current before the zero position drifts. During the operation of the controller 140, the motor system 10 generates heat due to operation, which causes the zero position of the three-phase current to drift. At this time, since the three-phase current is under current loop control and its magnitude is constant, it is impossible to determine the zero position of the three-phase current by measuring the magnitude of the three-phase current. However, since the bus current is not under current loop control, when the mechanical power is zero, the bus current value always corresponds to the zero position of the three-phase current. In other words, the first bus current value corresponds to the initial zero position of the three-phase current, and the second bus current value corresponds to the zero position of the three-phase current after the drift. Therefore, the difference between the second bus current value and the first bus current value can be used as the current zero position drift value.

[0100] S400: Determine a three-phase current zero point according to the current zero point drift value and the three-phase current value.

[0101] In step S400, the current zero drift value is the difference between the second bus current value and the first bus current value determined in step S300. The three-phase current value is the three-phase current value output by the inverter 120 to the motor 130 at the startup moment of the controller 140, determined in step S100, i.e., the aforementioned three-phase current initial zero position. Based on the three-phase current value (i.e., the three-phase current initial zero position) and the current zero drift value, the three-phase current zero position after drift can be calculated, thereby achieving the purpose of determining the three-phase current zero position during the operation of the controller 140. In this way, the three-phase current zero position of the motor 130 can be accurately determined, thereby facilitating the controller 140 to accurately control the motor 130 accordingly.

[0102] Specifically, in step S400 , the sum of the current zero drift value and the three-phase current value may be used as the three-phase current zero point.

[0103] As can be seen from the above description, the three-phase current includes the A-phase current, the B-phase current, and the C-phase current. The conductors used to transmit the three-phase current also include the A-phase line, the B-phase line, and the C-phase line. The three-phase current values also include the A-phase current value, the B-phase current value, and the C-phase current value. In this case, the three-phase current zero position includes the A-phase current zero position, the B-phase current zero position, and the C-phase current zero position.

[0104] Therefore, see Figure 4 In the embodiment of the present application, step S400 may specifically include the following steps S410 to S430.

[0105] S410 , taking the sum of the A-phase current value and the current zero-position drift value as the A-phase current zero-position.

[0106] S420: The sum of the B-phase current value and the current zero-position drift value is used as the B-phase current zero-position.

[0107] S430: The sum of the C-phase current value and the current zero-position drift value is used as the C-phase current zero-position.

[0108] At the start-up time of the controller 140, the second Hall current sensor 104 obtains the A-phase current value, the B-phase current value, and the C-phase current value output by the inverter 120 to the motor 130. After the current zero drift value is obtained in step S300, the current zero drift value can be added to the A-phase current value, the B-phase current value, and the C-phase current value, respectively, to obtain the A-phase current zero position, the B-phase current zero position, and the C-phase current zero position.

[0109] Further, see Figure 6 , after step S400, it also includes step S500.

[0110] S500 , controlling the magnitude of the three-phase current outputted from the inverter 120 to the motor 130 according to the three-phase current zero position.

[0111] As previously described, the purpose of the three-phase current zero position is to precisely control the magnitude of the three-phase current. Therefore, after determining the three-phase current zero position, the controller 140 can use this zero position as a reference to control the magnitude of the three-phase current output by the inverter 120, thereby precisely controlling the magnitude of the three-phase current input to the motor 130.

[0112] In an embodiment of the present application, at the startup moment of the controller 140, the mechanical power of the motor 130 is zero. At this time, the first bus current value and the three-phase current value of the motor 130 are obtained, and the obtained three-phase current value is the initial zero position of the three-phase current. During the operation of the controller 140, the temperature of the motor system 10 increases. During this operation, if the mechanical power of the motor 130 is still zero, the mechanical power of the bus 110 is also close to zero. At this time, the second bus current value can be obtained, and the difference between the second bus current value and the first bus current value is the current zero drift value caused by the increase in the temperature of the motor system 10. Therefore, according to the current zero drift value and the initial zero position of the three-phase current, the three-phase current zero position during the operation of the controller 140 can be determined, so that the controller 140 can accurately control the motor 130 accordingly.

[0113] Figure 7 1 is a schematic diagram of the structure of a current zero position determining device 20 provided in an embodiment of the present application. The current zero position determining device 20 is applied to a controller 140 in a motor system 10. The motor system 10 includes a bus 110, an inverter 120, a motor 130, and a controller 140. The inverter 120 is connected between the bus 110 and the motor 130. The controller 140 is connected to the inverter 120, thereby controlling the magnitude of the three-phase current input to the motor 130 by controlling the inverter 120.

[0114] See also Figure 7 The device includes a current acquisition module 201, a difference determination module 202 and a current zero position determination module 203.

[0115] The current acquisition module 201 is used to acquire the bus current value input from the bus 110 to the inverter 120 as the first bus current value when the controller 140 is started, and to acquire the three-phase current value output from the inverter 120 to the motor 130 .

[0116] The current acquisition module 201 is further configured to acquire a bus current value input from the bus 110 to the inverter 120 as a second bus current value if the mechanical power of the motor 130 is zero during operation of the controller 140 .

[0117] The difference determination module 202 is configured to use the difference between the second bus current value and the first bus current value as the current zero drift value.

[0118] The current zero position determining module 203 is configured to determine the three-phase current zero position according to the current zero position drift value and the three-phase current value.

[0119] Optionally, the rotation speed threshold is less than or equal to one third of the rated rotation speed of the motor 130 .

[0120] Optionally, the three-phase current value includes an A-phase current value, a B-phase current value, and a C-phase current value, and the current zero position determining module 203 is configured to:

[0121] The sum of the A-phase current value and the current zero-position drift value is taken as the A-phase current zero position;

[0122] The sum of the B-phase current value and the current zero-position drift value is taken as the B-phase current zero position;

[0123] The sum of the C-phase current value and the current zero-position drift value is taken as the C-phase current zero-position.

[0124] Optionally, the current acquisition module 201 is used to:

[0125] At the start-up moment of the controller 140, the bus current value input from the bus 110 to the inverter 120 is obtained as the first bus current value through the first Hall current sensor, and the three-phase current value output from the inverter 120 to the motor 130 is obtained through the second Hall current sensor.

[0126] Optionally, the device further comprises:

[0127] The control module is used to control the magnitude of the three-phase current output by the inverter 120 to the motor 130 according to the zero position of the three-phase current.

[0128] In an embodiment of the present application, at the startup moment of the controller 140, the mechanical power of the motor 130 is zero. At this time, the first bus current value and the three-phase current value of the motor 130 are obtained, and the obtained three-phase current value is the initial zero position of the three-phase current. During the operation of the controller 140, the temperature of the motor system 10 increases. During this operation, if the mechanical power of the motor 130 is still zero, the mechanical power of the bus 110 is also close to zero. At this time, the second bus current value can be obtained, and the difference between the second bus current value and the first bus current value is the current zero drift value caused by the increase in the temperature of the motor system 10. Therefore, according to the current zero drift value and the initial zero position of the three-phase current, the three-phase current zero position during the operation of the controller 140 can be determined, so that the controller 140 can accurately control the motor 130 accordingly.

[0129] It should be noted that: when the current zero position determination device 20 provided in the above embodiment determines the zero position of the three-phase current in the motor system 10, it only uses the division of the above-mentioned functional modules as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0130] The functional units and modules in the above embodiments may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The above integrated units may be implemented in the form of hardware or software functional units. In addition, the specific names of the functional units and modules are only for the purpose of distinguishing them from each other and are not intended to limit the scope of protection of the embodiments of this application.

[0131] The current zero position determining device 20 provided in the above embodiment and the current zero position determining method embodiment belong to the same concept. The specific working process and technical effects brought about by the units and modules in the above embodiment can be found in the method embodiment part and will not be repeated here.

[0132] Figure 8 This is a schematic diagram of the structure of a computer device 30 provided in an embodiment of the present application. Figure 8 As shown, the computer device 30 includes: a processor 33, a memory 31, and a computer program 32 stored in the memory 31 and executable on the processor 33. When the processor 33 executes the computer program 32, the steps of the current zero position determination method in the above embodiment are implemented.

[0133] In the embodiment of the present application, the computer device 30 may be the motor system 10 having the controller 140 . The processor 33 in the computer device 30 is the controller 140 in the motor system 10 .

[0134] Those skilled in the art will understand that Figure 8 This is merely an example of the computer device 30 and does not constitute a limitation on the computer device 30 . The computer device 30 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0135] The processor 33 may be a central processing unit (CPU), or may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0136] In some embodiments, the memory 31 may be an internal storage unit of the computer device 30, such as a hard disk or memory of the computer device 30. In other embodiments, the memory 31 may also be an external storage device of the computer device 30, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a flash memory card, etc. equipped on the computer device 30. Furthermore, the memory 31 may include both an internal storage unit of the computer device 30 and an external storage device. The memory 31 is used to store an operating system, application programs, a boot loader, data, and other programs, such as the program code of a computer program. The memory 31 may also be used to temporarily store data that has been output or is about to be output.

[0137] An embodiment of the present application also provides a computer device, which includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, wherein the processor implements the steps of any of the above-mentioned method embodiments when executing the computer program.

[0138] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it can implement the steps in the above-mentioned various method embodiments.

[0139] An embodiment of the present application provides a computer program product, which, when executed on a computer, enables the computer to execute the steps in the above-mentioned various method embodiments.

[0140] If the integrated unit is implemented as a software functional unit and sold or used as a standalone product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application can implement all or part of the processes in the above-mentioned method embodiments by using a computer program to instruct the relevant hardware. The computer program can be stored in a computer-readable storage medium. When executed by a processor, the computer program can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file, or some intermediate form. The computer-readable medium can at least include: any entity or device capable of carrying the computer program code to the camera / terminal device, recording medium, computer memory, ROM (Read-Only Memory), RAM (Random Access Memory), CD-ROM (Compact Disc Read-Only Memory), magnetic tape, floppy disk, and optical data storage device. The computer-readable storage medium mentioned in the present application can be a non-volatile storage medium, in other words, a non-transitory storage medium.

[0141] It should be understood that all or part of the steps for implementing the above embodiments may be implemented using software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the steps may be implemented in the form of a computer program product. The computer program product may include one or more computer instructions. The computer instructions may be stored in the above-mentioned computer-readable storage medium.

[0142] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0143] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0144] In the embodiments provided in this application, it should be understood that the disclosed apparatus / computer equipment and methods can be implemented in other ways. For example, the apparatus / computer equipment embodiments described above are merely schematic. For example, the division of modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of the apparatus or unit, which can be electrical, mechanical or other forms.

[0145] Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0146] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the scope of protection of the present application.

Claims

1. A method for determining current zero position, characterized in that: A controller applied to a motor system, the motor system comprising a bus, an inverter, a motor, and the controller, the inverter being connected between the bus and the motor, the controller being connected to the inverter, the method comprising: At the start-up moment of the controller, a bus current value input from the bus to the inverter is obtained as a first bus current value, and a three-phase current value output from the inverter to the motor is obtained; During operation of the controller, if the mechanical power of the motor is zero, obtaining a bus current value input from the bus to the inverter as a second bus current value; Taking the difference between the second bus current value and the first bus current value as the current zero drift value; Determining a three-phase current zero position according to the current zero position drift value and the three-phase current value; The method further comprises: Obtaining the speed and torque of the motor; If the rotation speed of the motor is less than or equal to the rotation speed threshold and the torque of the motor is zero, it is determined that the mechanical power of the motor is zero.

2. The method according to claim 1, wherein The rotation speed threshold is less than or equal to one third of the rated rotation speed of the motor.

3. The method according to claim 1, wherein The three-phase current values include an A-phase current value, a B-phase current value, and a C-phase current value, and determining the three-phase current zero position according to the current zero position drift value and the three-phase current values includes: The sum of the A-phase current value and the current zero drift value is used as the A-phase current zero position; The sum of the B-phase current value and the current zero drift value is used as the B-phase current zero position; The sum of the C-phase current value and the current zero drift value is taken as the C-phase current zero point.

4. The method according to claim 1, wherein The step of obtaining, at the startup moment of the controller, a bus current value input from the bus to the inverter as a first bus current value, and obtaining a three-phase current value output from the inverter to the motor, comprises: At the startup moment of the controller, the bus current value of the bus input to the inverter is obtained as the first bus current value through the first Hall current sensor, and the three-phase current value of the inverter output to the motor is obtained through the second Hall current sensor.

5. The method according to any one of claims 1 to 4, characterized in that: After determining the three-phase current zero position according to the current zero position drift value and the three-phase current value, the method further includes: According to the three-phase current zero position, the magnitude of the three-phase current output by the inverter to the motor is controlled.

6. A current zero position determination device, characterized in that: The device is applied to a controller in a motor system, wherein the motor system includes a bus, an inverter, a motor, and the controller, wherein the inverter is connected between the bus and the motor, and the controller is connected to the inverter. The device includes: a current value acquisition module, configured to acquire, at the startup moment of the controller, a bus current value input from the bus to the inverter as a first bus current value, and to acquire a three-phase current value output from the inverter to the motor; The current value acquisition module is further configured to, during operation of the controller, if the mechanical power of the motor is zero, acquire a bus current value input from the bus to the inverter as a second bus current value; a difference determination module, configured to use the difference between the second bus current value and the first bus current value as a current zero drift value; a current zero position determining module, configured to determine a three-phase current zero position according to the current zero position drift value and the three-phase current values; Wherein, the device further comprises: A motor data acquisition module, used to obtain the speed and torque of the motor; The judgment module is configured to determine that the mechanical power of the motor is zero if the rotational speed of the motor is less than or equal to a rotational speed threshold and the torque of the motor is zero.

7. The device according to claim 6, characterized in that The rotation speed threshold is less than or equal to one third of the rated rotation speed of the motor.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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