CN114553101A

CN114553101A - Current zero determination method and device and storage medium

Info

Publication number: CN114553101A
Application number: CN202011336146.5A
Authority: CN
Inventors: 沈彪; 翟国建; 谢玲玉; 卢琪
Original assignee: Wuxi Blue Sea Huateng Technology Co ltd
Current assignee: Wuxi Blue Sea Huateng Technology Co ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2022-05-27

Abstract

The application discloses a current zero position determination method, a current zero position determination device and a storage medium, and belongs to the technical field of motor control. The method comprises the following steps: at the starting time of the controller, acquiring a bus current value input to the inverter by a bus as a first bus current value, and acquiring a three-phase current value output to the motor by the inverter; in the operation process of the controller, if the mechanical power of the motor is zero, acquiring a bus current value input to the inverter by the bus as a second bus current value; taking the difference value of the second bus current value and the first bus current value as a current zero drift value; and determining the three-phase current zero position according to the current zero position drift value and the three-phase current value. The method and the device can accurately determine the three-phase current zero position of the motor, so that the controller can accurately control the motor conveniently.

Description

Current zero determination method and device and storage medium

Technical Field

The present disclosure relates to the field of motor control technologies, and in particular, to a method and an apparatus for determining a current zero position, and a storage medium.

Background

The motor system generally includes a bus, a motor, an inverter connected between the bus and the motor, and a controller connected to the inverter. In a motor system, a controller is very important for accurately controlling three-phase current input into a motor, and the zero position of the three-phase current needs to be determined to ensure the accuracy of the three-phase current.

In the related technology, the zero position of the three-phase current is not accurate enough, and the accurate control of the controller on the motor is influenced.

Disclosure of Invention

The application provides a current zero position determination method, a current zero position determination device and a storage medium, which can accurately determine the three-phase current zero position of a motor and facilitate a controller to accurately control the motor accordingly. The technical scheme is as follows:

in a first aspect, a current zero determination method is provided, which is applied to a controller in an electric motor system, where the electric motor system includes a bus, an inverter, an electric motor, and the controller, the inverter is connected between the bus and the electric motor, and the controller is connected to the inverter, and the method includes:

at the starting time of the controller, acquiring a bus current value input to the inverter by the bus as a first bus current value, and acquiring a three-phase current value output to the motor by the inverter;

in the operation process of the controller, if the mechanical power of the motor is zero, acquiring a bus current value input to the inverter by the bus as a second bus current value;

taking the difference value of the second bus current value and the first bus current value as a current zero drift value;

and determining the three-phase current zero position according to the current zero position drift value and the three-phase current value.

In the application, at the starting time of the controller, the mechanical power of the motor is zero, the current value of the first bus and the three-phase current value of the motor are obtained at the moment, and the obtained three-phase current value is the initial zero position of the three-phase current. During operation of the controller, the motor system temperature rises. If the mechanical power of the motor is still zero during this operation, the mechanical power of the bus bar is also close to zero. At this time, a second bus current value can be obtained, and the difference value between the second bus current value and the first bus current value is the current zero drift value generated due to the temperature rise of the motor system. Therefore, the three-phase current zero position in the operation process of the controller can be determined according to the current zero position drift value and the three-phase current initial zero position, so that the controller can conveniently and accurately control the motor.

Optionally, the method further comprises:

acquiring the rotating speed and the torque of the motor;

and if the rotating speed of the motor is less than or equal to the rotating speed threshold value and the torque of the motor is zero, determining that the mechanical power of the motor is zero.

Optionally, the rotational speed threshold is less than or equal to one third of a rated rotational speed of the electric machine.

Optionally, the determining, according to the current zero drift value and the three-phase current value, a three-phase current zero position includes:

taking the sum of the A-phase current value and the current zero-position drift value as an A-phase current zero position;

taking the sum of the B-phase current value and the current zero-position drift value as a B-phase current zero position;

and taking the sum of the C-phase current value and the current zero-position drift value as a C-phase current zero position.

Optionally, the obtaining, at a start time of the controller, a bus current value input by the bus to the inverter as a first bus current value, and obtaining a three-phase current value output by the inverter to the motor includes:

and at the starting time of the controller, acquiring a bus current value input to the inverter by the bus as a first bus current value through a first Hall current sensor, and acquiring a three-phase current value output to the motor by the inverter through a second Hall current sensor.

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

and controlling the size of the three-phase current output to the motor by the inverter according to the three-phase current zero position.

In a second aspect, there is provided a current zero determination apparatus, which is applied to a controller in an electric motor system, the electric motor system including a bus, an inverter, an electric motor, and the controller, the inverter being connected between the bus and the electric motor, and the controller being connected to the inverter, the apparatus including:

the current acquisition module is used for acquiring a bus current value input to the inverter by the bus as a first bus current value and acquiring a three-phase current value output to the motor by the inverter at the starting time of the controller;

the current obtaining module is further configured to obtain a bus current value input to the inverter by the bus as a second bus current value if the mechanical power of the motor is zero in the operation process of the controller;

the difference value determining module is used for taking the difference value between the second bus current value and the first bus current value as a current zero drift value;

and the current zero position determining module is used for determining the three-phase current zero position according to the current zero position drift value and the three-phase current value.

Optionally, the apparatus further comprises:

the motor data acquisition module is used for acquiring the rotating speed and the torque of the motor;

and the judging module is used for determining that the mechanical power of the motor is zero if the rotating speed of the motor is less than or equal to a rotating speed threshold value and the torque of the motor is zero.

Optionally, the three-phase current values include an a-phase current value, a B-phase current value, and a C-phase current value, and the current zero determination module is configured to:

Optionally, the current obtaining module is configured to:

Optionally, the apparatus further comprises:

and the control module is used for controlling the size of the three-phase current output to the motor by the inverter according to the three-phase current zero position.

In a third aspect, a computer device is provided, the computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the computer program, when executed by the processor, implementing the method of the first aspect.

In a fourth aspect, a computer-readable storage medium is provided, which stores a computer program that, when executed by a processor, implements the method of the first aspect described above.

It is to be understood that, for the beneficial effects of the second, third and fourth aspects, reference may be made to the description of the first aspect, and details are not repeated here.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic view of a structure of a motor system in the related art;

FIG. 2 is a flow chart of a first current zero determination method provided by an embodiment of the present application;

fig. 3 is a schematic structural diagram of an electric machine system provided in an embodiment of the present application;

FIG. 4 is a flow chart of a second current zero determination method provided by an embodiment of the present application;

fig. 5 is a flowchart of an operation of determining whether the mechanical power of the motor is 0 according to an embodiment of the present application;

FIG. 6 is a flow chart of a third current zero determination method provided by an embodiment of the present application;

FIG. 7 is a flow chart of a current zero determination device provided by an embodiment of the present application;

fig. 8 is a schematic structural diagram of a computer device according to an embodiment of the present application.

Wherein, the meanings represented by the reference numerals of the figures are respectively as follows:

10. a motor system;

102. a first hall current sensor;

104. a second Hall current sensor;

110. a bus bar;

120. an inverter;

130. a motor;

140. a controller;

150. a power source;

20. current zero determination means;

201. a current acquisition module;

202. a difference determination module;

203. a current zero determination module;

30. a computer device;

31. a memory;

32. a computer program;

33. a processor.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

It should be understood that reference to "a plurality" in this application means two or more. In the description of the present application, "/" means "or" unless otherwise stated, for example, a/B may mean a or B; "and/or" herein is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, for the convenience of clearly describing the technical solutions of the present application, the terms "first", "second", and the like are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance.

Before explaining the embodiments of the present application in detail, an application scenario of the embodiments of the present application will be described.

Fig. 1 is a schematic structural view of a motor system 10 in the related art. The motor system 10 may be applied to an electric vehicle or the like. Referring to fig. 1, the motor system 10 generally includes a bus 110, a motor 130, an inverter 120 connected between the bus 110 and the motor 130, and a controller 140. The bus bar 110 is connected between the power source 150 and the inverter 120, and transmits the dc power in the power source 150 to the inverter 120. The inverter 120 is used to convert the dc power into three-phase current (i.e., three-phase ac power) and transmit the three-phase current to the motor 130, so as to energize the motor 130 for operation. The controller 140 is connected to the inverter 120, and the controller 140 may control the magnitude, frequency, and the like of the three-phase current output from the inverter 120 to the motor 130. In the motor system 10, the controller 140 needs to accurately control the rotational speed of the motor 130, and the three-phase current input to the motor 130 needs to accurately position the zero position of the three-phase current.

In the related art, the magnitude of the three-phase current output from the inverter 120 to the motor 130 at the start time of the controller 140 is generally used as the zero position of the three-phase current. However, during operation of the motor system 10, the temperature may increase, thereby causing the zero of the three-phase currents to drift.

Therefore, the embodiment of the present application provides a current zero position determining 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.

The current zero determination method provided in the embodiments of the present application is explained in detail below.

The current zero determination method provided by the embodiment of the application is applied to the controller 140 in the motor system 10. Referring to fig. 1, the motor system 10 includes a bus 110, an inverter 120, a motor 130, and a controller 140. The bus bar 110 is used to output direct current to the inverter 120. The inverter 120 is connected between the bus 110 and the motor 130, and is configured to convert the dc power into a three-phase current and output the three-phase current to the motor 130, so as to energize the motor 130 for operation. The controller 140 is connected to the inverter 120, and the controller 140 may control the magnitude, frequency, and the like of the three-phase current output from the inverter 120 to the motor 130.

Fig. 2 is a flowchart of a current zero determination method according to an embodiment of the present application. Referring to fig. 2, the method includes the following steps.

S100, at the start time of the controller 140, a bus current value input to the inverter 120 by the bus 110 is acquired as a first bus current value, and a three-phase current value output to the motor 130 by the inverter 120 is acquired.

The activation time of the controller 140 refers to the time when the controller 140 is switched from the power-off state to the power-on state, powered on, and starts to operate. In the motor system 10, at the start time of the controller 140, the mechanical power of the motor 130 is zero. At this time, the bus current value input to inverter 120 by bus 110 is acquired 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 time of start-up of the controller 140. Meanwhile, at the start time of the controller 140, the magnitudes of the three-phase currents output by the inverter 120 to the motor 130, that is, the three-phase current values output by the inverter 120 to the motor 130, are also obtained.

In some embodiments, the operation of the controller 140 to obtain the first bus current value and the three-phase current value in step S100 may be implemented by hall current sensors, that is, the controller 140 may collect the first bus current value and the three-phase current value by the hall current sensors. The hall current sensor is a current sensor that detects the magnitude of current in a wire based on the hall effect.

Fig. 3 is a schematic structural diagram of an electric machine system 10 according to an embodiment of the present disclosure. Referring to fig. 3, a first hall current sensor 102 and a second hall current sensor 104 are disposed in the motor system 10. The first hall current sensor 102 is disposed on the bus 110 side, and is configured to obtain a bus current value input to the inverter 120 by the bus 110. The second hall current sensor 104 is disposed on the lead side of the three-phase current, and is configured to obtain a three-phase current value output to the motor 130 by the inverter 120.

It should be understood that the three-phase current includes a-phase current, a B-phase current, and a C-phase current, and the wires for transmitting the three-phase current also include a-phase line, a B-phase line, and a C-phase line, and the three-phase current value also includes an a-phase current value, a B-phase current value, and a C-phase current value. The phase A line is used for transmitting phase A current, and the magnitude of the phase A current is the current value of the phase A. The phase B line is used for transmitting phase B current, and the magnitude of the phase B current is a phase B current value. The C-phase line is used for transmitting C-phase current, and the magnitude of the C-phase current is a C-phase current value. Thus, in the present embodiment, three second hall current sensors 104 may be provided. The three second hall current sensors 104 are used to detect 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, respectively.

Thus, referring to fig. 4, step S100 may specifically include: at the start-up timing of the controller 140, the bus current value input to the inverter 120 by the bus 110 is acquired as a first bus current value by the first hall current sensor 102, and the three-phase current value output to the motor 130 by the inverter 120 is acquired by the second hall current sensor 104, that is, the a-phase current value, the B-phase current value, and the C-phase current value output to the motor 130 by the inverter 120 are acquired by the second hall current sensor 104.

S200, in the operation process of the controller 140, if the mechanical power of the motor 130 is zero, a bus current value input to the inverter 120 by the bus 110 is obtained as a second bus current value.

During operation of the controller 140, after the controller 140 is started, the controller 140 is powered on and in an operating state. During this operation, if the mechanical power of the motor 130 is zero, the mechanical power of the bus bar 110 is also approximately zero. At this time, the bus current value input to inverter 120 by bus 110 is again obtained and recorded as the second bus current value. In other words, the second bus bar current value is the magnitude of the current in bus bar 110 when the mechanical power of bus bar 110 is approximately zero during operation of controller 140.

In some embodiments, the operation of the controller 140 to obtain the second bus current value in step S200 may be implemented by a hall current sensor, that is, the controller 140 may collect the second bus current value by the hall current sensor.

As shown in fig. 3, the motor system 10 is provided with a first hall current sensor 102, and the first hall current sensor 102 is disposed on the bus 110 side and is used for acquiring a bus current value input to the inverter 120 by the bus 110.

Specifically, referring to fig. 4, step S200 may specifically include: during the operation of the controller 140, if the mechanical power of the motor 130 is zero, the bus current value input to the inverter 120 by the bus 110 is acquired as a second bus current value by the first hall current sensor 102.

Further, referring to fig. 5, the operation of determining whether the mechanical power of the motor 130 is zero during the operation of the controller 140 may include the following steps S001 and S002. Of course, it may also be determined whether the mechanical power of the motor 130 is zero by other manners, which is not limited in this embodiment of the application.

And S001, acquiring the rotating speed and the torque of the motor 130.

Generally, the mechanical power of the motor 130 is related to the rotational speed and torque of the motor 130. Thus, after the controller 140 is started, the rotation speed of the motor 130 and the torque of the motor 130 can be acquired in real time.

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, determining that the mechanical power of the motor 130 is zero.

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

The controller 140 may have a pre-stored speed threshold. The rotation speed threshold is used for comparing with the rotation speed of the motor 130 acquired by the controller 140 in real time in step S001. In the embodiment of the present application, 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, the mechanical power of the motor 130 is zero. At this time, step S200 is executed.

In the embodiment of the present application, the preset rotation speed threshold in the controller 140 may be much smaller than the rated rotation speed of the motor 130. For example, the rotation speed threshold may be less than one third, one fourth, etc. of the rated rotation speed of the motor 130, which is not limited in this embodiment. For example, when the rated speed of the motor 130 is 1500 rpm, the speed threshold may be set to 500 rpm, 400 rpm, 300 rpm, or the like.

When the rotation speed threshold is set to 300 rpm, if the real-time rotation speed of the motor 130 is 200 rpm and the torque of the motor 130 is zero, the controller 140 may determine that the mechanical power of the motor 130 is zero, and then execute the step S200. On the contrary, if the real-time rotation speed of the motor 130 is 400 rpm, or/and the torque of the motor 130 is not zero, the controller 140 may determine that the mechanical power of the motor 130 is not zero, and the step S200 is not performed.

And S300, taking the difference value of the second bus current value and the first bus current value as a current zero drift value.

After the first bus current value and the second bus current value are respectively obtained, the first bus current value is subtracted from the second bus current value to obtain a difference value between the second bus current value and the first bus current value.

At the starting time of the controller 140, the motor system 10 does not generate heat due to operation, and the three-phase current value output by the inverter 120 to the motor 130 at this time may be referred to as an 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 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 in the current loop control, the magnitude of the three-phase current is constant, and therefore the zero position of the three-phase current cannot be determined by measuring the magnitude of the three-phase current. And because the bus current is not in the current loop control, the bus current value always corresponds to the zero position of the three-phase current under the condition that the mechanical power is zero. 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 shifted zero position of the three-phase current. Therefore, the difference between the second bus current value and the first bus current value can be taken as the current zero drift value.

And S400, determining the three-phase current zero position according to the current zero position drift value and the three-phase current value.

In step S400, the current zero drift value is a difference value between the second bus current value and the first bus current value determined in step S300, and the three-phase current value is a three-phase current value determined in step S100 and output by the inverter 120 to the motor 130 at the start time of the controller 140, that is, the three-phase current initial zero. According to the three-phase current value (i.e., the initial zero position of the three-phase current) and the current zero position drift value, the three-phase current zero position after the drift can be calculated, so that the purpose of determining the three-phase current zero position in the operation process of the controller 140 is achieved. In this way, the three-phase current zero of the motor 130 can be accurately determined, thereby facilitating the controller 140 to accurately control the motor 130 accordingly.

Specifically, in step S400, the sum of the current zero shift value and the three-phase current value may be used as the three-phase current zero.

As is known from the above description, the three-phase current includes a-phase current, B-phase current, and C-phase current, and the conductor for transmitting the three-phase current also includes a-phase line, B-phase line, and C-phase line, and the three-phase current value also includes a-phase current value, B-phase current value, and C-phase current value. In this case, the three-phase current zero position includes a phase-a current zero position, a phase-B current zero position, and a phase-C current zero position.

Thus, referring to fig. 4, in the embodiment of the present application, step S400 may specifically include the following steps S410 to S430.

And S410, taking the sum of the current value of the phase A and the current zero drift value as the zero position of the current of the phase A.

And S420, taking the sum of the current value of the phase B and the current zero drift value as the zero position of the phase B current.

And S430, taking the sum of the C-phase current value and the current zero drift value as the C-phase current zero.

At the start timing of the controller 140, the a-phase current value, the B-phase current value, and the C-phase current value output to the motor 130 by the inverter 120 are acquired by the second hall current sensor 104. After the current zero-offset value is obtained in step S300, the current zero-offset value may be added to the a-phase current value, the B-phase current value, and the C-phase current value, respectively, to obtain an a-phase current zero-offset value, a B-phase current zero-offset value, and a C-phase current zero-offset value.

Further, referring to fig. 6, after step S400, step S500 is further included.

And S500, controlling the size of the three-phase current output to the motor 130 by the inverter 120 according to the zero position of the three-phase current.

As is known from the foregoing description, the effect of the three-phase current null is to precisely control the magnitude of the three-phase current. Therefore, after determining the three-phase current zero position, the controller 140 may control the three-phase current output by the inverter 120 based on the three-phase current zero position, and thus precisely control the three-phase current input by the motor 130.

In this embodiment of the application, at the starting time of the controller 140, the mechanical power of the motor 130 is zero, and at this time, the first bus current value and the three-phase current value of the motor 130 are obtained, where the obtained three-phase current value is the initial zero position of the three-phase current. During operation of the controller 140, the motor system 10 increases in temperature. If the mechanical power of the motor 130 remains zero during this operation, the mechanical power of the bus 110 also approaches zero. At this time, a second bus current value may be obtained, and a difference value between the second bus current value and the first bus current value is a current zero drift value generated due to the temperature rise of the motor system 10. Therefore, the three-phase current zero position in the operation process of the controller 140 can be determined according to the current zero position drift value and the three-phase current initial zero position, so that the controller 140 can accurately control the motor 130 according to the three-phase current zero position.

Fig. 7 is a schematic structural diagram of a current zero determination device 20 according to an embodiment of the present application. The current zero determination device 20 is applied to a controller 140 in the 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 bar 110 and the motor 130. The controller 140 is connected to the inverter 120 so as to control the magnitude of the three-phase current input to the motor 130 by controlling the inverter 120.

Referring to fig. 7, the apparatus includes a current acquisition module 201, a difference determination module 202, and a current zero determination module 203.

A current obtaining module 201, configured to obtain, at a start time of the controller 140, a bus current value input to the inverter 120 by the bus 110 as a first bus current value, and obtain a three-phase current value output to the motor 130 by the inverter 120.

The current obtaining module 201 is further configured to, during an operation of the controller 140, obtain a bus current value input to the inverter 120 by the bus 110 as a second bus current value if the mechanical power of the motor 130 is zero.

And the difference value determining module 202 is configured to use the difference value between the second bus current value and the first bus current value as a current zero drift value.

And the current zero position determining module 203 is used for determining a three-phase current zero position according to the current zero position drift value and the three-phase current value.

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

Optionally, the three-phase current values include an a-phase current value, a B-phase current value, and a C-phase current value, and the current zero determination module 203 is configured to:

taking the sum of the A-phase current value and the current zero-position drift value as the A-phase current zero position;

taking the sum of the current value of the phase B and the current zero drift value as the zero position of the current of the phase B;

and taking the sum of the C-phase current value and the current zero-position drift value as the C-phase current zero position.

Optionally, the current obtaining module 201 is configured to:

at the start-up timing of the controller 140, the bus current value input to the inverter 120 by the bus 110 is acquired as a first bus current value by the first hall current sensor, and the three-phase current value output to the motor 130 by the inverter 120 is acquired by the second hall current sensor.

Optionally, the apparatus further comprises:

and the control module is used for controlling the magnitude of the three-phase current output to the motor 130 by the inverter 120 according to the zero position of the three-phase current.

In this embodiment of the application, at the starting time of the controller 140, the mechanical power of the motor 130 is zero, and at this time, the first bus current value and the three-phase current value of the motor 130 are obtained, where the obtained three-phase current value is the initial zero position of the three-phase current. During operation of the controller 140, the motor system 10 increases in temperature. If the mechanical power of the motor 130 remains zero during this operation, the mechanical power of the bus 110 also approaches zero. At this time, a second bus current value may be obtained, and a difference between the second bus current value and the first bus current value is a current zero drift value generated due to the temperature rise of the motor system 10. Therefore, the three-phase current zero position in the operation process of the controller 140 can be determined according to the current zero position drift value and the three-phase current initial zero position, so that the controller 140 can accurately control the motor 130 according to the three-phase current zero position.

It should be noted that: the current zero position determining apparatus 20 provided in the above embodiment is only illustrated by dividing the above functional modules when determining the zero position of the three-phase current in the motor system 10, and in practical applications, the above function distribution may be completed by different functional modules according to needs, that is, the internal structure of the apparatus is divided into different functional modules to complete all or part of the above described functions.

Each functional unit and module in the above embodiments may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used to limit the protection scope of the embodiments of the present application.

The current zero position determining apparatus 20 provided in the above embodiment and the current zero position determining method embodiment belong to the same concept, and for specific working processes of units and modules and technical effects brought by the working processes in the above embodiments, reference may be made to the method embodiment portion, and details are not described here.

Fig. 8 is a schematic structural diagram of a computer device 30 according to an embodiment of the present application. As shown in fig. 8, 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, the steps in the current zero determination method in the above-described embodiments being implemented when the processor 33 executes the computer program 32.

In the present embodiment, the computer device 30 may be a motor system 10 having a controller 140. The processor 33 in the computer device 30 is the controller 140 in the motor system 10.

Those skilled in the art will appreciate that fig. 8 is merely an example of the computer device 30 and is not intended to limit the computer device 30 and may include more or less components than those shown, or some components may be combined, or different components may be included, such as input output devices, network access devices, etc.

The Processor 33 may be a Central Processing Unit (CPU), and the Processor 33 may be other 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 device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or any conventional processor.

The storage 31 may be an internal storage unit of the computer device 30 in some embodiments, such as a hard disk or a memory of the computer device 30. The memory 31 may also be an external storage device of the computer device 30 in other embodiments, such as a plug-in hard disk provided on the computer device 30, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and so on. Further, the memory 31 may also include both an internal storage unit and an external storage device of the computer device 30. The memory 31 is used for storing an operating system, an application program, a BootLoader (BootLoader), data, and other programs, such as program codes of a computer program. The memory 31 may also be used to temporarily store data that has been output or is to be output.

An embodiment of the present application further provides a computer device, where the computer device includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, the processor implementing the steps of any of the various method embodiments described above when executing the computer program.

The embodiments of the present application also provide a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps in the above-mentioned method embodiments.

The embodiments of the present application provide a computer program product, which when run on a computer causes the computer to perform the steps of the above-described method embodiments.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the above method embodiments may be implemented by a computer program, which may be stored in a computer readable storage medium and used by a processor to implement the steps of the above method embodiments. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include at least: any entity or apparatus capable of carrying computer program code to a photographing apparatus/terminal device, a recording medium, computer Memory, ROM (Read-Only Memory), RAM (Random Access Memory), CD-ROM (Compact Disc Read-Only Memory), magnetic tape, floppy disk, optical data storage device, etc. The computer-readable storage medium referred to herein may be a non-volatile storage medium, in other words, a non-transitory storage medium.

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

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/computer device and method may be implemented in other ways. For example, the above-described apparatus/computer device embodiments are merely illustrative, and for example, a module or a unit may be divided into only one logical function, and may be implemented in other ways, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. A current zero determination method applied to a controller in an electric motor system, the electric motor system including a bus, an inverter, an electric motor, and the controller, the inverter being connected between the bus and the electric motor, the controller being connected to the inverter, the method comprising:

2. The method of claim 1, wherein the method further comprises:

acquiring the rotating speed and the torque of the motor;

3. The method of claim 2, wherein the rotational speed threshold is less than or equal to one-third of a rated rotational speed of the electric machine.

4. The method of 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 wherein determining a three phase current null based on the current null shift value and the three phase current values comprises:

5. The method of claim 1, wherein the obtaining, at a start-up time of the controller, a bus current value of the bus input to the inverter as a first bus current value, and obtaining a three-phase current value of the inverter output to the motor, comprises:

6. The method of any of claims 1-5, wherein after determining a three-phase current null based on the current null shift value and the three-phase current values, further comprising:

7. A current zero determination device, applied to a controller in an electric motor system including a bus, an inverter, an electric motor, and the controller, wherein the inverter is connected between the bus and the electric motor, and the controller is connected to the inverter, the device comprising:

the current value acquisition module is used for acquiring a bus current value input to the inverter by the bus as a first bus current value and acquiring a three-phase current value output to the motor by the inverter at the starting time of the controller;

the current value obtaining module is further configured to obtain a bus current value input to the inverter by the bus as a second bus current value if the mechanical power of the motor is zero in the operation process of the controller;

8. The apparatus of claim 1, further comprising:

9. The apparatus of claim 8, wherein the rotational speed threshold is less than or equal to one-third of a rated rotational speed of the motor.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, implements the method of any one of claims 1 to 6.