Method and device for compensating for unbalance of three-phase current of motor and electronic equipment

Abstract

The application provides a motor three-phase current imbalance compensation method and device, electronic equipment and a computer readable storage medium. The method comprises: calculating a target peak current corresponding to a three-phase current of a motor in real time; performing peak sampling on the three-phase current to obtain a corresponding actual peak current; determining a three-phase current imbalance based on the target peak current and the actual peak current; determining a compensation voltage based on the three-phase current imbalance; and compensating the three-phase current based on the compensation voltage. Through the application, real-time compensation of three-phase current imbalance can be achieved without adding additional devices.

Description

Technical Field

[0001] This application relates to three-phase current technology, and more particularly to a method, apparatus, and electronic device for unbalanced compensation of three-phase current in a motor. Background Technology

[0002] Three-phase current imbalance in a motor refers to the presence of a DC component in the phase voltage, resulting in significant differences in the amplitude of the three-phase currents or the presence of a DC component. This causes DC flux in the magnetic field of the silicon steel sheets. This increases motor losses, and with prolonged use, leads to magnetic distortion of the permanent magnets, reduced efficiency, and exacerbates vibration and EMC problems.

[0003] In related technologies, the common approach is to perform offline measurements on the generator motor system, storing information such as imbalance in memory. During motor operation, the corresponding imbalance is compensated for based on the stored information. However, this method cannot achieve dynamic compensation, and the compensation may fail as the motor system ages. Furthermore, it requires additional storage devices, increasing production costs, and necessitates testing each system, making the offline process complex. Summary of the Invention

[0004] This application provides a method, apparatus, electronic device, and computer-readable storage medium for unbalanced compensation of three-phase current in a motor, which can achieve unbalanced compensation without adding additional components.

[0005] The technical solution of this application embodiment is implemented as follows:

[0006] This application provides a method for compensating for the imbalance of three-phase current in a motor, including:

[0007] Calculate the target peak current corresponding to the three-phase current of the motor in real time;

[0008] The peak values ​​of the three-phase currents are sampled to obtain the corresponding actual peak currents.

[0009] Based on the target peak current and the actual peak current, the three-phase current imbalance is determined;

[0010] Based on the aforementioned three-phase current imbalance, determine the compensation voltage;

[0011] The three-phase current is compensated based on the compensation voltage.

[0012] In the above scheme, the target peak current corresponding to the three-phase current of the motor includes:

[0013] The three-phase current of the motor is transformed into dq coordinates to obtain the target dq two-phase current;

[0014] Obtain the relationship between the target peak current and the dq two-phase current;

[0015] Based on the target dq two-phase current, the target peak current and the relationship between the dq two-phase current, the target peak current corresponding to the three-phase current of the motor is calculated in real time.

[0016] In the above scheme, determining the compensation voltage based on the three-phase current imbalance includes:

[0017] The three-phase current imbalance is used as the input of the bias magnetic compensation proportional integral PI loop for PI calculation to obtain the compensation voltage.

[0018] In the above scheme, the compensation of the three-phase current based on the compensation voltage includes:

[0019] When the three-phase voltage is output in the motor current closed loop, voltage compensation is performed based on the compensation voltage to obtain the compensated three-phase voltage, thereby realizing the compensation of the three-phase current.

[0020] The above solution is characterized in that the method further includes:

[0021] The compensated three-phase voltage is converted into a two-phase voltage;

[0022] The motor is controlled using the two-phase voltage.

[0023] This application provides a device for compensating for the imbalance of three-phase current in a motor, comprising:

[0024] A calculation module is used to calculate the target peak current corresponding to the three-phase current of the motor.

[0025] The sampling module is used to perform peak sampling on the three-phase current to obtain the corresponding actual peak current;

[0026] The first determining module is used to determine the three-phase current imbalance based on the target peak current and the actual peak current.

[0027] The second determining module is used to determine the compensation voltage based on the three-phase current imbalance.

[0028] The compensation module is used to compensate the three-phase current based on the compensation voltage.

[0029] This application provides an electronic device, including:

[0030] Memory, used to store executable instructions;

[0031] The processor, when executing executable instructions stored in the memory, implements the motor three-phase current imbalance compensation method provided in the embodiments of this application.

[0032] This application provides a computer-readable storage medium storing executable instructions for inducing a processor to execute and implement the motor three-phase current imbalance compensation method provided in this application.

[0033] This application embodiment calculates the target peak current corresponding to the three-phase current online in real time; performs peak sampling on the three-phase current to obtain the corresponding actual peak current; determines the three-phase current imbalance based on the target peak current and the actual peak current; determines the compensation voltage based on the three-phase current imbalance; and compensates the three-phase current based on the compensation voltage, thereby achieving imbalance compensation without adding additional components. Attached Figure Description

[0034] Figure 1 This is an optional structural schematic diagram of the electronic device 100 provided in the embodiments of this application;

[0035] Figure 2 This is an optional flowchart illustrating the method for compensating for the imbalance of three-phase current in a motor provided in this application embodiment;

[0036] Figure 3 This is an optional detailed flowchart of step 201 provided in an embodiment of this application;

[0037] Figure 4 This is an optional flowchart illustrating the steps following step 205 provided in the embodiments of this application;

[0038] Figure 5 This is an optional flowchart illustrating the method for compensating for the imbalance of three-phase current in a motor provided in this application embodiment. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0041] In the following description, the terms "first, second, third" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first, second, third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0043] This application provides a method, apparatus, electronic device, and computer-readable storage medium for unbalanced compensation of three-phase current in a motor, which can achieve unbalanced compensation without adding additional components.

[0044] First, the electronic equipment used to implement the above-described method for unbalanced compensation of three-phase current in a motor, as provided in the embodiments of this application, will be described. See [link to relevant documentation]. Figure 1 , Figure 1 This is an optional structural schematic diagram of the electronic device 100 provided in this application embodiment. Figure 1 The illustrated electronic device 100 includes at least one processor 101 and a memory 102. Various components within the electronic device 100 are coupled together via a bus system 103. It is understood that the bus system 103 is used to implement communication between these components. The bus system 104 includes, in addition to a data bus, a power bus, a control bus, and a status signal bus. However, for clarity, ... Figure 1 The general designated all buses as Bus System 103.

[0045] The processor 101 can be an integrated circuit chip with signal processing capabilities, such as a general-purpose processor, a digital signal processor (DSP), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0046] The memory 102 may be removable, non-removable, or a combination thereof. Exemplary hardware devices include solid-state storage, hard disk drives, optical disk drives, etc. The memory 102 may optionally include one or more storage devices physically located away from the processor 101.

[0047] The memory 102 may include volatile memory or non-volatile memory, or both. The non-volatile memory may be read-only memory (ROM), and the volatile memory may be random access memory (RAM). The memory 102 described in this application embodiment is intended to include any suitable type of memory.

[0048] In some embodiments, the memory 102 can store data to support various operations. Examples of such data include programs, modules, and data structures, or subsets or supersets thereof. In this embodiment, the memory 102 stores an operating system 1021 and a motor three-phase current imbalance compensation device 1022; specifically,

[0049] Operating system 1021 includes system programs for handling various basic system services and performing hardware-related tasks, such as the framework layer, core library layer, and driver layer, for implementing various basic business functions and handling hardware-based tasks.

[0050] In some embodiments, the motor three-phase current imbalance compensation device provided in this application can be implemented in software. Figure 1 A motor three-phase current imbalance compensation device 1022 stored in memory 102 is shown. This device can be software in the form of programs or plug-ins, and includes the following software modules: a calculation module 10221, a sampling module 10222, a first determination module 10223, a second determination module 10224, and a compensation module 10225. These modules are logically linked and can therefore be arbitrarily combined or further separated according to the functions they implement. The functions of each module will be described below.

[0051] In other embodiments, the motor three-phase current imbalance compensation device provided in this application can be implemented in hardware. As an example, the motor three-phase current imbalance compensation device provided in this application can be a processor in the form of a hardware decoding processor, which is programmed to execute the motor three-phase current imbalance compensation method provided in this application. For example, the processor in the form of a hardware decoding processor can be one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), or other electronic components.

[0052] The following will illustrate the method for compensating for the imbalance of three-phase current in a motor provided in this application, using examples of the electronic devices provided in the embodiments of this application.

[0053] See Figure 2 , Figure 2 This is a schematic flowchart of an optional method for compensating for the imbalance of three-phase current in a motor provided in this application embodiment, which will be combined with... Figure 2 The steps shown are explained.

[0054] Step 201: Calculate the target peak current corresponding to the three-phase current of the motor in real time;

[0055] Step 202: Perform peak sampling on the three-phase current to obtain the corresponding actual peak current;

[0056] Step 203: Determine the three-phase current imbalance based on the target peak current and the actual peak current;

[0057] Step 204: Determine the compensation voltage based on the three-phase current imbalance.

[0058] Step 205: Based on the compensation voltage, compensate the three-phase current.

[0059] In practice, the electronic equipment calculates the target peak current corresponding to the three-phase current of the motor online in real time. See also the following in some embodiments: Figure 3 , Figure 3 This is an optional detailed flowchart of step 201 provided in the embodiments of this application. Step 201 can be implemented in the following way:

[0060] Step 301: Perform dq coordinate transformation on the three-phase current of the motor to obtain the target dq two-phase current;

[0061] Step 302: Obtain the relationship between the target peak current and the dq two-phase current;

[0062] Step 303: Based on the target dq two-phase current, the target peak current and the relationship between the dq two-phase current, calculate the target peak current corresponding to the three-phase current of the motor in real time.

[0063] In practical implementation, the electronic device transforms the three-phase current of the motor onto the dq coordinate axis to obtain the target dq two-phase current under the dq coordinate axis. Then, the electronic device obtains the relationship between the target peak current and the dq two-phase current. Here, the relationship between the target peak current and the dq two-phase current is given by formula (1):

[0064]

[0065] Where id is the d-phase current in the d-phase current, iq is the q-phase current in the d-phase current, K is the coordinate transformation coefficient, and I... refmax The target peak current.

[0066] Next, the electronic equipment calculates the target peak current corresponding to the three-phase current of the motor in real time based on the relationship between the target dq two-phase current, the target peak current and the dq two-phase current.

[0067] In practical implementation, after obtaining the target peak current, the electronic equipment performs peak sampling on the three-phase current to obtain the sampled actual peak current. Then, the difference between the target peak current and the actual peak current is calculated using formula (2) to obtain the three-phase current imbalance ΔI (i.e., the bias magnetic characteristic quantity):

[0068] ΔI=I refmax -I max (2)

[0069] Among them, I max This represents the actual peak current.

[0070] In practical implementation, the electronic equipment determines the compensation voltage based on the three-phase current imbalance. Specifically, in some embodiments, step 204 can be implemented as follows: the three-phase current imbalance is used as the input of the bias magnetic compensation proportional-integral (PI) loop for PI calculation to obtain the compensation voltage.

[0071] In practical implementation, the electronic equipment uses the three-phase current imbalance as the input to the bias compensation PI loop for PI calculation to obtain the bias compensation voltage value. Taking phase U as an example, the bias compensation voltage value of phase U output by the PI loop is Δu. out1At this time, the compensation voltage values ​​for the other two phases are:

[0072] Δu out2 =-Δu out1 *Δi V / Δi U

[0073] Δu out3 =-Δu out1 *Δi w / Δi U

[0074] Where, Δi U ,Δi V ,Δi W It is a quantity that can reflect the three-phase bias state. When the compensation voltage is output, the bias compensation voltage value is limited. The specific limit value can be set according to the actual situation.

[0075] In some embodiments, step 205 can be implemented as follows: when the three-phase voltage is output in the motor current closed loop, voltage compensation is performed based on the compensation voltage to obtain the compensated three-phase voltage, thereby achieving compensation for the three-phase current.

[0076] In practical implementation, the compensation voltage value is applied during the motor closed-loop control process. Specifically, during the three-phase voltage output of the motor current closed loop, the calculated Δu is applied. out1 , Δu out2 , Δu out3 After compensation, the compensated three-phase voltage u is obtained. U u V u W .

[0077] In some embodiments, see Figure 4 , Figure 4 This is an optional flowchart illustrating the steps following step 205 provided in the embodiments of this application. After step 205, the following can also be performed:

[0078] Step 401: Convert the compensated three-phase voltage into a two-phase voltage;

[0079] Step 402: Control the motor using the two-phase voltage.

[0080] In practice, the electronic equipment converts the compensated three-phase voltage into a two-phase voltage to control the motor. At this time, the three-phase voltage u U u V u W They are respectively:

[0081] u U =A[sin(x)]+Δuout1

[0082]

[0083]

[0084] Where x = ωt, and A is the voltage amplitude.

[0085] This application embodiment calculates the target peak current corresponding to the three-phase current online in real time; performs peak sampling on the three-phase current to obtain the corresponding actual peak current; determines the three-phase current imbalance based on the target peak current and the actual peak current; determines the compensation voltage based on the three-phase current imbalance; and compensates the three-phase current based on the compensation voltage, thereby achieving imbalance compensation without adding additional components.

[0086] The following will describe an exemplary application of the embodiments of this application in a real-world application scenario.

[0087] See Figure 5 , Figure 5 This is an optional flowchart illustrating an embodiment of the motor three-phase current imbalance compensation method provided in this application, including:

[0088] Step 1: Calculate the maximum unbalanced current difference, which is the bias magnetic characteristic quantity:

[0089] 1) If a significant DC component appears in one phase of the current, the target three-phase current peak value corresponding to the target current can be calculated by using the relationship between the target peak current and the target current. The relationship is as follows:

[0090]

[0091] 2) Sample the peak current, and calculate the maximum unbalanced current difference by the difference between the target peak current and the actual peak current. This is the bias magnetic characteristic quantity.

[0092] ΔI=I refmax -I max

[0093] Where K is the coordinate transformation coefficient, I max I represents the actual peak value of the three-phase current. refmax This represents the peak value of the target three-phase current corresponding to the target current.

[0094] Step 2: Calculate the three-phase voltage compensation values:

[0095] 1) The maximum unbalanced current difference, i.e., the bias magnetization characteristic quantity, is used as the input to the bias magnetization compensation PI loop for PI calculation to obtain the bias magnetization compensation voltage value. Taking phase U as an example, the bias magnetization compensation voltage value of phase U output by the PI loop is Δuout1 At this point, the compensation values ​​for the other two items should be:

[0096] Δu out2 =-Δu out1 *Δi V / Δi U

[0097] Δu out3 =-Δu out1 *Δi w / Δi U

[0098] Δi U ,Δi V ,Δi W It is a quantity that can reflect the three-phase bias state. When the compensation voltage is output, the bias compensation voltage value is limited. The specific limit value can be set according to the actual situation.

[0099] Step 3: During the motor closed-loop control process, compensate for the above bias voltage values:

[0100] When the three-phase voltage output is in the motor current closed loop, the above-calculated Δu out1 , Δu out2 , Δu out3 After compensation, the three-phase voltage u is obtained. U u V u W Then, a three-phase to two-phase coordinate system conversion is performed to control the motor. At this time, the three-phase voltage output u U u V u W It should be:

[0101] u U =A[sin(x)]+Δu out1

[0102]

[0103]

[0104] Where x = ωt; A is the voltage amplitude.

[0105] This application utilizes the maximum unbalanced current difference to characterize the bias magnetization characteristic. A PI control method using the bias magnetization characteristic is used to calculate the single-phase compensation voltage. A proportional method is used to calculate the compensation voltages of other phases. After correcting the three-phase voltage output of the current closed-loop circuit with the three-phase voltage bias magnetization compensation, the motor control output is then performed. This allows for dynamic compensation of the three-phase current imbalance of the motor without adding hardware circuitry, improving the service life of the electric drive system, increasing motor efficiency, and reducing EMC and NVH problems in the electric drive system.

[0106] The following description continues to illustrate the exemplary structure of the motor three-phase current imbalance compensation method device 1055 provided in the embodiments of this application as a software module. In some embodiments, such as... Figure 1 As shown, the software modules in the motor three-phase current imbalance compensation method device 1055 stored in the memory 105 may include:

[0107] The calculation module 10551 calculates the target peak current corresponding to the three-phase current of the motor in real time.

[0108] The sampling module 10552 is used to sample the peak values ​​of the three-phase currents to obtain the corresponding actual peak currents.

[0109] The first determining module 10553 is used to determine the three-phase current imbalance based on the target peak current and the actual peak current.

[0110] The second determining module 10554 is used to determine the compensation voltage based on the three-phase current imbalance.

[0111] The compensation module 10555 is used to compensate the three-phase current based on the compensation voltage.

[0112] In some embodiments, the calculation module 10551 is further configured to perform dq coordinate transformation on the three-phase current of the motor to obtain the target dq two-phase current; obtain the relationship between the target peak current and the dq two-phase current; and calculate the target peak current corresponding to the three-phase current of the motor in real time based on the target dq two-phase current and the relationship between the target peak current and the dq two-phase current.

[0113] In some embodiments, the second determining module 10554 is further configured to use the three-phase current imbalance as the input of the bias magnetic compensation proportional integral PI loop for PI calculation to obtain the compensation voltage.

[0114] In some embodiments, the compensation module 10555 is further configured to perform voltage compensation based on the compensation voltage when the three-phase voltage output of the motor current closed loop is obtained, thereby realizing the compensation of the three-phase current.

[0115] In some embodiments, the device further includes: a control module for converting the compensated three-phase voltage into a two-phase voltage; and using the two-phase voltage to control the motor.

[0116] It should be noted that the description of the apparatus in this application is similar to the description of the method embodiments described above, and has similar beneficial effects as the method embodiments, so it will not be repeated.

[0117] This application provides a computer program product or computer program that includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the method described in this application.

[0118] This application provides a computer-readable storage medium storing executable instructions, wherein the executable instructions are stored and, when executed by a processor, will cause the processor to execute the method provided in this application.

[0119] In some embodiments, the computer-readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or it may be a variety of devices including one or any combination of the above-mentioned memories.

[0120] In some embodiments, executable instructions may take the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0121] As an example, executable instructions may, but do not necessarily, correspond to files in a file system. They may be stored as part of a file that holds other programs or data, for example, in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple collaborating files (e.g., a file that stores one or more modules, subroutines, or code sections).

[0122] As an example, executable instructions can be deployed to execute on a single computing device, or on multiple computing devices located in one location, or on multiple computing devices distributed across multiple locations and interconnected via a communication network.

[0123] In summary, the embodiments of this application enable imbalance compensation without adding additional components.

[0124] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of this application are included within the scope of protection of this application.

Claims

1. A method for compensating for the imbalance of three-phase current in a motor, characterized in that, include: Calculate the target peak current corresponding to the three-phase current of the motor in real time; The peak values ​​of the three-phase currents are sampled to obtain the corresponding actual peak currents. Based on the target peak current and the actual peak current, the three-phase current imbalance is determined; Based on the aforementioned three-phase current imbalance, determine the compensation voltage; The three-phase current is compensated based on the compensation voltage; The compensated three-phase voltage is converted into a two-phase voltage; The motor is controlled using the two-phase voltage; The real-time calculation of the target peak current corresponding to the three-phase current of the motor includes: The three-phase current of the motor is transformed into dq coordinates to obtain the target dq two-phase current; Obtain the relationship between the target peak current and the dq two-phase current; Based on the target dq two-phase current, the target peak current and the relationship between the dq two-phase current, the target peak current corresponding to the three-phase current of the motor is calculated in real time. The relationship between the target peak current and the dq two-phase current is as follows: in, Let d be the d-phase current in the two-phase current dq. Let q be the phase current in the two-phase current dq, and K be the coordinate transformation coefficient. The target peak current.

2. The method according to claim 1, characterized in that, The determination of the compensation voltage based on the three-phase current imbalance includes: The three-phase current imbalance is used as the input of the bias magnetic compensation proportional integral PI loop for PI calculation to obtain the compensation voltage.

3. The method according to claim 1, characterized in that, The compensation of the three-phase current based on the compensation voltage includes: When the three-phase voltage is output in the motor current closed loop, voltage compensation is performed based on the compensation voltage to obtain the compensated three-phase voltage, thereby realizing the compensation of the three-phase current.

4. A device for compensating for the imbalance of three-phase current in a motor, characterized in that, include: The calculation module calculates the target peak current corresponding to the three-phase current of the motor in real time; The sampling module is used to perform peak sampling on the three-phase current to obtain the corresponding actual peak current; The first determining module is used to determine the three-phase current imbalance based on the target peak current and the actual peak current. The second determining module is used to determine the compensation voltage based on the three-phase current imbalance. The compensation module is used to compensate the three-phase current based on the compensation voltage; The control module is used to convert the compensated three-phase voltage into a two-phase voltage; and to control the motor using the two-phase voltage. The calculation module is also used to perform dq coordinate transformation on the three-phase current of the motor to obtain the target dq two-phase current; obtain the relationship between the target peak current and the dq two-phase current; and calculate the target peak current corresponding to the three-phase current of the motor in real time based on the target dq two-phase current and the relationship between the target peak current and the dq two-phase current. The relationship between the target peak current and the dq two-phase current is as follows: in, Let d be the d-phase current in the two-phase current dq. Let q be the phase current in the two-phase current dq, and K be the coordinate transformation coefficient. The target peak current.

5. The apparatus according to claim 4, characterized in that, The second determining module is further configured to use the three-phase current imbalance as the input of the bias magnetic compensation proportional integral PI loop for PI calculation to obtain the compensation voltage.

6. An electronic device, characterized in that, include: Memory, used to store executable instructions; A processor, when executing executable instructions stored in the memory, implements the method according to any one of claims 1 to 3.

7. A computer-readable storage medium, characterized in that, It stores executable instructions for implementing the method of any one of claims 1 to 3 when executed by a processor.

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