Asynchronous motor control method and device, electronic equipment and storage medium

Abstract

The invention provides an asynchronous motor control method and device, electronic equipment and a storage medium. A first current instruction and a second current instruction corresponding to a current torque instruction, a current rotating speed and a current bus voltage can be searched from a database, the two current instructions are subjected to slip compensation processing to obtain a target slip frequency, and the target slip frequency and a current frequency corresponding to the current rotating speed are summed to obtain a sum of the target slip frequency and the current frequency corresponding to the current rotating speed. The target angle of the stator current is obtained through frequency conversion control processing; a first current instruction, a second current instruction, an acquired first feedback current instruction and an acquired second feedback current instruction are subjected to proportional integral control to obtain a first voltage result and a second voltage result, so that a third voltage result and a fourth voltage result can be obtained by performing reverse park conversion processing on the first voltage result and the second voltage result by using a target angle; and the three-phase duty ratio of the inverter can be obtained by carrying out space vector pulse width modulation, and the torque precision of the obtained three-phase duty ratio of the inverter for controlling the operation of the asynchronous motor is higher.

Description

Technical Field

[0001] The present application relates to the field of electronic control technology, and in particular to an asynchronous motor control method, device, electronic device and storage medium. Background Art

[0002] For asynchronous motors, torque and speed control can be achieved through slip frequency conversion, but asynchronous motor parameters are difficult to fully identify, especially its core parameter, rotor resistance, which is greatly affected by the motor rotor temperature. Generally speaking, when the asynchronous motor load is large, the rotor temperature rises quickly. At this time, the controller cannot normally know the size of the rotor resistance, resulting in the calculated slip not matching the actual working conditions. The output torque continues to drop as the temperature rises, and the torque control accuracy deteriorates.

[0003] Moreover, the motor rotor is always rotating. In mass-produced products, it is not suitable to place a temperature sensor for temperature sampling. Therefore, the existing technology often indirectly compensates the rotor resistance through the stator temperature. However, the stator temperature is quite different from the rotor temperature, especially under heavy load conditions, and the change pattern of the rotor resistance cannot be characterized.

[0004] In addition, the existing technology also has compensation through rotor temperature estimation scheme, but the thermal model of asynchronous motor temperature is complex, and it is difficult to estimate the temperature through the mathematical model of thermal resistance and heat capacity, or there is a certain deviation between the estimated result and the actual situation, and it may not be able to characterize the change law of rotor resistance. Summary of the invention

[0005] In view of this, the purpose of the present application is to propose an asynchronous motor control method, device, electronic device and storage medium to solve or partially solve the above technical problems.

[0006] Based on the above purpose, the present application provides an asynchronous motor control method, comprising:

[0007] Get the current torque command, current speed and current bus voltage;

[0008] Searching for the current first current instruction and the second current instruction corresponding to the current torque instruction, the current speed and the current bus voltage in a database, wherein each torque instruction, each speed and each current instruction corresponding to each bus voltage is pre-stored in the database;

[0009] Performing slip compensation processing according to the first current command and the second current command to obtain a target slip frequency;

[0010] Determine a current frequency corresponding to the current rotation speed, sum the current frequency and the target slip frequency to obtain an actual stator current frequency, and perform frequency conversion control on the stator current frequency to obtain a target angle of the stator current;

[0011] According to the first current command and the second current command, a proportional integral control process is performed with the first feedback current command and the second feedback current command obtained by collecting the asynchronous motor to obtain a first voltage result and a second voltage result;

[0012] Performing an inverse park transformation process on the first voltage result and the second voltage result using the target angle to obtain a third voltage result and a fourth voltage result;

[0013] The third voltage result and the fourth voltage result are subjected to space vector pulse width modulation processing to obtain a three-phase duty cycle of the inverter, and the operation of the asynchronous motor is controlled according to the three-phase duty cycle.

[0014] Based on the same inventive concept, the present application also provides an asynchronous motor control device, comprising:

[0015] An acquisition module is configured to acquire a current torque command, a current speed, and a current bus voltage;

[0016] A search module is configured to search a database for a current first current command and a second current command corresponding to the current torque command, the current speed, and the current bus voltage, wherein each torque command, each speed, and each current command corresponding to each bus voltage is pre-stored in the database;

[0017] a slip compensation module, configured to perform slip compensation processing according to the first current command and the second current command to obtain a target slip frequency;

[0018] A frequency conversion processing module is configured to determine a current frequency corresponding to the current rotation speed, sum the current frequency and the target slip frequency to obtain an actual stator current frequency, and perform frequency conversion control processing on the stator current frequency to obtain a target angle of the stator current;

[0019] The current loop module is configured to perform proportional integral control processing according to the first current command and the second current command and the first feedback current command and the second feedback current command acquired from the asynchronous motor to obtain the first voltage result and the second voltage result;

[0020] a coordinate transformation module, configured to perform an inverse park transformation on the first voltage result and the second voltage result using the target angle to obtain a third voltage result and a fourth voltage result;

[0021] The space vector pulse width modulation module is configured to perform space vector pulse width modulation on the third voltage result and the fourth voltage result to obtain the three-phase duty cycle of the inverter, and control the operation of the asynchronous motor according to the three-phase duty cycle.

[0022] Based on the same inventive concept, the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable by the processor, wherein the processor implements the method as described above when executing the computer program.

[0023] Based on the same inventive concept, the present application also provides a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a computer to execute the method as described above.

[0024] From the above, it can be seen that the asynchronous motor control method, device, electronic device and storage medium provided in the present application can search the first current instruction and the second current instruction corresponding to the current torque instruction, the current speed and the current bus voltage from the database. After the two current instructions are processed by slip compensation, the target slip frequency can be obtained, so that the target slip frequency can be summed with the current frequency corresponding to the current speed, and then the target angle of the stator current can be obtained through frequency conversion control; for the first current instruction and the second current instruction, after proportional integral control with the collected first feedback current instruction and the second feedback current instruction, the first voltage result and the second voltage result are obtained, so that the target angle can be used to perform inverse park transformation processing on them to obtain the third voltage result and the fourth voltage result, and then space vector pulse width modulation can be performed on them to obtain the final three-phase duty cycle of the inverter, so that the torque accuracy of the three-phase duty cycle of the inverter to control the operation of the asynchronous motor is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 A flowchart of an asynchronous motor control method according to an embodiment of the present application;

[0027] Figure 2 A schematic diagram of data flow of an asynchronous motor control method according to an embodiment of the present application;

[0028] Figure 3 A schematic diagram of data trends for slip compensation calculation in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of data trends of static compensation according to an embodiment of the present application;

[0030] Figure 5 A schematic diagram of data trends for dynamic compensation according to an embodiment of the present application;

[0031] Figure 6 This is a structural block diagram of an asynchronous motor control device according to an embodiment of the present application;

[0032] Figure 7 A schematic diagram of the structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0034] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0035] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0036] The asynchronous motor control method proposed in the embodiment of the present application is as follows: Figure 1 As shown, the method includes:

[0037] Step 101, obtaining the current torque command (TorqueCmd), the current speed (Speed) and the current bus voltage (Udc).

[0038] Step 102, such as Figure 2As shown, the current first current instruction (IdRef) and the second current instruction (IqRef) corresponding to the current torque instruction (TorqueCmd), the current speed (Speed) and the current bus voltage (Udc) are searched in the database, wherein the current instructions corresponding to the various torque instructions, various speeds and various bus voltages are pre-stored in the database.

[0039] In specific implementation, a current command table is pre-stored in the database. If the current command table is a three-dimensional table, the table can be directly looked up according to the current torque command (TorqueCmd), the current speed (Speed) and the current bus voltage (Udc) to obtain the corresponding current first current command (IdRef) and second current command (IqRef); if the current command table is a two-dimensional table, the current speed (Speed) is converted into an equivalent speed Speed / Udc*UdcCali (where UdcCali is the bus voltage during calibration) according to the current torque command (TorqueCmd) and the equivalent speed, and the corresponding current first current command (IdRef) and second current command (IqRef) are obtained by looking up the table in the two-dimensional table.

[0040] Step 103, as Figure 2 As shown, slip compensation processing is performed according to the first current command (IdRef) and the second current command (IqRef) to obtain a target slip frequency (Wslip).

[0041] In some embodiments, step 103 includes:

[0042] Step 1031, obtain the current current amplitude (Is), and determine the dynamic temperature (TempDynamic) based on the current current amplitude (Is), the current torque command (TorqueCmd), the current speed (Speed) and the current bus voltage (Udc).

[0043] The dynamic temperature (TempDynamic) obtained in this way is more accurate.

[0044] In some embodiments, step 1031 includes:

[0045] Step 10311, as Figure 3 As shown, the current current amplitude (Is) is obtained, and static compensation processing is performed according to the current current amplitude (Is) to obtain the rotor temperature value (TempStatic).

[0046] In some embodiments, step 10311 includes:

[0047] Step 103111, as Figure 4 As shown, the current current amplitude (Is) is obtained, and the current action coefficient table (a one-dimensional table) is queried according to the current current amplitude to determine the current action coefficient (IsCoef) corresponding to the current current amplitude (Is).

[0048] In specific implementation, the current action coefficient (IsCoef) corresponding to the current amplitude (Is) can be determined through the above current action coefficient table. The current action coefficient (IsCoef) represents the temperature rise rate of the motor rotor under the current current amplitude (Is).

[0049] For example, the current action coefficient table is as follows:

[0050] Is / A 0 100 200 300 400 500 600 700 IsCoef 0 0 0 0 0.25 0.5 0.75 1

[0051] The above current action coefficient table is only a representative example, and the specific values ​​can be adjusted and changed according to the actual situation. According to the current action coefficient table, when the current amplitude (Is) is below 300A, the rotor heats up less and no temperature compensation is required. When the current amplitude is above 300A, the motor heats up faster and the current action coefficient (IsCoef) increases gradually.

[0052] Step 103112, multiply the current amplitude (Is) by the current action coefficient (IsCoef), and then perform integration processing to obtain the current integration result (IsSum).

[0053] In specific implementation, the corresponding formula is IsSum=∫Is×IsCoef.

[0054] In some embodiments, step 103112 includes:

[0055] Determine whether the current amplitude (Is) is greater than or equal to a current threshold (for example, 300A), and obtain a determination result;

[0056] In response to the judgment result being yes, the current current amplitude (Is) is multiplied by the current action coefficient (IsCoef), and then integrated to obtain a current integration result (IsSum); or,

[0057] In response to the judgment result being negative, the current integration result (IsSum0) is cleared to obtain the current integration result (IsSum).

[0058] In specific implementation, whether the integral result is cleared is determined based on whether the current current amplitude (Is) reaches the current threshold value (for example, 300A) that requires static compensation, and the real current integral result (IsSum) of the subsequent calculation is obtained, so as to ensure that when the motor torque becomes smaller, integral saturation will not occur to affect the subsequent calculation results. According to the above table (current action coefficient table), the current threshold is set to 300A, so that when the current current amplitude (Is) is less than 300A, the current integral result (IsSum0) is cleared.

[0059] Step 103113, as Figure 4 As shown, the current integration result (IsSum) is divided by the integral saturation coefficient (Ksat) to obtain the temperature compensation coefficient (TempCoef).

[0060] In specific implementation, the corresponding formula is: TempCoef = IsSum / Ksat, the result TempCoef is limited between 0 and 1, and the integral saturation coefficient Ksat represents how long it takes to integrate to reach thermal steady state under different currents.

[0061] For example, if the integral saturation coefficient Ksat is set to 1750000, the timetable required to reach thermal steady state under different currents is shown in the following table:

[0062]

[0063] The above timetable required to reach thermal steady state under different currents is only a representative example, and the specific values ​​can be adjusted and changed according to actual conditions.

[0064] Step 103114, such as Figure 4 As shown, the corresponding maximum compensated temperature difference (TempMax) is queried according to the current current amplitude (Is).

[0065] In specific implementation, the compensation temperature difference corresponding to each current amplitude is stored in the database in advance, and the compensation temperature difference under each different current is determined by looking up the table according to the current current amplitude (Is), and the maximum compensation temperature difference (TempMax) is selected.

[0066] The maximum temperature difference of this compensation expresses the temperature difference between the stator temperature and the rotor temperature when the motor runs to thermal steady state. The temperature difference between the stator temperature and the rotor temperature is shown in the following table. It is assumed that under the 700A amplitude current, in thermal steady state, the stator and rotor temperatures differ by 20 degrees.

[0067] Is / A 0 100 200 300 400 500 600 700 Temperature difference / deg 0 0 0 0 5 10 15 20

[0068] The above temperature difference table of stator temperature and rotor temperature is only a representative example, and the specific values ​​can be adjusted and changed according to actual conditions.

[0069] Step 103115, as Figure 4 As shown, the stator temperature (TempStator) is obtained, the temperature compensation coefficient (TempCoef) is multiplied by the compensated maximum temperature difference (TempMax), and then added to the stator temperature to obtain the rotor temperature value (TempStatic).

[0070] It should be noted that the above-mentioned multiple values, such as how long it takes for the motor to reach thermal steady state under different currents, and the maximum temperature difference (TempMax) compensated when reaching thermal steady state, can all be obtained through offline calibration and testing based on simulation or manufacturing of a dedicated calibration prototype equipped with a rotor thermal sensor.

[0071] Step 10312, determine the dynamic compensation temperature difference (TempDynamic) based on the current torque command (TorqueCmd), the current speed (Speed) and the current bus voltage (Udc).

[0072] In some embodiments, step 10312 includes:

[0073] Step 103121, such as Figure 5 As shown, according to the current torque command (TorqueCmd), the current speed (Speed) and the current bus voltage (Udc), the corresponding theoretical voltage utilization rate (VoltRatioRef) is queried.

[0074] Step 103122, obtain the third voltage result (Ualpha) at the previous moment and the fourth voltage result (Ubeta) at the previous moment, calculate the square root of the third voltage result (Ualpha) at the previous moment and the fourth voltage result (Ubeta) at the previous moment, and divide them by the current bus voltage (Udc) to obtain the current voltage utilization rate (VoltRatio).

[0075] In specific implementation, the formula is VoltRatio=Sqrt(Ualpha*Ualpha+Ubeta*Ubeta) / Udc, where Sqrt represents a square root operation.

[0076] Step 103123, multiply the theoretical voltage utilization by the error coefficient (RatioCoef), subtract the current voltage utilization (VoltRatio), and obtain the voltage utilization error (DeltaRatio).

[0077] When implemented specifically, the formula is:

[0078] Voltage utilization error DeltaRatio = VoltRatioRef * RatioCoef - VoltRatio, where RatioCoef is the error coefficient, generally 1.05-1.1, to avoid introducing the fluctuation error caused by control into the calculation mode. If DeltaRatio is less than 0, DeltaRatio = 0.

[0079] When the asynchronous motor is running under load, if the slip deviation occurs, the actual Id and Iq on the motor winding will also deviate from the expected current distribution, and the magnetic field characteristics of the asynchronous motor will change, so the motor voltage will change, and the voltage utilization may be greater than the expected voltage utilization. Therefore, by performing closed-loop processing on the voltage utilization, the slip error caused by the rotor temperature and other factors can be compensated.

[0080] The theoretical voltage utilization rate VoltRatioRef can be recorded and tabulated simultaneously during torque calibration, indicating the value that the motor voltage should output under the current torque.

[0081] Step 103124, performing a proportional-integral (PI) operation on the voltage utilization error (DeltaRatio) to determine a dynamic compensation temperature difference (TempDynamic).

[0082] In some embodiments, step 103124 includes:

[0083] The current voltage utilization ratio (VoltRatio) is compared with the voltage utilization ratio error (DeltaRatio).

[0084] In response to the current voltage utilization (VoltRatio) being greater than or equal to the voltage utilization error (DeltaRatio), a first proportional parameter (Kp_ratio) is multiplied by the voltage utilization error (DeltaRatio) to obtain a first product result, a second proportional parameter (Ki_ratio) is multiplied by the voltage utilization error (DeltaRatio) to obtain a second product result, and an integral result of the first product result and the second product result is added to obtain a dynamically compensated temperature difference (DeltaTemp).

[0085] The specific formula is: DeltaTemp=Kp_ratio*DeltaRatio+∫Ki_ratio*DeltaRatio.

[0086] Alternatively, in response to the current voltage utilization rate (VoltRatio) being less than the voltage utilization rate error (DeltaRatio), a first product result obtained by multiplying a first proportional parameter (Kp_ratio) by the voltage utilization rate error (DeltaRatio) is used as the dynamic compensation temperature difference (DeltaTemp).

[0087] The dynamic compensation temperature difference (DeltaTemp) needs to be limited to above 0. In addition, if the current voltage utilization (VoltRatio) is less than the voltage utilization error (DeltaRatio), the integral result of the second product result in the calculation formula corresponding to the dynamic compensation temperature difference (DeltaTemp) will be cleared.

[0088] Step 10313, summing the rotor temperature (TempStatic) and the dynamic compensation temperature difference (DeltaTemp) to obtain the dynamic temperature (TempDynamic).

[0089] During specific implementation, the corresponding formula is TempDynamic=TempStatic+DeltaTemp.

[0090] Step 1032, as Figure 5 As shown, the rotor resistance (RrDynamic) corresponding to the dynamic temperature (TempDynamic) is determined, and the rotor time constant (Rt) is calculated based on the rotor resistance (RrDynamic).

[0091] In a specific implementation, the rotor resistance corresponding to each dynamic temperature is pre-stored, so that after the dynamic temperature (TempDynamic) is calculated, the corresponding rotor resistance (RrDynamic) can be determined by looking up the table.

[0092] The corresponding rotor time constant (Rt) calculation formula is: Rt = RrDynamic / Lr, where Lr is the rotor inductance, which can be obtained by querying the motor parameter table.

[0093] Step 1033, as Figure 3 As shown, the ratio of the first current command (IdRef) to the second current command (IqRef) is multiplied by the rotor time constant to obtain the target slip frequency (Wslip).

[0094] During specific implementation, the corresponding calculation formula is: Wslip=Rt*IqRef / IdRef.

[0095] Step 104, determine the corresponding current frequency according to the current speed (Speed), sum the current frequency and the target slip frequency (Wslip) to obtain the actual stator current frequency, and perform frequency conversion control on the stator current frequency to obtain the target angle Theta of the stator current (such as Figure 2 shown).

[0096] Step 105, according to the first current command (IdRef) and the second current command (IqRef), and the first feedback current command (IdFdb) and the second feedback current command (IqFdb) obtained by collecting the asynchronous motor, a proportional integral control (PI control) process is performed (specifically, Figure 2 As shown, it is performed within the current loop) to obtain a first voltage result (Ud) and a second voltage result (Uq).

[0097] Step 106: Perform inverse park transformation processing (such as Figure 2 As shown, the corresponding coordinate transformation processing) obtains the third voltage result (Ualpha) and the fourth voltage result (Ubeta).

[0098] In specific implementation, Ualpha = cos(Theta)*Ud-sin(Theta)*Uq;

[0099] Ubeta=cos(Theta)*Uq+sin(Theta)*Ud.

[0100] Step 107, performing space vector pulse width modulation (SVPWM, Space Vector Pulse Width Modulation) processing on the third voltage result (Ualpha) and the fourth voltage result (Ubeta) (such as Figure 2 As shown), the three-phase duty cycle of the inverter is obtained, and the operation of the asynchronous motor is controlled according to the three-phase duty cycle.

[0101] Through the above scheme, the first current instruction and the second current instruction corresponding to the current torque instruction, the current speed and the current bus voltage can be searched from the database, and the target slip frequency can be obtained after the two current instructions are processed by slip compensation, so that the target slip frequency can be summed with the current frequency corresponding to the current speed, and then the target angle of the stator current can be obtained through frequency conversion control processing; for the first current instruction and the second current instruction, after proportional integral control with the collected first feedback current instruction and the second feedback current instruction, the first voltage result and the second voltage result are obtained, so that the target angle can be used to perform inverse park transformation processing on them to obtain the third voltage result and the fourth voltage result, and then space vector pulse width modulation can be performed on them to obtain the final three-phase duty cycle of the inverter, so that the torque accuracy of the asynchronous motor operation controlled by the three-phase duty cycle of the inverter is higher.

[0102] It should be noted that the method of the embodiment of the present application can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of the embodiment of the present application, and the multiple devices will interact with each other to complete the described method.

[0103] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0104] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides an asynchronous motor control device.

[0105] refer to Figure 6 , the device comprises:

[0106] An acquisition module 201 is configured to acquire a current torque command, a current speed and a current bus voltage;

[0107] The search module 202 is configured to search the database for the current first current command and the second current command corresponding to the current torque command, the current speed and the current bus voltage, wherein each torque command, each speed and each current command corresponding to each bus voltage is pre-stored in the database;

[0108] A slip compensation module 203 is configured to perform slip compensation processing according to the first current command and the second current command to obtain a target slip frequency;

[0109] The frequency conversion processing module 204 is configured to determine a current frequency corresponding to the current rotation speed, sum the current frequency and the target slip frequency to obtain an actual stator current frequency, and perform frequency conversion control on the stator current frequency to obtain a target angle of the stator current;

[0110] The current loop module 205 is configured to perform proportional integral control processing according to the first current command and the second current command and the first feedback current command and the second feedback current command acquired by the asynchronous motor to obtain the first voltage result and the second voltage result;

[0111] A coordinate transformation module 206 is configured to perform an inverse park transformation on the first voltage result and the second voltage result using the target angle to obtain a third voltage result and a fourth voltage result;

[0112] The space vector pulse width modulation module 207 is configured to perform space vector pulse width modulation on the third voltage result and the fourth voltage result to obtain a three-phase duty cycle of the inverter, and control the operation of the asynchronous motor according to the three-phase duty cycle.

[0113] In some embodiments, the slip compensation module 203 includes:

[0114] a dynamic temperature determination unit configured to obtain a current current amplitude, and determine a dynamic temperature based on the current current amplitude, the current torque command, the current speed, and the current bus voltage;

[0115] a rotor time constant determination unit, configured to determine a rotor resistance corresponding to the dynamic temperature, and calculate a rotor time constant according to the rotor resistance;

[0116] The slip frequency determination unit is configured to multiply the ratio of the first current command to the second current command by the rotor time constant to obtain a target slip frequency.

[0117] In some embodiments, the dynamic temperature determination unit comprises:

[0118] A static compensation subunit is configured to obtain a current current amplitude, and perform static compensation processing according to the current current amplitude to obtain a rotor temperature value;

[0119] a dynamic compensation subunit, configured to determine a dynamic compensation temperature difference based on the current torque command, the current speed and the current bus voltage;

[0120] The summing subunit is configured to sum the rotor temperature and the dynamic compensation temperature difference to obtain the dynamic temperature.

[0121] In some embodiments, the static compensation subunit is specifically configured as follows:

[0122] Obtaining a current amplitude, querying a current action coefficient table according to the current amplitude, and determining a current action coefficient corresponding to the current amplitude;

[0123] After multiplying the current current amplitude by the current action coefficient, integrating the current amplitude to obtain a current integration result;

[0124] Dividing the current integration result by the integral saturation coefficient to obtain a temperature compensation coefficient;

[0125] Query the corresponding maximum compensation temperature difference according to the current current amplitude;

[0126] The stator temperature is acquired, and the temperature compensation coefficient is multiplied by the compensated maximum temperature difference, and then the resultant is added to the stator temperature to obtain a rotor temperature value.

[0127] In some embodiments, the static compensation subunit is specifically configured as follows:

[0128] Determine whether the current amplitude is greater than or equal to a current threshold, and obtain a determination result;

[0129] In response to the judgment result being yes, the current current amplitude is multiplied by the current action coefficient, and then an integration process is performed to obtain a current integration result; or,

[0130] In response to the judgment result being negative, the current integration result is cleared to zero.

[0131] In some embodiments, the dynamic compensation subunit is specifically configured as follows:

[0132] According to the current torque command, the current speed and the current bus voltage, query the corresponding theoretical voltage utilization rate;

[0133] Obtaining a third voltage result at a previous moment and a fourth voltage result at a previous moment, calculating a square root of the third voltage result at a previous moment and the fourth voltage result at a previous moment, and dividing the square root by the current bus voltage to obtain a current voltage utilization rate;

[0134] Multiply the theoretical voltage utilization by the error coefficient and subtract the current voltage utilization to obtain the voltage utilization error.

[0135] A proportional-integral operation is performed on the voltage utilization error to determine a dynamic compensation temperature difference.

[0136] In some embodiments, the dynamic compensation subunit is specifically configured as follows:

[0137] Comparing the current voltage utilization rate with the voltage utilization rate error;

[0138] In response to the current voltage utilization being greater than or equal to the voltage utilization error, a first product result is obtained by multiplying the voltage utilization error by a first proportional parameter, a second product result is obtained by multiplying the voltage utilization error by a second proportional parameter, and an integral result of the first product result and the second product result is added to obtain a dynamic compensation temperature difference; or,

[0139] In response to the current voltage utilization being less than the voltage utilization error, a first product obtained by multiplying a first proportional parameter by the voltage utilization error is used as a dynamic compensation temperature difference.

[0140] For the convenience of description, the above device is described in terms of functions divided into various modules. Of course, when implementing the present application, the functions of each module can be implemented in the same or multiple software and / or hardware.

[0141] The device of the above embodiment is used to implement the corresponding method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.

[0142] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in any of the above embodiments when executing the program.

[0143] Figure 7 A more specific schematic diagram of the hardware structure of an electronic device provided in this embodiment is shown, and the device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040, and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040 are connected to each other through the bus 1050 in the device.

[0144] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.

[0145] The memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.

[0146] The input / output interface 1030 is used to connect the input / output module to realize information input and output. The input / output module can be configured in the device as a component (not shown in the figure), or it can be externally connected to the device to provide corresponding functions. The input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.

[0147] The communication interface 1040 is used to connect a communication module (not shown) to realize communication interaction between the device and other devices. The communication module can realize communication through a wired mode (such as USB, network cable, etc.) or a wireless mode (such as mobile network, WIFI, Bluetooth, etc.).

[0148] The bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040).

[0149] It should be noted that, although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, it can be understood by those skilled in the art that the above device may also only include the components necessary for implementing the embodiments of the present specification, and does not necessarily include all the components shown in the figure.

[0150] The electronic device of the above embodiment is used to implement the corresponding method in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be described in detail here.

[0151] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments, the present application also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method described in any of the above embodiments.

[0152] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

[0153] The computer instructions stored in the storage medium of the above embodiments are used to enable the computer to execute the method described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.

[0154] Based on the same concept, corresponding to any of the above-mentioned embodiment methods, the present application also provides a computer program product, including computer program instructions. When the computer program instructions are run on a computer, the computer executes the method described in any of the above embodiments, which has the beneficial effects of the corresponding method embodiments and will not be repeated here.

[0155] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of simplicity.

[0156] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present application difficult to understand, the known power supply / ground connection with the integrated circuit (IC) chip and other components may or may not be shown in the provided drawings. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform to be implemented in the embodiments of the present application (that is, these details should be fully within the scope of understanding of those skilled in the art). In the case of elaborating specific details (e.g., circuits) to describe exemplary embodiments of the present application, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details or when these specific details are changed. Therefore, these descriptions should be considered to be illustrative rather than restrictive.

[0157] Although the present application has been described in conjunction with specific embodiments of the present application, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0158] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.

Claims

1. An asynchronous motor control method, characterized in that: include: Get the current torque command, current speed and current bus voltage; Searching for the current first current instruction and the second current instruction corresponding to the current torque instruction, the current speed and the current bus voltage in a database, wherein each torque instruction, each speed and each current instruction corresponding to each bus voltage is pre-stored in the database; Performing slip compensation processing according to the first current command and the second current command to obtain a target slip frequency; Determine a current frequency corresponding to the current rotation speed, sum the current frequency and the target slip frequency to obtain an actual stator current frequency, and perform frequency conversion control on the stator current frequency to obtain a target angle of the stator current; According to the first current command and the second current command, a proportional integral control process is performed with the first feedback current command and the second feedback current command obtained by collecting the asynchronous motor to obtain a first voltage result and a second voltage result; Performing an inverse park transformation process on the first voltage result and the second voltage result using the target angle to obtain a third voltage result and a fourth voltage result; The third voltage result and the fourth voltage result are subjected to space vector pulse width modulation processing to obtain a three-phase duty cycle of the inverter, and the operation of the asynchronous motor is controlled according to the three-phase duty cycle.

2. The method according to claim 1, characterized in that The step of performing slip compensation processing according to the first current command and the second current command to obtain a target slip frequency includes: Obtaining a current current amplitude, and determining a dynamic temperature based on the current current amplitude, the current torque command, the current speed, and the current bus voltage; Determining a rotor resistance corresponding to the dynamic temperature, and calculating a rotor time constant based on the rotor resistance; The ratio of the first current command to the second current command is multiplied by the rotor time constant to obtain a target slip frequency.

3. The method according to claim 2, characterized in that The obtaining of the current current amplitude and determining the dynamic temperature based on the current current amplitude, the current torque command, the current speed and the current bus voltage includes: Acquire the current current amplitude, and perform static compensation processing according to the current current amplitude to obtain a rotor temperature value; Determining a dynamic compensation temperature difference based on the current torque command, the current speed and the current bus voltage; The rotor temperature and the dynamic compensation temperature difference are summed to obtain the dynamic temperature.

4. The method according to claim 3, characterized in that The obtaining of the current current amplitude and performing static compensation processing according to the current current amplitude to obtain the rotor temperature value includes: Acquire the current current amplitude, query the current action coefficient table according to the current current amplitude, and determine the current action coefficient corresponding to the current current amplitude; After multiplying the current current amplitude by the current action coefficient, integrating the current amplitude to obtain a current integration result; Dividing the current integration result by the integral saturation coefficient to obtain a temperature compensation coefficient; Query the corresponding maximum compensation temperature difference according to the current current amplitude; The stator temperature is acquired, and the temperature compensation coefficient is multiplied by the compensated maximum temperature difference, and then the resultant is added to the stator temperature to obtain a rotor temperature value.

5. The method according to claim 4, characterized in that The multiplication of the current current amplitude and the current action coefficient and then integration processing to obtain the current integration result includes: Determine whether the current amplitude is greater than or equal to a current threshold, and obtain a determination result; In response to the judgment result being yes, the current current amplitude is multiplied by the current action coefficient, and then an integration process is performed to obtain a current integration result; or, In response to the judgment result being negative, the current integration result is cleared.

6. The method according to claim 3, characterized in that Determining a dynamic compensation temperature difference based on the current torque command, the current speed, and the current bus voltage includes: According to the current torque command, the current speed and the current bus voltage, query the corresponding theoretical voltage utilization rate; Obtaining a third voltage result at a previous moment and a fourth voltage result at a previous moment, calculating a square root of the third voltage result at a previous moment and the fourth voltage result at a previous moment, and dividing the square root by the current bus voltage to obtain a current voltage utilization rate; Multiply the theoretical voltage utilization by the error coefficient and subtract the current voltage utilization to obtain the voltage utilization error. A proportional-integral operation is performed on the voltage utilization error to determine a dynamic compensation temperature difference.

7. The method according to claim 6, characterized in that The performing proportional-integral operation on the voltage utilization error to determine the dynamic compensation temperature difference comprises: Comparing the current voltage utilization rate with the voltage utilization rate error; In response to the current voltage utilization being greater than or equal to the voltage utilization error, a first product result is obtained by multiplying the voltage utilization error by a first proportional parameter, a second product result is obtained by multiplying the voltage utilization error by a second proportional parameter, and an integral result of the first product result and the second product result is added to obtain a dynamic compensation temperature difference; or, In response to the current voltage utilization being less than the voltage utilization error, a first product obtained by multiplying a first proportional parameter by the voltage utilization error is used as a dynamic compensation temperature difference.

8. An asynchronous motor control device, characterized in that: include: An acquisition module is configured to acquire a current torque command, a current speed, and a current bus voltage; A search module is configured to search a database for a current first current command and a second current command corresponding to the current torque command, the current speed, and the current bus voltage, wherein each torque command, each speed, and each current command corresponding to each bus voltage is pre-stored in the database; a slip compensation module, configured to perform slip compensation processing according to the first current command and the second current command to obtain a target slip frequency; A frequency conversion processing module is configured to determine a current frequency corresponding to the current rotation speed, sum the current frequency and the target slip frequency to obtain an actual stator current frequency, and perform frequency conversion control processing on the stator current frequency to obtain a target angle of the stator current; The current loop module is configured to perform proportional integral control processing according to the first current command and the second current command and the first feedback current command and the second feedback current command acquired from the asynchronous motor to obtain the first voltage result and the second voltage result; a coordinate transformation module, configured to perform an inverse park transformation on the first voltage result and the second voltage result using the target angle to obtain a third voltage result and a fourth voltage result; The space vector pulse width modulation module is configured to perform space vector pulse width modulation on the third voltage result and the fourth voltage result to obtain the three-phase duty cycle of the inverter, and control the operation of the asynchronous motor according to the three-phase duty cycle.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 7.

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