Motor power estimation method and device, motor and storage medium

Abstract

The application discloses a motor power estimation method and device, a motor and a storage medium. The method comprises the following steps: calculating reconstructed phase currents of a to-be-tested motor and calculating reconstructed phase voltages of the to-be-tested motor; and calculating power of the to-be-tested motor according to the reconstructed phase currents and the reconstructed phase voltages to obtain estimated power. The application can improve the accuracy of estimated motor operation power.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a method, apparatus, motor, and storage medium for predicting motor power. Background Technology

[0002] A permanent magnet synchronous motor (PMSM) is a synchronous motor that uses permanent magnets to generate a magnetic field. It has advantages such as high efficiency, high power density, good speed regulation performance and low noise, and therefore has been widely used in fields such as outdoor compressors for variable frequency air conditioners.

[0003] To facilitate the control of permanent magnet synchronous motors, it is usually necessary to monitor multiple parameters of the motor. One of the more important parameters is the motor's operating power. However, since the motor's operating power is generally not directly available, it is usually estimated based on relevant parameters. But the accuracy of commonly used estimation methods is relatively low. Summary of the Invention

[0004] This invention provides a method, apparatus, motor, and storage medium for estimating motor power, aiming to solve the problem of low accuracy in estimating motor power.

[0005] In a first aspect, embodiments of the present invention provide a method for estimating motor power, applied to a motor, the method comprising:

[0006] Calculate the reconfigured phase current and the reconfigured phase voltage of the motor under test;

[0007] The power of the motor under test is calculated based on the reconstructed phase current and the reconstructed phase voltage to obtain the estimated power.

[0008] Secondly, embodiments of the present invention also provide a motor power estimation device, the device comprising:

[0009] The first calculation unit is used to calculate the reconfigured phase current of the motor under test and the reconfigured phase voltage of the motor under test.

[0010] The second calculation unit is used to calculate the power of the motor under test based on the reconstructed phase current and the reconstructed phase voltage to obtain the estimated power.

[0011] Thirdly, embodiments of the present invention also provide an electric motor, which includes a memory and a processor connected to the memory, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-described method.

[0012] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing a computer program that, when executed by a processor, can implement the above-described method.

[0013] This invention provides a method, apparatus, motor, and storage medium for estimating motor power. The method includes: calculating the reconfigured phase current and the reconfigured phase voltage of the motor under test; and calculating the power of the motor under test based on the reconfigured phase current and the reconfigured phase voltage to obtain an estimated power. This invention can calculate the reconfigured phase current and the reconfigured phase voltage of the motor under test separately, and then calculate the power of the motor under test based on the reconfigured phase voltage and the reconfigured phase current, thereby obtaining an estimated power and improving the accuracy of motor power estimation. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a flowchart illustrating the motor power estimation method provided in an embodiment of the present invention;

[0016] Figure 2 This is a circuit schematic diagram of dual-resistor current sampling provided in an embodiment of the present invention;

[0017] Figure 3 This is a sampling time diagram of dual-resistor current sampling provided in an embodiment of the present invention;

[0018] Figure 4 This is a circuit schematic diagram of a single-resistor current sampling method provided in an embodiment of the present invention;

[0019] Figure 5 This is a sampling time diagram of single-resistor current sampling provided in an embodiment of the present invention;

[0020] Figure 6 This is a schematic diagram of the first sub-process of the motor power estimation method provided in the embodiment of the present invention;

[0021] Figure 7 This is a schematic diagram of the second sub-process of the motor power estimation method provided in the embodiments of the present invention;

[0022] Figure 8 This is a schematic diagram of the third sub-process of the motor power estimation method provided in the embodiment of the present invention;

[0023] Figure 9This is a schematic diagram of the fourth sub-process of the motor power estimation method provided in the embodiments of the present invention;

[0024] Figure 10 This is a schematic diagram of the fifth sub-process of the motor power estimation method provided in this embodiment of the invention;

[0025] Figure 11 This is a schematic diagram of the sixth sub-process of the motor power estimation method provided in the embodiment of the present invention;

[0026] Figure 11 This is a schematic diagram of the sixth sub-process of the motor power estimation method provided in the embodiment of the present invention;

[0027] Figure 12 This is a schematic diagram of the power factor angle φ of a motor power estimation method provided in an embodiment of the present invention;

[0028] Figure 13 This is a graph showing the relative relationship between phase current and phase voltage in a motor power estimation method provided by an embodiment of the present invention.

[0029] Figure 14 This is a schematic diagram of the power factor angle φ of a motor power estimation method provided in another embodiment of the present invention;

[0030] Figure 15 This is a graph showing the relative relationship between phase current and phase voltage in a motor power estimation method provided in another embodiment of the present invention.

[0031] Figure 16 This is a schematic block diagram of a motor power estimation device provided in an embodiment of the present invention;

[0032] Figure 17 This is a schematic block diagram of a motor provided in an embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be understood that, when used in this specification and the appended claims, the terms “comprising” and “including” indicate the presence of the described features, integrals, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, operations, elements, components and / or collections thereof.

[0035] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0036] Please see Figure 1 , Figure 1 This is a flowchart illustrating the motor power estimation method provided in an embodiment of the present invention. The motor power estimation method of this embodiment can be applied to motors, such as permanent magnet synchronous motors, to estimate the operating power of the motor. Figure 1 As shown, the method includes steps S100 to S110.

[0037] S100, calculate the reconfigured phase current of the motor under test and the reconfigured phase voltage of the motor under test.

[0038] In this embodiment of the invention, the motor under test can be a permanent magnet synchronous motor. When the motor under test is running, the reconstructed phase current and reconstructed phase voltage can be acquired separately to facilitate subsequent calculation of the estimated power. Different sampling methods can be used to acquire the reconstructed phase current depending on the sampling circuit. For example... Figure 2 and Figure 4 As shown, Figure 2 This is a schematic diagram of the dual-resistor current sampling principle. Figure 2 RS1 and RS2 are two sampling resistors, and A, B, and C represent the first, second, and third phases, respectively. Figure 2 Two sampling currents can be obtained through sampling resistors RS1 and RS2 respectively. For example... Figure 4 As shown, Figure 4 This is a schematic diagram of a single-resistor current sampling principle. Figure 4 In the diagram, RS is the sampling resistor, and A, B, and C represent the first phase, second phase, and third phase, respectively. Figure 4 A sampling current can be obtained through the sampling resistor.

[0039] In the case of dual-resistor current sampling, such as Figure 5 As shown, step S100 further includes steps S101-S102.

[0040] S101, the first phase current of the motor under test is obtained through the first sampling resistor, and the second phase current of the motor under test is obtained through the second sampling circuit;

[0041] S102, calculate the third phase current based on the first phase current and the second phase current to obtain the reconstructed phase current.

[0042] In embodiments of the present invention, such as Figure 2 As shown, the first sampling resistor is RS1, and the second sampling resistor is RS2. The first phase current and the second phase current of the motor under test can be obtained through RS1 and RS2, respectively. Figure 3 As shown, Figure 3 For the sampling time of the dual resistors, by Figure 3 It can be seen that at the zero-crossing point of the triangular carrier wave, i.e., the midpoint of the zero vector, RS1 and RS2 sample at the same time, allowing us to obtain the first-phase current sampled by RS1 and the second-phase current sampled by RS2 at that moment. After obtaining the first and second-phase currents, the third-phase current can be calculated based on the fact that the sum of the three-phase currents is zero. The reconstructed phase current can then be obtained after obtaining the first, second, and third-phase currents. It is understandable that the above method primarily relies on two sampling resistors to calculate the reconstructed phase current. The currents sampled by the two resistors are not limited to the first and second-phase currents mentioned above. For example, the first-phase current can be obtained through RS1, the third-phase current through RS2, and the second-phase current can be calculated based on the fact that the sum of the three-phase currents is zero.

[0043] In the case of single-resistor current sampling, such as Figure 6 As shown, step S100 further includes steps S103-S105.

[0044] S103, acquire the first phase current of the motor under test at the first moment, and acquire the third phase current of the motor under test at the second moment;

[0045] S104, the third phase current at the second moment is traced back to the first moment to obtain the third phase current at the first moment;

[0046] S105, calculate the second phase current corresponding to the first time based on the first phase current and the third phase current at the first time to obtain the reconstructed phase current.

[0047] In embodiments of the present invention, such as Figure 4 As shown, the sampling resistor is RS. When sampling through a single resistor, sampling can be performed at the midpoint of two different valid vector points. Figure 5 As shown, Figure 5 Samp1 represents the first time point, and Samp2 represents the second time point. The current of phase A is sampled at the first time point to obtain the first phase current at the first time point, and the current of phase C is sampled at the second time point to obtain the third phase current at the second time point.

[0048] After obtaining the third-phase current at the second moment, this third-phase current can be traced back to the first moment to obtain the third-phase current at the first moment. The first-phase current at the first moment can be obtained from the sampling resistor, and the third-phase current at the first moment can be obtained by tracing back from the third-phase current at the second moment. Therefore, the second-phase current at the first moment can be calculated from the sum of the three-phase currents being zero, thus obtaining the reconstructed phase current. It is understandable that the above method is based on single-resistor sampling to calculate the reconstructed phase current. Besides collecting the first-phase current at the first moment and the third-phase current at the second moment, it is also possible to collect the first-phase current at the first moment and the second-phase current at the second moment, then trace back from the second-phase current at the second moment to the first moment, and finally calculate the third-phase current at the first moment based on the sum of the three-phase currents being zero, thus obtaining the reconstructed phase current.

[0049] See Figure 7 In some embodiments, such as this embodiment, step S104 further includes steps S1041-S1042.

[0050] S1041, Calculate the current increment between the first time point and the second time point;

[0051] S1042, calculate the third phase current at the first moment based on the current increment and the third phase current at the second moment.

[0052] When the third phase current at the second moment is traced back to the first moment, it can be obtained based on the current increment. After obtaining the current increment, the third phase current at the first moment can be calculated based on the current increment.

[0053] See Figure 8 In some embodiments, such as this embodiment, step S1041 further includes steps S10411-S10412.

[0054] S10411, Calculate the rate of change of current in the two-phase stationary coordinate system, and perform an inverse Clarke transformation on the rate of change of current in the two-phase stationary coordinate system to obtain the rate of change of current in the three-phase stationary coordinate system.

[0055] S10412, calculate the current increment based on the current change rate in the three-phase stationary coordinate system.

[0056] In this embodiment of the invention, the equations under two-phase stationary coordinates are as shown in formula (1):

[0057]

[0058] Among them, I α I β For the current in a stationary coordinate system, The back electromotive force in a two-phase stationary coordinate system can be obtained through the inverse Park transformation, U α U β Let L be the instantaneous voltage in the two-phase stationary coordinate system, and L be the inductance of the motor under test. Table (I) lists the instantaneous voltages under each effective vector:

[0059]

[0060] (one)

[0062] After obtaining the current change rate in two-phase stationary coordinates, the current change rate in three-phase stationary coordinates is obtained by inverse Clarke transformation, as shown in formula (2):

[0063]

[0064] in, Let A be the rate of change of phase current. The rate of change of phase B current. Let C be the rate of change of the phase current. Then, calculate the current increment according to formula (3):

[0065]

[0066] Where X represents any one of phases A, B, and C. Finally, the phase current corresponding to the first moment is calculated according to formula (4):

[0067] I X_samp1_rec =I X_samp2 -ΔI X2 -ΔI X1 (4)

[0068] Among them, I X_samp1_rec Let ΔI be the current at the first moment. X2 The current increment under the second voltage vector, ΔI X1 Let X be the current increment under the first voltage vector, where X = A, B, C. For example, the third phase current at the second moment can be calculated according to formula (4), which corresponds to the third phase current at the first moment.

[0069] See Figure 9 In some embodiments, such as this embodiment, step S100 further includes steps S106-S107.

[0070] S106, Calculate the phase voltage corresponding to the zero-crossing moment of the triangular carrier wave of the motor under test;

[0071] S107, perform dead-zone compensation on the phase voltage to obtain the reconstructed phase voltage.

[0072] In this embodiment of the invention, the method for calculating the reconstructed phase voltage under dual-resistor current sampling is similar to the method for calculating the reconstructed phase voltage under single-resistor current sampling. The following description uses the calculation of the reconstructed phase voltage under dual-resistor current sampling as an example.

[0073] When estimating power, it is necessary to know the voltage and current at the same moment. Under dual-resistor current sampling, the sampled current is obtained at the zero-crossing point of the triangular carrier wave. Correspondingly, the phase voltage at the zero-crossing point of the triangular carrier wave also needs to be obtained. After obtaining the phase voltage, dead-time compensation needs to be performed on the phase voltage to compensate for the error between the actual phase voltage and the reconstructed phase voltage caused by the dead time. Let the phase voltage be V. XS_zero For example, V can be calculated using formulas (5) and (6). XS_zero Compensation will be provided.

[0074] V XS_rec =V XS_zero -(Td*Vd) / ts (5)

[0075] V XS_rec =V XS_zero +(Td*Vd) / ts (6)

[0076] Where Td is the dead time, Vd is the bus voltage, Ts is the carrier period, and V XS_rec To reconstruct the phase voltage, X = A, B, C, formula (5) or formula (6) can be used to adjust the phase voltage V according to the current polarity. XS_zero To compensate, for example, when I x When I is greater than zero, formula (5) is used for compensation. x When the value is less than zero, use formula (6) for compensation. x Indicates the polarity of the phase current.

[0077] See Figure 10 In some embodiments, such as this embodiment, step S100 further includes steps S1061-S1062.

[0078] S1061, Obtain the phase voltage of the motor under test in the current cycle and the phase voltage of the previous cycle;

[0079] S1062, calculate the average of the phase voltage of the motor under test in the current cycle and the phase voltage of the previous cycle to obtain the phase voltage.

[0080] In this embodiment of the invention, the phase voltage and phase current of the permanent magnet synchronous motor are represented in a rotating coordinate system as the angle between the resultant voltage Us and the resultant current Is. This angle is called the power factor angle. Figure 3 and Figure 4A schematic diagram of the power factor angle is given. The relationship between the combined voltage (current) and the dq-axis voltage (current) components satisfies equation (7).

[0081]

[0082] Where Us is the composite voltage, Ud is the d-axis voltage, Uq is the q-axis voltage, Is is the composite current, Id is the d-axis current, and Iq is the q-axis current.

[0083] Generally, when the motor is operating at low speed, Id is 0, and Iq is determined by the load size. Once the current is determined, it is combined with the motor parameters (resistance Rs, d-axis inductance Ld, q-axis inductance Lq, permanent magnet flux linkage). The dq-axis voltage is obtained from equation (8):

[0084]

[0085] At this time, the synthesized current lags behind the synthesized voltage, such as Figure 3 As shown, the phase current lags behind the phase voltage; when the motor operates at high speed, the absolute value of Id is large, and at this time the combined current leads the combined voltage, such as... Figure 4 As shown, the phase current leads the phase voltage. From the above analysis, we can conclude that the power factor angle is affected by the motor's operating conditions and parameters. Within the entire operating range, the phase current phase can either lead or lag the phase voltage.

[0086] Furthermore, the controller's switching cycle is typically set to 200µs, corresponding to a frequency of 5kHz. When the motor operates at high speed, taking a mechanical frequency of 100Hz as an example, if the motor has 3 pole pairs, the electrical frequency is 300Hz, and the carrier ratio... In one switching cycle, the motor travels an electrical angle. If the phase voltage phase used in power calculation differs from the ideal voltage phase by 0.5 switching cycles, then approximately a phase deviation will occur.

[0087] At high speeds, if the phase current leads the phase voltage by 45°, the corresponding power factor is 0.707. If the actual active power is 1000W, the apparent power is 1414VA. If the active power P obtained by using the phase voltage phase leading by 10.75° in the power calculation is P = 1414 × cos(45° - 10.75°) W ≈ 1169W, then the deviation between the calculated power and the actual power is 169W.

[0088] Therefore, it is necessary to obtain the voltage and current at the same moment, that is, for dual-resistance current sampling, it is necessary to reconstruct the reconstructed phase voltage corresponding to the zero-crossing moment of the triangular carrier. Specifically, in the original motor control, a three-phase pulse width signal will be obtained, and the pole voltage will be obtained by combining the DC bus voltage with equation (9). The pole voltage is the voltage of A, B, and C relative to the midpoint of the imaginary bus. Where TX is the pulse width signal, X = A, B, C, Tmax is the value corresponding to the maximum duty cycle, Tmid is the value corresponding to the intermediate duty cycle, Vdc is the bus voltage, V XN The polarity is the voltage.

[0089]

[0090] The voltage at the neutral point of the motor relative to the midpoint of the hypothetical bus voltage is obtained from equation (10):

[0091]

[0092] Finally, the initial phase voltages of the motor, i.e., the voltages of A, B, and C relative to the neutral point S of the motor, are obtained from equation (11):

[0093] V XS =V XN -V SN (11)

[0094] Then, the phase voltage V corresponding to the zero-crossing moment can be calculated based on the phase voltage of the current cycle and the phase voltage of the previous cycle. XS_zero As shown in formula (12).

[0095]

[0096] Among them, V XS_previous V is the phase voltage of the previous cycle. XS This represents the phase voltage of the current cycle.

[0097] S110, calculate the power of the motor under test based on the reconstructed phase current and the reconstructed phase voltage to obtain the estimated power.

[0098] In this embodiment of the invention, after obtaining the reconstructed phase current and reconstructed phase voltage, the estimated power can be calculated according to formula (13).

[0099]

[0100] Where N is the total number of samples, P est For estimated power.

[0101] The reconstructed phase voltage under single-resistance current sampling can be calculated using the same method described above. The difference lies in the timing: dual-resistance current sampling calculates the reconstructed phase voltage at the zero-crossing point, while single-resistance current sampling calculates the reconstructed phase voltage at the first moment. The following table shows the difference in power estimation between dual-resistance current sampling and single-resistance current sampling. Table 2 lists the motor power factor angles measured by a three-phase power meter under various operating conditions under dual-resistance current sampling, as well as the measured and estimated power from the three-phase power meter. In the table, "leading" indicates that the phase current leads the phase voltage, and "lagging" indicates that the phase current lags behind the phase voltage.

[0102] frequency Power factor angle Leading / Lagging Measured power Estimated power error 30Hz 52° Lag 243W 245W -0.8％ 40Hz 43° Lag 366W 368W -0.5％ 50Hz 37° Advanced 508W 512W +0.7％ 60Hz 46° Advanced 666W 673W +1.0％ 70Hz 49° Advanced 832W 845W +1.5％ 80Hz 47° Advanced 1013W 1030W +1.6％ 90Hz 45° Advanced 1198W 1215W +1.4％

[0103] Table (II)

[0104] As can be seen from Table (II), the power factor angle of the permanent magnet synchronous motor varies considerably under different operating conditions. Table (III) shows the measured power and estimated power under single-resistor current sampling.

[0105] frequency Power factor angle Leading / Lagging Measured power Estimated power error 30Hz 52° Lag 239W 232W -2.9％ 40Hz 44° Lag 355W 351W -1.1％ 50Hz 37° Advanced 491W 498W +1.4％ 60Hz 46° Advanced 661W 672W +1.6％ 70Hz 49° Advanced 835W 849W +1.6％ 80Hz 47° Advanced 1016W 1037W +2.0％ 90Hz 45° Advanced 1200W 1230W +2.5％

[0106] Table (III)

[0107] Comparing Tables (II) and (III), it can be seen that the estimated power obtained under dual-resistor sampling is closer to the measured power and has higher accuracy. However, the calculation of the current change rate in the single-resistor sampling backtracking method is affected by the motor inductance parameters, so the final power estimation accuracy depends on the motor parameters.

[0108] The motor power estimation method disclosed in this invention can calculate the reconfigured phase current and reconfigured phase voltage separately, and then calculate the estimated power based on the reconfigured phase current and reconfigured phase voltage, which can improve the accuracy of estimating the motor operating power.

[0109] Figure 16 This is a schematic block diagram of a motor power estimation device 200 provided in an embodiment of the present invention. Figure 16 As shown, corresponding to the above-described motor power estimation method, the present invention also provides a motor power estimation device 200. This motor power estimation device 200 includes a unit for performing the above-described motor power estimation method. Specifically, please refer to... Figure 16 The motor power estimation device 200 includes a first calculation unit 201 and a second calculation unit 202.

[0110] The first calculation unit 201 is used to calculate the reconfigured phase current of the motor under test and the reconfigured phase voltage of the motor under test.

[0111] The second calculation unit 202 is used to calculate the power of the motor under test based on the reconstructed phase current and the reconstructed phase voltage to obtain the estimated power.

[0112] In some embodiments, such as this embodiment, the first calculation unit 201 further includes a first acquisition unit and a second acquisition unit.

[0113] The first acquisition unit is used to acquire the first phase current of the motor under test through a first sampling resistor, and to acquire the second phase current of the motor under test through a second sampling circuit.

[0114] The second acquisition unit is used to calculate the third phase current based on the first phase current and the second phase current to obtain the reconstructed phase current.

[0115] In some embodiments, such as this embodiment, the first calculation unit 201 further includes a third acquisition unit, a first backtracking unit, and a third calculation unit.

[0116] The third acquisition unit is used to acquire the first phase current of the motor under test at a first moment and to acquire the third phase current of the motor under test at a second moment.

[0117] The first backtracking unit is used to backtrack the third phase current at the second time to the first time to obtain the third phase current at the first time.

[0118] The third calculation unit is used to calculate the second phase current corresponding to the first time based on the first phase current and the third phase current at the first time to obtain the reconstructed phase current.

[0119] In some embodiments, such as this one, the first backtracking unit includes a fourth calculation unit and a fifth calculation unit.

[0120] The fourth calculation unit is used to calculate the current increment between the first time point and the second time point;

[0121] The fifth calculation unit is used to calculate the third phase current at the first moment based on the current increment and the third phase current at the second moment.

[0122] In some embodiments, such as this one, the fourth computing unit further includes a sixth computing unit and a seventh computing unit.

[0123] The sixth calculation unit is used to calculate the rate of change of current in a two-phase stationary coordinate system and to perform an inverse Clarke transformation on the rate of change of current in the two-phase stationary coordinate system to obtain the rate of change of current in a three-phase stationary coordinate system.

[0124] The seventh calculation unit is used to calculate the current increment based on the current change rate in the three-phase stationary coordinate system.

[0125] In some embodiments, such as this one, the first computing unit 201 further includes an eighth computing unit and a first compensation unit.

[0126] The eighth calculation unit is used to calculate the phase voltage corresponding to the zero-crossing moment of the motor under test;

[0127] The first compensation unit is used to perform dead-zone compensation on the phase voltage to obtain the reconstructed phase voltage.

[0128] In some embodiments, such as this one, the eighth computing unit further includes a fourth acquisition unit and a ninth computing unit.

[0129] The fourth acquisition unit is used to acquire the phase voltage of the motor under test in the current cycle and the phase voltage of the previous cycle.

[0130] The ninth calculation unit is used to calculate the average of the phase voltage of the motor under test in the current cycle and the phase voltage of the previous cycle to obtain the phase voltage.

[0131] It should be noted that those skilled in the art can clearly understand that the specific implementation process of the above-mentioned motor power prediction device and each unit can be referred to the corresponding description in the foregoing method embodiments. For the sake of convenience and brevity, it will not be repeated here.

[0132] The aforementioned motor power prediction device can be implemented as a computer program, which can, for example, Figure 17 The motor shown is running.

[0133] Please see Figure 17 , Figure 17 This is a schematic block diagram of a motor provided in an embodiment of this application. It can be a terminal or a server. The terminal can be an electronic device with communication functions, such as a smartphone, tablet, laptop, desktop computer, personal digital assistant, or wearable device. The server can be a standalone server or a server cluster composed of multiple servers.

[0134] See Figure 17 The motor 300 includes a processor 302, a memory, and an interface 307 connected via a system bus 301. The memory may include a non-volatile storage medium 303 and internal memory 304.

[0135] The non-volatile storage medium 303 may store an operating system 3031 and a computer program 3032. When the computer program 3032 is executed, it causes the processor 302 to execute a motor power estimation method.

[0136] The processor 302 provides computing and control capabilities to support the operation of the entire motor 300.

[0137] The internal memory 304 provides an environment for the execution of the computer program 3032 in the non-volatile storage medium 303. When the computer program 3032 is executed by the processor 302, the processor 302 can execute a motor power estimation method.

[0138] This interface 305 is used for communication with other devices. Those skilled in the art will understand that... Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the motor 300 to which the present application is applied. The specific motor 300 may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0139] It should be understood that, in the embodiments of this application, the processor 302 may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (FSPs), application-specific integrated circuits (ASICs), off-the-shelf programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0140] It will be understood by those skilled in the art that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program may be stored in a storage medium, which is a computer-readable storage medium. The computer program is executed by at least one processor in the computer system to implement the process steps of the embodiments of the above methods.

[0141] Therefore, the present invention also provides a storage medium. This storage medium can be a computer-readable storage medium. The storage medium stores a computer program. When executed by a processor, the computer program implements any embodiment of the above-described motor power estimation method.

[0142] The storage medium can be any computer-readable storage medium capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory (ROM), magnetic disk, or optical disk.

[0143] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0144] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of each unit is merely a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0145] The steps in the method of this invention can be adjusted, merged, or reduced in order according to actual needs. The units in the device of this invention can be merged, divided, or reduced according to actual needs. Furthermore, the functional units in the various embodiments of this invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0146] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a motor to execute all or part of the steps of the methods described in the various embodiments of the present invention.

[0147] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0148] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Since these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

[0149] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for predicting motor power, characterized in that, The method includes: Calculate the reconfigured phase current and the reconfigured phase voltage of the motor under test; The power of the motor under test is calculated based on the reconstructed phase current and the reconstructed phase voltage to obtain the estimated power; The step of calculating the reconfigured phase current of the motor under test includes: The first phase current of the motor under test is obtained at a first moment, and the third phase current of the motor under test is obtained at a second moment. The third phase current at the second moment is traced back to the first moment to obtain the third phase current at the first moment; The reconstructed phase current is obtained by calculating the second phase current corresponding to the first time based on the first phase current and the third phase current at the first time.

2. The method according to claim 1, characterized in that, The step of calculating the reconfigured phase current of the motor under test includes: The first phase current of the motor under test is obtained through the first sampling resistor, and the second phase current of the motor under test is obtained through the second sampling circuit. The reconstructed phase current is obtained by calculating the third phase current based on the first phase current and the second phase current.

3. The method according to claim 1, characterized in that, The step of tracing the third-phase current at the second moment back to the first moment to obtain the third-phase current at the first moment includes: Calculate the current increment between the first time point and the second time point; The third phase current at the first moment is calculated based on the current increment and the third phase current at the second moment.

4. The method according to claim 3, characterized in that, The step of calculating the current increment between the first time point and the second time point includes: Calculate the rate of change of current in a two-phase stationary coordinate system, and perform an inverse Clarke transformation on the rate of change of current in the two-phase stationary coordinate system to obtain the rate of change of current in a three-phase stationary coordinate system. The current increment is calculated based on the rate of change of current in the three-phase stationary coordinate system.

5. The method according to claim 1, characterized in that, The step of calculating the reconstructed phase voltage of the motor under test includes: Calculate the phase voltage corresponding to the zero-crossing moment of the triangular carrier wave of the motor under test; Dead-zone compensation is performed on the phase voltage to obtain the reconstructed phase voltage.

6. The method according to claim 5, characterized in that, The step of calculating the phase voltage corresponding to the zero-crossing moment of the triangular carrier wave of the motor under test includes: Obtain the phase voltage of the motor under test in the current cycle and the phase voltage of the previous cycle; The phase voltage is obtained by calculating the average of the phase voltage of the motor under test in the current cycle and the phase voltage of the previous cycle.

7. A motor power prediction device, characterized in that, The device includes: The first calculation unit is used to calculate the reconfigured phase current of the motor under test and the reconfigured phase voltage of the motor under test. The second calculation unit is used to calculate the power of the motor under test based on the reconstructed phase current and the reconstructed phase voltage to obtain the estimated power; The first computing unit includes: The third acquisition unit is used to acquire the first phase current of the motor under test at a first moment, and to acquire the third phase current of the motor under test at a second moment. The first backtracking unit is used to backtrack the third phase current at the second time to the first time to obtain the third phase current at the first time. The third calculation unit is used to calculate the second phase current corresponding to the first time based on the first phase current and the third phase current at the first time to obtain the reconstructed phase current.

8. An electric motor, characterized in that, The motor includes a memory and a processor connected to the memory; the memory is used to store a computer program; the processor is used to run the computer program stored in the memory to perform the steps of the method as described in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The storage medium stores a computer program that, when executed by a processor, can implement the steps of the method as described in any one of claims 1-6.

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