Method and apparatus for controlling a three-phase motor

Abstract

The invention relates to an apparatus and method for controlling a motor using a maximum torque per ampere field module and a direct flux vector control module. The invention: - determines a reference voltage in the fτ frame from the direct flux vector control module; - drives the motor with the summed voltage; - measures the motor current vector; - determines a high frequency injection voltage such that the high frequency current response of the motor to the high frequency injection voltage is perpendicular to the measured motor current vector; - determines an estimated flux from the measured motor current and voltage reference; - determines a reference flux from the estimated flux and a high frequency sinusoidal signal such that the high frequency flux response to the injection voltage is aligned with the measured current vector.

Description

Technical Field

[0001] This invention relates generally to a method and apparatus for controlling a three-phase motor. Background Technology

[0002] Electric motors are widely used in industry for factory automation or transportation. Many machine control technologies, such as permanent magnet synchronous motors (PMSM), synchronous reluctance motors (SyncRM), and wound rotor synchronous motors (WRSM), typically use rotary encoders to obtain the machine's speed and position as feedback.

[0003] The need for low-cost and robust motor drives has spurred the development of sensorless control. Without these sensors, machine drives become cheaper and more robust in dusty and harsh environments.

[0004] Many sensorless control techniques have been proposed. These techniques are based on estimations of machine position and speed, but one aspect often overlooked in sensorless controllers is the strategy for selecting the reference current of the FOC (Field-Oriented Control) controller based on a given desired torque reference. In CVC (Current Vector Control) controllers, the reference quantity is the current level on the dq axis in the rotor reference frame whose position must be estimated. In DFVC (Direct Flux Vector Control), the reference quantity is the flux norm and a current component. The latter technique is attractive because it can also be applied to stator flux reference frames where position estimation is not required.

[0005] The optimal current trajectory is MTPA (Maximum Torque Per Ampere), which is selected using a combination of references to maximize torque at a given current level (and given copper losses). The references propose using more than one lookup table (LUT) or different injection-based techniques to track MTPA. Using a lookup table, torque is measured as a function of Idq current to derive the ideal MTPA trajectory. This trajectory can be stored and used dynamically with varying torque levels. However, specific measurements are required before running the MTPA mode. This is the most common method for tracking the MTPA trajectory.

[0006] These methods have serious limitations. General Purpose Inverters (GPIs) often struggle to establish MTPA lookup tables for unknown motors. An alternative to direct measurement of MTPA is manipulating flux linkage or inductance diagram LUTs, which in turn require dedicated test or self-tuning sessions. For CVC controllers, MTPA representation requires knowledge of the incremental inductance and chordal inductance on both the d and q axes. Generally, MTPA control tends to require knowledge of inductance LUTs. Inductance uncertainties can lead to position errors and the risk of instability and deviation from the MTPA, which, in addition to potential loss of control, can result in energy misuse.

[0007] The references present techniques for tracking the MTPA and MTPV of a DFVC controller. However, these techniques rely on an inductive LUT measured for MTPA tracking.

[0008] The references have proposed injection methods for online MTPA tracking, but they are typically used for CVC controllers and not for DFVC controllers. Summary of the Invention

[0009] The present invention aims to provide a sensorless control method and device that uses DFVC control technology and achieves optimal MTPA operating conditions without any prior information about the motor to be controlled.

[0010] Therefore, the present invention relates to a method for controlling a motor using a maximum torque per ampere field module and a direct flux vector control module, characterized in that the method includes the following steps:

[0011] -Based on the estimated flux norm by the direct flux vector control module Reference flux Using estimated load angle The current motor vector i measured within the fτ frame fτ And from the reference torque T* and reference flux The obtained reference current on the τ axis To determine the reference voltage under the fτ frame.

[0012] -The reference voltage v that will be converted under the stator αβ frame * αβ With high frequency injection voltage Add,

[0013] - The motor is driven by the summed voltages.

[0014] -Measure motor current vector i αβ ,

[0015] -Based on the measured motor current vector iαβ and high-frequency sine wave signal i δ sin(ω h t) Determine the high-frequency injection voltage This causes the high-frequency current response of the motor to the high-frequency injected voltage to be perpendicular to the measured motor current vector.

[0016] -Based on the measured motor current i αβ and voltage reference v* αβ Determine the estimated magnetic flux

[0017] -Based on the estimated magnetic flux via the maximum torque per ampere module and the high-frequency sine wave signal sin(ω) h t) Determine the reference flux to be provided to the direct flux vector control module. This aligns the high-frequency magnetic flux response to the injected voltage with the measured current vector.

[0018] The present invention also relates to a device for controlling a motor using a maximum torque per ampere field module and a direct flux vector control module, characterized in that the device comprises:

[0019] - Used by the direct flux vector control module based on the estimated flux norm Reference flux Using estimated load angle The current motor vector i measured within the fτ frame fτ And from the reference torque T* and reference flux The obtained reference current on the τ axis A device for determining the reference voltage under the fτ frame.

[0020] - The reference voltage v used for conversion under the stator αβ frame * αβ With high frequency injection voltage Addition device,

[0021] - A device for driving the motor using the summed voltages,

[0022] - Used to measure motor current vector i αβ The device,

[0023] - Used to determine the measured motor current vector i αβ and high-frequency sine wave signal i δ sin(ω h t) Determine the high-frequency injection voltage A device that causes the motor's high-frequency current response to the high-frequency injected voltage to be perpendicular to the measured motor current vector.

[0024] - Used to determine the measured motor current i αβ and voltage reference v* αβ Determine the estimated magnetic flux The device,

[0025] - Used to determine the estimated magnetic flux through the maximum torque per ampere field module. and the high-frequency sine wave signal sin(ω) h t) Determine the reference flux to be provided to the direct flux vector control module. A device that aligns the high-frequency magnetic flux response to the injected voltage with the measured current vector.

[0026] Therefore, motor control on the MTPA track eliminates the need for lookup tables. LUT-free MTPA is applied to direct flux vector control. Overall stability is improved for sensorless control because rotor position estimation is unnecessary, and it conforms to MTPA standards under any saturation condition.

[0027] Based on specific characteristics, used to determine the high-frequency injection voltage The device includes:

[0028] - Used to determine the basic current vector i αβ_LF The device,

[0029] - The current vector i to be measured under the stator frame αβ αβ Transformed into the relationship between the current frame ij and the determined fundamental current vector i αβ_LF Aligned current vector i ij The device,

[0030] - for passing through the current vector i ij High-frequency filtering is used to determine the filtered current vector i. ijHF The device,

[0031] - used from the filtered current vector i ijHF Subtract the high-frequency sinusoidal signal i on the j-axis under the current frame δ sin(ω h t) and an apparatus for performing proportional-integral regulation to obtain a voltage injection signal under the current frame ij,

[0032] - Used to convert the voltage injection signal under the current frame ij into a high-frequency voltage under the stator frame αβ. The device.

[0033] Therefore, the HF (high-frequency) injection voltage is set to make the HF change in the current magnitude zero. The machine's HF response to the HF injection voltage is then orthogonal to the measured fundamental current vector.

[0034] Based on specific characteristics, the maximum torque per ampere module includes:

[0035] - Used to perform the estimated flux on the j-axis A device for heterodyne modulation and performing proportional-integral adjustment of the heterodyne demodulation result to provide the reference flux.

[0036] Therefore, the HF component of the estimated flux perpendicular to the current can be estimated. A proportional-integral method generates a reference flux that can drive this HF component to zero. In the absence of HF variation in the current amplitude, the obtained reference flux necessarily satisfies the MTPA criterion.

[0037] Based on specific characteristics, the direct flux vector control module includes:

[0038] - Reference current from the τ axis Subtract the measured current i on the τ axis τ And a device for performing the first proportional-integral adjustment of the subtraction result,

[0039] - for use from the reference magnetic flux A device for subtracting the estimated magnetic flux norm and performing a second proportional-integral adjustment on the result of the subtraction.

[0040] - A device for performing the first summation of the results of proportional-integral control.

[0041] - A means for adding the result of the first summation to a first value that depends on the stator resistance of the motor, the estimated motor speed, and the reference current on the τ-axis.

[0042] - A means for performing a second proportional-integral adjustment and adding the result to a second value that depends on the stator resistance of the motor and the reference current on the f-axis.

[0043] Therefore, the machine is directly controlled by estimating the magnetic flux and the measured current of the motor. Control requires no prior knowledge of the machine rotor's position, nor of the motor's saturation state, which varies with torque.

[0044] Based on specific characteristics, the flux estimation module also includes:

[0045] - Used to estimate the magnetic flux on the β axis Divide by the estimated magnetic flux on the α axis To provide the load angle An apparatus for estimating the tangent.

[0046] Therefore, the estimated load angle It can be fed to the DFVC controller and speed estimator without requiring any position sensors.

[0047] The features of the invention will become more apparent from the following description of exemplary embodiments, which is made with reference to the accompanying drawings. Attached Figure Description

[0048] [ Figure 1 ]

[0049] Figure 1 A first example of direct flux vector control using the maximum torque per ampere is shown for a motor according to the invention.

[0050] [ Figure 2 ]

[0051] Figure 2 An example block diagram of the direct flux vector control module according to the present invention is shown.

[0052] [ Figure 3 ]

[0053] Figure 3 An example block diagram of the magnetic flux estimation module according to the present invention is shown.

[0054] [ Figure 4 ]

[0055] Figure 4 An example block diagram of the maximum torque per ampere module according to the present invention is shown.

[0056] [ Figure 5 ]

[0057] Figure 5 An example of a block diagram of an injection block module according to the present invention is shown.

[0058] [ Figure 6 ]

[0059] Figure 6 A second example of direct flux vector control using the maximum torque per ampere is shown for a motor according to the invention.

[0060] [ Figure 7 ]

[0061] Figure 7 The motor frame used in this invention is shown.

[0062] [ Figure 8 ]

[0063] Figure 8 An example of an algorithm for controlling a motor according to the present invention is shown. Detailed Implementation

[0064] Figure 1 A first example of direct flux vector control using the maximum torque per ampere is shown for a motor according to the invention.

[0065] exist Figure 1 In the system shown, the reference torque T* is compared with the reference flux provided by the MTPA tracking module 155. The number of pole pairs of motor 135, along with 3 / 2 times the number of pole pairs, is fed to divider 100 to obtain the reference current provided to the τ axis of DFVC module 110.

[0066]

[0067] DFVC module 110 is based on the reference current on the τ axis Estimating magnetic flux Measuring current i under the norm and fτ framework ft and reference flux from MTPA tracking module 155 Determine the reference voltage v* under the fτ frame. fτ .

[0068] Reference voltage v under the fτ framework * fτ It is provided to the frame conversion module 115, which uses the estimated load angle The reference voltage v under the fτ frame * fτ Converted to reference voltage v under the αβ frame * αβ .

[0069] Reference voltage v under αβ framework * αβ The reference voltage V is provided to the summing module 120, which will then sum the reference voltage V. * αβ High-frequency injection voltage under the αβ framework The modified reference voltage v** under the αβ framework is obtained by summing the results. αβ .

[0070] Modified reference voltage v** under the αβ framework αβ The voltage source inverter VSI 130, connected to motor 135, is supplied. The motor current vector i is measured in the three phases abc. abc It is provided to the framework conversion module 140.

[0071] The frame conversion module 140 will measure the motor current i in the three-phase abc. abc Transformed into the motor current vector i measured under the αβ frame.αβ .

[0072] The current motor vector i measured within the αβ frame αβ It is provided to the flux estimation module 150, the j-axis injection module 125 and the frame conversion module 145.

[0073] Frame conversion module 145 uses estimated load angle The current motor vector i to be measured within the αβ frame αβ Transformed into the current motor vector i measured under the fτ frame. ft .

[0074] Current vector i measured on the fτ axis ft It is provided to DFVC module 110.

[0075] The j-axis injection module 125 uses the current motor vector i measured under the αβ frame. αβ and high-frequency sine wave signal i δ sin(ω h t) Determine the injection voltage under the αβ frame

[0076] Determine the high-frequency injection voltage It is intended to provide the motor with a high-frequency current response to an injected voltage perpendicular to the measured motor current vector.

[0077] High frequency injection voltage Within the frequency range from 100Hz to the switching frequency of the voltage source inverter VSI130.

[0078] The flux estimation module 150 estimates the current motor vector i measured under the αβ frame. αβ and voltage reference v* αβ Determine the estimated magnetic flux within the αβ frame and estimated load angle

[0079] The speed estimation module 152 determines the speed of the motor 135 based on the estimated load angle.

[0080] For example, using a phase-locked loop and a low-pass filter on the output of the phase-locked loop to estimate the speed.

[0081] Estimated magnetic flux under the αβ framework It is provided to MTPA tracking module 155 and DFVC module 110.

[0082] MTPA tracking module 155 estimates magnetic flux under the αβ framework and high-frequency sine wave signal sin(ω) h t) Determine the reference magnetic flux

[0083] According to the present invention, the system comprises:

[0084] - Used to control the magnetic flux via the direct flux vector control module based on the estimated flux. Norm, reference flux Using estimated load angle The current motor vector i measured within the fτ frame fτ And from the reference torque (T*) and reference flux The obtained reference current along the τ axis A device for determining a reference voltage using a reference current.

[0085] - Used to set the reference voltage (V) * αβ ) and high-frequency injection voltage Addition device,

[0086] - A device for driving a motor using summed voltages.

[0087] - Used to measure motor current vector (i αβ ) device,

[0088] - Used to determine the measured motor current vector (i αβ ) and high-frequency sine wave signals (i δ sin(ω h t)) Determine the high-frequency injection voltage A device that makes the high-frequency current response of a motor to a high-frequency voltage perpendicular to the measured motor current vector.

[0089] - Used to determine the measured motor current (i αβ ) and voltage reference (v * αβ Determine the estimated magnetic flux The device,

[0090] - Used to estimate magnetic flux based on the maximum torque per ampere field module and high-frequency sine wave signal (sin(ω) h t)) Determine the reference flux to be provided to the direct flux vector control module A device that aligns the high-frequency magnetic flux response to the injected voltage with the measured current vector.

[0091] Torque is given by T = i dq T Jλ dq Given, where J is i dq It measures current within the dq framework. T It is the transpose of the matrix, and λdq It is magnetic flux.

[0092] when At that time, the MTPA law is satisfied, where γ=∠i dq This represents the current injection angle under the dq frame.

[0093]

[0094] Where l represents the incremental inductance matrix, and L represents the string inductance matrix.

[0095] In MTPA, (λ) dq a ) T Ji dq When λ = 0, the auxiliary magnetic flux λ dq a =JLi dq -lJi dq Align with the measured current vector.

[0096] In which the i-axis and i dq Under the aligned ij framework, the magnetic flux λ is expressed as a function of the auxiliary magnetic flux. ij =e -Jγ Le Jγ i ij The derivative is:

[0097] dλ ij =e -Jγ le Jγ di ij -λ ij a dγ

[0098] At a constant current amplitude (di) ij Under the assumption that = 0), the differential equation is simplified to dλ. ij =-λ ij a dγ.

[0099] Because in λ j a When d = 0, the MTPA condition is satisfied, therefore in dλ j When = 0, the MTPA condition is satisfied.

[0100] Therefore, the present invention involves injecting a small HF current excitation on the j-axis to satisfy di ij =0 and a zero HF flux response dλ is obtained on this axis. j =0. To achieve this, λ j a =0, therefore the magnetic flux disturbance vector is aligned with the current vector, and the MTPA condition is satisfied.

[0101] In the variation, once the MTPA law is obtained, the high-frequency injection is turned off. Then, the magnetic flux is adapted to the torque condition according to the newly obtained MTPA law.

[0102] In another variation, the injection can be turned on occasionally to assess any changes in the machine over time and reset the MTPA law.

[0103] Figure 2 An example block diagram of the direct flux vector control module according to the present invention is shown.

[0104] The direct flux vector control module 110 includes a subtraction module 220, which receives a reference current from the τ axis. Subtract the measured current i on the τ axis τ .

[0105] The output of the subtraction module 220 is provided to the PI regulator 225, and the output of the PI regulator 225 is provided to the multiplication module 230. The multiplication module 230 multiplies the output of the PI regulator 225 by the decoupling constant value 1 / b.

[0106] The direct flux vector control module 110 includes a subtraction module 200, which receives data from a reference flux vector. Subtract the estimated flux norm The output of subtraction module 200 is provided to PI regulator 205, and the output of PI regulator 205 is provided to multiplication module 210. Multiplication module 210 multiplies the output of PI regulator 205 by a decoupling constant value -a / b calibrated according to the motor nameplate rating. As an example, the values ​​of a and b are a = 4 and b = 13.

[0107] The outputs of multiplication modules 230 and 210 are added together by summation module 235.

[0108] The output of summation module 235 is provided to summation module 240, which then sums the result of the summation performed by summation module 235 with... Add them together to provide a reference voltage v on the τ axis. * τ , where R s It is the stator resistor, and It estimates the motor speed.

[0109] Stator resistance R s For example, it can be obtained from the self-tuning process. The load angle is used to track and estimate the magnetic flux vector. To estimate the motor speed.

[0110] The output of PI controller 205 is provided to summing module 215, which sums the result of the output of PI controller 205 with R. s if Add them together to provide a reference voltage v on the f-axis. * f .

[0111] Figure 3 An example block diagram of the magnetic flux estimation module according to the present invention is shown.

[0112] The flux estimation module 150 includes a subtraction module 300, which obtains a reference voltage v on the α axis. * α Subtract the current i on the α axis α Multiply by resistance R s .

[0113] The result of subtraction module 300 is provided to subtraction module 305.

[0114] Subtraction module 305 subtracts the result provided by multiplication module 315 from the result of subtraction module 300.

[0115] The output of subtraction module 305 is provided to integrator 310 to provide an estimated flux on the α-axis.

[0116] Estimated magnetic flux on the α axis The estimated flux on the α-axis is provided to divider 320 and multiplier module 315, which multiplies the flux by the multiplier module 315. Multiply by the coefficient k used as the observation gain obs .

[0117] The flux estimation module 150 includes a subtraction module 330, which obtains a reference voltage v on the β axis. * β Subtract the current i on the β axis β Multiply by the resistance R of the motor 135 s .

[0118] The result of subtraction module 330 is provided to subtraction module 335.

[0119] Subtraction module 335 subtracts the result provided by multiplication module 345 from the result of subtraction module 330.

[0120] The output of subtraction module 335 is provided to integrator 340 to provide an estimated flux on the β axis.

[0121] Estimated magnetic flux on the β axis The estimated flux on the β-axis is provided to divider 320 and multiplier module 345, which multiplies the flux by the multiplier module 345. Multiply by coefficient k obs .

[0122] The division module 320 estimates the magnetic flux on the β axis. Divide by the estimated magnetic flux on the α axis

[0123] The result from division module 320 is subjected to arctangent transformation by module 350 to provide an estimated load angle.

[0124] Figure 4 An example block diagram of the maximum torque per ampere module according to the present invention is shown.

[0125] The maximum torque per ampere module 155 includes a frame conversion module 400, which uses a measuring angle γ between the measuring current and the α-axis of the αβ frame. s Estimating magnetic flux within the αβ framework Transformation into estimated magnetic flux under the ij framework

[0126] Estimated magnetic flux on the j-axis The estimated flux on the j-axis is provided to multiplier 415, which multiplies the flux by the multiplier 415. Multiplied by the high-frequency sine wave signal sin(ω) h t).

[0127] The output of multiplication module 415 is processed by low-pass filter 420.

[0128] Modules 415 and 420 form heterodyne demodulation 410.

[0129] The output of the heterodyne modulation 410 is provided to a PI regulator 425 with an integral gain kλ and a proportional gain of zero to provide a reference flux.

[0130] Reference flux Therefore, it is controlled to ensure that the flux response to the high-frequency injected voltage is null on the j-axis and thus only on the i-axis. The high-frequency flux response to the injected voltage is aligned with the measured current vector.

[0131] Figure 5 An example of a block diagram of an injection block module according to the present invention is shown.

[0132] Injection module 125 includes a method for determining the basic current vector i αβ_LF Device 500. As an example, the basic current vector i αβ_LF Through the measured current vector i αβ The low-pass filter is used to determine this. As another example, the basic current vector i αβ_LF It is the current vector of past memories.

[0133] The injection module 125 includes a frame conversion module 501, which converts the measured current motor vector i under the αβ frame. αβ Converting to the measurement current motor vector i under the ij framework ij The ij frame uses the determined fundamental current vector. Derived angle γ s It is derived from the rotation of the αβ framework.

[0134] The output of frame conversion module 501 is provided to high-pass filter HPF 510. The output of high-pass filter 510 is provided to subtraction module 515, which subtracts the high-frequency sine wave signal i on the j-axis from the output of high-pass filter 510. δ sin(ω h t).

[0135] The output of subtraction module 515 is provided to PI regulator 520 to obtain the voltage injection signal under the ij frame. The voltage injection signal under the ij frame is provided to frame conversion module 525, which converts the voltage injection signal under the ij frame into a voltage injection signal under the αβ frame.

[0136] The high-frequency current response to the high-frequency injected voltage is therefore controlled to follow a reference located only on the j-axis. The motor's high-frequency current response to the high-frequency injected voltage is perpendicular to the measured motor current vector.

[0137] Figure 6 A second example of direct flux vector control using the maximum torque per ampere is shown for a motor according to the invention.

[0138] The motor device 60 uses direct flux vector control for maximum torque per ampere, having, for example, based on components connected by bus 601 and such Figure 8 The architecture of the processor 600 controlled by the publicly disclosed program.

[0139] Bus 601 links processor 600 to read-only memory ROM 602, random access memory RAM 603, and input / output (I / O) interface 605.

[0140] The input / output (I / O) interface 605 enables a device used to monitor the state of the motor 135 to sense a signal representing the current flowing through the motor 135.

[0141] Memory 603 includes registers, which are designed to receive, for example Figure 8 The program's variables and instructions related to the algorithm are publicly disclosed.

[0142] Read-only memory or, if possible, flash memory 602 includes, such as Figure 8The instructions for the algorithm-related program disclosed herein are loaded into the random access memory 603 when the device 60 is powered on. Alternatively, the program can also be executed directly from the ROM memory 602.

[0143] The calculations performed by device 60 can be implemented in software by a programmable computing machine such as a PC (personal computer), DSP (digital signal processor), or microcontroller executing a set of instructions or programs; or in hardware by a machine or special component such as FPGA (field-programmable gate array) or ASIC (application-specific integrated circuit).

[0144] In other words, device 60 includes circuitry or a device including circuitry, causing device 60 to perform actions such as Figure 8 The publicly available algorithm-related programs.

[0145] Figure 7 The motor frame used in this invention is shown.

[0146] exist Figure 7 The image shows the αβ two-phase stator frame. The αβ frame is static relative to the motor stator.

[0147] The dq two-phase rotor frame is shown. The dq frame is dynamic and follows the rotor position θ.

[0148] The two-phase current frame (i, ij) is shown. The i-axis follows the current vector and forms an angle γ with the α-axis. s The j-axis is perpendicular to the current vector.

[0149] The two-phase flux frame fτ is shown. The f-axis follows the estimated flux vector and forms an angle δ with the α-axis. s The τ axis is perpendicular to the estimated magnetic flux vector.

[0150] The response of HF current to high-frequency voltage injection is shown. HF HF current response i HF Perpendicular to the i-axis, and therefore perpendicular to the measured current vector.

[0151] The HF response λ to the high-frequency injection voltage is shown. HF HF response λ HF Aligned with the i-axis, and therefore with the measured current vector. The j-axis flux is constant.

[0152] Figure 8 An example of an algorithm for controlling a motor according to the present invention is shown.

[0153] This algorithm is disclosed as an example, wherein it is executed by a processor 600 controlled by a direct flux vector of a motor device 60.

[0154] In step S800, the processor 600 uses the reference torque T* along with the reference magnetic flux. The reference current on the τ axis is determined by 3 / 2 times the number of pole pairs of motor 135. as follows:

[0155]

[0156] In step S801, the processor 600 determines the reference current on the τ axis. Estimating magnetic flux Measuring current i under the norm and fτ framework ft and reference flux Execute Direct Flux Vector Control (DFVC). Processor 600 determines the reference voltage v* under the fτ frame. fτ .

[0157] In step S802, the processor 600 uses the estimated load angle The reference voltage v* under the fτ frame fτ Converted to reference voltage v under the αβ frame * αβ .

[0158] In step S803, the processor 600 sets the reference voltage v under the αβ frame. * αβ Injection voltage under αβ framework The modified reference voltage v** under the αβ framework is obtained by summing the results. αβ .

[0159] In step S804, the processor 600 provides the modified reference voltage v** under the αβ frame to the voltage source inverter VSI connected to the motor 135. αβ .

[0160] In step S805, the processor 600 measures the motor current vector i in the three-phase abc. abc .

[0161] In step S806, the processor 600 will measure the motor current vector i in the three-phase abc. abc Transformed into the measurement current motor vector i under the αβ frame αβ .

[0162] In step S807, the processor 600 measures the current motor vector i under the αβ frame. αβ Transformed into the current motor vector i measured under the fτ frame. fτ .

[0163] In step S808, the processor 600 measures the current motor vector i under the αβ frame. αβand high-frequency sine wave signal i δ sin(ω h t) Determine the injection voltage under the αβ frame The injection voltage was determined to be the driving high-frequency current perpendicular to the measured current vector.

[0164] In step S809, the processor 600 measures the current vector i under the αβ frame. αβ and voltage reference v* αβ Determine the estimated magnetic flux within the αβ frame. and estimated load angle

[0165] In step S810, the processor 600 estimates the magnetic flux under the αβ framework. and high-frequency sine wave signal sin(ω) h t) Determine the reference magnetic flux The reference flux is determined to be aligned with the high-frequency response measurement current vector of the driving flux.

[0166] Of course, many modifications can be made to the above embodiments of the present invention without departing from the scope of the present invention.

Claims

1. A method for controlling a motor using a maximum torque per ampere field module and a direct flux vector control module, characterized in that the method includes the following steps: The direct flux vector control module determines the reference voltage under the fτ frame based on the estimated flux norm, reference flux, current motor vector measured under the fτ frame using the estimated load angle, and reference current on the τ axis obtained from the reference torque and the reference flux. The reference voltage converted under the stator αβ frame will be added to the high-frequency injection voltage. - The motor is driven by the summed voltages. -Measure the motor current vector - The high-frequency injection voltage is determined based on the measured motor current vector and the high-frequency sine wave signal, such that the high-frequency current response of the motor to the high-frequency injection voltage is perpendicular to the measured motor current vector. - Determine the estimated magnetic flux based on the measured motor current and voltage reference. - The reference flux to be provided to the direct flux vector control module is determined by the maximum torque per ampere field module based on the estimated flux and the high-frequency sine wave signal, such that the high-frequency flux response to the injected voltage is aligned with the measured current vector.

2. A device for controlling a three-phase motor using a maximum torque per ampere field module and a direct flux vector control module, characterized in that the device comprises: - A means for determining a reference voltage under the fτ frame by means of the direct flux vector control module based on the estimated flux norm, a reference flux, a current motor vector measured under the fτ frame using the estimated load angle, and a reference current on the τ axis obtained from the reference torque and the reference flux. - A means for adding the reference voltage, converted under the stator αβ frame, to the high-frequency injection voltage. - A device for driving the motor using the summed voltages, - A device used to measure the vector current of a motor. - A device for determining the high-frequency injection voltage based on a measured motor current vector and a high-frequency sinusoidal signal, such that the high-frequency current response of the motor to the high-frequency voltage is perpendicular to the measured motor current vector. - A device for determining the estimated magnetic flux based on a reference of measured motor current and voltage. - A means for determining, by means of the maximum torque per ampere field module, the reference flux to be provided to the direct flux vector control module based on the estimated flux and the high-frequency sinusoidal signal, such that the high-frequency flux response to the injected voltage is aligned with the measured current vector.

3. The apparatus according to claim 2, characterized in that the means for determining the high-frequency injection voltage comprises: - A device for determining the fundamental current vector. - A device for converting a current vector measured in the stator frame into a current vector aligned with a determined fundamental current vector in the current frame. - A device for determining a filtered current vector by high-frequency filtering of the current vector. - A means for subtracting a high-frequency sinusoidal signal on the j-axis under the current frame from the filtered current vector and performing proportional-integral regulation to obtain a voltage injection signal under the current frame. - A device for converting a voltage injection signal under the current frame into a high-frequency voltage under the stator frame.

4. The device according to claim 2 or 3, characterized in that the maximum torque per ampere field module comprises: - A means for performing heterodyne modulation of the estimated flux on the j-axis and performing proportional-integral adjustment of the heterodyne demodulation result to provide the reference flux.

5. The device according to any one of claims 2 to 4, characterized in that the direct flux vector control module comprises: - Used to subtract the measured current i on the τ axis from the reference current on the τ axis. τ And a device for performing the first proportional-integral adjustment of the subtraction result, - A device for subtracting the estimated flux norm from the reference flux and performing a second proportional-integral adjustment on the subtraction result. - A device for performing the first summation of the results of proportional-integral control. - A means for adding the result of the first summation to a first value that depends on the stator resistance of the motor, the estimated motor speed, and the reference current on the τ-axis. - A means for performing a second proportional-integral adjustment and adding the result to a second value that depends on the stator resistance of the motor and the reference current on the f-axis.

6. The apparatus according to any one of claims 2 to 5, characterized in that the means for determining the estimated magnetic flux comprises: - A device for subtracting the motor current multiplied by the stator resistance on the α-axis from the reference voltage on the α-axis. - An apparatus for subtracting the current on the α-axis multiplied by the stator resistance from the reference voltage on the α-axis, subtracting the estimated magnetic flux on the α-axis multiplied by a coefficient, and performing a third proportional-integral adjustment on the subtraction result to obtain the estimated magnetic flux on the α-axis. - A means for subtracting the current multiplied on the β-axis by the stator resistance from the reference voltage on the β-axis. - A device for subtracting the result of the current multiplied by the stator resistance on the β-axis from the reference voltage on the β-axis, subtracting the estimated magnetic flux on the β-axis multiplied by a coefficient, and performing a fourth proportional-integral adjustment of the subtraction result to obtain the estimated magnetic flux on the β-axis.

7. The device according to claim 6, characterized in that the magnetic flux estimation module further comprises: - A means for dividing the estimated magnetic flux on the β axis by the estimated magnetic flux on the α axis to provide an estimated tangent of the load angle.

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