A global control method and device for a permanent magnet synchronous motor and the permanent magnet synchronous motor

Abstract

The application discloses a kind of global control method, device and permanent magnet synchronous motor of permanent magnet synchronous motor, by calibration, the three-dimensional current pulse spectrum of non-field weakening area is obtained, and the three-dimensional current pulse spectrum of field weakening area is also obtained by calculation, wherein, three-dimensional current pulse spectrum is voltage-speed-torque three-dimensional current pulse spectrum, in the first working condition, according to the three-dimensional current pulse spectrum of non-field weakening area, maximum torque current ratio control strategy is used, in the second working condition, according to the three-dimensional current pulse spectrum of field weakening area, maximum torque voltage ratio control strategy is used, on the one hand, non-field weakening area uses the method of calibration to obtain three-dimensional current pulse spectrum, field weakening area obtains three-dimensional current pulse spectrum by calculation, while reducing calibration time, reduce calibration cost, can make the current MAP more accurate, on the other hand, different control strategies are used for different working conditions, reduce the mutual coupling influence of field weakening ring and current ring, greatly improve the reliability and stability of field weakening control.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of permanent magnet synchronous motor control, and particularly relates to a permanent magnet synchronous motor global control method and device and a permanent magnet synchronous motor. BACKGROUND

[0002] In order to alleviate the increasingly serious environmental pollution and energy depletion problems, electric vehicles have emerged as the times require due to their green and environmentally friendly characteristics and have received extensive attention. Permanent magnet synchronous motors are used as core components of electric vehicles to replace other motors due to their good control performance, high power density and energy saving advantages. In order to improve system efficiency, the maximum torque current ratio (MTPA) control algorithm is used in the low-speed non-field weakening region of the motor, and the maximum torque voltage ratio (MTPV) field weakening control algorithm is used in the high-speed field weakening region to reduce the back electromotive force so that the motor can operate normally at high speed.

[0003] At present, the permanent magnet synchronous motor is generally calibrated manually. The operator manually calibrates the motor data using a test bench. A two-dimensional current MAP of speed-torque-current is obtained through a large amount of calibration work. The working process is complicated and inefficient, and the original id field weakening vector control target current distribution speed is slow, and the torque control accuracy is greatly affected by motor parameters. SUMMARY

[0004] The present application provides a permanent magnet synchronous motor global control method and device and a permanent magnet synchronous motor to reduce calibration time and cost, obtain more accurate three-dimensional current pulse spectrum, and improve the reliability and stability of field weakening control.

[0005] In a first aspect, the present application provides a permanent magnet synchronous motor global control method. A three-dimensional current pulse spectrum of a non-field weakening region is obtained by calibration, and a three-dimensional current pulse spectrum of a field weakening region is obtained by calculation. The three-dimensional current pulse spectrum of the non-field weakening region and the three-dimensional current pulse spectrum of the field weakening region are both voltage-speed-torque three-dimensional current pulse spectrums. In a first working condition, a maximum torque current ratio control strategy is adopted according to the three-dimensional current pulse spectrum of the non-field weakening region and the three-dimensional current pulse spectrum of the field weakening region. In a second working condition, a maximum torque voltage ratio control strategy is adopted according to the three-dimensional current pulse spectrum of the non-field weakening region and the three-dimensional current pulse spectrum of the field weakening region.

[0006] Optionally, the three-dimensional current pulse spectrum of the non-field weakening region is obtained by calibration, including: at a rated voltage, a fixed speed of the permanent magnet synchronous motor is given; the fixed speed is less than a base speed of the permanent magnet synchronous motor; a current step is set, and a plurality of current amplitudes are given according to the current step and current angle θ, traverse each group of current amplitude according to the current step and current angle θ, and record each group of current amplitude actual torque under each group of current amplitude direct axis control voltage quadrature axis control voltage .

[0007] Optionally, the traverse each group of current amplitude according to the current step and current angle θ, and record each group of current amplitude actual torque under each group of current amplitude direct axis control voltage quadrature axis control voltage Optionally, the traverse each group of current amplitude according to the current step and current angle θ, and record each group of current amplitude actual torque under each group of current amplitude direct axis control voltage quadrature axis control voltage Optionally, the traverse each group of current amplitude according to the current step is the direct axis control current, is the quadrature axis control current, and the torque map is fitted to obtain the maximum torque current ratio control curve.

[0008] Optionally, the three-dimensional current map of the field-weakening region is obtained by calculation, comprising: determining a flux curve surface according to relevant data in the three-dimensional current map calibration process of the non-field-weakening region; and obtaining the three-dimensional current map according to the flux curve surface, wherein is the bus voltage; and the flux curve surface is expressed as:

[0009]

[0010]

[0011] wherein, is the direct axis control voltage, is the quadrature axis control voltage, ω is the motor speed, is the phase resistance, is the direct axis flux, is the quadrature axis flux.

[0012] Optionally, the three-dimensional current map is obtained according to the flux curve surface, and specifically comprises: setting an initial working condition point, and setting the bus voltage

[0013] according to the initial working condition point respectively ​The voltage range and step size, the motor speed ω, the speed range and step size, and the torque. The torque range and step size are used to obtain multiple operating points;

[0014] Calculate the rotational voltage amplitude at each operating point based on the process parameters at each operating point. ;

[0015] Among them, the amplitude of rotating voltage The expression is:

[0016]

[0017] .

[0018] Optionally, in calculating the rotational voltage amplitude at each operating point... Next, this includes: determining the rotational voltage amplitude at each operating point. Does it exceed the allowable voltage? If the rotational voltage amplitude at the operating point... The operating point shall not exceed the allowable voltage. Data; if the rotational voltage amplitude at the operating point If the voltage exceeds the allowable voltage, then according to Receive direct-axis control current command ,in The current for adjusting the field weakening depth is based on the direct-axis control current command. Maximum actual torque as well as Torque pulse spectrum, to obtain quadrature axis control current command Direct axis control current command and cross-axis control current command Substitute the rotational voltage amplitude back in The expression iteratively determines the amplitude of the rotating voltage at this operating point. Does it exceed the allowable voltage? Up to the rotational voltage amplitude at this operating point. If the voltage does not exceed the allowable voltage, record this operating point. , data.

[0019] Optionally, if the current at the operating point exceeds the maximum current amplitude of the current limit circle, or the rotating voltage amplitude... Adjusting the current as the depth of magnetic weakening If the value decreases and increases, then the operating point calculation stops; record the previous value. , data.

[0020] Optionally, iterate through the bus voltage at each operating point. motor speed ω, torque to obtain a three-dimensional current map of the field weakening region.

[0021] Optionally, in the first working condition, a maximum torque current ratio control strategy is adopted according to the three-dimensional current map, including: in the first working condition, a three-dimensional current map is obtained according to bus voltage, motor speed and torque to obtain an instruction value, the instruction value being a direct-axis control current instruction and a quadrature-axis control current instruction .

[0022] Optionally, in the second working condition, a three-dimensional current table is obtained to obtain a direct-axis control current , a direct-axis control current instruction is obtained according to and a quadrature-axis control current instruction is obtained according to

[0023] In a second aspect, the embodiment of the present application further provides a global control device of a permanent magnet synchronous motor, and the global control device comprises:

[0024] a calibration module, which obtains a three-dimensional current map of a non-field weakening region through calibration;

[0025] a calculation module, which obtains a three-dimensional current map of a field weakening region through calculation, wherein the three-dimensional current map of the non-field weakening region and the three-dimensional current map of the field weakening region are voltage-speed-torque three-dimensional current maps;

[0026] a control module, which adopts a maximum torque current ratio control strategy according to the three-dimensional current map of the non-field weakening region and the three-dimensional current map of the field weakening region in a first working condition, and adopts a maximum torque voltage ratio control strategy according to the three-dimensional current map of the non-field weakening region and the three-dimensional current map of the field weakening region in a second working condition.

[0027] In a third aspect, the embodiment of the present application further provides a permanent magnet synchronous motor, which adopts the global control method according to any of the above embodiments.

[0028] The present application obtains the three-dimensional current pulse spectrum of the non-field-weakening area through calibration, and obtains the three-dimensional current pulse spectrum of the field-weakening area through calculation, wherein the three-dimensional current pulse spectrum of the non-field-weakening area and the three-dimensional current pulse spectrum of the field-weakening area are voltage-speed-torque three-dimensional current pulse spectrums, under a first working condition, according to the complete three-dimensional current pulse spectrum, a maximum torque current ratio control strategy is adopted, and under a second working condition, according to the complete three-dimensional current pulse spectrum, a maximum torque voltage ratio control strategy is adopted, on the one hand, the three-dimensional current pulse spectrum of the non-field-weakening area is obtained through calibration, and the three-dimensional current pulse spectrum of the field-weakening area is obtained through calculation, the motor parameters and motor loss are considered, the calibration time is reduced, the calibration cost is reduced, the obtained three-dimensional current table is more accurate, on the other hand, different control strategies are adopted for different working conditions, the mutual coupling influence of the field-weakening ring and the current ring is reduced, the reliability and stability of the field-weakening control are greatly improved, and the problems of the prior art, such as complicated calibration process, low efficiency, slow target current distribution speed of the original id field-weakening vector control, and large influence of motor parameters on torque control precision are solved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A permanent magnet synchronous motor global control method flow chart is provided for the embodiment one of the present application.

[0030] Figure 2 A non-field-weakening area calibration method flow chart is provided for the embodiment one of the present application.

[0031] Figure 3 A calibration control schematic diagram is provided for the embodiment one of the present application.

[0032] Figure 4 A field-weakening area calculation method flow chart is provided for the embodiment two of the present application.

[0033] Figure 5 A global current control method specific flow chart is provided for the embodiment three of the present application.

[0034] Figure 6 A global current control method strategy block diagram is provided for the embodiment three of the present application.

[0035] Figure 7 A permanent magnet synchronous motor global control device structure schematic diagram is provided for the embodiment four of the present application. DETAILED DESCRIPTION

[0036] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort should belong to the protection scope of the present application.

[0037] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification and claims of the present application and the above-described drawings are intended to cover not exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to the clearly listed steps or units, but can include other steps or units not clearly listed or inherent to the process, method, product or device.

[0038] Embodiment one

[0039] Figure 1 A flow chart of a global control method of a permanent magnet synchronous motor is provided for the embodiment one of the present application. The embodiment can be applicable to the global control of the permanent magnet synchronous motor. The method can be executed by a global control device, which can be realized in the form of hardware and / or software. As shown in the figure, the method comprises: Figure 1

[0040] S110, obtaining a three-dimensional current pulse spectrum of a non-field weakening region through calibration.

[0041] Specifically, in the d-q rotating coordinate system, the actual torque formula of the motor is:

[0042]

[0043] wherein, is a permanent magnet flux linkage, is a motor pole pair number, is a direct-axis inductance, is a quadrature-axis inductance, is a direct-axis control current, is a quadrature-axis control current, that is, the actual torque of the motor is jointly determined by the permanent magnet flux linkage, the motor pole pair number, the direct-axis inductance, the quadrature-axis inductance, the direct-axis control current and the quadrature-axis control current. In addition, the control operation of the permanent magnet synchronous motor is driven by the inverter output, so that the motor operation performance is restricted by the inverter. When operating in the non-field weakening region below the base speed, the most important limiting condition is the maximum output current of the inverter, that is, the current limit circle, which satisfies the formula: .

[0044] ​At this point, if the three-dimensional current pulse spectrum of the non-weak magnetic region is obtained through calculation, that is... Calculating a three-dimensional current pulse spectrum is extremely complex, and the computational load during control is also substantial. Furthermore, the influence of motor and inverter losses cannot be eliminated. Therefore, this embodiment of the invention obtains the spectrum through calibration. Three-dimensional current pulse spectrum. Figure 2 The flowchart of the non-weak magnetic region calibration method provided in Embodiment 1 of the present invention is shown below. Figure 2 The specific calibration process is explained below:

[0045] S1101. Under rated voltage, a fixed speed is given to the permanent magnet synchronous motor; the fixed speed is less than the base speed of the permanent magnet synchronous motor.

[0046] For details, see Figure 3 Under rated voltage, a dynamometer is used to drive the permanent magnet synchronous motor to a relatively stable fixed speed below the base speed. This fixed speed is lower than the base speed to ensure that all torque states at this fixed speed will not cause the permanent magnet synchronous motor to enter the field weakening condition.

[0047] S1102. Set the current step size and assign multiple sets of current amplitudes according to the current step size. and the current angle θ.

[0048] Specifically, by setting the current step size, multiple different current amplitudes can be given. And the current angle θ, as well as the maximum current amplitude and the maximum current angle.

[0049] S1103. According to the current step size, iterate through each group of current amplitudes. And the current angle θ, and record the current amplitude for each group. Actual torque at current angle θ Direct axis control voltage and cross-axis control voltage Specifically, during the calibration process, the temperature of the permanent magnet synchronous motor stator must be within a stable range. Within the current limit circle, the second and third quadrants must traverse all motoring and generating regions, with the current angle θ ranging from 90 degrees to 270 degrees. The current amplitude at this point must be recorded. and the current angle θ, and the actual torque detected by the dynamometer ,get Torque pulse spectrum and direct-axis control voltage pulse spectrum transformed into the dq rotating coordinate system at this time and cross-axis control voltage pulse spectrum .

[0050] S1104, at each current amplitude Next, find the maximum actual torque. Record the current amplitude at the current angle θ. Current angle θ and the corresponding maximum actual torque .

[0051] S1105, Perform coordinate transformation to obtain Torque pulse spectrum, The torque pulse spectrum is fitted to obtain the maximum torque-to-current ratio control curve, which is the three-dimensional current pulse spectrum in the non-weak magnetic region.

[0052] Furthermore, the three-dimensional current pulse spectrum of the non-weak magnetic region can be obtained through calibration.

[0053] S120. Obtain the three-dimensional current pulse spectrum of the weak magnetic region through calculation.

[0054] Specifically, the weak magnetic field region can be obtained through calculation. Three-dimensional current pulse spectrum. During calibration in the non-weakening magnetic region, different direct-axis control currents have been recorded. Cross-axis control current Corresponding direct-axis control voltage and cross-axis control voltage Therefore, the voltage surface corresponding to the maximum torque-current ratio control curve can be obtained. and .

[0055] Then through the formula and The transformation yields the expression for the magnetic flux linkage surface:

[0056]

[0057] in, For direct axis control voltage, The quadrature-axis control voltage is ω, and the motor speed is ω. For phase resistance, It is a direct-axis magnetic flux linkage. Given the quadrature-axis flux linkage, the formula can be used to obtain the maximum torque-current ratio control curve. and The flux linkage pulse spectrum, since the direct-axis and quadrature-axis flux linkages are only related to inductance (current) and rotor flux (temperature), can be used to calculate voltages at various speeds. Based on the above, a three-level traversal calculation process can be set up, and the weak magnetic region can be obtained according to this calculation process. Three-dimensional current pulse spectrum.

[0058] S130, in the first working condition, according to the three-dimensional current pulse spectrum of the non-field-weakening region and the three-dimensional current pulse spectrum of the field-weakening region, a maximum torque current ratio control strategy is adopted, and in the second working condition, according to the three-dimensional current pulse spectrum of the non-field-weakening region and the three-dimensional current pulse spectrum of the field-weakening region, a maximum torque voltage ratio control strategy is adopted.

[0059] The first working condition is a normal working condition, and the field-weakening depth adjustment is not triggered in the first working condition, and the second working condition is a working condition of low temperature, rapid acceleration and deceleration or extremely poor road, that is, the field-weakening ring is triggered only in the working condition of low temperature, rapid acceleration and deceleration or extremely poor road, in the first working condition, according to the obtained complete three-dimensional current pulse spectrum, a maximum torque current ratio control strategy is adopted, that is, the required stator current amplitude of the permanent magnet synchronous motor is minimum under the condition of output target torque, and this control mode can reduce the motor stator copper loss, improve the efficiency, and is beneficial to the work of the inverter switching device. In the second working condition, according to the obtained complete three-dimensional current pulse spectrum, a maximum torque current ratio control strategy is adopted, that is, when the voltage provided by the inverter is constant, the output torque of the permanent magnet motor can be maximized, and the maximum operating power of the motor is improved.

[0060] The technical scheme of the embodiment, the three-dimensional current pulse spectrum of the non-field-weakening region is obtained by calibration, and the three-dimensional current pulse spectrum of the field-weakening region is obtained by calculation, wherein the three-dimensional current pulse spectrum of the non-field-weakening region and the three-dimensional current pulse spectrum of the field-weakening region are voltage-speed-torque three-dimensional current pulse spectrums, in the first working condition, according to the complete three-dimensional current pulse spectrum, a maximum torque current ratio control strategy is adopted, and in the second working condition, according to the complete three-dimensional current pulse spectrum, a maximum torque voltage ratio control strategy is adopted, on the one hand, the three-dimensional current pulse spectrum of the non-field-weakening region is obtained by calibration, and the three-dimensional current pulse spectrum of the field-weakening region is obtained by calculation, the motor parameters and motor loss are considered while reducing the calibration time and reducing the calibration cost, so that the obtained current MAP is more accurate, on the other hand, different control strategies are adopted for different working conditions, the mutual coupling influence of the field-weakening ring and the current ring is reduced, the reliability and stability of the field-weakening control are greatly improved, and the problems of complicated calibration process, low efficiency, slow target current distribution speed of the original negative id field-weakening vector control, and large influence of motor parameters on torque control precision in the prior art are solved.

[0061] Embodiment two

[0062] Figure 4 The flowchart of the field-weakening region calculation method provided in the embodiment two, the embodiment is based on the above-mentioned embodiments, and the specific process of calculating the three-dimensional current pulse spectrum of the field-weakening region is specifically described.

[0063] S210, setting an initial working condition point, and setting a bus voltage according to the initial working condition point voltage range and step size of the bus voltage, the rotating speed range and step size of the motor rotating speed ω, and the torque range and step size of the actual torque , to obtain a plurality of working condition points.

[0064] Specifically, an initial working condition point is set, the initial working condition point including an initial bus voltage, an initial motor rotating speed, and an initial actual torque, and step sizes are set for the initial bus voltage, the initial motor rotating speed, and the initial actual torque, respectively, to obtain a voltage range of the bus voltage , a rotating speed range of the motor rotating speed ω, and a torque range of the actual torque , and a plurality of working condition points including the bus voltage , the motor rotating speed ω, and the actual torque are also obtained.

[0065] S220, calculating a rotating voltage amplitude of each working condition point according to a process parameter of each working condition point .

[0066] wherein each working condition point includes the initial working condition point and a plurality of working condition points set through the initial working condition point. The process parameter refers to a parameter recorded in a non-field weakening region calibration process. Specifically, at each working condition point, the of the maximum torque current ratio curve is substituted into an expression of the rotating voltage amplitude .

[0067]

[0068]

[0069] calculating a rotating voltage amplitude of each working condition point , wherein is a direct-axis control voltage, is a quadrature-axis control voltage, ω is a motor rotating speed, is a phase resistance, is a direct-axis flux linkage, is a quadrature-axis flux linkage.

[0070] S230, judging whether the rotating voltage amplitude of each working condition point exceeds a permissible voltage.

[0071] wherein the permissible voltage is a voltage limit value , and the voltage limit value is restricted by an inverter, and in a d-q rotating coordinate system, the voltage limit value is generally the bus voltage divided by the square root of three. After the rotating voltage amplitude of the working condition point is calculated, it is judged whether the rotating voltage amplitude Does it exceed the voltage limit? If the amplitude of the rotating voltage at this operating point... Not exceeding the voltage limit value Then retain that operating condition point. Data; if the rotational voltage amplitude at this operating point Exceeding the voltage limit According to Receive direct-axis control current command And through actual torque and direct axis control current command In the process of reverse checking the calibration of non-weak magnetic regions Torque pulse spectrum, to obtain quadrature axis control current command At this time, the direct axis control current command will be applied. and cross-axis control current command Substituting the values ​​back into the expression for the amplitude of the rotating voltage, we obtain the amplitude of the rotating voltage. ,in The current is adjusted to the depth of magnetic field weakening.

[0072] S240, cyclically determine the amplitude of the rotating voltage at this operating point. Does it exceed the allowable voltage, up to the rotational voltage amplitude? The voltage should not exceed the allowable voltage, and this operating point should be recorded. , data.

[0073] Specifically, if after step S220, the rotational voltage amplitude Still exceeds voltage limit Then continue according to Receive direct-axis control current command and cross-axis control current command And calculate the amplitude of the rotating voltage at this time. The amplitude of the rotating voltage at this operating point is determined again. Does it exceed the voltage limit? Repeat this step until the voltage amplitude is rotated. Not exceeding the voltage limit value Record the operating condition at this time. , data.

[0074] S250. If the current at the operating point exceeds the maximum current amplitude of the current limit circle, or the rotating voltage amplitude... along with If the value decreases and increases, then the operating point calculation stops; record the previous value. , data.

[0075] S260, Traverse the bus voltage at each operating point Motor speed ω, torque The three-dimensional current pulse spectrum of the weak magnetic region is obtained. Specifically, for each operating point, steps S220-S240 are performed to obtain the magnetic region's... Three-dimensional current pulse spectrum can simultaneously obtain the external torque characteristics under fixed voltage and speed.

[0076] The technical solution of this embodiment, by using a calculation method in the weak magnetic region, can obtain the maximum torque output at the same terminal voltage under a certain operating point, thereby achieving maximum torque-voltage ratio control, improving the bus voltage utilization rate of the electric drive system, and thus improving system efficiency.

[0077] Example 3

[0078] Figure 5 This is a flowchart illustrating the global current control method provided in Embodiment 3 of the present invention. Figure 6 This is a strategy block diagram of the global current control method provided in Embodiment 3 of the present invention. Based on the above embodiments, this embodiment specifically describes the control method for different operating conditions. The method specifically includes:

[0079] S310. Obtain the three-dimensional current pulse spectrum of the non-weak magnetic region through calibration.

[0080] S320. Obtain the three-dimensional current pulse spectrum of the weak magnetic region through calculation.

[0081] S330, Under the first operating condition, refer to the three-dimensional current pulse spectrum table based on the bus voltage, motor speed, and torque. Obtain the instruction value.

[0082] For details, see Figure 6 The permanent magnet synchronous motor's global control system may include a three-dimensional current lookup table module, a current control module, a coordinate transformation module, a pulse width modulation module, a decoupling module, a field weakening depth adjustment module, and an inverter. Under most normal operating conditions, field weakening depth adjustment will not be triggered, and the field weakening depth adjustment current... It was consistently limited to 0A. At this point, the bus voltage could be used as a reference. Motor speed Actual torque Look up the three-dimensional current pulse spectrum table This yields the command value, namely the direct-axis control current command. and cross-axis control current command .

[0083] S340. Under the second operating condition, refer to the table for the three-dimensional current pulse spectrum. Obtain direct-axis control current ,according to get direct axis control current instruction , and according to get quadrature axis control current instruction .

[0084] Specifically, due to the accuracy of the three-dimensional flux of the field weakening region, the field weakening depth adjustment current is triggered only in the working conditions of low temperature, sudden acceleration and deceleration, or extremely poor road surface, at which time the negative field weakening depth adjustment current is output to increase the field weakening depth, ensure that the entire field weakening region does not exceed the limit of the voltage limit circle, and look up the table the direct axis control current obtained by the three-dimensional current pulse spectrum is summed up as the new direct axis control current instruction , at which time in order to ensure that the entire control does not exceed the limit of the current limit circle, the new quadrature axis control current instruction is obtained from the three-dimensional current table the direct axis control current and the quadrature axis control current and the new direct axis control current instruction together determine, that is at this time, it is ensured that the entire control process neither exceeds the current limit circle nor exceeds the voltage limit circle, ensuring the stability of the control.

[0085] In summary, the control method of the embodiment first needs to obtain the instruction value, that is, the direct axis control current instruction and the quadrature axis control current instruction The instruction value is different under different working conditions. Specifically, by looking up the three-dimensional current table , the original data is queried, and the corresponding direct axis control voltage and the quadrature axis control voltage are calculated to obtain the rotating voltage amplitude .

[0086] When the rotating voltage amplitude does not reach the voltage limit value , the field weakening depth adjustment current output after PI regulation is limited to 0A, that is, at this time, it is the first working condition, and the actual instruction value, the direct axis control current instruction and the quadrature axis control current instruction are the same as the original data obtained by looking up the table.

[0087] When the rotating voltage amplitude reaches the voltage limit value , the PI regulation is triggered, and the negative field weakening depth adjustment current is output , at which time it is the second working condition, and look up table to get direct axis control current sum up as new direct axis control current command and according to formula calculate new quadrature axis control current command .

[0088] the command value obtained by the above steps and is the control command. Specifically, the actual three-phase current of the permanent magnet synchronous motor , , is obtained by coordinate transformation to get the actual d-q rotating coordinate system current and , through the current control module, the actual d-q axis current and follow the direct axis control current command and the quadrature axis control current command , the output of the current control module is the d-q axis voltage, namely the direct axis control voltage and the quadrature axis control voltage , through coordinate transformation to get axis voltage and , so that axis voltage and are calculated as the input of pulse width modulation to control the time of each phase switch of the inverter, and the current and torque output by the inverter meet the command.

[0089] The technical scheme of the embodiment adopts a semi-calibration and semi-computation method to significantly shorten the calibration time while ensuring calibration accuracy, improve calibration efficiency, and ensure the consistency, reliability and efficiency of the calibration data, and obtain a three-dimensional current table is applied to a three-dimensional global current control strategy, different command values are obtained according to different working conditions, and the current and torque output by the inverter meet the command according to the command value. Compared with the traditional negative id current control strategy, the weak magnetic depth regulation current is reduced in most working conditions control closed loop, only two current closed loops and are retained, the mutual coupling influence of the weak magnetic ring and the current ring is reduced, and the reliability and stability of the weak magnetic control are greatly improved.

[0090] Embodiment four

[0091] Figure 5The diagram below shows the structure of the global control device for a permanent magnet synchronous motor according to Embodiment 4 of the present invention. This embodiment is applicable to the global control of a permanent magnet synchronous motor. The specific structure of the global control device for the permanent magnet synchronous motor is as follows:

[0092] Calibration module 51 obtains the three-dimensional current pulse spectrum in the non-weak magnetic region through calibration;

[0093] The calculation module 52 obtains the three-dimensional current pulse spectrum of the weak magnetic region through calculation. The three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region are both voltage-speed-torque three-dimensional current pulse spectra.

[0094] In the first operating condition, the control module 53 adopts a maximum torque-to-current ratio control strategy based on the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region; in the second operating condition, it adopts a maximum torque-to-voltage ratio control strategy based on the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region.

[0095] Specifically, calibration module 51 is used to set a fixed speed for the permanent magnet synchronous motor under rated voltage; the fixed speed is less than the base speed of the permanent magnet synchronous motor; set the current step size, and set multiple sets of current amplitudes according to the current step size. And the current angle θ; according to the current step size, iterate through each group of current amplitudes. And the current angle θ, and record the current amplitude for each group. Actual torque at current angle θ Direct axis control voltage and quadrature axis control voltage .

[0096] Calibration module 51 is also used for each current amplitude Next, find the maximum actual torque. Record the current amplitude at the current angle θ. Current angle θ and the corresponding maximum actual torque Perform coordinate transformation to obtain Torque pulse spectrum, in which For direct-axis control current, For quadrature axis control current; The torque pulse spectrum is fitted to obtain the maximum torque-to-current ratio control curve.

[0097] Calculation module 52 is also used to determine the flux linkage surface based on relevant data from the three-dimensional current pulse spectrum calibration process in the non-weak magnetic region; and to obtain the flux linkage surface based on the data. Three-dimensional current pulse spectrum.

[0098] Calculation module 52 is specifically used to set the initial operating point and, based on the initial operating point, to set the bus voltage. Voltage range and step size, motor speed ω speed range and step size, and actual torque. The torque range and step size are determined to obtain multiple operating points; based on the process parameters of each operating point, the rotational voltage amplitude of each operating point is calculated. .

[0099] Determine the rotational voltage amplitude at each operating point Does it exceed the allowable voltage? If the rotational voltage amplitude at the operating point... The operating point shall not exceed the allowable voltage. Data; if the rotational voltage amplitude at the operating point If the voltage exceeds the allowable voltage, then according to Receive direct-axis control current command ,in The current is adjusted to control the depth of the weakened field; based on the direct axis control current command. Actual torque as well as Torque pulse spectrum, to obtain quadrature axis control current command ;Transfer direct axis control current command and cross-axis control current command Substitute the rotational voltage amplitude back in The expression iteratively determines the amplitude of the rotating voltage at this operating point. Does it exceed the allowable voltage? Up to the rotational voltage amplitude at this operating point. If the voltage does not exceed the allowable voltage, record this operating point. , data.

[0100] If the current at the operating point exceeds the maximum current amplitude of the current limit circle, or the rotating voltage amplitude... along with If the value decreases and increases, then the operating point calculation stops; record the previous value. , data.

[0101] Iterate through the bus voltage at each operating point Motor speed ω, torque The three-dimensional current pulse spectrum of the weak magnetic region was obtained.

[0102] Control module 53 also includes a first control unit and a second control unit; the first control unit is used to look up a three-dimensional current spectrum table based on bus voltage, motor speed, and torque under the first operating condition. The command value is obtained, wherein the command value is the direct axis control current command. and cross-axis control current command .

[0103] The second control unit is configured to, in the second working condition, look up the three-dimensional current table to obtain a direct-axis control current obtain a direct-axis control current obtain a direct-axis control current obtain a direct-axis control current obtain a direct-axis control current obtain a direct-axis control current .

[0104] The technical scheme of the embodiment adopts a semi-calibration and semi-computation method to significantly shorten calibration time while ensuring calibration accuracy, improve calibration efficiency, and ensure consistency, reliability, and high efficiency of calibration data, and obtain a three-dimensional current table The three-dimensional current table is applied to a three-dimensional global current control strategy, different instruction values are obtained according to different working conditions, and the inverter is controlled according to the instruction values to output a current and a torque that meet the instructions, and compared with a traditional negative id current control strategy, a weak magnetic depth regulation current is reduced in most working conditions control a closed loop, only two current closed loops and are retained, the mutual coupling influence of the weak magnetic ring and the current ring is reduced, and the reliability and stability of the weak magnetic control are greatly improved.

[0105] Embodiment five

[0106] Based on the above-mentioned inventive concept, the embodiment of the present application also provides a permanent magnet synchronous motor adopting the global control method of the permanent magnet synchronous motor of any embodiment of the present application, therefore, the permanent magnet synchronous motor provided by the embodiment of the present application has the corresponding beneficial effects of the global control method of the permanent magnet synchronous motor provided by the embodiment of the present application, which will not be repeated here.

[0107] Note that the above is only the preferred embodiment of the present application and the technical principle applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, readjustments and substitutions without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the inventive concept, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A method for global control of a permanent magnet synchronous motor, characterized in that, include: Three-dimensional current pulse spectrum in the non-weak magnetic region was obtained through calibration. The three-dimensional current pulse spectrum of the weak magnetic region is obtained by calculation, wherein the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region are both voltage-speed-torque three-dimensional current pulse spectra. Under the first operating condition, a maximum torque-to-current ratio control strategy is adopted based on the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region. Under the second operating condition, a maximum torque-voltage ratio control strategy is adopted based on the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region. The process of obtaining the three-dimensional current pulse spectrum of the weak magnetic region through calculation includes: The flux linkage surface is determined based on relevant data from the calibration process of the three-dimensional current pulse spectrum in the non-weak magnetic region. Based on the magnetic flux linkage surface, we obtain Three-dimensional current pulse spectrum, in which The bus voltage is given; the flux linkage surface expression is: in, For direct axis control voltage, The quadrature-axis control voltage is ω, and the motor speed is ω. For phase resistance, It is a direct-axis magnetic flux linkage. It is a cross-axis magnetic flux linkage.

2. The global control method according to claim 1, characterized in that, The process of obtaining the three-dimensional current pulse spectrum of the non-weak magnetic region through calibration includes: Under rated voltage, the permanent magnet synchronous motor is given a fixed speed; the fixed speed is less than the base speed of the permanent magnet synchronous motor. Set the current step size, and give multiple sets of current amplitudes according to the current step size. and current angle θ; According to the stated current step size, iterate through each group of current amplitudes. And the current angle θ, and record the current amplitude for each group. Actual torque at current angle θ Direct axis control voltage and cross-axis control voltage .

3. The global control method according to claim 2, characterized in that, The current amplitude is traversed according to the current step size. And the current angle θ, and record the current amplitude for each group. Actual torque at current angle θ Direct axis control voltage and cross-axis control voltage Following that, it also includes: At each current amplitude Next, find the maximum actual torque. Record the current amplitude at the current angle θ. Current angle θ and the corresponding maximum actual torque Perform coordinate transformation to obtain Torque pulse spectrum, in which For direct-axis control current, For quadrature axis control current; Will The torque pulse spectrum is fitted to obtain the maximum torque-to-current ratio control curve.

4. The global control method according to claim 1, characterized in that, The result is obtained based on the magnetic flux surface. Three-dimensional current pulse spectrum, specifically including: Set the initial operating point, and set the bus voltage according to the initial operating point. Voltage range and step size, motor speed ω speed range and step size, and actual torque. The torque range and step size are used to obtain multiple operating points; Calculate the rotational voltage amplitude at each operating point based on the process parameters at each operating point. ; Among them, the amplitude of rotating voltage The expression is: 。 5. The global control method according to claim 4, characterized in that, Calculate the rotational voltage amplitude at each operating point. After that, including: Determine the rotational voltage amplitude at each operating point Does it exceed the allowable voltage? If the amplitude of the rotating voltage at the operating point The operating point shall not exceed the allowable voltage. data; If the amplitude of the rotating voltage at the operating point If the voltage exceeds the allowable voltage, then according to Receive direct-axis control current command ,in The current is adjusted to the depth of magnetic field weakening; According to the direct axis control current command Actual torque as well as Torque pulse spectrum, to obtain quadrature axis control current command ; Direct axis control current command and cross-axis control current command Substitute the rotational voltage amplitude back in The expression iteratively determines the amplitude of the rotating voltage at this operating point. Does it exceed the allowable voltage? Up to the rotational voltage amplitude at this operating point. If the voltage does not exceed the allowable voltage, record this operating point. data.

6. The global control method according to claim 5, characterized in that, If the current at the operating point exceeds the maximum current amplitude of the current limit circle, or the rotating voltage amplitude... along with If the value decreases and increases, then the operating point calculation stops; record the previous value. , data.

7. The global control method according to claim 6, characterized in that, Iterate through the bus voltage at each operating point Motor speed ω, torque The three-dimensional current pulse spectrum of the weak magnetic region was obtained.

8. The global control method according to claim 3, characterized in that, Under the first operating condition, based on the three-dimensional current pulse spectrum, a maximum torque-to-current ratio control strategy is adopted, including: Under the first operating condition, the three-dimensional current pulse spectrum is looked up from the table based on the bus voltage, motor speed, and torque. The command value is obtained, wherein the command value is the direct axis control current command. and cross-axis control current command .

9. The global control method according to claim 7, characterized in that, In the second operating condition, based on the three-dimensional current pulse spectrum, a maximum torque-to-voltage ratio control strategy is adopted, including: Under the second operating condition, refer to the three-dimensional ammeter table. Obtain direct-axis control current ,according to Receive direct-axis control current command and according to Receive quadrature axis control current command .

10. A global control device for a permanent magnet synchronous motor, characterized in that, include: The calibration module obtains the three-dimensional current pulse spectrum in the non-weak magnetic region through calibration; The calculation module obtains the three-dimensional current pulse spectrum of the weak magnetic region through calculation. The three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region are both voltage-speed-torque three-dimensional current pulse spectra. The control module, under the first operating condition, adopts a maximum torque-to-current ratio control strategy based on the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region; under the second operating condition, it adopts a maximum torque-to-voltage ratio control strategy based on the three-dimensional current pulse spectrum of the non-weak magnetic region and the three-dimensional current pulse spectrum of the weak magnetic region. The calculation module is also used to determine the flux linkage surface based on relevant data from the three-dimensional current pulse spectrum calibration process in the non-weak magnetic region. Based on the magnetic flux linkage surface, we obtain Three-dimensional current pulse spectrum; among which The bus voltage is given; the flux linkage surface expression is: in, For direct axis control voltage, The quadrature-axis control voltage is ω, and the motor speed is ω. For phase resistance, It is a direct-axis magnetic flux linkage. It is a cross-axis magnetic flux linkage.

11. A permanent magnet synchronous motor, wherein the permanent magnet synchronous motor employs the global control method according to any one of claims 1-9.

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