CN104967382A - A sensorless control method for permanent magnet synchronous motor - Google Patents

Abstract

The invention discloses a permanent magnet synchronous motor position sensorless control method, comprising a rotating speed stabilization ring for correcting voltage synthesizing vector speed and a voltage amplitude correction ring for realizing vector control. The permanent magnet synchronous motor position sensorless control method essentially solves the problem that the motor is easy to lose synchronization and collapse, brings forwards a novel control strategy algorithm for realizing vector control, and realizes the stable, reliable and efficient operation of the driving system of the permanent magnet synchronous motor.

Description

A sensorless control method for permanent magnet synchronous motor

technical field

The invention relates to a position sensorless control method of a permanent magnet synchronous motor, which belongs to the field of motor control.

Background technique

The increasing energy consumption requires the application of more efficient control systems in industrial equipment. Power electronics and control technology can effectively improve the efficiency of most current industrial drive systems. Due to its high efficiency, high power density, high dynamic response and other advantages, the permanent magnet synchronous motor has been valued by the industry, so it has gradually been widely used in industrial equipment. For some devices that need to run continuously for a long time, such as fans, pumps, and compressors, if the efficiency can be improved, it will save huge energy. Applying permanent magnet synchronous motors to these occasions can significantly improve energy utilization and save energy.

The control methods of permanent magnet synchronous motor mainly include: 1) Vector control, including current vector control, field oriented control, direct torque control and flux linkage control, etc. These control strategies have high dynamic performance, high control precision, and anti-interference Strong ability. 2) Scalar control, including conventional V/f control, V/f control with a stable correction loop, etc. This type of control strategy is relatively simple to implement and has strong robustness, but the dynamic response speed is not high. In the past ten years, position sensorless control has been vigorously developed, mainly because the omission of position sensors helps to reduce costs, and at the same time avoids the problem of inaccurate measurement and failure of sensors caused by signal interference and chattering at high speeds. Relevant research focuses on improving performance and reliability, improving control accuracy and dynamic responsiveness on the basis of considering cost.

Applying the permanent magnet synchronous motor position sensorless drive system based on scalar V/f control to fan applications is a high-quality choice at present, mainly because such loads do not require high dynamic performance. As we all know, the damping winding designed and manufactured on the permanent magnet synchronous motor rotor can ensure that the rotor speed is synchronized with the stator electrical frequency. Due to the difficulty and cost of design and manufacture, most existing permanent magnet synchronous motor rotors do not have damping windings installed, so the traditional open-loop V/f control strategy cannot guarantee the synchronous and stable operation of the motor. In addition, for applications such as fans, water pumps, and compressors, the efficiency and output capacity of the drive system are a major concern. In the past, most researches on the sensorless control of permanent magnet synchronous motors have not paid enough attention to it. It is of great significance to study the effect similar to current vector control on V/f control based on position sensorless technology.

Contents of the invention

Aiming at the problems existing in the prior art, this application provides a position sensorless control method for a permanent magnet synchronous motor, in which the specific structure and setting method of the stabilization loop and the voltage amplitude correction loop are studied and involved, which is different from the existing Compared with other products, it is easier for the synchronous and stable operation of the motor and vector control, and has a certain starting and loading capacity.

In order to achieve the above purpose, according to one aspect of the present invention, a position sensorless control method for a permanent magnet synchronous motor is provided, which specifically includes the following steps:

Step (1): Give the electrical angular velocity command signal, input the target electrical angular velocity, and change from the original electrical angular velocity command signal to the new target electrical angular velocity with a certain rising or falling slope according to a linear function relationship, where ω _e0 ^* is defined as the target Electrical angular velocity, ω _e is defined as the electrical angular velocity command during the change process;

Step (2): Determination of voltage synthesis vectors u _s ^* and θ _v ^* ;

Step (3): Utilize the voltage synthesis vector determined in step (2) for processing to drive the permanent magnet synchronous motor;

Step (4): Measure the two-phase stator currents i _A and i _B of the permanent magnet synchronous motor, perform speed stabilization loop and voltage amplitude correction loop control, and finally complete the sensorless control of the permanent magnet synchronous motor.

Preferably, the step (2) specifically includes the following steps:

Step (21): pass the electrical angular velocity command ω _e obtained in step (1) through a proportional link, the proportional coefficient is the permanent flux linkage λ _m , and output the rotor back EMF e _s ;

Step (22): voltage synthesis vector magnitude processing, specifically including:

Step (221): Add the e _s obtained in step (21), the initial start-up boost voltage u ₀ and the output voltage Δu of the voltage amplitude correction loop, and the output value is the voltage amplitude u _s ;

Step (222): Limiting the voltage amplitude u _s obtained in step (221), the upper limit of the limiting link is Among them, the DC bus voltage input by the inverter bridge is defined as U _dc , the lower limit of the limiting link is 0, and the output value is the voltage synthesis vector amplitude u _s ^* ;

Step (23): Voltage synthesis vector angle processing, specifically including:

Step (231): the ω _e described in the step (1) and the output electrical angular velocity Δω _e of the speed stabilization loop are passed through a subtractor to output the electrical angular velocity value ω _e ^* of the voltage vector;

Step (232): Integrate the electrical angular velocity ω _e ^* obtained in step (231) through an integral link to obtain the voltage synthesis vector angle value θ _v ^* .

Preferably, the step (3) specifically includes the following steps:

Step (31): Transform the voltage synthesis vector amplitude u _s ^* and angle value θ _v ^* obtained in step (2) into the rectangular coordinate αβ axis, and obtain the voltage values of the α axis and β axis Quantitatively recorded as u _α ^* and u _β ^* respectively;

Step (32): Carry out SVPWM modulation to the voltage given values u _α ^* and u _β ^* in step (31), to obtain the driving signals of six switching tubes in the three-phase full-bridge inverter bridge, and the above-mentioned inverter bridge is used for Drive permanent magnet synchronous motor.

Preferably, said step (4) specifically includes the following steps:

Step (41): Measure the stator two-phase currents i _A and i _B of the permanent magnet synchronous motor, and convert the measured two-phase stator currents i _A and i _B through Clark transformation to obtain the current in the two-phase stationary rectangular α-β coordinate system i _α and i _β ;

Step (42): Use the given voltage u _α ^* and u _β ^* obtained in step (31) and the current i _α and i _β obtained in step (41) to calculate the input power, and calculate the active power of the input motor respectively P and reactive power Q;

Step (43): Use the motor input active power P outputted in step (42) to perform speed stabilization loop control, specifically including the following processing:

Step (431): Input the active power P of the motor, and pass through a first-order high-pass filter to obtain the disturbance active power Δp of the input motor;

Step (432): Utilize the disturbance active power Δp that step (431) obtains, through an amplification link whose proportional coefficient is _kp , the output obtains the output electrical angular velocity Δω _e of the speed stabilization loop;

Step (44): Use the motor input active power P and reactive power Q obtained in step (42) and the voltage vector electrical angular velocity ω _e ^* obtained in step (231) to perform voltage amplitude correction loop control, specifically including the following deal with:

Step (441): Using the motor input active power P obtained in step (42) and the voltage vector electric angular velocity ω _e ^* obtained in step (231) output, through the Q _ref calculation link, calculate the output motor at Command reactive power Q _ref under the maximum torque-to-current ratio, _id = 0 control strategy;

Step (442): Utilize the command reactive power Q _ref obtained in step (441) output and the reactive power Q of the input motor obtained in step (42), through a subtractor, output to obtain the reactive power deviation value ΔQ;

Step (443): Use the reactive power deviation ΔQ obtained in step (442) to adjust and control through the PI regulator, and output the output voltage Δu of the voltage amplitude correction loop.

Generally speaking, compared with the prior art, according to the above-mentioned technical concept of the present invention, it mainly possesses the following technical advantages:

1. Less hardware implementation requirements, only need to collect two-phase stator current, less dependence on motor parameters, and less calculation amount. At the same time, by properly increasing the starting voltage, the system has a certain starting load capacity;

2. Starting from the essential cause of motor out-of-step collapse, it is proposed to add a speed stabilization loop to solve the problem that the motor cannot maintain synchronous and stable operation in the medium and high frequency domain or when the load changes suddenly;

3. From controlling the reactive power of the input motor as a breakthrough point, it is proposed The maximum torque current ratio ( _MTPA ), id = 0 and other vector control strategy algorithms are added to the voltage amplitude correction loop to finally realize the vector control.

Description of drawings

Fig. 1 is a control structure and a functional block diagram of a position sensorless control method for a permanent magnet synchronous motor designed in the present invention.

Detailed ways

In order to make the control structure, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 shows the principle block diagram of the control method according to the present invention, which specifically includes: the electric angular velocity command acceleration and deceleration link, the proportional link for calculating the rotor back EMF, the voltage limiting link, the electric angular velocity integral link, the polar coordinate system/two-phase static αβ coordinate system transformation, SVPWM modulation, three-phase inverter power supply, permanent magnet synchronous motor, current sensor, three-phase stationary ABC coordinate system/two-phase stationary αβ coordinate system transformation (Clark transformation), power calculation in two-phase stationary αβ coordinate system link, high-pass filter, speed stabilization proportional regulator, ( _MTPA , id = 0) command reactive power calculation, voltage amplitude correction PI regulator, etc. during the control strategy.

The present invention proposes a position sensorless control method for a permanent magnet synchronous motor, which specifically includes the following specific steps:

Step (1): Give the electrical angular velocity command signal, input the target electrical angular velocity, and change from the original electrical angular velocity command signal to the new target electrical angular velocity with a certain rising or falling slope according to a linear function relationship, where ω _e0 ^* is defined as the target Electrical angular velocity, ω _e is defined as the electrical angular velocity command during the change process;

Step (2): The determination of the voltage synthesis vector specifically includes the following processing:

Step (21): pass the ω _e obtained in the step (1) through a proportional link, the proportional coefficient is the permanent flux linkage λ _m , and the output is the rotor back EMF e _s ;

Step (22): voltage synthesis vector magnitude processing, specifically including:

Step (221): add the e _s obtained in step (21), the initial start-up boost voltage u ₀ and the output voltage Δu of the voltage amplitude correction loop, and the output value is the voltage amplitude u _s ;

Step (222): Limiting the voltage amplitude u _s obtained in step (221), the upper limit of the limiting link is Among them, the DC bus voltage input by the inverter bridge is defined as U _dc , and the lower limit of the limiting link is 0. The output is the voltage synthesis vector magnitude u _s ^* ;

Step (23): Voltage synthesis vector angle processing, specifically including:

Step (231): the ω _e obtained in step (1) and the output electrical angular velocity Δω _e of the speed stabilization loop are passed through a subtractor to output the electrical angular velocity value ω _e ^* of the voltage vector;

Step (232): the electric angular velocity ω _e ^* that step (231) obtains is integrated through the integration link, obtains voltage composite vector angle value θ _v ^* ;

Step (3): The voltage synthesis vector determined in step (2) is used for processing to drive the permanent magnet synchronous motor, which specifically includes the following processing:

Step (31): Convert the magnitude and angle of the voltage synthesis vector obtained in step (2) into the polar coordinate system and the Cartesian coordinate αβ axis system, and obtain the given voltage values of the α axis and β axis as u _α ^* , u _β ^* ;

Step (32): Carry out SVPWM modulation to the voltage given values u _α ^* and u _β ^* in step (31), to obtain the driving signals of six switching tubes in the three-phase full-bridge inverter bridge, and the above-mentioned inverter bridge is used for Drive permanent magnet synchronous motor;

Step (4): Measure the two-phase stator currents i _A and i _B of the permanent magnet synchronous motor, and perform speed stabilization loop and voltage amplitude correction loop control, specifically including the following processing:

Step (41): Measure the two-phase currents i _A and i _B of the stator of the permanent magnet synchronous motor, and transform the two-phase currents i _A and i _B through Clark transformation to obtain the currents i _α and i _β in the two-phase stationary rectangular α-β coordinate system ;

Step (42): Use the given voltage u _α ^* and u _β ^* obtained in step (31) and the current i _α and i _β obtained in step (41) to calculate the input power, and calculate the active power of the input motor respectively P and reactive power Q;

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}^{<span\; class="notranslate">\; *</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}^{<span\; class="notranslate">\; *</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}<span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}^{<span\; class="notranslate">\; *</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; u</span>}}_{\mathrm{<span\; class="notranslate">\; \&alpha;</span>}}^{<span\; class="notranslate">\; *</span>}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; \&beta;</span>}}<span\; class="notranslate">\; )</span>\end{array}\right.$

Step (43): Use the motor input active power P outputted in step (42) to perform speed stabilization loop control, specifically including the following processing:

Step (431): using the motor input active power P obtained in step (42), through a first-order high-pass filter (HPF), to obtain the disturbance active power Δp of the input motor;

Step (432): Use the disturbance active power Δp of the input motor obtained in step (431), and pass through an amplification link with a proportional coefficient k _p to output the output electrical angular velocity Δω _e of the speed stabilization loop. Among them, the value of k _p is obtained by solving and analyzing the characteristic root of the state transfer matrix of the mathematical model of the motor, that is, under certain working conditions, the value of k _p is selected by numerical analysis method to ensure that the characteristic roots of the state transfer matrix are all on the left half of the s plane area, so as to ensure the stable speed;

Step (44): Use the motor input active power P and reactive power Q obtained in step (42) and the voltage vector electrical angular velocity ω _e ^* obtained in step (231) to perform voltage amplitude correction loop control, specifically including the following deal with:

Step (441): Using the motor input active power P obtained in step (42) and the voltage vector electric angular velocity ω _e ^* obtained in step (231) output, through the Q _ref calculation link under a certain control strategy, calculate the output motor at The maximum torque-to-current ratio ( _MTPA ), the commanded reactive power Q _ref under the control strategy of id = 0, is specifically discussed in the following three cases:

①

in selection As the control strategy to be realized, it is required that the final reactive power input to the motor is zero, that is, Q _ref =0

②Maximum torque current ratio (MTPA)

When the motor is running stably, Its voltage equation is

v _d =R _s i _d -w _r L _q i _q (1)

v _q ＝R _s i _q +w _r (λ _m +L _d i _d ) (2)

The electromagnetic torque equation of the motor is

T _e ＝1.5pi _q [λ _m +(L _d -L _q )i _d ] (3)

Among them, (v _d , v _q ), (i _d , i _q ) are the stator voltage and current components, R _s is the resistance of each phase of the stator, L _d , L _q are the inductances of d and q axes respectively, ω _r is the inductance of the rotor electrical angular velocity. _ωm is the mechanical angular velocity of the rotor, _ωe ^* is the electrical angular velocity of the voltage synthesis vector, is the power factor angle. λ _m is the flux linkage of the permanent magnet, T _e is the electromagnetic torque, and p is the number of pole pairs of the motor.

Obtain the active power P and reactive power Q of the input motor, where

P＝1.5(v _d i _d +v _q i _q )＝1.5R _s i ² + (4)

1.5w _r i _q [λ _m +(L _d -L _q )i _d ]

$\begin{array}{c}\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1.5</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\\ \mathrm{<span\; class="notranslate">\; 1.5</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; \&lsqb;</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&rsqb;</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

According to formula (3) and formula (4), the electromagnetic torque calculated from the input active power is

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1.5</span>}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Combining equations (1)(2)(3), it can be obtained that the motor needs to satisfy the maximum torque-current ratio control

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

Substituting (7) into (5), the reactive power can be further expressed as

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1.5</span>}{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

Thus, when the maximum torque-to-current ratio is used as the control strategy, the commanded reactive power

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; P</span>}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; P</span>}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; P</span>}\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\\ \mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 9</span>}<span\; class="notranslate">\; )</span>$

After combing, the calculation process of the command reactive power under the control of the maximum transfer current ratio is obtained as follows:

③i _d =0

Under the premise of stable operation of the motor, When i _d = 0 control strategy is adopted, i _q = i, then the reactive power of the input motor is

$\mathrm{<span\; class="notranslate">\; Q</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1.5</span>}{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 10</span>}<span\; class="notranslate">\; )</span>$

At this time, the electromagnetic torque is

T _e =1.5pλ _m i _q (11)

From this, it can be obtained that when _id = 0 is used as the control strategy, the command reactive power

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; Q</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; q</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; d</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\\ \mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; ,</span>{\mathrm{<span\; class="notranslate">\; w</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}^{<span\; class="notranslate">\; *</span>}<span\; class="notranslate">\; )</span>\end{array}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 12</span>}<span\; class="notranslate">\; )</span>$

After combing, the calculation process of the command reactive power when i _d = 0 control is obtained is as follows:

Step (442): Utilize the command reactive power Q _ref obtained in step (441) output and the reactive power Q of the input motor obtained in step (42), through a subtractor, output to obtain the reactive power deviation value ΔQ;

Step (443): Use the reactive power deviation ΔQ obtained in step (442) to adjust and control through the PI regulator, and output the output voltage Δu of the voltage amplitude correction loop.

Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (4)

1. a permanent magnet synchronous motor position sensorless control method, is characterized in that, the method comprises the following concrete steps: Step (1): Give the electrical angular velocity command signal, input the target electrical angular velocity, and change from the original electrical angular velocity command signal to the new target electrical angular velocity with a certain rising or falling slope according to a linear function relationship, where ω _e0 ^* is defined as the target Electrical angular velocity, ω _e is defined as the electrical angular velocity command during the change process; Step (2): Determination of voltage synthesis vectors u _s ^* and θ _v ^* ; Step (3): Utilize the voltage synthesis vector determined in step (2) for processing to drive the permanent magnet synchronous motor; Step (4): Measure the two-phase stator currents i _A and i _B of the permanent magnet synchronous motor, perform speed stabilization loop and voltage amplitude correction loop control, and finally complete the sensorless control of the permanent magnet synchronous motor. 2. control method as claimed in claim 1, is characterized in that: described step (2) specifically comprises the following steps: Step (21): pass the electrical angular velocity command ω _e obtained in step (1) through a proportional link, the proportional coefficient is the permanent flux linkage λ _m , and output the rotor back EMF e _s ; Step (22): voltage synthesis vector magnitude processing, specifically including: Step (221): Add the e _s obtained in step (21), the initial start-up boost voltage u ₀ and the output voltage Δu of the voltage amplitude correction loop, and the output value is the voltage amplitude u _s ; Step (222): Limiting the voltage amplitude u _s obtained in step (221), the upper limit of the limiting link is Among them, the DC bus voltage input by the inverter bridge is defined as U _dc , the lower limit of the limiting link is 0, and the output value is the voltage synthesis vector amplitude u _s ^* ; Step (23): Voltage synthesis vector angle processing, specifically including: Step (231): the ω _e described in the step (1) and the output electrical angular velocity Δω _e of the speed stabilization loop are passed through a subtractor to output the electrical angular velocity value ω _e ^* of the voltage vector; Step (232): Integrate the electrical angular velocity ω _e ^* obtained in step (231) through an integral link to obtain the voltage synthesis vector angle value θ _v ^* . 3. control method as claimed in claim 1 is characterized in that: described step (3) specifically comprises the following steps: Step (31): Transform the voltage synthesis vector amplitude u _s ^* and angle value θ _v ^* obtained in step (2) into the rectangular coordinate αβ axis, and obtain the voltage values of the α axis and β axis Quantitatively recorded as u _α ^* and u _β ^* respectively; Step (32): Carry out SVPWM modulation to the voltage given values u _α ^* and u _β ^* in step (31), to obtain the driving signals of six switching tubes in the three-phase full-bridge inverter bridge, and the above-mentioned inverter bridge is used for Drive permanent magnet synchronous motor. 4. control method as claimed in claim 1 is characterized in that: described step (4) specifically comprises the following steps: Step (41): Measure the stator two-phase currents i _A and i _B of the permanent magnet synchronous motor, and convert the measured two-phase stator currents i _A and i _B through Clark transformation to obtain the current in the two-phase stationary rectangular α-β coordinate system i _α and i _β ; Step (42): Use the given voltage u _α ^* and u _β ^* obtained in step (31) and the current i _α and i _β obtained in step (41) to calculate the input power, and calculate the active power of the input motor respectively P and reactive power Q; Step (43): Use the motor input active power P outputted in step (42) to perform speed stabilization loop control, specifically including the following processing: Step (431): Input the active power P of the motor, and pass through a first-order high-pass filter to obtain the disturbance active power Δp of the input motor; Step (432): Utilize the disturbance active power Δp that step (431) obtains, through an amplification link whose proportional coefficient is _kp , the output obtains the output electrical angular velocity Δω _e of the speed stabilization loop; Step (44): Use the motor input active power P and reactive power Q obtained in step (42) and the voltage vector electrical angular velocity ω _e ^* obtained in step (231) to perform voltage amplitude correction loop control, specifically including the following deal with: Step (441): Using the motor input active power P obtained in step (42) and the voltage vector electric angular velocity ω _e ^* obtained in step (231) output, through the Q _ref calculation link, calculate the output motor at Command reactive power Q _ref under the maximum torque-to-current ratio, _id = 0 control strategy; Step (442): Utilize the command reactive power Q _ref obtained in step (441) output and the reactive power Q of the input motor obtained in step (42), through a subtractor, output to obtain the reactive power deviation value ΔQ; Step (443): Use the reactive power deviation ΔQ obtained in step (442) to adjust and control through the PI regulator, and output the output voltage Δu of the voltage amplitude correction loop.