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Position Error Elimination Method Based on High Frequency Square Wave Injection Position Sensorless Control

An error elimination, sensor technology, applied in the direction of controlling electromechanical transmission, control system, control generator, etc., can solve the problems of weakening motor control performance, increasing, estimated position error, etc., to facilitate engineering and practicality , dynamic and steady-state performance improvements, easy-to-achieve effects

Active Publication Date: 2021-06-22
SOUTHEAST UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At zero speed and low speed, the high-frequency square wave voltage injection method can effectively estimate the position and speed. It has the characteristics of strong signal-to-noise ratio and high bandwidth, and is widely used in positionless control. Stable and effective extraction of position information, but there is always a certain error in the estimated position, and the error will gradually increase with the increase of speed, which weakens the motor control performance to a certain extent

Method used

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  • Position Error Elimination Method Based on High Frequency Square Wave Injection Position Sensorless Control
  • Position Error Elimination Method Based on High Frequency Square Wave Injection Position Sensorless Control
  • Position Error Elimination Method Based on High Frequency Square Wave Injection Position Sensorless Control

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Embodiment 1

[0039] A position error elimination method based on high-frequency square wave injection without position sensor control, comprising the following steps:

[0040] S1, injecting a high-frequency square wave voltage on the direct axis to excite a high-frequency quadrature-axis current containing position information, the high-frequency square wave is:

[0041]

[0042] Among them, f c is the carrier frequency of space vector modulation; f s is the current sampling frequency; The positive and negative alternating high-frequency voltage command superimposed at the PI output of the d-axis current loop; f h its frequency; f b is the execution frequency of the current loop in vector control. ;

[0043] S2, obtain the five-phase motor current through the phase current sensor;

[0044] S3, separate the fundamental frequency and high-frequency current in the five-phase motor current obtained in step S2 through the fundamental frequency and high-frequency current extraction alg...

Embodiment 2

[0059] Based on the program of the digital controller, the Ewm1 and Epwm2 modules of the controller count synchronously, and an interruption occurs at the valley of Epwm1 and the peak of Epwm2. The specific steps of the valley interruption of Epwm1 are as follows:

[0060] Step1: Voltage and current sampling;

[0061] Step2: Use Carry out Park transformation on five-phase current, and use algebraic method to extract high-frequency current i qh ;

[0062] Step3: Use i qh Estimated by software phase-locked loop with

[0063] Step4: Use Carry out coordinate transformation on the five-phase current to obtain the fundamental frequency current i dqb Perform vector control to get

[0064] Step5: Negate the given value of high-frequency injection voltage,

[0065] Step6: Calculate the voltage used for space vector modulation then use Carry out space vector modulation and calculate the comparison value of each phase PWM;

[0066] Step7: save the given value of fun...

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Abstract

The patent of the present invention discloses a position error elimination method based on high-frequency square wave injection without position sensor control. The control object is a five-phase permanent magnet synchronous motor. High-frequency square wave voltage, including low-frequency and high-frequency five-phase current, extracts the fundamental frequency current and the quadrature-axis high-frequency current containing position information through the modified signal separation link, and the fundamental frequency current is used for the current in vector control Feedback, the extracted high-frequency signal gets the estimated angle and speed through the software phase-locked loop. This method can effectively eliminate the estimated position deviation and realize the advanced estimation of the position. The compensation is brought by the digital controller and the inverter. The phase delay of the output voltage is more accurate and reliable.

Description

[0001] Field [0002] The invention belongs to the field of motor control processing, and in particular relates to a position error elimination method based on high-frequency square wave injection without position sensor control. Background technique [0003] The permanent magnet synchronous motor has the advantages of high efficiency, high power density, easy maintenance and strong adaptability to the environment. It has been widely used in aerospace, numerical control, electric vehicles and other fields. However, the stable and efficient operation of the permanent magnet synchronous The information is very dependent. When assembling the motor, a sensor for detecting the position of the motor must be attached. The position detection devices for permanent magnet synchronous motors with sinusoidal magnetic fields are generally incremental encoders, absolute encoders, and resolvers. Among them, the absolute Incremental encoders and rotary transformers have the best stability, bu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H02P21/24
CPCH02P21/24
Inventor 樊英李令张秋实
Owner SOUTHEAST UNIV