Method for starting motor without position sensor

Abstract

The invention discloses a method for starting a motor without a position sensor, which includes: applying a fixed voltage vector to the motor and obtaining Is; subjecting the Is to Clark conversion and obtaining i <alpha> and i <beta>; presetting rotation speed omega r and torque T<e> as 0 by computing to obtain rotor flux-linkage vector angle theta r, subjecting omega r and omega r to PI operation to obtain Te, then subjecting Te and the T3 to PI operation to obtain delta, obtaining theta<s> according to the formula theta <s>=theta <r> +delta, giving Psi* <s> to obtain U<alpha> and U<beta>, subjecting the U<alpha> and the U<beta> to inverse Clark conversion and obtaining U, U and U<c>, acquiring I, I and I<c> through current, subjecting the I, the I and the I<c> to Clark conversion and obtaining I alpha and I beta, obtaining Psi <s> alpha and Psi<s> beta by stator flux linkage operation, obtaining Psi<s> and theta<s> by modular angle operation, obtaining the Te by torque estimate, discretizing the theta<s> to obtain omega<r>, and finishing motor starting process if the omega<r> is equal to the omega*<r>. The method for starting the motor without the position sensor has the following advantages that by combining initial position detection technology with DTC (direct torque control) strategy, loop-locked stable control of the integral control strategy is realized.

Description

technical field [0001] The invention belongs to the technical field of electronic engineering, in particular to an advanced motor starting method that does not require a position sensor by using an initial position detection method combined with a direct torque control strategy, that is, a position sensorless motor starting method. Background technique [0002] Space Vector Pulse Width Modulation Abbreviation: SVPWM [0003] Direct Torque Control Direct Torque Control Abbreviation: DTC [0004] Field Oriented Control Abbreviation: FOC [0005] Integral proportional operation Proportion Integral abbreviation: PI [0006] Although the existing motor field-oriented control FOC strategy does not require a position sensor, it is necessary to drag the motor to a certain speed when the motor starts, so that the motor speed can be continuously adjusted, that is to say, the speed open-loop control strategy is adopted during the motor startup process , when the motor accelerates to...

AI Technical Summary

Problems solved by technology

[0006] Although the existing motor field-oriented control FOC strategy does not require a position sensor, it is necessary to drag the motor to a certain speed when the motor starts, so that the motor speed can be continuously adjusted, that is to say, the speed open-loop control strategy is adopted during the motor startup process , when the motor accelerates to the set speed, it switches to the speed closed-loop control strategy, which prolongs the start-up time of the motor; in order to overcome the defect that the motor starts in the field-oriented control FOC strategy and needs open-loop dragging, the motor direct torque control appears The DTC strategy does not need to drive the motor to a certain speed when the motor is started, but it needs to be used in conjunction with a position sensor or a speed sensor, so the following problems will occur during use:

[0007] 1) In the design process, it is necessary to increase the hardware circuit supporting the sensor, resulting in an increase in the design cost;

[0008] 2) The supporting hardware circuit of the sensor is easily subject to electromagnetic interference, resulting in signal transmission errors, and thus invalidating the control strategy;

[0009] 3) Restricted by the service life of the sensor itself, the sensor needs to be replaced regularly. When replacing the sensor, the entire motor package needs to be disassembled, and the replacement work is cumbersome

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