A controller design method for doubly-fed motor without speed sensor

Abstract

The invention discloses a design method for a controller of a double-fed motor speedless sensor. The design method comprises the following steps: for rotor position angle observation errors of a rotor current-based model-reference adaptive observer when excitation inductance Lm is saturated, calculating the maximum variation range of the rotor position angle observation errors in a whole operation range of a double-fed motor; designing main controller output voltages and auxiliary controller output voltages of a double-fed motor speedless sensor control algorithm; calculating the sum of the main controller output voltages and the auxiliary controller output voltages of the d axis and the q axis respectively so as to obtain rotor control voltages in a synchronous rotating reference frame; adopting a space vector PWM modulation to generate drive pulses used for controlling the rotor side converter of the double-fed motor. The controller of the double-fed motor speedless sensor has strong robustness for magnetic inductance saturation, enables a double-fed motor speedless sensor control method to be more reliable and has important significance on promotion of practical engineering application.

Description

technical field [0001] The invention belongs to the field of electric drive, relates to a speed sensorless control of a doubly-fed motor, in particular to a design method for a speed-sensorless controller of a doubly-fed motor. Background technique [0002] The electromagnetic torque and reactive power of the double-fed motor can be adjusted flexibly and independently, and the capacity of the converter used for excitation control is only about 30% of the rated capacity of the motor, and the cost is low. One of the mainstream models. The speed sensorless control of double-fed motor can reduce system cost, improve system reliability, reduce system installation and maintenance work, and make the system more adaptable to work in harsh environments, so it has always been a research hotspot in the field of electric drive. [0003] At present, the speed sensorless control of DFIG mainly uses the model reference adaptive observer to obtain the speed and rotor position angle informa...

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Problems solved by technology

[0004] The existing model refers to the adaptive observer, which cannot overcome the influence of the parameter error of the doubly-fed motor on the observation results of the rotor position angle

Taking the model reference adaptive observer based on the rotor current as an example, when the excitation inductance is saturated, there is a large error in the observed value of the rotor position angle, which will affect the performance of the speed sensorless control of the doubly-fed motor, and even under certain conditions lead to system instability

This problem seriously restricts the application of doubly-fed motor speed sensorless control method in practical engineering

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