Speed sensorless vector control method for induction motor

Abstract

The invention discloses a speed sensorless vector control method for an induction motor, which comprises the followings steps: performing flux linkage control: setting an instruction value of field current and performing closed-loop control of the field current; performing coordinate transformation: transforming the detected stator current value of the induction motor into a field current component and a torque current component of the motor; performing speed control to obtain synchronous angular frequency; performing flux linkage evaluation to obtain the position of a rotor flux linkage; performing torque voltage calculation to obtain the instruction value of the torque voltage; and performing coordinate transformation: transforming the instruction value of exciting voltage and the instruction value of the torque voltage into a three-phase static coordinate, performing corresponding pulse-width modulation, and driving a power inverter unit to generate three-phase alternating voltage to drive the induction motor to operate. According to an experimental result, a speed sensorless induction motor control system has good dynamic performance, and is fast in current response under sudden load increase and decrease conditions, strong in loading capacity in the whole speed regulation range, small in parameter dependence, stable, reliable, and strong in robustness.

Description

technical field [0001] The invention relates to a vector control method, in particular to a speed sensorless vector control method of an induction motor, and belongs to the technical field of motor control. Background technique [0002] The current variable frequency speed control methods of induction motors mainly include constant voltage frequency ratio control (V / F), vector control (VC) and direct torque control (DTC). The V / F method is widely used in fans, pumps and other occasions that do not require high speed and dynamic response. However, this method is a voltage source open-loop control strategy based on the steady-state model of the motor, and has no current control loop, so it cannot achieve high dynamic response of electromagnetic torque and high steady-state accuracy of rotational speed. The VC method is derived from the control principle of the DC motor. Based on the orientation of the rotor flux linkage, the decoupling control of the electromagnetic torque an...

AI Technical Summary

Problems solved by technology

However, the common problems of these methods are that the motor model used in the control algorithm is complex, the required motor parameters are too many and highly dependent, there are too many PI regulators, and the debugging in actual application is extremely complicated

For fan and pump load speed regulation systems, the cost performance is not high

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