Electrical appliance equipment, motor control system and control method and device of induction motor

Abstract

The invention discloses electrical appliance equipment, a motor control system and a control method and device of an induction motor. The control method comprises the following steps of acquiring a frequency instruction value of the motor; acquiring a synchronous frequency instruction value of the motor according to the frequency instruction value of the motor, and performing current calculation by a motor mathematical model to obtain a d-axis current instruction value and a q-axis current instruction value; performing voltage calculation by the motor mathematical model to obtain a d-axis voltage instruction value and a q-axis voltage instruction value according to the synchronous frequency instruction value of the motor, the d-axis current instruction value and the q-axis current instruction value; performing angle calculation to obtain a synchronous rotation angle of the motor according to the synchronous frequency instruction value of the motor; performing coordinate conversion on the d-axis voltage instruction value and the q-axis voltage instruction value to obtain an Alpha-axis voltage instruction value and a Beta-axis voltage instruction value according to the synchronous rotation angle of the motor, and generating a control signal according to the Alpha-axis voltage instruction value and the Beta-axis voltage instruction value so as to control the motor by an inverter.The cost of the control method is superior to that of vector control, and the performance is superior to that of V / F control.

Description

technical field [0001] The invention relates to the technical field of electrical appliances, in particular to a control method for an induction motor, a control device for an induction motor, a motor control system and an electrical device. Background technique [0002] Induction motors are widely used in industry and home appliances because they have no brush commutation problems like brushed motors and no risk of demagnetization like permanent magnet synchronous motors, and have the advantages of simple structure, low cost, and high reliability. [0003] At present, the frequency conversion control methods of three-phase induction motors are roughly divided into two categories: [0004] One is V / F control (constant voltage frequency ratio control). Such as figure 1 as shown, are the first frequency command value and the second frequency command value of the motor respectively, is the voltage vector magnitude, θ * is the voltage vector angle. After the first freque...

AI Technical Summary

Problems solved by technology

[0007] However, because vector control is a closed-loop current, it is necessary to accurately sample the phase current of the motor, or estimate the phase current by accurately sampling the DC bus current, which not only increases the hardware cost of the controller, but also increases the requirements for circuit board wiring

In addition, in order to remove the motor speed sensor to reduce the cost of the entire system, the rotor flux position is generally obtained through the observer software of the controller, but the algorithm of the observer software is complex and highly dependent on the motor parameters. When it changes, the estimated flux angle will deviate from the actual flux angle, which will reduce the control performance of the motor, and even cause the problem that it cannot run

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