Deadbeat Control of Induction Motor Current using State Observer with Adaptive Poles Selection

Abstract

For a high power induction motor drive, the switching frequency of inverter can not become higher than several kHz, and such switching, frequency produces a large current ripple, which in turn, produces torque ripple. To minimize the current ripple, a new method based on deadbeat control theory for current regulation is proposed. The PWM pattern is determined at every sampling instant based on stator currents measurements, motor speed, current references and rotor flux vector, which is predicted by a full-order observer with adaptive poles selection, so that the stator currents are controlled to be exactly equal to the reference currents at every sampling instant.
The proposed method consists of two parts: (1) derivation of a deadbeat control; (2) construction of a full-order observer which predicts the rotor flux and the stator currents in the next sampling instant. This paper describes a theoretical analysis and computer simulations under various system conditions.