Implementation of a New Wavelet Controller for Interior Permanent Magnet Motor Drives

This paper presents real-time implementation of a novel wavelet based multiresolution proportional-integral-derivate (PID) controller for accurate speed control of an interior permanent magnet synchronous motor (IPMSM) drive under system uncertainties. The discrete wavelet transform is used to decompose the error signal into different frequency components at various scales. The wavelet transformed coefficients of different scales, which represent many underlying phenomena such as process dynamics, measurement noise, and effects of external disturbances, are scaled by its respective gain and then added together to generate the control signal. The performance of this newly devised wavelet controller is evaluated by simulation results as well as by experimental results. The complete vector control scheme incorporating the wavelet based PID controller is successfully implemented in real-time using the ds1102 digital signal processor board for the laboratory 1-hp IPM motor. In order to prove the superiority of the proposed controller over the conventional controllers a comparison between the proposed and the conventional proportional-integral (PI) controller based systems is made at different dynamic operating conditions.