Real-Time Testing of an Intelligent Controller for a WM Inverter-Fed 1ϕ Capacitor Induction Motor

This paper presents a novel speed control scheme using a resolution-level controller (RLC) for a single-phase (1phi) voltage-source (VS) four-pulse wavelet-modulated (WM) inverter-fed capacitor-run induction motor (IM). The wavelet modulation technique generates switching pulses using a non-dyadic type multiresolution analysis (MRA) that is constructed by scale-based linearly-combined scaling function. The change in the scale of the synthesis scaling function is based on the change of the sign of the first derivative of the reference-modulating signal. It proposes adjusting zero-crossing locations of the first derivative of the reference-modulating signal to change scales of successive dilated and shifted versions of phi(t). The proposed change in scales can be incorporated to adjust the speed of the motor to meet load changes. The complete drive incorporating the RLC is successfully implemented in real-time using a digital signal processor board DS 1102 for a 1/2 hp, 1750 RPM capacitor-run IM. The efficacy of the proposed RLC-based 1phi IM drive is verified by experimental results at various operating conditions. A performance comparison with a conventional proportional-integral (PI) controller is also provided to show the superiority of the proposed controller. Experimental test results of the proposed RLC demonstrate robust performance, simple implementation, significant dynamic responses improvements and an ability to maintain high quality outputs.