Analysis and Real-Time Testing of a Controlled Single-Phase Wavelet-Modulated Inverter for Capacitor-Run Induction Motors

This paper presents the experimental performance of an inverter-fed single-phase ( 1Phi) capacitor-run induction motor (IM) drive. The new 1Phi voltage-source four-pulse H-bridge wavelet-modulated (WM) inverter is employed to implement the proposed 1Phi motor drive. The WM inverter is operated by switching pulses generated by a unique nondyadic wavelet basis-functions-based multiresolution analysis (MRA). The synthesis part of this MRA has a scale--time structure such that the scale increase/decrease patterns are related to the sign of the first derivative of the reference-modulating signal. Adjusting zero-crossing locations of the first derivative of the reference-modulating signal can change scales of successive dilated and shifted versions of the synthesis scaling function. This approach of changing inverter switching pulses is called the resolution-level control (RLC) strategy, and can be used to adjust the motor input voltage. The proposed 1Phi motor drive incorporating an RLC WM inverter is successfully implemented in real time using a digital signal processor board ds1102 for a 1/2 hp, 1750 r/min capacitor-run IM. The efficacy of the proposed WM-based 1Phi IM drive is verified by both simulation and experimental results at various operating conditions. A performance comparison with a conventional proportional-integral controller is also provided to show the superiority of the proposed technique. Simulation and experimental test results of the proposed WM-based drive demonstrate robust performance, simple implementation, significant dynamic response improvements, and an ability to maintain high-quality inverter outputs.