An on-line PC-based converter PWM modulator

Developments in power control techniques for pulsewidth-modulated (PWM) inverters are often ignored because of lack of time for adequate testing and evaluation. The programmable PC-based PWM described is designed to alleviate this problem. The modulator is capable of generating, in ready-to-use form, gating signals for any type of PWM scheme and most types of converters. It can also generate and display associated converter-output voltage and current waveforms and their respective frequency spectra for further evaluation of selected PWM schemes. Therefore, tasks such as the selection of optimum PWM strategies, switching frequencies, and voltage/frequency curves (for variable-speed AC drives) are easier to perform. Moreover, the proposed research and development tool differs from similar devices in that it is user-friendly, multipurpose, and versatile. Selected performance features of the developed prototype are demonstrated by presenting the associated experimental waveforms.<>