An intelligent single-chip microcontroller-based power controller for real-time applications

During the last decade, microprocessor-based control systems have changed from being a technical novelty to a practical reality in industrial automation. Microprocessors and microcontrollers, because of their considerable processing and control power, small size and cost, are replacing the conventional analogue and discrete digital methods of controlling in the power control industry. However, in the area of AC drives, though there has been much academic work reported, there are very few microprocessor-based controllers available. This is because, despite a number of pulse-width-modulation (PWM) techniques existing for power converters, most microprocessor-based implementations suffer from an inflexibility that arises as a consequence of their approach of computing the switching angles in non-real time and using them as a mere look-up table facility, under-utilizing the microprocessor capabilities. It is also for this reason that the development of microprocessor-based inverters has not kept pace with the instrumentation and control technology in general. This paper describes an implementation that merges microcontroller and power electronics technologies using compatible PWM algorithms to build a versatile `smartpower´ controller system and opens the possibility for real-time expert monitoring and control