High-performance current regulation and efficient PWM implementation for low-inductance servo motors

This paper reports on a standard microcontroller implementation of a pulsew idth modulator and near-deadbeat current regulator for high switching frequ ency. The application is in high-performance positioning systems. The contr ol strategy relies on a simplified machine model without incurring performa nce degradations. Changes between different modulation strategies are progr amed depending on the modulation index. The values of switching time durati ons are obtained exclusively by decision making, thus minimizing computatio nal load. Features like over-modulation (OVM), dynamic OVM, anti-windup, an d reduction of switching frequency at thermal overload are included.