Microcomputer Control of PWM Inverters

A method is proposed for implementing on a microcomputer the control of inverters modulated with a digital technique. It consists of storing in the microcomputer memory the switching patterns relative to a limited number of levels of the first harmonics of the inverter output voltage and of computing on line the actual pattern by interpolating the stored values. This allows the inverter output voltage to take a continuous range of values, while the microcomputer operates in real time and needs reduced memory requirements. A mathematical analysis of the accuracy of the method is performed. A brief description of a single-chip microcomputer controller based on the proposed method and some experimental results are included.