Digital power factor correction with nonsinewave current

Following the emergence of European and International standards concerning power factor and giving new limits to current harmonics content, electronic designers have to face the power factor correction (PFC) problem. The authors give an example of a pre-regulator on 230 V mains in which the harmonic correction function is made by software using a standard microcontroller. This application, well-suited in the power range below one thousand Watts, allows flexible adaptation to specific application features and avoids the use of PFC dedicated ICs. Showing that such an incomplete harmonic compensation is a realistic solution in this power range, the author describes the principle and method to generate the adequate current waveform to be drawn from the mains. The closed loop voltage regulation, made by software is also described. It can be easily adapted to different types of loads. Practical results are given