Abstract:

Proposed in this paper is a new method to reduce the switching loss of active power filter （APF） through adjusting the hysteresis band width. In this method, the hysteresis band width of each phase of APF is adjusted according to the output reference current, and the switching number of the phase with high switching loss is reduced while that of the phase with low loss is increased. Thus, the total switching loss is decreased without reducing the overall control precision. Only an adjusting circuit may significantly decrease the switching loss. Computer simulation with the electromagnetic transient program shows that, by using the proposed method, the switching loss of APF decreases by more than 10%, the temperature rise of each phase switch becomes smoother, while the control precision and switching frequency are almost unchanged.

Key words: active power filter, hysteresis current control, switching loss, hysteresis band width