Switching losses analysis of a DC link fuzzy logic controller scheme applied to a VSC

The main objective of a soft switching circuit is to reduce the switching losses in a static converter when is switched at high frequency. In this paper is presented a DC link fuzzy logic controller applied to a VSC (voltage source converter). First, is shown the reconstruction of the input membership functions according to current and voltage signals generated in open loop. A simple algorithm is used to generate the switching pulses from the output membership and defuzzification, the control surfaces are showed as well. The lossless switching is tested in a parallel VSC and is verified the effect of the soft switching circuit in simulation and hardware application with the controller.