High performance of fuzzy direct power control for PWM converters

This paper presents a new approach of direct power control (FLC-DPC) strategy for to three phase PWM converters. In this novel strategy the fuzzy logic control (FLC) has been used. The converter lookup table is based on fuzzy logic rules, using the instantaneous active and reactive power errors and the position of grid voltage vector. The basic idea of fuzzy rules synthesis is based on the knowledge of the instantaneous variation of active and reactive power flows to the grid. The main advantages of the improved approach of DPC strategy are that it is not necessary to use hysteresis comparators, smooth control of active and reactive power flows and maintaining the dc-bus voltage of the converter close to the reference value. The robustness of the FLC-DPC to sampling frequency variations, line inductance variations and tracking capability are also presented. Results have proven excellent performance, and verify the validity of the proposed DPC strategy which is much better than the classical direct power control strategies.