Shunt active power filter for harmonic and reactive current compensation in wind conversion systems

This paper presents an analysis of a shunt active power filter (SAPF) for harmonic and reactive current compensation. This filter is used in wind energy systems that uses a permanent magnet synchronous generator (PMSG). The system uses supply current measurements instead of load current measurements, therefore, harmonic and reactive current measurements are not required. This simplifies the control system. To keep the PMSG voltage constant, the system uses PMSG terminal voltage control, which regulates the PMSG magnetization.To synchronize the d-q current, the control system uses a new decoupled double synchronous reference frame phase-locked loop (DDSRF-PLL) that can operate under varying rotor frequencies. The DDSRF-PLL provides fast, precise, robust current detection, even under unbalanced and distorted voltages. Experimental results show the accuracy and validity of the proposed control scheme for the PMSG-SAPF system.