Power Quality Improvement of Pv Power Generation Systems Using Hybrid Filter

A hybrid filter constructed of a shunt active filter and distributed passive filters used for power quality improvement in PV power generating systems is presented. The distribution system consists of a photovoltaic power generation system and several dynamic nonlinear loads. The power quality problems of dispersed generation low voltage systems are introduced and the necessity of using hybrid filters instead of active or passive filters alone for power quality improvement are discussed. The simulation is done with PSCAD/EMTDC software for a distribution system with four dynamic nonlinear loads and a PV system that the DC output voltage of the PV is inverted to AC through an inverter which is hysterisis band controlled, making the system to behave as an active filter. The distribution system is simulated without any filters, with usage of just passive filters or the PV connected active filter and the hybrid filter structure, introduced in the paper. Studying and comparing the waveforms, frequency spectrums, harmonic contents and THD of system current with different filter structures mentioned, proves the effectiveness of power quality improvement by the applied hybrid filter.