Implementation of LC and LCL passive filters for harmonic reduction in PV based renewable energy systems

Standards applied to electrical energy systems require pure sinusoidal waveforms, with lesser harmonic contents. This work aims to design and perform a comparative analysis of LC and LCL type passive filters for harmonic reduction in standalone PV systems. The work provides procedural steps to choose the filter component values that include the reactive elements and damping resistance. The design steps for the filters consider harmonics emerging due to inverter switching. Frequency response characteristics are obtained to assess the filter performance. A 110V/250 W inverter is implemented to examine the designed filter performance on an experimental platform with the modulation algorithm implemented using a SPARTAN 3E-XCS250E FPGA processor. Simulation and experimental results are incorporated to assess the LC and LCL filter designs with regard to harmonic distortion reduction and output waveform quality.