Four leg VSI based active filter in distribution system

A four leg voltage source inverter (VSI) based active filter is implemented for elimination of neutral current, harmonics compensation with load balancing. It is controlled through an algorithm based on learning vector quantization (LVQ) under current fed type nonlinear load. This double stage supervisory control algorithm is used for extraction of reference supply currents. A small rating VSI based active filter is developed using DSP-dSPACE1103 processor to analyze its performance under different loads. Satisfactory performance of the active filter is observed with regulated constant dc link voltage.