Shunt Active Power Filter Using Three Level Inverter without PI Controller

Abstract

This paper presents simulation and analysis of shunt active power filter using three level inverter. Different types of filters can be used for elimination of harmonics in the power system with nonlinear load. Three level VSI (Voltage Source Inverter) can be used for high voltage application. Three level NPC (Neutral Point Clamped) VSI is used for active power filter. In this paper, FFT (Fast Fourier Transform) algorithm for reference current generation is discussed. Also space vector hysteresis current control method is implemented for simulation. DC link voltage control can be achieved through calculating the energy required to stabilize the DC bus. NPC topology has problem of capacitor voltage unbalancing.  In this work capacitors voltage are balanced by using redundant space vectors of three level inverter. Control algorithms are verified using Power Simulator Software (PSIM) simulation results with DLL block and C code. In this proposed work, PI controller has not been used for overall control of shunt active power filter.

Keywords: Shunt active power filter, NPC (Neutral Point Clamped) inverter, FFT (Fast Fourier Transform), space vector hysteresis current control, DC link voltage control