A novel SRF based cascaded multilevel active filter for power line conditioners

This paper presents a novel synchronous reference frame (SRF) controlled five-level cascaded multilevel inverter based shunt active filter for power line conditioners (PLCs) to improve the power quality in the distribution system. The SRF based compensation is developed by sensing load currents only, which require for harmonics and reactive power compensation due to non-linear loads. The attempt is to come up with a simple control strategy. Incidentally it is different from conventional methods and provides superior performance. The cascaded multilevel voltage source inverter switching signals are generated from proposed triangular-periodical current controller; that gives better dynamic performance under transient and steady state conditions. The proportional integral (PI) controller is used to maintain the capacitance voltage of the cascaded inverter almost constant. The extensive simulation results demonstrate that the cascaded multilevel inverter based active power filter using the synchronous reference frame controller effetely compensates the current harmonics and reactive volt amperes under both steady state and transient conditions.