Capacitor Coupled Multilevel Custom Power Topology for the Refinement of Polluted Power System
This paper proposes a novel control strategy for a unified power quality conditioner integrated with a 7- level flying capacitor multilevel inverter to compensate the power quality problems in distribution system. Power quality problems have been increasing due to the wide use of nonlinear loads,which cause harmonic currents in networks and consequently distort the voltage and current at the point of common coupling. This distorted voltage and current harmfully affects the other loads connected at the PCC. To avoid this problem and protect loads from distortions, the harmonic components of the voltage and current must be fully compensated. UPQC is an efficient custom power device for enhancing the electric power quality at distribution levels, which is a combination of series and shunt active power filters sharing a common dc-link capacitor. In this paper the realization of shunt active power filteris carried out using a three-phase seven level flying capacitor multilevel inverterand the series active power filter is realized using a three-phase voltage source inverter. The flying capacitor multilevel inverter offers several advantages like, good power factor control due to the effect of large amount of storage capacitors, reduced harmonic current and different voltage levels etc. The control of shunt connected FCMLI is achieved by a new control strategy known as IARC control. The performance of the proposed system is analyzed through simulations with MATLAB SIMULINK software.
Jibin Joseph, Ajan A