Abstrakt

Analysis and Modelling of a Multilevel Inverter in Distribution System with FACTS Capability

K.Sonia, G.Seshadri

This paper presents the design of a multi-level inverter with Flexible AC transmission systems (FACTS) capability for small to medium size (10–20kW) permanent-magnet wind applications using modular multi-level converter (MMC) topology. The aim of the paper is to design a new type of inverter with Distribution static synchronous compensator (D-STATCOM) option to provide utilities with more control on active and reactive power transfer of distribution lines. The proposed inverter is placed between the renewable energy source, specifically a wind turbine, and the distribution grid in order to fix the power factor (PF) of the grid at a target value, regardless of wind speed, by regulating active and reactive power required by the grid. The D-STATCOM inverter is capable of controlling active and reactive power by controlling the phase angle (�?�) and modulation index (m), respectively. The unique contribution of the proposed work is to combine the two concepts of inverter and D-STATCOM using a voltage source converter (VSC) multi-level topology in a single unit without additional cost. Simulations of the proposed inverter, with 11 levels, have been conducted in MATLAB/Simulink. The main function of the proposed inverter is to transfer the active power to the grid as well as keeping the powerfactor (PF) of the local power lines constant at a target PF regardless of the incoming active power from the wind turbine.