Harmonics mitigation in distribution system by SMES sourced multilevel D-STATCOM

This paper discusses the harmonics elimination in non-linear distribution system using a D-STATCOM, which is based on a Five level flying capacitor multilevel inverter with a superconducting magnetic energy storage (SMES) as its source. Power system currents are distorted due to the intensive use of power converters/switches and other non-linear loads. Harmonic distortions are the one of the main loss in the power lines, which results in greater heat losses in distribution, interference problems in communication systems etc. The D-STATCOM can provide a better protection against the harmonics problems and load balancing. The building block of a D-STATCOM is a voltage source converter (VSC) consisting of self-commutating valves and also there should be a DC bus/supply. In this proposed work the DC supply is SMES. A quite well-known topology of multilevel inverter is Flying Capacitor Multilevel Inverter, which is adopted in this system. Flying capacitor multilevel inverter (FCMLI) is a multiple voltage level inverter topology intended for high voltage and power operations with low distortion. It uses capacitors, called flying capacitors for clamping the voltage across the power semiconductor devices. A hysteresis current control technique for controlling the injected current by the FCMLI-based D-STATCOM is used in this particular work. This proposed system is analysed and simulated using MATLAB/Simulink.