Optimized feed forward control of a STATCOM with limited energy storage capability for flicker compensation

Flicker is a totally stochastic variation in the mains voltage which affects lighting sources and is also a power quality problem for both power suppliers and industrial process manufacturers. Currently the main cause of customer complaints due to light flicker is the voltage fluctuation generated by arc furnaces, which often represent the largest single load of an electric power utility. Because of cost efficiency the energy storage capability of static synchronous compensators (STATCOM) for the mitigation of voltage flicker can still only be small compared to the energy taken by an arc furnace during one period of the line voltage. This leads to high demands on compensation strategies. In this paper different feed forward control structures of a STATCOM with limited energy storage capability for flicker compensation are discussed and assessed by simulations based on voltages and currents measured at an arc furnace.