Evaluation of cascade-multilevel converter based STATCOM for arc fumace flicker mitigation

As an industry customer of electric power, electrical arc furnace (EAF) is a major flicker source that causes major power quality problem. For a 40 MVA EAF at Tennessee, USA, a cascade-multilevel converter (CMC) based STATCOM with high bandwidth is proposed for EAF flicker mitigation. In this paper, flicker mitigation techniques by using a CMC-based STATCOM are presented and verified through a transient network analyzer (TNA) system. The required STATCOM capacity is first studied through a generalized steady-state analysis. Secondly, the STATCOM control strategy for flicker mitigation is introduced and simulation results are given. Finally, a TNA system of the STATCOM and EAF system are designed and implemented. Experimental results from the TNA test show that the proposed CMC-based STATCOM and its controller can efficiently and rapidly mitigate the EAF flicker.