Mobile QR Code QR CODE : The Korean Institute of Power Electronics
Title Current Control in Cascaded H-bridge STATCOM for Electric Arc Furnaces
Authors Byung-Ki Kwon ; Seung-Ki Jung ; Tae-Hyeong Kim ; Yun-Hyun Kim
DOI 10.6113/TKPE/2015.20.1.19
Page pp.19-30
ISSN 1229-2214
Keywords STATCOM; Electric arc furnace; Unbalanced load; Voltage imbalance; Positive-sequence current control; Negative-sequence current control; Zero-sequence current control
Abstract A static synchronous compensator (STATCOM) applied to rapidly changing, highly unbalanced loads such as electric arc furnaces (EAFs), requires both positive-sequence and negative-sequence current control, which indicates fast response characteristics and can be controlled independently. Furthermore, a delta-connected STATCOM with cascaded H-bridge configuration accompanying multiple separate DC-sides, should have high performance zero-sequence current control to suppress a phase-to-phase imbalance in DC-side voltages when compensating for unbalanced load. In this paper, actual EAF data is analyzed to reflect on the design of current controllers and a pioneering zero-sequence current controller with a superb transient performance is devised, which generates an imaginary -axis component from the presumed response of forwarded reference. Via simulation and experiments, the performance of the positive, negative, and zero-sequence current control of a cascaded H-bridge STATCOM for EAF is verified.