Linearized model of electrical arc furnace suitable for analysis of flicker mitigation

摘要

Hitherto, the flicker has been compensated for mainly by using Static Var Compensators (SVC). Recently, some studies and tests have been done to prove advantages of active filters (AF) over SVC in this field. The Unified Power Quality Conditioner (UPFC) consists of the parallel and series AF, so it offers more possibilities to solve instantaneous active and reactive power fluctuation than either the parallel or series AF alone. For the analysis of the control systems of AFs and UPQCs, and synthesis of its parameters the frequency domain approach or transfer functions are usually used. For some simulation studies the Cassie-Mayr formula describing the function of EAF was successfully used. Unfortunately this representation is not linear. It was found that the simulation of the EAF is possible even in the frequency domain by using a linearized model based on this formula. Based on equations presented a linearized model of the power system with the EAF and UPQC has been developed and analysed in the frequency domain.