REACTIVE POWER AND AC VOLTAGE CONTROL OF LCC HVDC WITH SFCL SYSTEM WITH CONTROLLABLE CAPACITORS

This paper implements the AC voltage control of HVDC using superconducting fault current limiter (SFCL) in AC voltage control of LCC HVDC using controllable capacitors. Also to analyze the behavior of a Voltage Source Converter Based HVDC system under DC pole to ground fault & AC fault. HVDC (HVDC) systems involving overhead transmission lines are prone to severe over-currents and over-voltages during dc line faults. The development of VSC-based dc networks is constrained by the lack of operational experience, the immaturity of appropriate protective devices and the lack of appropriate fault analysis techniques. VSCs are vulnerable to dc cable short-circuits and ground faults due to the high discharge current from the dc link capacitance. The SFCL utilizes both superconducting coils (SCs) and resistance to limit the rapidly growing current. Firstly, the working principle and operating characteristics of the SFCL are studied. Secondly, the rules of parameters coordination are analyzed in order to obtain the best current limiting effect of the SFCL. Thirdly, the electromagnetic design of SCs is done to prove the feasibility of the scheme.