APPLICATION AND FEASIBILITY ANALYSIS OF HYBRID TYPE HVDC CIRCUIT BREAKER IN VOLTAGE SOURCE CONVERTER BASED HVDC SYSTEM

Abstract

Advances in Voltage Source Converter based HVDC systems (VSC-HVDC) have shown it to be a better alternative than conventional thyristor based HVDC systems. VSC-HVDC offer numerous advantages including compact size, independent active and reactive power control, reactive power generation, and ability to integrate into Multi-terminal HVDC systems. Unfortunately, VSC-HVDC’s full potential cannot be adequately utilized up till now due to absence of suitable HVDC protection system. With the latest developments in high power and high voltage IGBT valves, hybrid type HVDC circuit breakers for VSC-HVDC have been developed and successfully lab tested. However, their application and feasibility in actual VSC-HVDC needs to be investigated. In this research paper we have modelled an existing hybrid type HVDC Circuit Breaker (HDCCB) and evaluated its impact on fault reduction and interruption in VSC-HVDC systems. The working principles of the HDCCB, it’s modelling, and the design of its controller module was explained. Furthermore, the modelled HDCCB was applied in Korean Jeju-Haenam VSC-HVDC power system model. HVDC cable line-to-ground and line-to-line faults along with three phase AC fault at Jeju-island microgrid were made. The impact of these faults on HVDC system and the source AC system was analysed in the absence and presence of HDCCB. HDCCB successfully interrupted the fault current and prevented the damages to converter station equipment including costly IGBTs and transformers.