Study of various types of faults in HVDC transmission system

High Voltage Direct Current technology has certain characteristics which make it especially attractive for transmission system applications. HVDC transmission system is useful for long-distance transmission, bulk power delivery and long submarine cable crossings and asynchronous interconnections. The study of faults is essential for reasonable protection design because the faults will induce a significant influence on operation of HVDC transmission system. This paper provides the most dominant and frequent faults on the HVDC systems such as DC Line-to-Ground fault and Line-to-Line fault on DC link and some common types of AC faults occurs in overhead transmission system such as Line-to-Ground fault, Line-to-Line fault and L-L-L fault. In HVDC system, faults on rectifier side or inverter side have major affects on system stability. The various types of faults are considered in the HVDC system which causes due to malfunctions of valves and controllers, misfire and short circuit across the inverter station, flashover and three phase short circuit.