HVDC over HVAC power transmission system: Fault current analysis and effect comparison

`Fault current´ is the flow of abnormal current through an improper path due to electric faults which causes enormous damages. In HVAC transmission system, Fault current due to electric faults is too large which affects the overall power system including-Receiving & Sending end bus, Transmission system, Load and even also the Power Generation Unit. HVDC transmission system dramatically reduces these effects, as the fault current due to electric faults is much lower, and only affects the individual faulty section of the overall transmission system. In favor of HVDC system, this paper presents a `fault current´ (due to asymmetric faults) analysis and comparisons between HVAC and HVDC transmission system. MATLAB (Simulink) simulation software is used to simulate both HVAC & HVDC power transmission system topologies. From the comparison of the simulation output-lower fault current, less fault effect, better performance & higher reliability is demonstrated for HVDC transmission system.