Fault current limiting dynamic voltage restorer for power quality improvement in distribution system (case study: air force feeder)

Abstract

Abstract Air force distribution feeder, or R1-G4, in Bahir Dar substation is affected by total harmonic distortion from nonlinear loads, voltage sag from short-circuit faults that occurred on the system, and voltage swell. In this paper, dual-function fault current limiter dynamic voltage restorer (FCL-DVR) topology is proposed. The proposed structure can perform both compensate supply voltage fluctuations and limit fault current. The proposed device intended to deliver increased dynamic performance, a cost-effective, compact and a quick response time to network outages. The performance ability of the proposed device has been investigated by MATLAB Simulink. When the system is disturbed to a short-circuit fault which magnitude is 1500 A, the supply voltage and load voltage have been distorted in 0.55 pu; then, by using this device the fault current was limited to 481.5 A and the simulation has shown that the voltage is improved to 1.011 p.u. Different scenarios, such as single line to ground fault, double line to ground fault and three phases to ground fault, have been realized to verify the operation and performance of the designed system in the MATLAB/Simulink program. Voltage sag, voltage harmonics and voltage swell are mitigated by using this device. The voltage source with total harmonics distortion of 16.50% was reduced to 0.11% in single line to ground fault, 46.88% to 0.13% in double line to ground fault and 42.76% to 0.15% in three line to ground fault, and the voltage swell also compensated from 1.141 pu value to 0.987 pu value and its total harmonic distortion values also reduced from 48.73 to 0.20% after FCL-DVR compensation.