Superconducting Fault Current Limiter (SFCL) can be regarded as a key component for future electric power systems which are capable of contemporarily eliminating the hazards during faults by increasing the short-circuit power of an electric network. That is attributed to the behaviour of resistive SFCL (R-SFCL) and inductive SFCL (I-SFCL) devices which show negligible resistance and reactance, respectively, under normal operating conditions and reliably switch to a high impedance state in case of extra-current. This paper presents a comparative study for the use of R-SFCL and I-SFCL by investigating their impacts on the shortcircuit calculations of a high voltage line. The case study is for a 220 kV transmission line in the northern transmission network of Algeria which is subjected to a phase to ground fault in the presence of a fault resistance. The impact of the impedance of SFCL (ZSFCL), which varies between minimum and maximum values for these two SFCL devices, is studied to show its effect on the short-circuit parameters including symmetrical current components, transmission line currents, voltage symmetrical components, and transmission line voltages, without and with SFCL devices. Presented theoretical analysis is verified by simulation results.

The control of voltage and reactive power is a major issue in power systems control and operation. Because of the topological differences between distribution and transmission systems, different strategies have evolved. Flexible AC Transmission Systems (FACTS) controllers, such as the Thyristor Controlled Voltage Regulator (TCVR), employ the latest technology of power electronic switching devices in electric power transmission systems to control voltage and improve voltage regulation. This paper presents an impact study of using TCVR on the fault current calculations in case of a ground fault. The case study is a high voltage transmission line in the Algerian power network. The analysis is based on symmetrical components method which includes symmetrical components of current and voltage as well as the transmission line currents and line voltages, without and with TCVR in the presence of fault resistance. In this research work, the obtained simulation results match the presented theoretical analysis.

This paper presents the impact of three series Flexible AC Transmission System (FACTS) devices, namely the Thyristor Controlled Series Capacitor (TCSC), GTO Controlled Series Capacitor (GCSC) and Thyristor Controlled Series Reactor (TCSR), on the short circuit calculations of a 400 kV electrical transmission line in case of a phase to earth fault in the presence of a fault resistance (RF). The case study is a 400 kV single transmission line in the northern Algerian transmission network which is compensated by each of the three mentioned FACTS devices, consequently. Each compensator is connected at the midpoint of the line to control the reactive power and reactance of the line. The obtained simulations results investigate the impact of the fault resistance, which varies between 0 to 50 Ω, on the parameters of short circuit calculations, without compensation and with each FACTS device. The obtained simulation results match the presented theoretical analysis.

This paper presents the impact study of GTO Controlled Series Capacitor (GCSC) Parameters on MHO distance relays measured impedance for 220 kV protected electrical transmission line in the presence of phase to earth fault. The study deals with a 220 kV single electrical transmission line of Eastern Algerian transmission networks at Group Sonelgaz (Algerian Company of Electrical and Gas), compensated by series Flexible AC Transmission System (FACTS) i.e. GCSC connected at midpoint of the line. The transmitted active and reactive powers are controlled by three GCSC’s. The effects of maximum reactive power injected as well as injected maximum voltage by GCSC on distance relays measured impedance is treated. The simulations results investigate the effects of GCSC injected parameters on measured resistance and reactance in the presence of earth fault with resistance fault for three cases study.

This paper presents a study on the performances of distance relays setting in 400 kV in Eastern Algerian transmission networks at Sonelgaz Group (Algerian Company of Electricity) compensated by shunt Flexible AC Transmission System (FACTS). The facts are used for controlling transmission voltage, power flow, reactive power, and damping of power system oscillations in high power transfer levels. The direct impacts of SVC devices, i.e. Thyristor Controlled Reactor (TCR) and the Thyristor Switched Capacitors (TSC) insertion on the total impedance of a transmission line (ZAB) protected by MHO distance relay, are investigated. The modified setting zones protections (Z1, Z2 and Z3) have been calculated in order to improve the performances of distance relay protection and prevent circuit breaker nuisance tripping. The simulation results are performed in MATLAB software and show the direct impact of the thyristors firing angle (α) and substance on the total impedance of the protected line.