Improvement of Power System Stability by Using New Switching Technique in Bridge-type Fault Current Limiter

Abstract

The bridge-type fault current limiter has the capability of controlling the fault current by controlling the DC reactor current. This fault current limiter is mainly composed of a diode bridge rectifier and a DC reactor. To achieve this capability, a resistor parallel with a semiconductor switch has been used in series with a DC reactor. For this fault current limiter, a control scheme is proposed that uses the DC reactor current as a control variable to improve transient stability of the model power system without measuring any parameters of system. In this article, an analytical and simulation study was conducted on a one-machine infinite-bus system including a bridge-type fault current limiter and the proposed control scheme. Simulation results show that by controlling the turn-on and turn-off times of the switch, i.e., the switching technique, the proposed fault current limiter can not only limit the fault current but also absorb the accelerating energy of the generator, thereby improving power system transient stability. The rotor velocity, maximum output power of the generator, and critical fault clearing time are studied in this article to evaluate the effects of the proposed fault current limiter on power system transient stability.

Keywords:

• bridge-type fault current limiter
• power system stability
• critical clearing time
• switching technique

Additional information

Notes on contributors

Mehdi Firouzi

Mehdi Firouzi received his B.S in electrical engineering from Islamic Azad University, Abhar, Iran, in 2005, and his M.S. in electrical engineering from Tafresh University, Tafresh, Iran, in 2008. He is currently working toward his Ph.D. in electrical engineering at Islamic Azad University, Research and Science Branch, Tehran. His current research interests include fault current limiters, wind turbines, power electronics, and power quality.

Gevork Babamalek Gharehpetian

Gevork Babamalek Gharehpetian received his Ph.D. in electrical engineering in 1996 from Tehran University, Tehran, Iran, graduating with first class honors. As a Ph.D. student, he received scholarship from German Academic Exchange Service from 1993 to 1996 and was with the High Voltage Institute of RWTH Aachen, Aachen, Germany. He was an assistant professor position at Amirkabir University of Technology from 1997 to 2003, an associate professor from 2004 to 2007, and a professor since 2007. He was selected by the Ministry of Higher Education as Distinguished Professor of Iran, selected by IAEEE as Distinguished Researcher of Iran, and was awarded the National Prize in 2008 and 2010, respectively. He is the author of more than 600 journal and conference papers. His teaching and research interests include power system and transformers transients and power electronics applications in power systems.

Babak Mozafari

Babak Mozafari received his B.S., M.S., and Ph.D. in electrical engineering in 1998, 2001, and 2007, respectively, from Sharif University of Technology, Tehran, Iran. Currently, he is an Associate Professor at the Department of Power Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran. His research interests include power system protection, and power system dynamics.