Applying Hybrid Interval Linear Programming and Genetic Algorithm to Coordinate Distance and Directional Over-current Relays

Abstract

Interval linear programming (ILP) is a powerful tool for modeling problems with uncertain and bounded parameters. In real power systems, planned/unplanned events lead to changes in network topology. The changes cause altered distribution and magnitude of fault currents. Since protective relays are usually coordinated based on the fault currents of the main topology, mal-operation of the relays in such situations is likely. By covering the uncertainties, this paper aims to achieve the robust coordination of distance and directional overcurrent relays (D&DOCRs), as the main protections of transmission/subtransmission systems. Generally, relay coordination is a complicated nonlinear optimization problem. The complexity increases drastically by increasing coordination constraints, due to considering uncertainties. In this study, the problem is modeled as an ILP problem. The salient advantage of using ILP is that the number of constraints remains the same as in the main network topology, which greatly improves solving performance. Finally, to overcome the nonlinearity of the problem, a hybrid genetic algorithm and ILP (HGA/ILP), as a new optimization algorithm, is proposed. The proposed approach is applied to the IEEE 14-bus test system, and the results show that ILP is a useful tool to obtain robust settings of D&DOCRs in a power system.

Keywords:

• interval linear programming
• uncertainty
• relay coordination
• change in network topology
• directional over-current relay
• distance relay
• genetic algorithm

Additional information

Notes on contributors

Yaser Damchi

Yaser Damchi was born in Babol, Iran, in 1983. He received his B.Sc. in electrical power engineering from Zanjan University, Zanjan, Iran, in 2006 and his M.Sc. and Ph.D. in electrical power engineering from Ferdowsi University of Mashhad, Mashhad, Iran, in 2010 and 2015, respectively. Currently, he is an assistant professor at Shahrood University of Technology, Shahrood, Iran. His research interests are power system protection and reliability.

Javad Sadeh

Javad Sadeh was born in Mashhad, Iran, in 1968. He received his B.Sc. and M.Sc. with honors both in electrical engineering from Ferdowsi University of Mashhad, Mashhad, Iran, in 1990 and 1994, respectively, and his Ph.D. in electrical engineering from Sharif University of Technology, Tehran, Iran, with the collaboration of the Electrical Engineering Laboratory of the Institute National Polytechnique de Grenoble (INPG), France in 2001. Currently, he is a professor at Ferdowsi University of Mashhad, Mashhad, Iran. His research interests are power system protection, dynamics, and operation.

Habib Rajabi Mashhadi

Habib Rajabi Mashhadi was born in Mashhad, Iran, in 1967. He received his B.Sc. and M.Sc. with honors from Ferdowsi University of Mashhad, Mashhad, Iran, both in electrical engineering, and his Ph.D. from the Department of Electrical and Computer Engineering of Tehran University, Tehran, Iran, under joint cooperation of Aachen University of Technology, Germany, in 2002. He is a professor of electrical engineering at Ferdowsi University of Mashhad and is with the Center of Excellence on Soft Computing and Intelligent Information Processing, Ferdowsi University of Mashhad. His research interests are power system operation and planning, power system economics, and biological computation.