In a normal electrical network, it is crucial to design a system complete with protection to prevent any abnormalities or fault occurrence to disturb the whole source of electrical to be shut down. Only a portion of effected area should be closed and fault duration at high current value should be closely monitored. Overcurrent protection device discrimination play vital roles to ensure protecti...

This paper presents a practical and effective novel approach to curve fit electromechanical EM overcurrent OC relay characteristics. Based on singular value decomposition SVD , the curves are fitted with equation in state space under modal coordinates. The relationships between transfer function and Markov parameters are adopted in this research to represent the characteristic curves of EM OC r...

In this paper the effect of presence of wind farms on relay coordination at fault condition and transient response at reclosing condition is studied. Wind farms as one of the important distribution generations (DGs) are so effective on overcurrent relay coordination in power systems. As well as Wind farms cause to severe oscillations on voltage, power and frequency in power system after reclosi...

Most studies in relay coordination have focused solely on coordination of overcurrent relays while distance relays are used as the main protection of transmission lines. Since, simultaneous coordination of these two types of relays can provide a better protection, in this paper, a new approach is proposed for simultaneous coordination of distance and directional overcurrent relays (D&DOCRs). Al...

The coordination of directional over current relays in interconnected power networks is formulated as an optimization problem. When two protective apparatus installed in series have characteristics, which provide a specified operating sequence, they are said to be coordinated or selective. The coordination of directional overcurrent relays pose serious problems in the modern complex power syste...

This paper presents a hybrid optimization approach for the optimal coordination of Inverse Definite Minimum Time (IDMT) directional overcurrent relays in meshed power systems, namely Immune Algorithm and Particle Swarm Optimization (IA-PSO) algorithm. The algorithm is employed by coupling the immune information processing mechanism with the particle swarm optimization algorithm in order to achi...