one of the major problems that may occur in the differential protection systems of power transformers is mal-operation of the protection relays in sake of internal fault detection, because of similarity between this current and inrush current. this paper presents a novel approach for discriminating inrush current from internal fault in power transformers based on improved gravitational search a...

This research presents a new voltage regulation philosophy that enhances the magnitude in power distribution network where distributed generation (DG) is prevalent. Voltage networks relies heavily on On-Load Tap-Changer (OLTC) installed transformers. Since it was designed for without DG, OLTC's current scheme uses fixed reference and hence cannot regulate network. Therefore, proposed novel syst...

This study addresses a shuffled frog leaping algorithm for solving the multi-objective reactive power dispatch problem in a power system. Optimal Reactive Power Dispatch (ORPD) is formulated as a nonlinear, multimodal and mixed-variable problem. The intended technique is based on the minimization of the real power loss, minimization of voltage deviation and maximization of the voltage stability...

Optimal Power Flow (OPF) problem in electrical power system is considered as a constrained nonlinear, single objective or multiobjective optimization problem with multiple variables and multiple constraints. As the Power Transmission companies have been moving into much more competitive markets , this necessitates the implementation of Optimal Power Flow Programs for both, the planning and oper...

One of the most crucial functions in the operation and control of power system is reactive power dispatch (RPD).A hybrid Big Bang–Big Crunch (HBB–BC) optimization algorithm which consists of A Big Bang– Big Crunch algorithm combined with particle swarm optimization (PSO) is proposed in this paper in order to solve optimal reactive power dispatch (ORPD) problem. The L-index of load buses is base...

This paper presents solution of optimal power flow (OPF) problem of electrical power system via a genetic algorithm of real type. The objective is to minimize the total fuel cost of generation and environmental pollution caused by fossil based thermal generating units and also maintain an acceptable system performance in terms of limits on generator real and reactive power outputs, bus voltages...

Abstract—Reducing the weight of transformers while providing good performance, cost reduction and increased efficiency is important. Weight is one of the most significant factors in all electrical machines, and as such, many transformer design parameters are related to weight calculations. This study presents a comparison of the weight of oil type transformers and dry type transformer weight. O...

Distribution companies are increasingly turning to active network management improve how networks perform with respect different metrics or objectives. This includes Conservation Voltage Reduction (CVR) that seeks minimize energy usage of consumers (mostly connected low voltage, LV, levels) by reducing their supply voltage. However, if medium voltage (MV) levels have be reduced achieve CVR, it ...