Phasor measurement units (PMUs) are considered as a promising tool for future monitoring, protection and control of power systems. In this paper, a unified approach is proposed in order to determine the optimal number and locations of PMUs to make the system measurement model observable and thereby can be used for power system state estimation. The PMU placement problem is formulated as a binary integer linear programming (BILP), in which the binary decision variables (0, 1) determine whether to install a PMU at each bus, while preserving the system observability and lowest system metering economy. The proposed approach integrates the impacts of both existing conventional power injection/flow measurements (if any) and the possibility of single or multiple PMU loss into the decision strategy of the optimal PMU allocation. Unlike other available techniques, the network topology remains unaltered for the inclusion of conventional measurements, and therefore the network connectivity matrix is built only once based on the original network topology. The mathematical formulation of the problem maintains the original bus ordering of the system under study, and therefore the solution directly points at the optimal PMU locations. Simulations using Matlab are conducted on a simple testing seven-bus system, as well as on different IEEE systems (14-bus, 30-bus, 57-bus, and 118-bus) to prove the validity of the proposed method. The results obtained in this paper are compared with those published before in literature.
Summary
Egypt is a country with high solar energy potential and the exploitation of such promising energy resource is critical for national sustainable development through efficient energy planning with gradual independence from fossil fuels. Successive incentive polices had been introduced by the Egyptian electricity authority to encourage the deployment of small‐scale residential rooftop photovoltaic (PV) systems. This article studies the techno‐economic feasibility of grid‐connected rooftop PV system in Egypt under the currently applied retail electricity price and the net energy metering policy. The study investigates three types of residential households with different electricity demand levels; low, medium, and high consumptions. The economic evaluation of various sizes of the PV system is carried out based on different economic measures such as net present value, cost of energy, payback period, and electricity bill saving. Hybrid Optimization of Multiple Energy Resources software has been utilized to carry out such economic evaluation. The results identify that the viability of PV installation in residential applications is clearly affected by the energy consumption pattern, the parameters of the incentive policy applied, and the economical indices of the system.
The concepts of microgrids (MGs) and smart grid represent the recent targeted revolution towards fully smart electrical network integrated with high penetration of renewable energy sources (RESs). The protection system of MGs becomes a challenge due to variable characteristics of its currents, bidirectional power flow and output power fluctuations of RES, causing selectivity and sensitivity issues for conventional protective devices (PDs) with fixed setting. In this paper, a smart protection scheme (SPS) is proposed using micro-phasor measurement units (µPMUs) to obtain the continuous rapid synchronized phasor measurement data. And it is communicated with a microgrid central controller (MGCC) through highly reliable communication architecture to carry out online smart adaptive protection scheme. Fault index coefficients and abnormality coefficients are calculated for each feeder to detect the fault location and the abnormality case. Detailed modeling of an MG including 10-bus connected distribution system with integrated distributed generation (DG) is simulated using ETAP software. The proposed protection algorithm is modeled and evaluated using MATLAB software. The proposed fault detector and abnormality detector can enable quick and accurate fault identification and isolation.
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