Power-system protection

About: Power-system protection is a research topic. Over the lifetime, 6353 publications have been published within this topic receiving 117961 citations.

An Adaptive Reclosure Scheme for Parallel Transmission Lines With Shunt Reactors

Abstract: A new reclosure scheme applied to parallel transmission lines with shunt reactors is proposed to improve the adaptability of the autoreclosure. Detailed analysis of the fault phase voltage is performed to derive the criteria to distinguish the temporary fault from the permanent fault. For different types of ground faults, the integral of the fault phase's recovery voltage is used to identify the permanent grounded faults. For different types of cross-line ungrounded faults, the integral of the $\beta $ modulus of the fault phase's recovery voltage is used to identify the permanent cross-line ungrounded faults. Besides, the phase reclosure sequence principle is used for all fault types. The performance of the proposed scheme is verified by the digital and analog simulation test for a 500-kV parallel transmission line with shunt reactors for several cases on different fault types and fault conditions. The Electromagnetic Transients Program-based and physical analog simulation results show that the proposed scheme is effective.

Computationally Efficient Methodology for Analysis of Faulted Power Systems With Series-Compensated Transmission Lines: A Phase Coordinate Approach

Abstract: A capacitor in series with a transmission line is protected from overvoltage due to a large fault current by a nonlinear metal-oxide varistor (MOV) connected in parallel. Fault analysis, as well as the evaluation of performance of the transmission protection system, in the presence of MOV action becomes complex because (1) v-i characteristics of the MOV are nonlinear; (2) un- symmetrical MOV action for unsymmetrical faults will introduce coupling in sequence networks; and (3) MOV action will influence voltage or current inversion phenomenon. This paper presents a computationally efficient and simple methodology for fault analysis wherein the linear part of the network is modeled by an equivalent multiport Thevenin network. The proposed approach handles nonlinearity in fault analysis efficiently. It also provides an elegant approach to model unbalance in a network due to MOV action. The proposed approach can be used to determine relays prone to voltage or current inversion. Results on a real-life 716-bus Indian system illustrate the efficiency of the proposed approach.

Comparing Network-Centric and Power Flow Models for the Optimal Allocation of Link Capacities in a Cascade-Resilient Power Transmission Network

Abstract: In this paper, we tackle the problem of searching for the most favorable pattern of link capacity allocation that makes a power transmission network resilient to cascading failures with limited investment costs. This problem is formulated within a combinatorial multiobjective optimization framework and tackled by evolutionary algorithms. Two different models of increasing complexity are used to simulate cascading failures in a network and quantify its resilience: a complex network model [namely, the Motter–Lai (ML) model] and a more detailed and computationally demanding power flow model [namely, the ORNL–Pserc–Alaska (OPA) model]. Both models are tested and compared in a case study involving the 400-kV French power transmission network. The results show that cascade-resilient networks tend to have a nonlinear capacity–load relation: In particular, heavily loaded components have smaller unoccupied portions of capacity, whereas lightly loaded links present larger unoccupied portions of capacity (which is in contrast with the linear capacity–load relation hypothesized in previous works of literature). Most importantly, the optimal solutions obtained using the ML and OPA models exhibit consistent characteristics in terms of phrase transitions in the Pareto fronts and link capacity allocation patterns. These results provide incentive for the use of computationally cheap network-centric models for the optimization of cascade-resilient power network systems, given the advantages of their simplicity and scalability.

Modeling of Electromagnetic Interference and PLC Transmission for Loads Shedding in a Microgrid

Abstract: This paper presents an electric line study of microgrid. To optimize the management of electric sources, generally a proposed solution is the load shedding. To achieve it, the power line communication (PLC) is often used to communicate when it is not possible to add cables. Such technologies use the power line network as a propagation and communication medium. The network quality depends mainly on the power grid topology, but also on the connected household electrical appliances that have a large impact on the PLC systems due to their impedances and noise. In this paper, we propose a new simulation program with integrated circuit emphasis (SPICE) approach for modeling both the electromagnetic (EM) disturbances generated by a printer and the power network. First, the high-frequency power cable characteristics are extracted from S parameter measurements. Then, the model of EM noise generated by a printer is deduced from time-domain measurement and integrated to the SPICE simulator by means of its Laplace transform. Simulation and modeling results of a simple power grid are given in terms of insertion loss evaluation (S21 parameter). A validation of the EM noise model is performed by means of a comparison between simulation and measurement results in frequency domain at several points of a simple power network. The present approach allows the prediction of EM interference generated by all household devices at any access points of a power line network without carrying out a systematic measurement.

North east pacific time-integrated undersea networked experiments (NEPTUNE): cable switching and protection

Abstract: The objective of the North East Pacific Time-Integrated Undersea Networked Experiments (NEPTUNE) is to establish a permanent, subsea observatory surrounding the Juan de Fuca tectonic plate. To achieve this objective, a special power distribution system is designed to provide continuous power to science equipment, vehicles, and laboratories located as deep as 5 km below the water surface. The NEPTUNE power system is significantly different from terrestrial power systems in many aspects and it requires different switching, protection, and control strategies. In this paper, we address the design of system switching and fault isolation equipment.