Topic
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.
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TL;DR: In this article, the authors describe techniques for keeping the solution time in networks with such elements as low as possible, by using the compensation method or network equivalents, and they describe how to simulate the effects of lightning arresters, transformer saturation, circuit breakers and other nonlinear and time-varying effects.
Abstract: Simulation programs for electromagnetic transients must provide models for lightning arresters, transformer saturation, circuit breakers and other nonlinear and time-varying effects. This paper describes techniques for keeping the solution time in networks with such elements as low as possible, by using the compensation method or network equivalents.
144 citations
TL;DR: In this article, a composite correlation output is used to recognize the reflection from the fault and distinguish it from other reflections from points behind the fault, and the correlation output magnitude is also used to achieve UHS (ultra high speed) fault detection for close-up faults.
Abstract: The authors examine some problem areas and suggest techniques to improve the proposed distance protection based on travelling waves outlined by P.A. Crossley and P.G. McLaren (1983). A composite correlation output is used to recognize the reflection from the fault and distinguish it from other reflections from points behind the fault. The correlator output magnitude is also used to achieve UHS (ultra high speed) fault detection for close-up faults. Effects of fault inception angle are compensated. Fault-resistance effects and external faults are also examined. >
144 citations
TL;DR: In this article, the authors developed a CIREPP model suitable for relaying studies, and highlighted the CIREP properties by which the protection system is endangered the most, including in-zone short circuits missed by the relay and incorrect tripping for out-of-zone faults.
Abstract: The fault ride-through (FRT) requirement of modern grid codes results in interactions between full-scale converter-interfaced renewable energy power plants (CIREPPs) and the protection systems of high-voltage transmission grids, which normally involve distance elements either as the primary or the backup relay. Such interactions are influenced by the CIREPPs' exclusive fault behavior, and have been left largely unnoticed in relaying literature. Part I of this paper develops a CIREPP model suitable for relaying studies, and highlights the CIREPP properties by which the protection system is endangered the most. Then, the operating scenarios leading to the malfunction of a distance relay that is located at a CIREPP substation and protects the adjacent line are unveiled. These scenarios include in-zone short circuits missed by the relay and incorrect tripping for out-of-zone faults, which would, in turn, neutralize FRT schemes implemented inside CIREPPs. The findings of this study also hold true for the ac lines emanating from voltage-sourced converter-based HVDC connections.
144 citations
TL;DR: An advanced protection scheme is presented that addresses the outstanding challenges for protecting an LVDC last mile distribution network and provides fast dc fault detection and interruption during dc transient periods, in addition to achieving fault limitation and fast reliable restoration.
Abstract: Low voltage direct current (LVDC) distribution systems have the potential to support future realisation of smart grids and enabling of increased penetration of distributed renewables, electric vehicles, and heat pumps. They do however present significant protection challenges that existing schemes based on DC fuses and conventional electro-mechanical circuit breakers (EMCBs) cannot manage due to the nature of DC faults and slow device performance. Therefore, this paper presents an advanced protection scheme that addresses the outstanding challenges for protecting an LVDC last mile distribution network. The scheme takes advantage of advanced local measurements and communications that will be naturally integrated in smart grids, and the excellent level of controllability of solid state circuit breakers. It thus provides fast DC fault detection and interruption during DC transient periods in addition to achieving fault limitation and fast reliable restoration. The introductory part of the paper quantifies the potential benefits of LVDC last mile distribution networks, and discusses the potential LVDC architectures that best utilise the existing plant. Based on the new LVDC architectures, a typical UK LV network is energised using DC and modelled, and used as a case study for investigating the protection issues and evaluating the new protection scheme performance through simulation.
144 citations
03 Oct 1999
TL;DR: In this paper, a new concept of protection coordination by time is introduced to formulate all the system relays and system equipment operation into a set of optimization equations and constraints, and an evolutionary algorithm is applied as a constraint satisfaction optimization tool to search for the optimal relay setting.
Abstract: A typical industrial power network may consist of hundreds of pieces of equipment and even more protection relays to protect the system are required. Each protection relay in the power network needs to be coordinated with the relays protecting the adjacent equipment. The overall protection coordination is, thus, very complicated. A new concept of protection coordination by time is introduced in this paper to formulate all the system relays and system equipment operation into a set of optimization equations and constraints. Its purpose is to search for an optimal protection setting to minimize the system disturbance time as well as the time of interruption of the power supply. An evolutionary algorithm is applied as a constraint satisfaction optimization tool to search for the optimal relay setting. This method can find the best protection relay coordination, which cannot be achieved by traditional methods. This is the most significant achievement of the paper.
143 citations