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 paper, a new approach for protection of transmission lines has been presented, which consists of preprocessing the fault current and voltage signal sample using hyperbolic S-transform (HS-transform) to yield the change in energy and standard deviation at the appropriate window variation.
103 citations
TL;DR: In this paper, a voltage stability constrained optimal power flow (VSC-OPF) approach based on static line voltage stability indices was proposed to simultaneously improve voltage stability and minimise power system losses under stressed and contingency conditions.
Abstract: Voltage stability improvement is a challenging issue in planning and security assessment of power systems. As modern systems are being operated under heavily stressed conditions with reduced stability margins, incorporation of voltage stability criteria in the operation of power systems began receiving great attention. This study presents a novel voltage stability constrained optimal power flow (VSC-OPF) approach based on static line voltage stability indices to simultaneously improve voltage stability and minimise power system losses under stressed and contingency conditions. The proposed methodology uses a voltage collapse proximity indicator (VCPI) to provide important information about the proximity of the system to voltage instability. The VCPI index is incorporated into the optimal power flow (OPF) formulation in two ways; first it can be added as a new voltage stability constraint in the OPF constraints, or used as a voltage stability objective function. The proposed approach has been evaluated on the standard IEEE 30-bus and 57-bus test systems under different cases and compared with two well proved VSC-OPF approaches based on the bus voltage indicator L - index and the minimum singular value. The simulation results are promising and demonstrate the effectiveness of the proposed VSC-OPF based on the line voltage stability index.
103 citations
TL;DR: In this article, a wide-area back-up protection and artificial intelligence techniques are employed to minimize the impact of a fault on a power network, which can prevent cascading outages in power systems.
Abstract: A strategy to prevent cascading outages in power systems is proposed in this paper. The strategy employs wide-area back-up protection and artificial intelligence techniques to minimize the impact of a fault on a network. There are two ways in which wide-area backup protection can prevent cascading trips leading to a wide spread blackout: 1) Precise location of a fault so that only the circuit breakers necessary to isolate the fault are tripped; and 2) Avoidance of unnecessary trips, due to hidden failure or overloading, by blocking the trip signals of conventional back-up protection relays. The limitations of conventional back-up protection are examined and methods of improvement are presented.
103 citations
TL;DR: In this article, a comprehensive review of the latest protection methods proposed for distribution systems embedding DGs is presented, and the differences between the protection algorithms employed in/proposed for AC and DC systems are also discussed.
Abstract: The integration of distributed generation (DG) units into distribution networks has challenged the operating principles of traditional AC distribution systems, and also motivated the development of emerging DC systems. Of particular concern are the challenges associated with the operation of conventional protection schemes and/or devices. This paper first analyses the fault current characteristics in AC and DC distribution systems; it then presents a comprehensive review of the latest protection methods proposed for distribution systems embedding DGs. In addition, the advantages and disadvantages of each method are outlined and compared. The differences between the protection algorithms employed in/proposed for AC and DC systems are also discussed. Finally, this study identifies the future trends and provides recommendation for researches in the field of protections of DC distribution networks.
103 citations
TL;DR: The expected load curtailment (ELC) index is used in this paper to quantify potential system losses due to cyber attacks and the Monte Carlo simulation is applied to calculate ELC for assessing attackers’ capabilities as bus arrangements are altered.
Abstract: This paper presents a risk assessment method for evaluating the cyber security of power systems considering the role of protection systems. This paper considers the impact of bus and transmission line protection systems located in substations on the cyber-physical performance of power systems. The proposed method simulates the physical response of power systems to malicious attacks on protection system settings and parameters. The relationship among settings of protection devices, protection logics, and circuit breaker logics is analyzed. The expected load curtailment (ELC) index is used in this paper to quantify potential system losses due to cyber attacks. The Monte Carlo simulation is applied to calculate ELC for assessing attackers’ capabilities as bus arrangements are altered. The effectiveness of the proposed risk assessment method is demonstrated using a 9-bus system and the IEEE 68-bus system.
103 citations