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.

Study on the dynamic performance characteristics of HVDC control and protections for the HVDC line fault

Abstract: The travelling wave protection and under voltage protection which are initiated by the rate of change of voltage can not detect the high impedance fault. The operation time of differential protection is so long that it can not play the role of back-up protection of the DC line fault. What's more, the HVDC control system has great influence on the performance characteristic of the DC line protection, especially in case of the low load level. The differential protection will miss tripping because of the current fluctuation caused by the control system. Based on the EMTDC simulation including the actual HVDC line parameters, control and protection models, the currently used DC line protection and the influence of the control system are evaluated in this paper, which is analyzed by combination of the fault records and the simulation results. The improvement scheme is also proposed for the actual system.

Impact of distributed generation on distribution protection and power quality

Abstract: The impact of distributed generation (DG) on voltage sags in a distribution network depends on the design of the protection system and the coordination between the different protective devices. DG changes the radial nature of distribution systems and affects the performance of the protection system. This paper summarizes the impact of conventional synchronous machine-based DG on the present protection practices for distribution systems, analyzes the effect of small generation units on voltage sags, and discusses the different alternatives for distribution and DG intertie protection design.

Ground Distance Relaying With Fault-Resistance Compensation for Unbalanced Systems

Abstract: Fault resistance is a critical variable in distance relaying If not considered due to underreaching phenomenon, it may cause the misoperation of ground distance relays for internal faults Still, as a consequence of the overreaching phenomenon, the unbalanced nature of loads and asymmetry of lines can affect the distance protection operation efficiency Mainly due to these aspects, there is low precision in protection zone limits of ground distance relays In this paper, a new algorithm is proposed to increase the precision of these limits, improving efficiency in the distance protection process The proposed method is based in phase coordinates and uses a fault resistance estimate to develop the trip decision procedure The results show that the algorithm is suitable for online applications, and that it has an independent performance from the fault resistance magnitude, the fault location, and the line asymmetry

Adaptive Agent-Based Wide-Area Current Differential Protection System

Abstract: This paper proposes a multiagent-based adaptive wide-area current differential protection system. A power grid is divided into primary and backup protection zones dynamically online with the help of a developed expert system, and the relay agents of these zones cooperate to perform a differential relaying function. Predictive self-healing strategies have been proposed to prevent misoperation of the relay agent, and the communication system has been simulated. The performance of the proposed adaptive wide-area current differential protection system based on computer simulation is presented in this paper.