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.

The Real-Time Publisher/Subscriber Communication Model for Distributed Substation Systems

Abstract: In the past decade, new communication schemes have been designed and retrofitted into substations by utilities to integrate data from relays and intelligent electronic devices (IEDs) and capitalize on the protection, control, metering, fault recording and communication functions available in digital devices. The introduction of IEC 61850 has made it possible and justifiable to integrate station IEDs on a high-speed peer-to-peer communication network (Ethernet) through standardization. However, more advances are needed in order to establish an open and standard working environment allowing for more functions to be developed. In this paper, the authors propose a real-time publisher/subscriber communication model as a means of satisfying the unique behavior and communications needs of the IEC 61850 protocol. The authors provide a detailed design and implementation detail of this model along with interesting performance results. The target audience for this paper includes power system protection and automation engineers and technicians as well as research personnel who have at least a basic understanding of the IEC 61850 international standard and other technology mechanisms addressed in this paper.

Determination of the optimum routine test and self-checking intervals in protective relaying using a reliability model

Abstract: Relaying reliability is generally separated into the two different aspects of dependability and security. The reliability of a protection relay can be improved by carrying out routine maintenance or by including built-in monitoring and self-checking facilities during the design stages. A Markov model is described in this paper which can be used to examine these features. The model also recognizes common-cause failures, temporary and permanent faults and the associated clearing times, operation of back-up protection, and relay mal-trips. Studies have been conducted to illustrate the expected reliability benefits by inclusion of monitoring and self-checking facilities within the relay.

The Effects of Arcing Ground Faults on Low-Voltage System Design

Abstract: Recurring reports of arcing ground fault burndowns have generated a considerable amount of interest in the subject on the part of those individuals who are responsible for the design of power systems In fact the interest is so widespread that as one consequence, article 230-95 of the 1972 edition of the National Electrical Code requires that service entrance devices of specific types be equipped with additional ground fault protection

A survey of distributed power system — AC versus DC distributed power system

Abstract: The history of the centralized and distributed power system is introduced far away from the power system being first built by Edison, which started the first confrontation between ac and dc power system. Although ac power system has dominated for a long century because of easy transmission and some other benefits, dc power system has still gave some good performances and attracted more attention during the past three decades. This paper will discuss the current developing stage of dc distributed power system by the following contents: the basic structure and characteristics; the benefits of the dc distribution system; the development of current techniques adopted in DPS and its analysis of protection and system interaction. In additional, the comparisons between dc and ac distributed power system are presented in detail, and finally, the challenge in future is also summarized.

New protection method for HVDC lines including cables

Abstract: For the third project of the Hokkaido-Honshu HVDC Link in Japan, called the HVDC Link III project (rated at 250 kVDC-1200 A-300 MW), we developed an HVDC transmission line protection method based on a new working principle that allows high-speed and highly sensitive detection of faults, enhancing reliability in the supply of electric power. In general, increasing the sensitivity of relays will lead to an increased likelihood of undesired operation whereas lowering the sensitivity will impair the responsiveness of the relays. Our proposed method meets these apparently incompatible requirements very well. Basically classified as a differential scheme, the HVDC transmission line protection method compensates for a charging and discharging current that flows through the line-to-ground capacitance at times of voltage variations caused by a line fault or by the operation of DC power systems. The developed protection method is also characterized in that it uses current changes induced by voltage variations to restrain the operation of a relay. This configuration has made the proposed method far superior in responsiveness and sensitivity to the conventional protection method. A simulation using an EMTP (Electro-Magnetic Transients Program) was conducted on this method. Developed relay equipment embodying the new protection method was subjected to various verification tests, where this equipment was connected to a power system simulator, before being delivered to the HVDC Link III facility. >