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.

Validation of fast and selective protection scheme for an LVDC distribution network

Abstract: Low Voltage Direct Current (LVDC) distribution systems potentially enable more efficient power distribution and wider uptake of distributed renewables and energy storage. They do however present significant fault protection and safety challenges. To address these, the use of advanced protection techniques or significant system redesign is required. This paper reviews these protection key challenges, and presents experimental results of a prototype advanced protection scheme designed to help enable LVDC distribution networks for utility applications. The developed scheme is DC current direction-based and uses multiple intelligent electronic devices (IEDs) relays in combination with controllable solid-state circuit breakers to detect and locate DC faults. This scheme provides selective protection tripping within sub-millisecond timescales. A scaled laboratory demonstrator that emulates an LVDC distribution network is used as a test platform. It allows the characterisation of the transient behaviour for various fault conditions and locations. The developed protection algorithm is implemented in LabVIEW, and its performance against such fault conditions is tested within this environment.

Knowledge based alarm handling and fault location in distribution networks

Abstract: A knowledge-based system for fault analysis in the area of medium-voltage distribution networks is described. It is based on an expert system shell developed for applications in the field of power supply. Applications like contingency analysis or corrective switching have been realized. The solution for fault analysis attaches great importance to portability, simple integration in different telemetry and control systems, integration of different protection relay types, and capability of working with little information about the electrical network and the triggering of the protection devices. >

Performance of Third Harmonic Ground Fault Protection Schemes for Generator Stator Windings

Abstract: The paper shows how the normally generated third-harmonic voltage can be used to protect the lower ten to twenty percent of generator stator windings against ground faults. A method of determining the applicability of the scheme to a given machine is described which takes into account the design of the generator and its externally connected apparatus. The effects of finite resistence ground faults are also investigated and other advantages of the scheme, such as protection of the neutral, are also highlighted.

System grounding and ground-fault protection in the petrochemical industry: a need for a better understanding

Abstract: This paper provides an in-depth discussion on system grounding and ground fault protection on systems from 480 volts and above. The paper also discusses modeling of ground faults, the proper design for ground fault protection and common problems associated with ground fault protection. The paper addresses many real life problems associated with system grounding and ground fault protection including safety issues and how to avoid those problems. The topics to be included in the paper include low voltage systems, under 600 volts, through high voltage transmission systems.

The influence of inverter-based DGs and their controllers on distribution network protection

Abstract: The ever growing penetration of distributed generation (DG) in a distribution network has a profound impact on the network protection and stability. Traditional protection schemes and algorithms need to be extensively investigated as more and more DGs get introduced into the network. The current version of IEEE Std 1547 does not present a comprehensive solution for fault current detection in the presence of various kinds of DGs. Power electronic inverter-based DGs are of special concern in distribution network protection as they are often incapable of providing sufficient fault current and their controllers play a principal role in the DG behavior. In this paper, the effects of voltage and current controllers for inverter-based DGs on industrial and commercial power system distribution network protection schemes are investigated. It is shown that the type of controller and its design parameters during the fault have a direct impact on fault current levels and duration. A simplified distribution network model with inverter-based DG operating under voltage and current control modes was tested to verify the effects of these controllers. This paper also proposes an adaptive relaying algorithm to detect the faults in the presence of inverter-based DGs with various types of controllers.