scholarly journals Power supply risk assessment method for relay protection system faults

2016 ◽  
Vol 65 (4) ◽  
pp. 803-814
Author(s):  
Si Tuyou ◽  
Wu Jiekang ◽  
Yuan Weideng ◽  
Du Anan
Keyword(s):  
Power Supply ◽  
Distribution Systems ◽  
Probability Model ◽  
Relay Protection ◽  
Assessment Method ◽  
Protection System ◽  
Supply Risk ◽  
Load Power ◽  
Risk Assessment Method ◽  
Protection Systems

Abstract The influence and the potential risk due to hidden faults of a relay protection system on power supply in distribution systems are paid more and more attention to. A probability analysis method is used to analyse fault characteristics and action mechanism of dominant faults, hidden misoperation and non-operation of the relay protection systems, and failure probability model of relay protection system is constructed and simplified. The effects of dominant faults, hidden misoperation and non-operation of the relay protection systems on the reduced power supply load power are analysed, and a probabilistic model for reduced power supply load power is constructed by three parts corresponding to dominant faults, hidden misoperation and non-operation. A probability calculation method of power supply risk occurrence due to hidden faults of relay protecttion system is proposed considering the fault probability of the relay protection systems, the frequency of the hidden faults occurring in operation period, the reduced power supply load power or load power outage, and the connection mode of the in-lines, out-lines and transformers in a substation. The feasibility and applicability of the proposed method for estimation of risk value probability of the relay protection systems is verified by two studied examples.

scholarly journals The Analysis of the Power Supply System Reliability with Relay Protection Fail-Safe Features

2020 ◽  
Vol 26 (4) ◽  
pp. 564-570
Author(s):  
V. I. Zatsepina ◽  
◽  
S. S. Astanin ◽  
Keyword(s):  
Power Supply ◽  
Power Supply System ◽  
Relay Protection ◽  
Supply System ◽  
Design Stage ◽  
Mathematical Expressions ◽  
Automation Systems ◽  
Protection Systems ◽  
Protection Devices ◽  
Fail Safe

The problem of reliability of relay protection systems and automation is considered. Based on the analysis results, for the construction of automation systems, a number of mathematical expressions have been proposed that allow at the design stage to assess the fault tolerance of the power supply system with the selected protection devices, thereby simplifying the process of choosing the most preferred system based on the obtained indicators.

Assessment of Power System Risk in Cyber-Attacks in View of the Role Protection Systems

2017 ◽  
Vol 8 (1) ◽  
pp. 184
Author(s):  
Hui Hwang Goh ◽  
Sy yi Sim ◽  
Omar Abdi Mohamed ◽  
Ahmed Farah Mohamed ◽  
Chin Wan Ling ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Power Systems ◽  
Cyber Security ◽  
Circuit Breaker ◽  
Assessment Method ◽  
Cyber Attacks ◽  
Risk Assessment Method ◽  
Protection Systems ◽  
System Risk ◽  
Bus System

<p>This paper presents a risk assessment method for assessing the cyber security of power systems in view of the role of protection systems. This paper examines the collision of transmission and bus line protection systems positioned in substations on the cyber-physical performance of the power systems. The projected method simulates the physical feedback of power systems to hateful attacks on protection system settings and parameters. The relationship between protection device settings, protection logic, and circuit breaker logic is analyzed. The expected load reduction (ELC) indicator is used in this paper to determine potential losses in the system due to cyber attacks. The Monte Carlo simulation is used to calculate ELC’s account to assess the capabilities of the attackers and bus arrangements are changed. The influence of the projected risk assessment method is illustrated by the use of the 9-bus system and the IEEE-68 bus system.</p>

scholarly journals Fault Protection Considerations for MVDC Shipboard Power Systems Operating with Pulsed-Power Loads

2021 ◽  
Vol 16 ◽  
pp. 139-148
Author(s):  
Marounfa ` Djibo ◽  
Paul Moses ◽  
Ike Flory
Keyword(s):  
Fault Detection ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Pulsed Power ◽  
Fault Detection And Isolation ◽  
Protection System ◽  
Shipboard Power ◽  
Power Load ◽  
Protection Systems

Medium Voltage Direct Current (MVDC) power distribution architectures are of immense interest for various shipboard power applications due to their advantages over classical MVAC distribution systems with respect to power quality, power density, and efficiency. However, MVDC are far away from maturity when compared to MVAC with respect to fault detection and isolation. Currently, there are no standards available for applying MVDC protection systems in shipboard applications. Furthermore, due to the absence of zero crossings in DC waveforms and unique transient fault signatures, it is challenging to design effective protection system schemes to isolate faults via conventional protection systems. This paper investigates and analyses various types of shipboard MVDC dynamic fault behaviours and signatures under different DC bus disturbances such as: bus to ground, bus to bus to ground, and impact of Pulsed-Power Load (PPL) with and without faults on a shipboard MVDC distribution system. Furthermore, a communication-based fault detection and isolation system controller that improves upon a directional ac overcurrent relay protection system is proposed offering additional protection discrimination between faults and PPLs in MVDC systems. To validate the effectiveness of the proposed protection controller, different bus current disturbances are simulated within a time-domain electromagnetic transient simulation of a shipboard power system including a PPL system operating with different ramp rate profiles, pulse widths, peak powers, and fault locations

scholarly journals Research on Risk Assessment Method of Enterprise's Arrears Based on Block-Chain Credit Consensus

2021 ◽  
Author(s):  
Qian Zhang ◽  
Sujie Xing
Keyword(s):  
Risk Assessment ◽  
Credit Risk ◽  
Power Supply ◽  
Credit Scoring ◽  
Assessment Method ◽  
Scoring Model ◽  
Blockchain Technology ◽  
Risk Assessment Method ◽  
Credit Data ◽  
Credit Scoring Model

Abstract Background:At present, the power supply market has always acquiesced to the rule of ‘use electricity first, pay later’,some electricity users may delay payment or even default on electricity bills due to various reasons, causing problems such as a long recovery period for electricity bills and difficulty in debt settlement. In order to reduce this kind of phenomenon, the power supply company must understand the user's historical electricity consumption data, capital status, credit status and other information, but the establishment of such a database requires a lot of time and human resource costs.Methods:Based on the distributed storage technology of blockchain, this paper abstracts power supply companies, power users, banking financial institutions, government regulatory agencies, etc. into nodes on the alliance chain.After that,this paper introduces a credit scoring model to judge the credit rating of user information based on characteristic indicators, and select the corresponding electricity fee recovery policy after the result is obtained, so as to reduce the operating risk of the power supply company.Results:This article combines the power and energy market with blockchain technology to establish a secure and distributed credit data blockchain, and at the same time establish a credit scoring model based on expert review questionnaire data. The analysis results show that this mechanism is suitable for credit data storage and sharing in energy transactions. Conclusions:Research and analysis indicate that the credit risk assessment method of electricity transaction data proposed in this article provides a theoretical basis for the combination of electricity transaction credit risk assessment and blockchain technology,which will help improve the company's ability to assess the risk of arrears and reduce the operating risk of power supply companies.

scholarly journals Relay protection system of transmission line based on AI

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0246403
Author(s):  
Xiangyu Zheng ◽  
Rong Jia ◽  
Linling Gong ◽  
Aisikaer ◽  
Xiping Ma ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Power Systems ◽  
High Reliability ◽  
Relay Protection ◽  
Protection System ◽  
Test Results ◽  
Protection Systems ◽  
Protection Technology ◽  
Self Learning ◽  
The Ideal

With the development of modern power systems, higher requirements are imposed on relay protection technology. Traditional relay protection and fault diagnosis technologies have been unable to meet the requirements of the continuous development of power systems, and relay protection systems based on artificial intelligence(AI) technology have received increasing attention. Therefore, this document first analyses the weaknesses of traditional broadcast line protection and uses the adaptability and self-learning of artificial intelligence(AI); to propose the concept of protection of a relay line based on AI. In combination with the artificial nervous network, the AI-based relay protection system shall be studied and the experimental model shall be developed. This paper validates it with simulation experiments. The research results show that for the analysis of the ANN test results of the subnetwork, the actual output of the subnetwork is very close to the ideal output, and the error does not exceed 0.2%. The system has good performance and high reliability.

scholarly journals A short communication to define the overcurrent protection system of the CIGRE European benchmark distribution networks for RES penetration studies

2021 ◽  
Author(s):  
J. M. Maza-Ortega ◽  
F. J. Zarco-Soto ◽  
S. Gkavanoudis ◽  
D. Tampakis ◽  
C. Demoulias
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Positive Impact ◽  
Task Force ◽  
Renewable Energy Sources ◽  
Distribution Networks ◽  
Protection System ◽  
Lack Of Information ◽  
Protection Systems ◽  
European Distribution

AbstractThe use of clean energies in distribution networks is an unstoppable trend which has a significant positive impact on the progressive power system decarbonization. However, it has to be considered that conventional distribution systems have been designed to operate as passive networks. Therefore, a massive penetration of distributed generation may create several operational problems, such as malfunction of the protection systems, which may limit the deployment of this technology. The analysis of these limitations by means of representative benchmark networks is of utmost importance. Most of the proposed benchmark networks proposed so far, however, lack of information about their protection system. To overcome this shortcoming, this letter specifies the protection system of the benchmark European distribution networks proposed by the CIGRE Task Force C06.04.02 for this purpose. In this way, this letter facilitates the analysis of the possible impact that renewable energy sources may have in the distribution system protections.

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