A fuzzy relation based fault section diagnosis method for power systems using operating sequences of protective devices

2001 ◽  
Author(s):  
Sang-Won Min ◽  
Jong-Keun Park ◽  
Kwang-Ho Kim ◽  
In-Ho Cho ◽  
Heung-Jae Lee
Keyword(s):  
Power Systems ◽  
Fuzzy Relation ◽  
Protective Devices ◽  
Diagnosis Method

scholarly journals Probability-Based Customizable Modeling and Simulation of Protective Devices in Power Distribution Systems

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 199
Author(s):  
Chengwei Lei ◽  
Weisong Tian
Keyword(s):  
Power Systems ◽  
Power Distribution ◽  
Distribution System ◽  
Distribution Systems ◽  
Short Circuit ◽  
Current Data ◽  
System Level ◽  
Power Distribution Systems ◽  
Power Distribution System ◽  
Protective Devices

Fused contactors and thermal magnetic circuit breakers are commonly applied protective devices in power distribution systems to protect the circuits when short-circuit faults occur. A power distribution system may contain various makes and models of protective devices, as a result, customizable simulation models for protective devices are demanded to effectively conduct system-level reliable analyses. To build the models, thermal energy-based data analysis methodologies are first applied to the protective devices’ physical properties, based on the manufacturer’s time/current data sheet. The models are further enhanced by integrating probability tools to simulate uncertainties in real-world application facts, for example, fortuity, variance, and failure rate. The customizable models are expected to aid the system-level reliability analysis, especially for the microgrid power systems.

scholarly journals Application of Superconducting Fault Current Limiter (SFCL) in Power Systems: A Review

2018 ◽  
Vol 3 (7) ◽  
pp. 28 ◽  
Author(s):  
Ignatius K. Okakwu ◽  
P. E. Orukpe ◽  
E. A. Ogujor
Keyword(s):  
Power Systems ◽  
System Stability ◽  
Normal Operation ◽  
Fault Current ◽  
Fault Current Limiter ◽  
Operational Flexibility ◽  
Superconducting Fault Current Limiter ◽  
Protective Devices ◽  
High Impedance ◽  
Current Limiter

The fault current levels of an interconnected power network have witnessed a general rise due to increase in power demand. This rise in fault current if not properly mitigated may exceed the maximum ratings of the switchgear. Many conventional protective devices such as series reactors, fuses, high impedance transformers, etc. have high cost, increased power loss and loss of power system stability, which may ultimately cause lower reliability and reduced operational flexibility. Superconducting Fault Current Limiter (SFCL) is a flexible alternative to the use of conventional protective devices, due to its effective ways of reducing fault current within the first cycle of fault current, reduced weight and zero impedance during normal operation. This paper reviews various concepts of SFCLs and its applications in power systems.

scholarly journals Probabilistic Optimal Power Flow Using Linear Fuzzy Relation

2021 ◽  
Author(s):  
Inderdeep S. Arneja
Keyword(s):  
Power Systems ◽  
Stochastic Models ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Large Scale ◽  
Hessian Matrix ◽  
Optimal Solution ◽  
Fuzzy Relation ◽  
Monte Carlo Simulation Technique ◽  
Optimal Power

Optimal Power Flow (OPF) is a very important tool for planning and analysis of power systems. In the recent times, uncertain renewable energy is being integrated into power systems in a large scale. Appropriate modeling of renewables in optimal power flow requires using stochastic models. Using stochastic models of renewables in optimal power flow is numerically and algorithmically challenging due to the complexity of stochastic models and nonlinear nature of bus power balance equations. Hitherto, Monte Carlo simulation technique and Cumulant technique have been proposed, but they are not computationally viable for large systems. In this thesis, we propose the use of linear fuzzy relation technique to relate stochastic models of dependent variables of optimal power flow formulation in terms of control variables that include power output of renewables. This fuzzy relation uses Hessian matrix of the LaGrangian of the optimal power flow formulation at optimal solution point. The technique is tested on a six bus system and results are reported. One can intuitively see that this technique can be easily extended to larger systems.

scholarly journals Selected Issues of Safe Operation of the Railway Traffic Control System in the Event of Exposition to Damage Caused by Lightning Discharges

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5808
Author(s):  
Renata Markowska ◽  
Zofia Wróbel
Keyword(s):  
Control System ◽  
Power Systems ◽  
Traffic Control ◽  
Lightning Discharge ◽  
Lightning Protection ◽  
Current Standard ◽  
Protection Measures ◽  
Railway Traffic ◽  
Protective Devices ◽  
Traffic Control System

Lightning discharge becomes a serious source of interference and damage for electronic and electrical power systems. Safe and reliable operation of railway traffic control systems requires proper protection against the effects of lightning. However, the current standards on lightning protection, PN-EN/EN/IEC 62305, do not cover railway objects. Moreover, there are no other standards or recommendations dedicated to the railway. The paper is an attempt to apply the procedure of lightning risk management according to PN-EN 62305-2 to select the proper protection measures in railway objects. A case study for the signal box with installed relaying and digital stations of the railway traffic control system is analyzed. The analysis comprises calculations based on the current standard PN-EN 62305-2:2012 but including the issues specific to railway traffic control. The risks of lightning losses have been calculated for two cases: without lightning protection measures and with protection measures proposed to decrease the risks below the tolerable values. The results show that a practically effective solution to reduce the risks is applying surge protective devices with proper characteristics. Another way is replacing unshielded incoming lines with shielded ones of given shield bonding way, and supplementing it with surge protective devices when necessary.

A Fault Diagnosis Method of Power Systems Based on Improved Objective Function and Genetic Algorithm-Tabu Search

2010 ◽  
Vol 25 (3) ◽  
pp. 1268-1274 ◽  
Author(s):  
Xiangning Lin ◽  
Shuohao Ke ◽  
Zhengtian Li ◽  
Hanli Weng ◽  
Xionghui Han
Keyword(s):  
Genetic Algorithm ◽  
Fault Diagnosis ◽  
Tabu Search ◽  
Power Systems ◽  
Objective Function ◽  
Diagnosis Method

scholarly journals A Novel OLTC Fault Diagnosis Method Based on Optimized Long Short-Term Memory Parameters

2021 ◽  
Author(s):  
Yan Yan ◽  
Hongzhong Ma
Keyword(s):  
Fault Diagnosis ◽  
Power Systems ◽  
Short Term Memory ◽  
Permutation Entropy ◽  
Short Term ◽  
Term Memory ◽  
Mode Decomposition ◽  
Diagnosis Method ◽  
Long Short Term Memory ◽  
Grasshopper Optimization

Recently, long short-term memory (LSTM) networks have been widely adopted to help with fault diagnosis for power systems. However, the parameters of LSTM networks are determined by prior knowledge and experience and thereby not capable of dealing with unexpected faults in volatile environments. In this paper, we propose and apply an improved grey wolf optimization (IGWO) algorithm to optimize the parameters of LSTM networks, aiming to circumvent the drawback of empirical LSTM parameters and enhance the fault diagnosis accuracy for on-load tap changers (OLTCs). The composite multiscale weighted permutation entropy and energy entropy yielded by the grasshopper optimization algorithm and variational mode decomposition (GOA-VMD) method are used as the inputs of LSTM networks. The IGWO algorithm is applied in an iterative manner to optimize the relevant super arithmetic of the LSTM. In this way, an IGWO-LSTM combination model is constructed to classify different faults diagnosed in OLTCs. Experimental results verify the diagnosis performance superiority of the proposed method over several widely used comparison benchmarks

scholarly journals Fault Diagnosis Algorithm and Protection of Electric Power Systems in an Alternative Distribution System

2020 ◽  
Vol 1 (3) ◽  
pp. 8-16
Author(s):  
Oshin Ola Austin ◽  
Oluwasanmi Alonge ◽  
Ajayi Joseph Adeniyi
Keyword(s):  
Power Systems ◽  
Distribution System ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Research Work ◽  
Short Circuit Current ◽  
Phase System ◽  
Fault Current ◽  
Circuit Breakers ◽  
Protective Devices

In any power systems, protective devices will detect fault conditions and operate circuit breakers in order to disconnect the load from the fault current and limit loss of service due to failure. This fault may involve one or more phases and the ground, or may occur between two or more phases in a three-phase systems. In ground, fault’ or ‘earth fault, current flows into the earth. In a poly-phase system, a fault may affect each of the three phases equally which is a symmetrical fault. If only some phases are affected, the resulting ‘asymmetrical fault’ becomes more complicated to analyze due to the simplifying assumption of equal current magnitude in all the phases being no longer applicable. Therefore, the prospective short circuit current of the fault can be calculated for power systems analysis procedures. This will assist in the choice of protective devices like circuit breakers, current transformers and relays. This research work evaluated and analyzed the occurrence of faults in a distribution system. Fault currents were obtained and the maximum tripping time required for the protective devices to operate were determined. Hence, it was possible to select appropriate relay and circuit breaker for effective operation of a distribution

scholarly journals An Analytic Method for Power System Fault Diagnosis Employing Topology Description

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1770 ◽  
Author(s):  
Biao Xu ◽  
Xianggen Yin ◽  
Dali Wu ◽  
Shuai Pang ◽  
Yikai Wang
Keyword(s):  
Fault Diagnosis ◽  
Power Systems ◽  
Power System ◽  
Analytic Method ◽  
Integer Programming Problem ◽  
Protective Devices ◽  
Cooperative Relationship ◽  
Abnormal Operation ◽  
Power Recovery ◽  
Relationship Of

When a fault occurs in a power system, fault section estimation is the primary premise for troubleshooting and power recovery, and an effective fault diagnosis system will play a big role in decision making. However, the topology information is not well employed in existing fault diagnosis methods, and it is complex and time consuming to analyze the relationship between the protective devices and the sections. In this paper, a novel analytic method which employs topology description is proposed for fault diagnosis. The topology descriptions of the sections and the protective devices are firstly established according to the network structure, and based on which the operating logic and the cooperative relationship of the protective devices can be easily analyzed by matrix operation. Considering the factors of logic error and communication error, the fault diagnosis problem is formulated as an integer programming problem and can be solved by intelligent algorithm. The case studies of different power systems show that the proposed method can quickly identify the fault section, even with the abnormal operation or error alarm of protective devices.

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