scholarly journals A Novel Protective Logic for Optimal Coordination of Overcurrent Relays

2015 ◽  
Vol 16 (3) ◽  
pp. 439
Author(s):  
Sajad Samadinasab ◽  
Farhad Namdari ◽  
Nader Shojaei
Keyword(s):  
Short Circuit ◽  
Dynamic Changes ◽  
Communication Links ◽  
Overcurrent Relays ◽  
Measurement Units ◽  
Optimal Coordination ◽  
Pmu Placement ◽  
Protective Relays ◽  
And Performance ◽  
Full Network

Usually coordination of overcurrent relays is done by taking into account the specific structure of the system which does not show the real state of the system. On the other hand, dynamic changes in network can occur due to short circuit conditions, the malfunctioning relays, development, operation and repairs on any part of the power system. Also the most of the new protective schemes are based on a communication channel, which cannot be guaranteed in practice. Therefore, solving the problem of relay coordination is extremely difficult in case of dynamic changes in the network structure and the absence of communication links between some relays. In this article, a novel protective logic based on phasor measurement units (PMUs) data is proposed for optimal coordination of overcurrent relays. In this method, by using the PMU measurements, phasor information can be obtained continuously at any node where PMUs are installed in the power grid. For this purpose, in the first the Optimal PMU placement is determined for full network observability. Then, the dynamic changes of network will be observe by using wide area measurements based on PMUs data. Finally this information is sent via communication links PMUs for the optimal coordination of overcurrent relays. The use of PMU for the coordination of overcurrent relays improve the decision making capability and performance of protective relays and help them to form a reliable and robust protection system. The proposed method is tested on IEEE 8-bus and 14-bus standard networks.

Analyzing the Impacts of Wind Generator on the Optimal Coordination of Overcurrent Relays

2012 ◽  
Vol 516-517 ◽  
pp. 1316-1321
Author(s):  
Ming Ta Yang ◽  
Jin Lung Guan ◽  
Jhy Cherng Gu
Keyword(s):  
Distribution Systems ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Original System ◽  
Wind Generator ◽  
Linear Programming Methods ◽  
Protection Strategies ◽  
Overcurrent Relays ◽  
Optimal Coordination ◽  
The Impact

Wind generator and distribution systems after interconnection would change the short circuit fault characteristics of the original system and may lead to protection relay malfunctions, and review of the protection coordination. It is necessary to research the impact of existing protection strategies for distribution systems after wind generator interconnection. Linear programming methods were adopted for this study to review the coordination problems among feeder circuit breaker, lateral circuit breaker, and power fuse after radial distribution systems and wind generator interconnections.

PMU Placement Optimization for Fault Observation Using Different Techniques

2021 ◽  
pp. 196-220
Author(s):  
Hamid Bentarzi
Keyword(s):  
Cuckoo Search ◽  
Optimal Number ◽  
Optimization Techniques ◽  
Grey Wolf Optimizer ◽  
Placement Optimization ◽  
Teaching Learning Based Optimization ◽  
Measurement Units ◽  
Pmu Placement ◽  
Teaching Learning ◽  
Full Network

This chapter presents different techniques for obtaining the optimal number of the phasor measurement units (PMUs) that may be installed in a smart power grid to achieve full network observability under fault conditions. These optimization techniques such as binary teaching learning based optimization (BTLBO) technique, particle swarm optimization, the grey wolf optimizer (GWO), the moth-flame optimization (MFO), the cuckoo search (CS), and the wind-driven optimization (WDO) have been developed for the objective function and constraints alike. The IEEE 14-bus benchmark power system has been used for testing these optimization techniques by simulation. A comparative study of the obtained results of previous works in the literature has been conducted taking into count the simplicity of the model and the accuracy of characteristics.

scholarly journals Implementation of Hybrid ABC-PSO Algorithm for Directional Overcurrent Relays Coordination Problem

2020 ◽  
Vol 9 (7) ◽  
pp. 721-727
Keyword(s):  
Power System ◽  
Optimal Solution ◽  
Pso Algorithm ◽  
Fast Response ◽  
Vital Role ◽  
Coordination Problem ◽  
Bee Colony ◽  
Overcurrent Relays ◽  
Optimal Coordination ◽  
Protective Relays

In modern power system, protective relays are playing a vital role for protection of the whole system. The efficiency and reliability of whole protection system depends upon the combined and coordinated operation of protective devices such as relays, circuit breakers etc. Moreover, both types of relays viz., primary and backup relays have been used for smooth and reliable operation of the power system from years. A primary directional over current relay (DOCR) is setup for the fast response of any faulty condition. If it fails, then backup relay perform the same task after some time gap. Three different setting such as plug-setting multiplier (PSM), pickup current settings and time multiplier setting (TMS) are required of performing the operation. In this paper, three very popular swarm based meta-heuristic such as particle swarm optimization (PSO), artificial bee colony (ABC) and a recent hybridization of both, i.e., hybrid ABC-PSO have been implemented for the calculation of optimal coordination problem. This coordination problem is treated for continuous settings optimization for TMS and pickup current. An IEEE 8 bus system without grid has been opted for validation of the results. It is evident from the study that the hybrid ABC-PSO based proves to generate optimal solution providing better convergence rate as compared to individual PSO and ABC algorithm.

scholarly journals Hybrid Harmony Search Algorithm Applied to the Optimal Coordination of Overcurrent Relays in Distribution Networks with Distributed Generation

2021 ◽  
Vol 11 (19) ◽  
pp. 9207
Author(s):  
Sergio D. Saldarriaga-Zuluaga ◽  
Jesús M. López-Lezama ◽  
Nicolás Muñoz-Galeano
Keyword(s):  
Distributed Generation ◽  
Search Algorithm ◽  
Short Circuit ◽  
Harmony Search ◽  
Distribution Networks ◽  
Harmony Search Algorithm ◽  
Small Scale ◽  
Coordination Problem ◽  
Overcurrent Relays ◽  
Optimal Coordination

In recent years, distributed generation (DG) has become more common in modern distribution networks (DNs). The presence of these small-scale generation units within a DN brings new challenges to protection engineers, since short-circuit currents tend to increase; additionally, as with microgrids, modern DNs may feature several operational modes depending on their topology and the availability of DG. This paper presents a methodology for the optimal coordination of overcurrent relays (OCRs) in modern DNs with a high presence of DG. Given the fact that protection coordination is a non-linear and non-convex optimization problem, a hybrid harmony search and simulated annealing (HS-SA) approach was implemented for its solution and compared against other techniques, such as conventional HS, genetic algorithm (GA), particle swarm optimization (PSO) and hybrid PSO-HS. Several tests were performed on a DN, considering different operative scenarios as a function of the DG available within the network. A comparison with other works reported in the specialized literature was carried out, evidencing the applicability and effectiveness of the HS-SA technique in solving the optimal OCR coordination problem in modern DNs.

scholarly journals Inter-trip links incorporated optimal protection coordination

2020 ◽  
Vol 10 (1) ◽  
pp. 72
Author(s):  
Ali Abbasi ◽  
Hossein Kazemi Karegar ◽  
Tohid Soleymani Aghdam
Keyword(s):  
Genetic Algorithm ◽  
Smart Grid ◽  
System Performance ◽  
Distribution Network ◽  
Communication Links ◽  
Overcurrent Relays ◽  
Optimal Coordination ◽  
Search Approach ◽  
Fault Clearance ◽  
Optimal Protection

Due to advances in smart grid, different communication links as delay, inter-trip and activation are used between relays to enhance the protection system performance. In this paper, the effect of inter-trip links on optimal coordination of directional overcurrent relays (DOCRs) is analytically investigated and modelled. Moreover, an index is proposed to find the optimum locations for inter-trip link installation to reach the minimal fault clearance times under the selectivity constraint. Then a method is proposed to determine the candidate locations of inter-trip links and the associated reduced operating times. An Exhaustive search approach is also used to validate the efficiency of the proposed method. The method is simulated and tested on distribution network of IEEE 33 bus using the Power Factory software and MATLAB optimization toolbox. Genetic algorithm is used as an optimization tool to find optimal settings of relays. The results indicate the capability of proposed method in optimal protection coordination with optimum inter-trips.

Application of Teaching Learning-Based Optimization to the Optimal Placement of Phasor Measurement Units

2018 ◽  
pp. 407-438
Author(s):  
Abdelmadjid Recioui
Keyword(s):  
Phasor Measurement Units ◽  
Optimal Placement ◽  
Placement Problem ◽  
Electric Transmission ◽  
Phasor Measurement ◽  
Teaching Learning Based Optimization ◽  
Measurement Units ◽  
Pmu Placement ◽  
Teaching Learning ◽  
Full Network

In recent years, the placement of phasor measurement units (PMUs) in electric transmission systems has gained much attention. This chapter presents a binary teaching learning based optimization (BTLBO) algorithm for the optimal placement of phasor measurement units (PMUs). The optimal PMU placement problem is formulated to minimize the number of PMUs installation subject to full network observability at the power system buses. The efficiency of the proposed method is verified by the simulation results of IEEE14-bus, 30-bus, 57-bus-118 bus systems, respectively. The results show that the whole system can be observable with installing PMUs on less than 25% of system buses. For verification of our proposed method, the results are compared with some newly reported methods which show the method as a novel effective solution to obtain system measurements with the least number of phasor measurement units.

A New Method for Optimal Coordination of Overcurrent Relays Considering the Communication Channels Constraints

2016 ◽  
Vol 1 (1) ◽  
pp. 17
Author(s):  
Farhad Namdari ◽  
Sajad Samadinasab
Keyword(s):  
Decision Making ◽  
Information Exchange ◽  
Communication Channel ◽  
Power Grid ◽  
Communication Channels ◽  
Optimal Solution ◽  
Positive Sequence ◽  
Overcurrent Relays ◽  
Optimal Coordination ◽  
Protective Relays

<p>The most of the new protective schemes are based on a communication channel, which cannot be guaranteed in practice. However, during blackouts or cascading failures in the power grid, as system conditions change significantly and rapidly, more information exchanges may be required by the control centers and substations. In other words, the communication channels are operating with high load and therefore become more vulnerable when the power grid is in contingent conditions. Thus, relying on the communication channel for decision making may not be the optimal solution for protective relays, although it might be beneficial to have information exchange. In this article, a novel protective logic is proposed based on phasor measurement units (PMUs) data for optimal coordination of overcurrent relays. PMUs measure the positive sequence voltage at two substations separated by hundreds of miles which are synchronized precisely with the aid of a GPS satellite system. The precise time-tags are attached with samples, and this information is exchanged over communication channels and collected by control centers and/or substations. By extracting the relevant information from these measurements, phasor information can be obtained at any node where PMUs are installed in the power grid. This can be used to do more accurate state estimation, control, and protection. In these relays, besides current and voltage, phasor information has become an important measurement in decision making. The proposed method is tested on IEEE 8-bus standard network.</p>

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