scholarly journals Novel Protection Coordination Scheme for Active Distribution Networks

Electronics ◽  
2021 ◽  
Vol 10 (18) ◽  
pp. 2312
Author(s):  
Muhammad Fawad Shaikh ◽  
Sunny Katyara ◽  
Zahid Hussain Khand ◽  
Madad Ali Ali Shah ◽  
Lukasz Staszewski ◽  
...  
Keyword(s):  
Phase Angle ◽  
Power Flow ◽  
Distribution Networks ◽  
Test System ◽  
Laboratory Setup ◽  
Distributed Generators ◽  
Simulated Environment ◽  
Optimal Coordination ◽  
The One ◽  
Hardware In Loop

Distribution networks are inherently radial and passive owing to the ease of operation and unidirectional power flow. Proper installation of Distributed Generators, on the one hand, makes the utility network active and mitigates certain power quality issues e.g., voltage dips, frequency deviations, losses, etc., but on the other hand, it disturbs the optimal coordination among existing protection devices e.g., over-current relays. In order to maintain the desired selectivity level, such that the primary and backup relays are synchronized against different contingencies, it necessitates design of intelligent and promising protection schemes to distinguish between the upstream and downstream power flows. This research proposes exploiting phase angle jump, an overlooked voltage sag parameter, to add directional element to digital over-current relays with inverse time characteristics. The decision on the direction of current is made on the basis of polarity of phase angle jump together with the impedance angle of the system. The proposed scheme at first is evaluated on a test system in a simulated environment under symmetrical and unsymmetrical faults and, secondly, as a proof of the concept, it is verified in real-time on a laboratory setup using a Power Hardware-in-loop (PHIL) system. Moreover, a comparative analysis is made with other state-of-the-art techniques to evaluate the performance and robustness of the proposed approach.

scholarly journals Modeling and Validation of a Directional Overcurrent Relay as an Island Interconnection Device

2020 ◽  
Author(s):  
Wandry R. Faria ◽  
Jonas V. Souza ◽  
Rodrigo B. Otto ◽  
Benvindo R. Pereira Jr.
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Distribution Systems ◽  
Short Circuit ◽  
Electrical Power ◽  
Distribution Networks ◽  
Test System ◽  
Electrical Power Systems ◽  
Distributed Generators ◽  
Overcurrent Relay

The growing number of decentralized generators in the distribution systems and the consequent increase in the penetration level in the networks have prompted the inclusion of this scenario in researches involving the planning of electrical power systems. The planning of protection systems for distribution networks considering distributed generators requires adaptations in the approach due to modifications in characteristics of the network, such as passivity and unidirectional power flow. Furthermore, the insertion of generators in distribution networks allows the implementation of new operation methods, such as the possibility of disconnecting some loads from the main feeder and supplying them through distributed generators. The island operation can improve the service continuity indexes, as well as reduce the costs of non-supplied energy. Although the island operation is widely proposed in the literature as a means to improve the system's reliability, the simulation of a protective device to intentionally island a region and the verification of its limitations is not. In this paper, we present the modeling of a directional overcurrent relay through ATP-EMTP, and its employment as a device for island interconnection, analyzing its zone of non-operation. CIGRE 14-bus test system is used to conduct short-circuit tests with the variation of resistance and type of fault applied. Theresults show the effectiveness of the device, which is able to identify all faults with real impact on the network, placing the region in island operation in less than 20 ms.

scholarly journals Hybrid GA-SOCP Approach for Placement and Sizing of Distributed Generators in DC Networks

2020 ◽  
Vol 10 (23) ◽  
pp. 8616 ◽  
Author(s):  
Oscar Danilo Montoya ◽  
Walter Gil-González ◽  
Luis Fernando Grisales-Noreña
Keyword(s):  
Power Flow ◽  
Optimal Power Flow ◽  
Mathematical Optimization ◽  
Optimal Solution ◽  
Distribution Networks ◽  
Optimization Approach ◽  
Global Optimal Solution ◽  
Distributed Generators ◽  
Second Order Cone ◽  
Global Optimal

This research addresses the problem of the optimal location and sizing distributed generators (DGs) in direct current (DC) distribution networks from the combinatorial optimization. It is proposed a master–slave optimization approach in order to solve the problems of placement and location of DGs, respectively. The master stage applies to the classical Chu & Beasley genetic algorithm (GA), while the slave stage resolves a second-order cone programming reformulation of the optimal power flow problem for DC grids. This master–slave approach generates a hybrid optimization approach, named GA-SOCP. The main advantage of optimal dimensioning of DGs via SOCP is that this method makes part of the exact mathematical optimization that guarantees the possibility of finding the global optimal solution due to the solution space’s convex structure, which is a clear improvement regarding classical metaheuristic optimization methodologies. Numerical comparisons with hybrid and exact optimization approaches reported in the literature demonstrate the proposed hybrid GA-SOCP approach’s effectiveness and robustness to achieve the global optimal solution. Two test feeders compose of 21 and 69 nodes that can locate three distributed generators are considered. All of the computational validations have been carried out in the MATLAB software and the CVX tool for convex optimization.

Artificial Neural Network Application in Optimal Coordination of Directional Overcurrent Protective Relays in Electrical Mesh Distribution Network

2015 ◽  
Vol 785 ◽  
pp. 48-52 ◽  
Author(s):  
Osaji Emmanuel ◽  
Mohammad Lutfi Othman ◽  
Hashim Hizam ◽  
Muhammad Murtadha Othman
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Response Time ◽  
Short Circuit ◽  
Distribution Networks ◽  
Test System ◽  
Wrong Response ◽  
Optimal Coordination ◽  
Artificial Neural ◽  
Short Circuit Fault

Directional Overcurrent relays (DOCR) applications in meshed distribution networks (MDN), eliminate short circuit fault current due to the topographical nature of the system. Effective and reliable coordination’s between primary and secondary relay pairs ensures effective coordination achievement. Otherwise, the risk of safety of lives and installations may be compromised alongside with system instability. This paper proposes an Artificial Neural Network (ANN) approach of optimizing the system operation response time of all DOCR within the network to address miscoordination problem due to wrong response time among adjacent DOCRs to the same fault. A modelled series of DOCRs in a simulated IEEE 8-bus test system in DigSilent Power Factory with extracted data from three phase short circuit fault analysis adapted in training a custom ANN. Hence, an improved optimized time is produced from the network output to eliminate miscoordination among the DOCRs.

scholarly journals Black hole optimizer for the optimal power injection in distribution networks using DG

2021 ◽  
Vol 2135 (1) ◽  
pp. 012010
Author(s):  
Oscar Danilo Montoya ◽  
Diego Armando Giral-Ramírez ◽  
Luis Fernando Grisales-Noreña
Keyword(s):  
Black Hole ◽  
Power Distribution ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Distribution Networks ◽  
Test System ◽  
Load Flow ◽  
Optimization Strategy ◽  
Optimal Power ◽  
Distribution Company

Abstract The optimal sizing of Distributed Generators (DG) in electric power distribution networks is carried out through a metaheuristic optimization strategy. To size DG it is proposed an optimal power flow model is formulated by considering that the location of these sources has been previously defined by the distribution company. The solution of the optimal power flow is reached with the Black Hole Optimizer (BHO). A methodology is used master-slave optimization methodology, where the BHO (i.e., master stage) defines the sizes of the DG and the slave stage evaluates the objective function with a load flow algorithm, this work using the triangular-based power flow method. Numerical results in the 33-node and the 69-node test system demonstrates the effectiveness and robustness of the proposed approach when compared with literature results.

scholarly journals Exploiting OLTC and BESS Operation Coordinated with Active Network Management in LV Networks

2020 ◽  
Vol 12 (8) ◽  
pp. 3332
Author(s):  
Konstantinos Kotsalos ◽  
Ismael Miranda ◽  
Jose Luis Dominguez-Garcia ◽  
Helder Leite ◽  
Nuno Silva ◽  
...  
Keyword(s):  
Power Flow ◽  
Optimal Power Flow ◽  
Low Voltage ◽  
Distribution Networks ◽  
Small Scale ◽  
Data Set ◽  
Economical Analysis ◽  
Distribution Transformers ◽  
Optimal Coordination ◽  
Battery Energy

The large number of small scale Distributed Energy Resources (DER) such as Electric Vehicles (EVs), rooftop photovoltaic installations and Battery Energy Storage Systems (BESS), installed along distribution networks, poses several challenges related to power quality, efficiency, and reliability. Concurrently, the connection of DER may provide substantial flexibility to the operation of distribution grids and market players such as aggregators. This paper proposes an optimization framework for the energy management and scheduling of operation for Low Voltage (LV) networks assuring both admissible voltage magnitudes and minimized line congestion and voltage unbalances. The proposed tool allows the utilization and coordination of On-Load Tap Changer (OLTC) distribution transformers, BESS, and flexibilities provided by DER. The methodology is framed with a multi-objective three phase unbalanced multi-period AC Optimal Power Flow (MACOPF) solved as a nonlinear optimization problem. The performance of the resulting control scheme is validated on a LV distribution network through multiple case scenarios with high microgeneration and EV integration. The usefulness of the proposed scheme is additionally demonstrated by deriving the most efficient placement and sizing BESS solution based on yearly synthetic load and generation data-set. A techno-economical analysis is also conducted to identify optimal coordination among assets and DER for several objectives.

scholarly journals A Mixed-Integer Quadratic Formulation of the Phase-Balancing Problem in Residential Microgrids

2021 ◽  
Vol 11 (5) ◽  
pp. 1972
Author(s):  
Alejandro Garces ◽  
Walter Gil-González ◽  
Oscar Danilo Montoya ◽  
Harold R. Chamorro ◽  
Lazaro Alvarado-Barrios
Keyword(s):  
Power Distribution ◽  
Power Flow ◽  
Heuristic Algorithms ◽  
Low Voltage ◽  
Distribution Networks ◽  
Test System ◽  
Mixed Integer ◽  
Flow Equations ◽  
Distribution Grids ◽  
Selection Of

Phase balancing is a classical optimization problem in power distribution grids that involve phase swapping of the loads and generators to reduce power loss. The problem is a non-linear integer and, hence, it is usually solved using heuristic algorithms. This paper proposes a mathematical reformulation that transforms the phase-balancing problem in low-voltage distribution networks into a mixed-integer convex quadratic optimization model. To consider both conventional secondary feeders and microgrids, renewable energies and their subsequent stochastic nature are included in the model. The power flow equations are linearized, and the combinatorial part is represented using a Birkhoff polytope B3 that allows the selection of phase swapping in each node. The numerical experiments on the CIGRE low-voltage test system demonstrate the use of the proposed formulation.

Homotopy-Enhanced Power Flow Methods for General Distribution Networks With Distributed Generators

2014 ◽  
Vol 29 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Hsiao-Dong Chiang ◽  
Tian-Qi Zhao ◽  
Jiao-Jiao Deng ◽  
Kaoru Koyanagi
Keyword(s):  
Power Flow ◽  
Distribution Networks ◽  
General Distribution ◽  
Distributed Generators

scholarly journals Optimal Placement of Remote-Controlled Switches in Distribution Networks in the Presence of Distributed Generators

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1025 ◽  
Author(s):  
Maziar Isapour Chehardeh ◽  
Constantine J. Hatziadoniu
Keyword(s):  
Cost Function ◽  
Distribution Networks ◽  
Optimization Method ◽  
Test System ◽  
Optimal Number ◽  
Optimal Placement ◽  
Expected Cost ◽  
Protective Devices ◽  
Distributed Generators ◽  
Optimum Placement

A two-level optimization method is presented to find the optimal number and location of conventional protective devices to be upgraded to remote-controlled switches (RCSs) for an existing distribution network (DN). The effect of distributed generation (DG) on this problem is considered. In the first level, a nonlinear binary program is proposed to maximize the restored customers subject to technical and topological constraints. All feasible interchanges between protective devices and ties involved in the restoration, when a fault occurs at all possible locations are found considering switching dependencies. In the second level, a nonlinear cost function, combining the expected cost of interruptions (ECOST) and the switch cost, is minimized with respect to the location of RCSs. The expected cost function is computed based on the optimum restoration policies obtained from the first level. The optimum placement of RCSs using the proposed algorithm is tested on a 4-feeder 1069-node test system and compared to the solution obtained with a genetic algorithm (GA) on the same system.

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