https://isiarticles.com/bundles/Article/pre/pdf/46311.pdf

A review on interval type-2 fuzzy logic applications in intelligent control

During recent decades with the power system restructuring process, centralized energy sources are being replaced with decentralized ones. This phenomenon has resulted in a novel concept in electric power systems, particularly in distribution systems, known as Distributed Generation (DG). On one hand, utilizing DG is important for secure power generation and reducing power losses. On the other hand, widespread use of such technologies introduces new challenges to power systems such as their optimal location, protection devices' settings, voltage regulation, and Power Quality (PQ) issues. Another key point which needs to be considered relates to specific DG technologies based on Renewable Energy Sources (RESs), such as wind and solar, due to their uncertain power generation. In this regard, this paper provides a comprehensive review of different types of DG and investigates the newly emerging challenges arising in the presence of DG in electrical grids.

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Impact of distributed generation on protection and voltage regulation of distribution systems: A review

This paper proposes a communication assisted dual setting relay protection scheme for micro-grids with grid connected and islanded capability. Previous work on dual setting relays has been applied to grid connected distributed generation systems only, but one major shortcoming is the failure of the backup scheme to operate in a coordinated manner. The proposed scheme relies on the use of dual setting directional overcurrent relays that are capable of operating in both forward and reverse directions, with different settings, and with a low bandwidth communication to maintain proper protection coordination. The problem is formulated as a non-linear constrained programming problem where the relay settings are optimally determined to minimize the overall relay operating time for primary and backup operation. The scheme is tested on a modified version of the IEEE 30 bus test system equipped with distributed generation and with capability of operating in an islanded mode. The proposed scheme is compared against the conventional scheme and the results show that it is capable of overcoming the problem of infeasibility, experienced by the conventional method, without the need of installing fault current limiters. Furthermore, it achieves remarkable reduction in both the primary and backup relay operating times, which was reflected in a reduction in the total relay operating time.

Protection Coordination for Microgrids With Grid-Connected and Islanded Capabilities Using Communication Assisted Dual Setting Directional Overcurrent Relays

Display Omitted We solved the Directional Over Current Relays (DOCRs) optimal coordination problem.We used the Electromagnetic Field Optimization Algorithm (EFO).We improved the EFO algorithm for the optimal coordination of DOCRs.The proposed algorithm is better than other optimization algorithms. The optimal coordination of Directional Overcurrent Relays (DOCRs) is of paramount importance for power systems protection. The optimization model of this problem is non-linear and highly constrained. The main objective of this paper is to develop a modified version of the Electromagnetic Field Optimization (EFO) algorithm referred to as MEFO for the optimal coordination of DOCRs. The EFO is inspired by the behaviour of particles of electromagnets with different polarities where attractionrepulsion forces among these electromagnets lead particles toward global minima. It uses also the golden ratio. The proposed algorithm has been applied to three test systems including the 8-bus, the 9-bus and the 15-bus test systems. Furthermore, the results obtained using the proposed MEFO are compared with those obtained using the traditional EFO and a number of well-known algorithms. The obtained results show the effectiveness of the proposed MEFO to minimize the relay operating time for the optimal coordination of DOCRs.

Optimal coordination of directional overcurrent relays using a modified electromagnetic field optimization algorithm

Introduction of distributed generation (DG) to the power system may lead to nonselective protection actions. For every future DG installation, the relay settings need to be modified to guarantee protection coordination that can lead to numerous changes in relay settings. This paper presents a novel approach to plan relay protection coordination considering future DG installations. Thus, this paper aims at proposing a method capable of optimally identifying one set of relay settings valid for all possible future DG planning scenarios. The proposed algorithm is formulated as a linear programming problem and the simplex algorithm is utilized to solve it. The proposed approach is tested on the distribution part of the modified meshed IEEE 14-bus system and the IEEE 13-bus radial test system. Comparative studies have been conducted to highlight the advantages of the proposed approach under various planning scenarios considering application of fault current limiters.

Planning the Coordination of Directional Overcurrent Relays for Distribution Systems Considering DG

The authors would like to sincerely thank T. Aghdam et al. for their thoughtful discussion on our paper. They raise a valid, important and excellent point where the backup scheme of dual setting relays will not be fully coordinated properly. As such, one will experience, as stated by the discussers, for a fault at F1, R5 forward operation operating before R3 reverse operation. As suggested by the discussers, a possible solution would be to add (2) and this would yield both dual setting and conventional relay results the same and thus no improvement in operating times can be achieved by utilizing dual setting relays. The issue of possible loss of selecitivity but for definite time relays was reported in [1] and to resolve this issue, a communication link was used to block the operation of upstream relays [1] . This same approach can be applied to the dual settings relays and thus, another solution to resolve the dual setting selectivity problem would be to utilize a low bandwidth communication between relays which can then realize the full advantages of dual setting relays. The reported results in the paper can be achieved with proper protection coordination by amending dual setting relays with a low bandwidth communication that is utilized such that R1, once it detects an increase in current, would send a signal to block the unwanted operation of forward operating relays that are affected by that fault (for example, for a fault at F1, R1 forward operation sends a signal to block R5 forward operation and R5 forward operation sends a signal to block the forward operation of R4). This would apply to all relays in the system. Once again, we thank the reviewers for their careful review of the paper.

Closure to “Optimal Protection Coordination for Meshed Distribution Systems With DG Using Dual Setting Directional Over-Current Relays”

Beside being a good neighbor and not causing harmonic voltage for others that are connected to your electrical distribution circuit, complying with the legal requirements of IEEE standards 519, and maintaining safe and economical operating environments for electrical equipment within your physical load, there is another very good reason to maintain a good power factor: saving money on your electrical utility bill. Utilities often encourage consumers to maintain a high PF by applying tariff clauses, which penalize consumers for low PF. This letter discusses the topic.

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Power factor and your electrical utility bill in Egypt

Proportional integral derivative (PID) controller tuning is an area of interest for researchers. This paper presents a novel method for PID controller tuning using a modified biogeography-based optimization(MBBO) algorithm. Biogeography-based optimization (BBO) is a novel evolutionary algorithm that is based on the mathematical models of biogeography. Biogeography is the study of the geographical distribution of biological organisms. In the BBO model, problem solutions are represented as islands, and the sharing of features between solutions is represented as immigration and emigration between the islands. In this paper, a modified version of the BBO is proposed to improve its convergence. The MBBO algorithm is compared with the BBO using benchmarks functions. The proposed algorithm is applied to the problem of PID controller tuning and is compared with conventional biogeography-based optimization (BBO), and Particle swarm optimization (PSO).

A novel method for PID tuning using a modified biogeography-based optimization algorithm

Improving the performance of the Egyptian second testing nuclear research reactor using interval type-2 fuzzy logic controller tuned by modified biogeography-based optimization

In this paper we apply the modified biogeography-based Optimization (MBBO) to design type-2 fuzzy logic controller (T2FLC) to improve the performance of the plant control system. Biogeography-based optimization (BBO) is a novel evolutionary algorithm that is based on the mathematical models of biogeography. Biogeography is the study of the geographical distribution of biological organisms. In the BBO model, problem solutions are represented as islands, and the sharing of features between solutions is represented as immigration and emigration between the islands. A modified version of the BBO is applied to design the T2FLC to get the optimal parameters of the membership functions of the controller. We test the optimal T2FLC obtained by modified biogeography-based Optimization (MBBO) using benchmark plants and is compared with Particle swarm optimization (PSO).

E.E. Abou Elzahab

Papers

Closure to “Optimal Protection Coordination for Meshed Distribution Systems With DG Using Dual Setting Directional Over-Current Relays”

Power factor and your electrical utility bill in Egypt

A novel method for PID tuning using a modified biogeography-based optimization algorithm

Improving the performance of the Egyptian second testing nuclear research reactor using interval type-2 fuzzy logic controller tuned by modified biogeography-based optimization

A novel method for type-2 fuzzy logic controller design using a modified biogeography-based optimization