Abstract

This paper presents an adaptive protection scheme (APS) for solving the coordination problem that deals with coordination directional overcurrent relays (DOCRs) and distance relays second zone time, in relation to coordination with DOCRs. The coordination problem becomes more complex with the impact of renewable energy sources (RES) when added to the distribution grid. This leads to a change in the grid topology, caused by the on/off states of the distribution generators (DG). The frequency of topological changes in distribution grids poses a challenge to the power system’s protection components. The change in the state of DGs leads to malfunction in reliability and miscoordination between protection relays, since that causes a direct effect to the short circuit currents. This paper used the school-based optimization (SBO) algorithm, which simulates the educational process, in order to deal with coordination problems. That algorithm is modified (MSBO) by modified both learning and teaching processes. The IEEE 8-bus test system and IEEE 14-bus distribution network are used to validate the proposed coordination system’s effectiveness when dealing with the coordination process between distance and DOCRs, at both the near- and far-end in the typical topological grid and with DGs in working order.

Highlights

  • Directional overcurrent relays (DOCRs) and distance relays are both commonly used for protecting transmission lines

  • The optimization setting of TDS, IP, and TZ2 were tuned by the MATLAB program, used for both school-based optimization (SBO) and MSBO to solve the optimization problem

  • During the tuning process for relays setting by optimization algorithms SBO and MSBO, the penalty of both are shown in Figures 14 and 15 for the normal case and the other distribution generators (DG) case, respectively

Read more

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The main problem in this paper regards reducing the protection relay’s operation times, to provide the ability for protection devices to isolate the fault area. The effect of distance relays complicates this coordination problem in the DOCR’s coordination process, in addition to the impact of DGs. The original SBO algorithm was modified to improve the response and convergence of the proposed algorithm. Two main points were modified, learning and the teacher-selected process This algorithm could be effective in solving other power systems’ important topics, such as load frequency control, parameter estimation of the solar cell, optimal location, and the sizing of DGs. The proposed protection system in this paper was tested on both IEEE 8-bus and IEEE.

The Mathematical Modelling of Coordination Problem
Original
Original School-Based Optimization Algorithm
Flow chart of of SBO
Teaching
Learning Phase
Modified SBO Algorithm
First Point: A Modified Learning Phase
Flow of MSBO
Results and Discussion
Test System I
Test System II
Varification
5.5.Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call