Abstract

The microgrid protection strategy encounters major obstacles because of the varying fault current capacities that result from the diverse modes of microgrid operations. The challenges are heightened with the incorporation of large-scale systems. Protecting microgrids has become a complex task due to various factors. This includes 1) increased fault current contribution during grid-connected operation, 2) insufficient current contribution during islanded operation, 3) sympathetic tripping, 4) blinding, and 5) loss of mains. These factors can render existing protection devices ineffective in clearing faults. And thus, current alone cannot be only key factor for detecting a fault among various modes of operation. To address this issue, a total harmonic distortion (THD) based communication free adaptive protection strategy is proposed. The voltage THD would be lesser during the grid connected mode of operation and slightly higher during the islanded mode of operation. Hence, this is considered to be primary factor to shift the settings among various operating conditions which provide the communication-free adaptive protection strategy of the microgrids. The current and voltage parameters are used to detect the fault conditions in the grid connected and the islanded mode of operation respectively. Performance evaluation was made on a modified IEEE 13-node distribution system. The fault detection time is less than 3 milliseconds (ms) and 7 ms for the primary and back up protection respectively for the grid-connected mode of operation. Also, the fault detection times are within 6 ms and 10 ms for the primary and backup protection respectively for the islanded mode of operation. This makes a cumulative 50% reduction in the fault detection-time compared to literature work done on the 13-node distribution system.

Library of Congress Subject Headings

Microgrids (Smart power grids)--Security measures; Electric fault location; Smart structures

Publication Date

5-2024

Document Type

Thesis

Student Type

Graduate

Degree Name

Electrical Engineering (MS)

Department, Program, or Center

Electrical Engineering

Advisor

Abdulla Ismail

Advisor/Committee Member

Boutheina Tlili

Advisor/Committee Member

Haris M. Khalid

Comments

This thesis has been embargoed. The full-text will be available on or around 6/27/2025.

Campus

RIT Dubai

Plan Codes

EEEE-MS

Download

Available for download on Friday, June 27, 2025

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