A Bounded Exhaustive Search Technique for Optimal Phasor Measurement Unit Placement in Power Grids

Ahmad Asrul Ibrahim,Hussain Shareef,Nor Azwan Mohamed Kamari,Khairuddin Khalid

doi:10.3390/sym12122021

Ahmad Asrul Ibrahim, Hussain Shareef + Show 2 more

Open Access

https://doi.org/10.3390/sym12122021

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Abstract

This paper proposes a technique to determine the possible optimal placement of the phasor measurement unit (PMU) in power grids for normal operating conditions. All possible combinations of PMU placement, including infeasible combinations, are typically considered in finding the optimal solution, which could be a massive search space. An integer search algorithm called the bounded search technique is introduced to reduce the search space in solving a minimum number of PMU allocations whilst maintaining full system observability. The proposed technique is based on connectivity and symmetry constraints that can be derived from the observability matrix. As the technique is coupled with the exhaustive technique, the technique is called the bounded exhaustive search (BES) technique. Several IEEE test systems, namely, IEEE 9-bus, IEEE 14-bus, IEEE 24-bus and IEEE 30-bus, are considered to showcase the performance of the proposed technique. An initial Monte Carlo simulation was carried out to evaluate the capability of the bounded search technique in providing a smaller feasible search space. The effectiveness of the BES technique in terms of computational time is compared with the existing exhaustive technique. Results demonstrate that the search space can be reduced tremendously, and the computational burden can be eased, when finding the optimal PMU placement in power grids.

Highlights

Power grids are vulnerable to fault occurrences that are subject to more frequent power system failures, resulting in financial and production losses
A comparison between the IEEE test systems in terms of system topology is provided in Table 1 for better understanding
The results show that the proposed bounded exhaustive search (BES) technique can provide the same optimum number of phasor measurement unit (PMU) compared with the existing technique

Summary

Introduction

Power grids are vulnerable to fault occurrences that are subject to more frequent power system failures, resulting in financial and production losses. Monitoring power grid conditions over a wide area is important to ensure more reliable power system operation. Phasor measurement units (PMUs) with global positioning systems (GPSs) are installed in power grids to provide synchronised data measurements at substations or system buses. The first prototype of PMU was developed in. 1980s by Virginia Tech, and currently, there are a number of PMU technologies being deployed all over the world to get precise power system state measurements [1]. The data collected from PMUs can be used to identify fault location [2], detect power quality events [3] and evaluate power system stability [4]. PMUs are suggested to be installed at all buses to ensure full system observability

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Results

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