Selectable PMU algorithms for smart grid applications

Abstract

Modern day power grids have become more complex with the inclusion of renewable energy sources, increasing non-linear loads, and a growing demand for electricity by industry. This has resulted in dynamic power grids and a need for advanced techniques for improving support, protection, communication and control within the power network. Wide area measurement systems (WAMS) are utilised for monitoring these dynamic power networks, providing an overall status of the electrical grid in real time. They play a crucial role in maintaining grid stability and safeguarding against faults, blackouts, and damages to the network. The phasor measurement unit (PMU) is an essential component in a WAMS as they provide accurate phasor measurements of voltage and current propagating in the power grid. Each phasor measurement is synchronised with UTC in order to analyse and compare the magnitude, phase angle and frequency values of the electrical waveform, occurring at different locations across the power grid. This phasor information is relayed to devices such as phasor data concentrators (PDCs) for aggregation, storage, and further processing and analysis. This research work presents the study of dynamic synchrophasor estimation techniques with focus on the Taylor Fourier Transform (TFT). The aim of this research project is to design and implement a low-cost phasor measurement prototype for performing both P class and M class measurements. This shall be achieved by utilising two selectable versions of the TFT phasor estimation algorithm deployed on a STM32 Nucleo development board. By combining P and M class measurements on a single measurement device enhances the PMU for applications in both protection and monitoring. This notion is extensible to other smart grid applications and illustrates the multi-functional potential of a PMU on a single hardware platform. The performance and accuracy of the phasor and frequency estimations are evaluated via simulation and actual testing. The results are analysed and verified according to the requirements stipulated by the IEEE C37.118.1-2011 standard.