Design and construction of phasor measurement unit for ZETDC power system.

Abstract

Due to the increasingly complex nature of the electricity grid, it is very critical to provide the grid controllers with information that helps them make quality decisions and interventions to prevent catastrophic blackouts. Synchrophasors can be used on top of the traditional SCADA data to give controllers the instantaneous snapshot of the health of the grid. This work gives details of the design and prototyping of a Phasor Measurement Unit for the Zimbabwe Electricity Transmission and Distribution (ZETDC) electricity grid. The PMU is designed using Open Hardware Platform (Arduino Due with ARM cortex M3 Micro-controller) and gives voltage magnitude and phase angle of a three-phase system in real time. A Global Positioning System (GPS) is used to provide precise one pulse per second signal, which in turn is used to generate 3200 pulses per second. These pulses synchronize sampling by the Arduino Due Analog to Digital Converter (ADC). A 64-point Discrete Fourier Transform (DFT) is then used by the microcontroller to estimate the synchrophasors. The synchrophasors will be time stamped by the time reference obtained from the GPS module.