AN INSTRUMENT FOR REAL-TIME MEASUREMENTS IN ELECTRIC POWER SYSTEMS

Abstract

Conventional methods of measuring electrical parameters of a power system are based on electromechanical instruments. These electromechanical instruments suffer from inherent limitations common to all mechanical systems. In recent years, digital electronic techniques have been adapted to work with electromechanical instruments, resulting in hybrid devices with better features and a clearer presentation. However, these devices also have the same limitations as the mechanical systems. With modern developments in integrated circuit technology, microcomputers have become more powerful, yet less expensive, smaller and easier to use. This thesis presents a digital approach to measuring the operating parameters of a power system. Voltage and current signals derived from the individual phases are converted to discrete values and the system parameters are computed using a digital signal processing technique. The voltages, currents, active and reactive powers, energies, power factors, and frequency in a three phase power system are displayed, in real-time, on a standard video screen.