Single-phase virtual power and energy analyzer in compliance with IEEE Std 1459–2000 for harmonic measurements on discharge lamps

This paper presents a single phase power-energy analyser with the required specifications for the investigation of the electrical performance of non-linear loads and especially of discharge lamps. It has been developed using a graphical programming language. The definitions of the quantities that can be measured (spectrum, power and energy analysis) are in compliance with IEEE Std 1459-2000. All the necessary measurements are taken in real time, on line. A DAQ board through two analogue input channels samples the voltage and current waveforms. Their frequency spectra are determined using FFT and DFT. An innovation of the designed instrumentation is that powers and energies can be recorded in time bands that are independent each other so can be overlapped. Another considerable innovation is that the virtual instrument is easily adapted to take additional measurements for new quantities, modifying the software, while the measurement of the nonlinear load is in progress. The cost of the system is very low compared with a conventional one consisting of a number of meters as oscilloscope, true rms multifunction meter, power and energy analyser.