An improved three phase digital recorder system for calibrating power instrumentation

摘要

The paper describes an improved digital recorder system which is being used to measure accurately voltage, current, active, reactive and apparent powers and harmonic quantities for three phase sinusoidal and non-sinusoidal calibrations. The system has been designed to be used in the laboratory at the National Research Council of Canada (NRC) or transported on-site for tests in electrical utility facilities. Preliminary tests have shown that for sinusoidal waveforms, the accuracy of the voltage and current measurements of the digital recorder is better than 30 ppm and better than 50 ppm for active, reactive and apparent power measurements (with respect to full scale). The accuracy of the system for harmonic measurements is related to the harmonic content of the test waveforms and is estimated for individual tests.