Supply voltage dip monitoring with a sparse sampling kWh-meter

摘要

An advanced kWh-meter can be used simultaneously both for versatile billing tariff measurements and for power quality monitoring. The needs and potential for developing dip measurements, and experience with new fairly inexpensive sparse sampling kWh-meters, are discussed. The effects of sparse sampling on the accuracy of voltage dip measurements are studied and the requirements the dip measurements impose on the sampling rate are analyzed. Principles, simulations, laboratory tests and field measurements are presented. Evaluation of phase-to-phase dips from phase-to-neutral measurements is also discussed. The sampling rate of the tested meter was as low as about 409 Hz. The ability to measure voltage dips has been quite an important new feature of this kwh-meter and has promoted its use.