Primary AC Power Standard Based on Programmable Josephson Junction Arrays

Josephson series arrays have been operated as digital-to-analog converters with fundamental accuracy to generate precision waveforms with accuracies better than one part in 10⁷ at power frequencies. These waveforms have been used in the past to calibrate the sampling voltmeter in the primary standard for electrical power at the Physikalisch-Technische Bundesanstalt (PTB). The present contribution reports the integration of such a Josephson waveform synthesizer into the PTB primary power standard in order to continuously calibrate the sampling voltmeter and thus reduce the uncertainty for the measurement of active, reactive, and apparent power at the 120-V and 5-A levels