The experimental studies to improve the measurements synchronization accuracy in the 10 kV feeder at zero crossing by calculated compensation of phase shift of voltage

Abstract

The article research a low-cost method for synchronization of measurements in distribution networks in terms of a mains' voltage signal zero crossing. In order to improve the accuracy of synchronization it is suggested compensating for the phase shift of voltage in the network nodes using the algorithmic technique relative to the power supply voltage. It calculates the network mode for the positive sequence of the fundamental harmonic to compute the phase shifts. The experimental field studies have been performed with the operating municipal 10 kV feeder and twelve 10/0.4 kV step-down transformers. The synchronized measurements of the phase voltages and currents have been executed with specially designed experimental 24 bit sigma-delta ADC IED with 10 minute periodicity at 40 ms intervals with a sampling frequency of 16 kHz in low voltage buses of all 12 substations and in the supply center of the feeder. The results of experimental studies have shown that algorithmic compensation of phase shift can improve the accuracy of measurements synchronization up to 0.5-3 microsecond