On the Impact of Winding Selection of Current Instrument Transformers for PMU Measurements

Monitoring and control of the energy transfer in electricity grids is performed using the information provided by complex measurement systems, most of them including voltage and current instrument transformers. Inductive current transformers have two sets of windings, one supplying information to the control and protection units, while a second one is reserved to transactions mediated by the energy meters. The advent of synchronized measurements and the need of complex, fast and accurate control algorithms in smart grids, there is less and less difference among the use of measurement information. In this paper we investigate the use of measurement data from protection windings of current instrument transformers as input for steady-state control loops. Several examples show that the quality of such measurements is compatible with that of data quality obtained from the measurement windings of same instrument transformers.