The error analysis of measuring method in PT secondary circuit

A method of measuring the PT secondary voltage drop based on GPS is introduced, Because it get the reference time through GPS, two instrument in different place can collect data at the same time. Take no account of harmonic and the magnetic disturbance which affect the voltage acquisition, This article analyzed the distinction error caused by ADC accuracy and the data numbers which are sampled in one period of the signal; and analyzed the angular difference error caused by the GPS´s accuracy of time. In order to meet demand of the angular difference error and angular difference error, the AD´s length, sampling data per period, and GPS´s accuracy are given. The data is very helpful to design the PT Secondary Voltage Drop Monitoring System.