Harmonic voltage measurements using CVTs

A method for harmonic measurements in EHV systems is proposed that is based on the measurement of currents in capacitor voltage transformers (CVT) and values of capacitor elements of CVTs. This is the basis of a new technique, which uses current sensors installed within CVTs. Simulation studies and field tests have confirmed the validity and practicability of the technique. In the new method the input terminal voltage is directly determined and no information about transfer function and burden is required. In order to verify the field test results, errors in the CVT output voltage recorded during tests were compensated by the use of the transfer function determined independently in transfer function tests for the same burden. A very good correlation was observed between the two results. The results of field measurements are also presented.