Factors Influencing The Frequency Response Of Capacitive Voltage Transformer

Abstract

Instrument transformers are the integral components of power system protection and metering. The objective of instrument transformers is to provide scaled down replicas of high voltages and currents of the power system. In case of high voltage transmission network (≥132KV), capacitive voltage transformers are widely used as an alternative to electromagnetic voltage transformers due to their techno economic advantages. They transform higher voltages to lower values which are easily measurable and can be directly used for metering, protection and control applications. During the system transient conditions, there is a deviation in the scaled down secondary voltage signal from the actual signal which comprises of wide range of frequencies, due to energy storing elements of capacitive voltage transformer. There are several practices in the industry to mitigate the deviation in the secondary voltage signal of capacitive voltage transformer. For satisfactory operation of capacitive voltage transformer, better frequency response is desirable. The simulation study to determine the effect of various factors influencing the frequency response of capacitive voltage transformer are presented in this paper.

Frequency Response Test of MV Inductive Voltage Transformers for Power Quality Applications

“…2 shows the electric diagram, where V1 represents the voltage at the high voltage terminal, V2 the voltage at the low voltage terminal, and C1 and C2 are the capacitances connected in series. This transducer has as its main characteristic the linearity over the frequency domain [5], [8]. This relationship is observed in (1), which indicates voltage V2 as a function of the high voltage V1.…”