Electromagnetic Voltage Transformer (PT) and Capacitive Voltage Transformer (CVT) are widely used in power system. Although capacitive voltage transformers and electromagnetic current transformers commonly used in power grids have mature technology and long-term operation and maintenance experience, their measurement linearity is poor, the transient response speed is slow, and the transient error characteristics of electromagnetic current transformers are not ideal.

A power transformer is a static machine used for transforming power from one circuit to another without changing the frequency. As there is no rotating or moving parts, a transformer is classified as a static device. Transformer operates on an AC supply. Transformers operate based on the principle of mutual induction.