Electronic instrument transformer is one of the key equipments for the construction of smart grid, of which performance directly influences safety and economic benefit of digital substation and the necessary condition of accurate power measurement. The output signal of electronic instrument transformers is different from that of conventional electromagnetic transformers, which is classified into digital output and analogue output. Therefore, conventional calibration methods are not suitable for testing electronic instrument transformers. This paper takes electronic instrument transformer with analogue output as example; innovatively put forward employing precise shunt and oscilloscope to measure ratio error and phase displacement. Meanwhile, the data were verified and the results were satisfied.
