Development of Substation Secondary Signal Phase Wireless Testing Device

Aiming at the problem of phase test of secondary signal, a new phase test device was designed. In the field application process of 220kV substation, when the secondary current of current transformer is 2mA, the device can accurately measure the ratio, polarity and phase. When the transformer differential protection circuit is checked, because of the high short-circuit impedance for the main transformer, there is no way to accurately read the data of the secondary current in the protection, the using of the new phase testing device can complete the checking of the secondary wiring, the charge checking protection and polarity error of the metering circuit are avoided effectively.