In order to transmit electricity power system, often using AC voltage, high current loop power sent to the user, can not be directly measured with instruments. Transformers and measurement instruments and measurement devices with Baoji high-voltage current transformer, can measure a voltage, current and power systems; and relay protection and automatic device with high-voltage current transformer Tongchuan, may constitute various faults on the grid electrical protection and automatic control. Transformer performance will Yan'an high voltage current transformer, a direct impact on the accuracy and reliability of relay protective devices power system measurements, measure. DC transformer error measuring method: 1.5 ~ 3V battery to the positive terminal of the transformer primary winding on L1, L2 then negative, the secondary side of the transformer connected milliammeter K1 positive and negative pole K2, take a good line, The K closed milliammeter pointer positive side, opened the milliammeter pointer after a negative bias, indicating that the transformer connected to the battery positive terminal head and connected to the positive terminal milliammeter ends of the same polarity. 1.K1 the same polarity that transformer is minus polarity. Contrary to the above, such as pointers to swing plus polarity. Hanzhong high voltage power transformers _ Huayi (certified) _ transformer provided by Xian Huayi power plant. Xian Huayi power plant (www.xahy.com) is a leader in Xi'an, high voltage circuit breakers, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Huayi power in leadership with the staff warmly welcome all inquiries negotiations to create electricity Huayi a better future.