Transformers (instrument transformer), also known as instrument transformers transformers, current transformers and voltage transformers are collectively. High voltage can become a low voltage, high current into a small current for measurement or protection system. Its main function is to high voltage or high current in proportion converted into standard low voltage (100V) or standard low-current (5A or 1A, refer to the rating), in order to realize the measurement instruments, standardized equipment protection and automatic control equipment, small technology. At the same time the high voltage transformer can be used to separate high voltage transformer system Yan'an, in order to ensure the safety of persons and equipment. The basic principle of zero sequence transformer zero sequence current protection is based on Kirchhoff's current law: any node in the circuit flows into the complex algebra and zero current. In line with the electrical equipment under normal circumstances, each phase current vector and zero, therefore, zero-sequence current transformer secondary winding no signal output, the actuator does not operate. When each phase current ground fault occurs in the vector is not zero, the fault current to zero sequence current transformer toroidal magnetic flux is generated in the secondary induced voltage zero-sequence current transformer so that the high-pressure actuator action Hanzhong transformers, driven tripping device, switching power supply network, to ground fault protection purposes. Xianyang 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.