Research Of 10kV Electronic Voltage Transformer Based On Resistive Voltage Divider

The voltage transformer is an important equipment of relay protection and energy measurement in power system, whose performance is related with the safe, reliable and economical operation of the power system. With the development of the power system, the power grid voltage level is rising constantly, and at present the highest voltage level has reached up to 750kV. It makes new demands about the equipments of measurement and protection. As the critical equipment of measurement and protection, the voltage transformer also has an increase in demand. But the traditional electromagnetic voltage transformer faces some insurmountable weaknesses because of the restrictions of its sensing principle. The resistor voltage transformer is a brand new voltage transformer which uses the technology of Electronics and Material. It can be made as an electronic voltage transformer(EVT), and it also has a traditional analog signals output. The resistor voltage transformer has many advantages, such as high precision, high reliability, and wide frequency bandwidth, etc.Based on the requirements of EVT in current power system, this paper designed a resistor voltage transformer which can work well and meet the standard of IEC 60044-7 and the national standard. The resistor voltage transformer uses resistive voltage divider as the sensor. After processed by secondary circuit, the voltage signals from the sensor can be transmitted to the next intelligence electronic devices (IED) as analog signal or digital signal.IEC 61850 for substation automation is the first integrated communication standards. It uses an object-oriented modeling technique and an open architecture facing the future. Its goal is to achieve the interoperability of the equipments from different manufacturers. IEC 61850-9-1 standardize the communication services between merging unit (MU) which collects the signal from the electronic transformers and IED served in the bay level. This paper discusses a method to realize the MU and the interface between EVT and the MU. The application of new EVT must make a great effect on the structure of the substation automation.