Study On Non-traditional Electronic Voltage Transformer

Traditional voltage transformer has many disadvantages. Insulation cost is high, the measuring frequency band is narrow, dynamic range is small, which makes it difficult to adapt to the digital development of power system. This paper studies two kinds of non-traditional voltage transformers based on new principle. Electrostatic diaphragm voltage transformer integrated use of optical fiber technology, microelectronics technology; its insulation is simple and reliable, wide measurement bandwidth, large dynamic range, by choosing appropriate film can achieve good measurement effect. The electronic voltage transformer based on parallel plate capacitor voltage divider, which has simple structure, reliable insulation, low cost, and at the same time can guarantee accuracy of measurement. This could be used for voltage monitoring.This paper discusses the basic principle of electrostatic diaphragm type voltage transformer based on electrostatic drive microstructure. Under the effects of the electric field in the plate with high pressure, the polarization film with static charges can produce displacement; by measuring the displacement of the thin film can obtain the voltage being measured. In the electrostatic diaphragm physical model, film movement is analyzed, film forced vibration equation is derived, and the thin film vibration displacement expression is solved. Results show that thin film vibration displacement and the measured voltage into a linear relationship. And through the modeling and simulation, test the diaphragm sensor measurement accuracy can meet the requirements of the accuracy of measuring 0.1 degree in theory. Combined with the electronic voltage transformer design standards given by the International Electrotechnical Commission, put forward the total design scheme block diagram of electrostatic diaphragm type voltage transformer, introduce the specific implementation method of each part respectively.Then, this paper proposes a parallel plate electrode capacitive voltage divider as a sensor of electronic voltage transformer, and its steady state and transient performance is analyzed, and combining the analysis results, optimize the parameter design, makes the voltage divider meet the requirements of transient characteristics. Combined with the electronic voltage transformer design standards given by the International Electrotechnical Commission, put forward the total design scheme block diagram of the electronic voltage transformer based on parallel plate capacitor voltage divider, introduce the specific implementation method of each part respectively.Finally, combined with the electronic voltage transformer calibration standards and national standards for the accuracy of measuring degree of electronic voltage transformers, according to the definition of electronic current transformer ratio error and phase error, the accuracy test of principle prototype of the electrostatic diaphragm type voltage transformer and the electronic voltage transformer based on parallel plate capacitor voltage divider ware tested respectively. Experimental results show that the principle prototype of the electrostatic diaphragm type voltage transformer and the electronic voltage transformer based on parallel plate capacitor voltage divider can meet the requirements of the accuracy of measuring 3.0 degree.