Research Of Resistive-Capacitive Divider Electronic Voltage Transformer

Recently years, with the development of our country's economy construction, electric utility industry has grown quickly. The power capacity is expanding more and more, remote transmit electricity are improving rapidly, voltage grade is escalated. These all provided wider development foreground to high voltage transformer. As for measuring equipment in power system, the precision and reliability of instrument transformer has contacted tightly with the security, economical operation of power system, therefore with high voltage or ultrahigh voltage system's expanding more strictly requirements are put forth. Otherwise, the automatic and intelligent trend on measure, monitor, control and protection of the power system, as well as the virtues of high dependability, low cost and compacted structure that compared with conventional transformer, which promoted the research on the new electronic transformer.This paper summarized the survey of present ET study, aiming at the problem of the transient response of capacitive divider, author put forward a new measuring voltage principle—resistive-capacitive divider transducer. Firstly the structure and measure principle are presented; the frequency characteristic, error characteristic and stable/transient response are analyzed in theory. Then the electro magnetic compatibility (EMS), energy supply system and safeguard are researched on. Author has made an experiment model, and accomplished linearity and transient response test by using existing laboratory facility and instruments. Through the test result, it was testified that the transducer based on the new principle has good characteristics in stable response and transient response.For reducing the cost of construction and operation of power system, and to be good at realization of the digital fiber and intelligent substation, this paper analyzed electronic transformer data collection and signal processing system, which included lowpass filter, integrator, A/D convertor and fiber transmission unit etc. In respect of IEC standard on ET output with the interface of protection and control, not only the definition, communication character, function model and technical difficulty are discussed in detail, but also the realization principle of interface technique based on FPGA.