Digital Measurement System Research Based On The Electronic Instrument Mutual Inductor

Intelligent substation is an important development direction of smart grid.Intelligent substation is a traditional substation reformation direction and trend of new substation construction. As intelligent substation measurement function unit, digital measurement system based on the electronic instrument transformer has received more applications. However, digital measurement system exist many problems now. It's mainly reflected in the lack of relatively discipline and research about digital measuring transmission system comparison. Then, the technical index is not clear, can't test the value in its source. The influence of power quality problems at scene not be quantified.This paper mainly discusses the digital measurement system, error source, sampling value of transmission, communication links and so on has carried on the detailed research and analysis. The main results are as follows.First of all, this paper analyzes the digital substation digital measurement system composition, function and working principle of the various components, which based on the analysis digital measurement research status on domestic and international. Second,this paper theoretical analyzed the AD sampling dc imbalance of electronic instrument mutual inductor. Analyzed the influence of voltage, current harmonic, harmonics, the transient impact and network anomalies to digital watt-hour meter measuring accuracy.Puts forward the measures to improve the measurement accuracy. Again, the paper analyzes the working principle of electronic transformers and merging units, studied the frame transmission format and transmission principle of sampling values. Finally, this paper studied the digital measurement based on IEC61850 standard of communication,put forward the electric energy calibration method based on MMS protocol, which included the real load, virtual load calibration a variety of ways, work process of calibration is presented.To sum up, this paper's research have some practical value in engineering, which have a certain role in promoting improve the accuracy and security of the measurement system, improve the intelligent substation and operational level.