Study Of AC Electric Parameter Measuring System Based On Digital Sampling Principle

This thesis studies a measuring system of three phrase electricity parameter based digital sampling method. Its function includes the measuring of current, voltage,fre-quency, phrase, factor, active power and energy, reactive power and energy. The accuracy class of our system is 0.5 degree,its reactive accuracy is 2.0. With the rapid development of economy,the requirement of electric power is getting more and more, and electricity plays a more important pole as a commodity .This system will be more extended used to use for paying standard. The paper discusses the advent and development of digital sampling theory,inc- luding the synchronous sampling method,asynchronous sampling method and quasi-synchronous sampling method. Of all the methods, hardware synthronous sampling method cost less and its software is small. It takes less time to measure,so it is suit for real time measurement online and adopted in this paper. The paper gives its comments, theory, application, error analysis and software chart. Electromagnetic compatibility(EMC)is more and more important because it is an important standard of evaluating quality.But many technicians do not take it seriously. So the products designed in this way can not meet electromagnetic compatibility requirement and become flaw products。 To prevent the above occurrence,it is proposed in this paper that EMC design should be carefully treated in early product design.The methods such as grounding masking, filtering transient noise reduction are used to guarantee the electromagneticCompatibility.