Application and Research of Virtual Instruments Technology in the Power System Measuring
|School||PLA Information Engineering University|
|Course||Applied Computer Technology|
|Keywords||Virtual instrument LabVIEW Quasi - synchronization algorithm Worse than the Angle difference Online check|
At present , the power industry reform and the implementation of the generation , transmission separation makes energy metering accuracy and impartiality and more aroused great concern of all parties . The error of the current transformer is directly related to the energy metering error , so the need for monitoring current transformer is running error is undoubted . In order to ensure the accuracy of energy metering , monitoring current transformer needs to run online without blackout . In this paper, the virtual instrument technology to build a current transformer calibration system using pure software way worse than angle difference calculation , to make it suitable for the calibration of analog and digital signals . This paper first introduces the basic concepts of the virtual instrument , and then introduced the system hardware and software . The hardware includes the choice of sensor, a high - pressure side of the power supply mode , the signal modulation method . The software part includes synchronous sampling the high pressure side , and fiber optic data transmission , the low pressure side of the dual data reception , the communication between the low pressure side of the PC, microcontroller design , the VC design the underlying data processing section , LabVIEW design data analysis . In the bottom part of the data processing portion of to design simple frequency-locking algorithm and quasi - synchronization algorithm for processing the sampled data . The main design idea is to accurately measure the frequency of the measured analog signal at the same time extend the FFT calculation of the number of data samples and tested to verify the algorithm can effectively compensate for the out-of-sync error \The experiments show that , under the system in the frequency 50Hz worse than the change is less than 0.05% , and changes in the angle difference of less than 0.03 ° , frequency error 49.8Hz-50.2Hz volatility changes do not exceed 0.02% . The design of the 0.1 technical requirements for online verification system , to achieve the goal of the current transformer online check .