Research On Data Of Dynamic Real-Time Monitoring On Transformer

With the development and the applications of GPS and PMU in power system, the monitoring on transformer based on SCADA is changed to the dynamic monitoring based on the instantaneous data acquisition.The datum of voltage and current values are gained from PMU and embedded the synchronous singnals.The synchronous datum are transported to the dispatching center in order to make them master the synchronous running status of every transformer in substation.So, the real-time analysis and the exact dispatching can be assured.The dynamical stable control are realized so as to improve the automatical monitoring level. Meanwhile,the loss can be reduced when the trouble are happened and the power safty are guaranteed.In this paper, the dynamic and real-time monitoring on transformer are proposed and the four parts of data acquisition,data processing ,data storage and data interviewer have been designed.Firstly, the data acquisition flat roof of dynamic real-time monitoring on the transformer is constructed.The serial port communications between the data acquisition device and position machine are realized by using VC++ programmable language. The data acquisitions of current and voltage instantaneous values are recorded and their curves of serval periods are displayed.Secondly,the phase values of voltage and current are calculated by using the aquision datum.The median filter method is selected to delete the data noise before the phase calculation.The fourier algorithm,Recursive least square algorithm and Kalman algorithm are chosen to apply in the phase calculation.The calculational precisions of three algorithms are compared with according to the calculational errors.Two singnals in which the harmonic component and decaying dc component are included are considered separately and the calculational results are analyzed.At the same time,the errors caused by the non-synchronization sample is solved by tracing the real-time frequency.The errors caused by PT,CT,white noise and A/D converter bits are analyzed.Lastly, SQL Server 2000 is selected as the database management system because of greater storage abilities and better real-time properties.Two manners are designed to interview the database management.One is the modal of client to server, and the other is the one of brower to server.According to this,the shortages of limited interview and smallest safty on C/S are overcomed.The specifical realization processes of dynamic and real-time monitoring on transformer are described in this paper by which the powerful reference bases are provided for transformer monitoring.