The Application Of Over Sampling Technology On Intelligent Monitoring Of Thetransformer

The transformer is the important equipment in the substation, as the development ofdigital substation and smart grid, the high precision acquisition of parameters and theintelligent cooling control has become the inevitable tendency of power career when thetransformer is monitored. Considering the actual project of electric power monitoringproducts, in order to improve the acquisition accuracy of the analog acquisition board in theintelligent monitoring of the transformer,this paper tells how to apply over samplingtechnology based on FPGA to analog acquisition board first time.By reducing quantizationnoise and increasing signal noise rate of the ADC, over sampling technology can increase theresolution of N bit ADC. This can not only balance the optimum between resolution and speedbut also reduce the cost of ADC. At the same time, it can simplify the anti aliasing analog filterbefore sampling, decrease the complexity of hardware circuit design.This work is mainly about the application of over sampling technology on intelligentmonitoring of the transformer. Firstly, FPGA is the controller, proper ADC chip and bustransceiver chip are selected as needed, and hardware circuit of sampling module isdesigned.Then, achieve that effective bit in FPGA is increased by over sampling, the mainwork includes as follow, sequence control for sixteen rate over sampling is achieved by statemachine. Pingpang operation is designed to decrease requirement for sequence. Windowfunction method and kaser window are used to calculate coefficients by modelsimsoftware.Distributed algorithms is applied to design FIR low pass filter to turn the keymultiplication into LUT process and the addition based on the LUT structure of FPGA and thedisadvantage of LUT is optimized,which can save hardware resource and improve hardwarerunning speed. Next, accomplish communication with monitoring board. Finally, the results ofover sampling before and after are analysised and the performance is verified. The results show that over sampling technology improved acquisition accuracy ofintelligent monitoring system of the transformer. So, over sampling technology can be appliedto all kands of acquisition systems for improving the resolution of the low precision ADC.