Designation Of The On-Site Monitoring Data Acquisition System Based On Complex Programmable Logic Device

This Master degree thesis,based on the observing of developing actuality of on-site electrical apparatus monitoring technology,aims at overcoming the problems existing in former on-site monitoring system,such as unable to realize multiple channels sampling and hold,unable to carry out multiple channel programmable magnification,unable to monitor frequency,low pick up bits,external ROM low speed data saving,inefficient data query method,inflexible debugging and installation,low precision etc. By introducing EDA(Electrical Design Automation) technology,we put forward a creative circuit design scheme,which can considerable updated the on-site monitor system.By comprehending the theory of computer programmable logic device and comparing of various of CPLD structures,we choose FLEX10K series chip as the central controlling part of data acquisition card,which is theoretically fit for on-site monitoring technology. High speed 14 bits 4 channels synchronous A/D converter is also chosen,which can successfully lead to sampling and hold of multiple channels signals.This CPLD based on-site monitoring data acquisition card can flexibly realize 3 triggering ways,including software triggering,hardware triggering and external triggering. In addition,this card can also realize optional 128 or 256 signal multiple frequency sampling. The FIFO module in CPLD's inner EABs (Embed Array Blocks) further lead to the convenience of data saving and loading. The function simulation by using MAXPLUSU software for CPLD internal modules proves the availability of design.Computer controlling software is also programmed,by which the software miss simulation and analysis are processed to discover possible disturbing factors and present practical resolutions. To fulfill the sampling need,a VXD interruption driver program is composed by utilizing VtoolsD software. Inaddition,a creative dielectric loss measuring method-enhanced orthogonal arithmetic method waspresented based on the flexibility design of the monitoring system.Finally,this CPLD based on-site monitoring data acquisition card went through laboratory debugging. All test data indicate the precision,stability and flexibility of this product in measuring multiple parameters in power system.