Design And Realization Of Accuracy Tester For Current Transformer Based On Embedded System

With the expansion of the power grid size and the increasing application of electrical current transformers, due to the heavy task of accuracy test of traditional current transformer, heavy measurement equipment, difficult connections, it greatly increased the detection of the labor intensity measurement. Therefore, the development of new portable current transformer accuracy tester is of great significance.The paper introduces the concept of current transformers.The development of the current transformer calibrator accuracy is studied, as well as the significance of improving the accuracy of calibration errors.Meanwhile, the principle of the current transformer and error checking methods and principles are deeply analyzed.On this basis, the current transformer accuracy test instrument design thinking is proposed, which use ARM9 (S3C2410) as the CPU chip and embedded Linux as the core of software.Based on linux embedded development environment, the basic hardware design and software design are completed. In the part of hardware design, according to CT data acquisition and processing of precision, the multi-channel signal sampling and rapid conversion circuit are designed by AD7707 chip in the front acquisition module in hardware. the software synchronized sampling method ensure sample voltage and current signals.Besides RS-232 communication which can be used to connect the printer, Ethernetand and USB with transmission, storage of data are adopted which can improve device flexiblility. In the part of software design, the linux core is tailoring and transplanted successfully to embedded ARM processor on the basis of functions to be achieved. Application programs are realized and the detailed flow diagram is given, also the man-machine interface (GUI) is designed based on Qt/Embedde.The accuracy tester of current transformer based on embedded system not only has such advantages as automatically testing the current transformer accuracy, good man-machine interface, storing testing data through high-capacity USB, but also to achieve the original characteristics of the data validation results and comparison.On this basis, it can be further developed to be micro and highly intelligent in order tomeet the diffrerent needs. It has great value and broad prospects.