Investigations On Practicality And Design Of Electronic Current Transformer

With the continuous improvement of transmission capacity and voltage level in power system,the traditional electromagnetic current transformers have more and more weaknesses and have been difficult to meet the need that network develops towards automation and digitized direction.In recent years,the electronic current transformer(ECT)is studied extensively at home and abroad,become a revolutionary research. This dissertationg is devoted to correlative research on the practical application for several aspects, including product design of sensors, practical application of integrator for electronic current transformer, research on standardize interface.(1) Rogowski coil is the current sensor. The basic principles of Rogowski coil are summarized, the analysis to static characteristic and transient characteristic, and the calculation of electomagnetism parameter. On the basis of theory, two industrial problems are discussed: the realization of exchangeability and temperature compensation.(2) The performance of integrator is always one of the important factors which influence the accuracy and reliability of Rogowski current transformer. The digital integrator have made it a hot problem of studying the utility of Rogowski current transformer in recent years. This paper puts forwards a set of methods of digital integrator designing , which include the choice of integration algorithm, the determine of the sampling rate and the resolution of the integration input, dealing with the input drift, the initial value and input saturation.Also it realizes a model of digital integrator and makes some experiments.(3) The standard data interface is the demand of industrialization, and the assurance of elecronic current transformer products entering practice, realizing exchanging and operating. This paper discusses elecronic transformer and its standard interface structure and model, and summarizes the designing method of standard interface, which include the analogue interface and the digital interface in IEC61850-9-1.(4) According to the study of the standard interface of elecronic transformer, this paper put forward the whole designing idea based on standard interface and also concerning the system reliability and the electromagnetic compatible. With regard to standard interface, three problems are discussed: the synchronization of transformers, the low power design of circuit on the high voltage side and the realization of standard interface.