Research On The Electronic Current Transformer

Traditional current transformers are hard to meet the developmental requirement of the online testing, high accurate hitch testing and the computer controlling because of its own mechanism limits. And the Electronic Current Transformers have been the head tide because they have the greater dynamic bound, higher testing accuracy, wider frequency answering bound, more saving room, lighter weight, better anti-jamming, higher security and more simple configuration. Those virtues are conformance to the developmental request of the electric power system's testing, controlling and protecting which are towards to the digital, micromation and intelligentizing direction.Firstly, this paper introduces the research actuality and the developmental situation of electronic current transformers. Discussing the design principle of the electronic current transformers. And then, presenting the particular design method. This text directs against the requisition for the electronic current transformer of Power industry, we design a Rogowski coil as sensor on the high-voltage line. The analysis of simulation shows that this Rogowski coil could measure steady AC current accurately, it also has a good performance in describing the transient process of fault current, and it has been verified in the dynamic test. From the simulation analysis, we know that improve the integrator capacitor parameters of the ntegrator with negative feedback can improve its transient response performance. I-U experiment shows this Rogowski coil has a good linear relation, after digitizing the output of Rogowski coil, we convey it to the low-voltage Part by digital transmission system, and resume it into original signal in order to realize the measurement of the current of the high-voltage bus, System adopts the way of low-voltage Part controlling high-voltage Part to realize the synchronization of the two Parts. We make use of digital transmission system to realize totally isolate and signal transmission between the high-voltage Part and low-voltage Part. This method has improved the anti-interference of signal transmission, and it has been proved that Optical transmission is very reliable and effective. And then a DSP displaying system based on the kernel SED1335 controller is introduced, which can display the waveform, virtual value, frequency and cycle period of the sampling signal, and supply a friendly human-machine interface to users. In the end, the paper summarizes the research content. Pointing out the research deficiency, And the Problems that need to be further researched and resolved are proposed.