Study And Design On Rogowski Coil

Current transformers (CTs) are important components in power system. And they play a primary role for working well and calculating precisely in power system. With the development of national economy, all kinds of new voltage levels and current levels emerge continuously, the high precise of measurement and protection are demanded increasingly. When traditional electromagnetic type CTs are used for measurement and protection, they are found to have many insurmountable questions. Especially the problem of their magnetic path saturation always disturbs people. With the development of the computerized and digital technology of measurement and protections devices, the devices don't match with CTs of big output power. Thus electronic current transformers (ECA) based on Rogowski coil with the advantages of small output power, simple construction and ideal linearity attract people's attention and come into extensive research. The main work we have done is:(l)The ECA based on Rogowski coil is compared with traditional electromagnetic type CT in this paper. From the basic concept of Rogowski coil, it introduces the primary parameters' measurement of the Rogowski coil-mutual inductance coefficient and analyzes the characteristics of Rogowski coil between amplitude and frequency. In addition, it researches into the thermal expansion effect on measurement precision of Rogowski coils and compensation method.(2)From theoretical analysis, the excellent characteristics and feasibility of Rogowski coil are demonstrated. Furthermore, three shapes of former section of Rogowski coil are finded and the thermal expansion effect on performance ofRogowski coil is evaluated.(3)For the electromagnetic disturbance, the influence on Rogowski coil isanalysed and the measure of electromagnetic Shield is educed. Moreover,Rogowski coils are fabricated and some experiments are done.(4)Finally, the experimental result and error such as assemblage, temperature are analysed.