Current transformers （TAs） 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 TAs are used for measurement and protection, the problems of their magnetic path saturation always disturb people. With the development of the computerized and digital technology of measurement and protections devices, the devices don＇t match with TAs 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. Rogowski coils are increasingly used to measure high voltage AC current, pulse current and transient current in power industry. Rogowski coils have the advantages of small output power, simple construction and ideal linearity. There are three different cross sections of Rogowski coils, that are Rogowski coils with rectangular cross section, with circular cross section and with cross section in racetrack shape. Three typical mathematical models of Rogowski coils are introduced in this paper. The relations between dimensions （width, thickness and central radii of Rogowski coils） and electromagnetic parameters （inductance, mutual inductance and resistance of Rogowski coils,） of the Rogowski coil have been studied. Furthermore, the graph between dimensions and electromagnetic parameters is gained. By means of software MATLAB, it is verified by theory that Rogowski coil with circular cross section is the best in three different configuration and Rogowski coil with cross section in racetrack shape is better than Rogowski coil with rectangular cross section.
High Voltage Engineering
cross section shape