Research On Weak Current(mA) Measurement By Rogowski Coil

With the development of power system to digitalization, automatization and intellection, it puts forward greatly demanding for facility of control, measurement, protection and inspection. At present, that makes new kinds of transducers and transformers is disquisitive hotspot at mainland and overseas. The paper introduces general situation of power system at first, and it also introduces principle and disadvantage of conventional TA/TV, CVT. It introduces principle and advantage of new kind of transformers. The paper introduces general situation of making new transformer national and international. Which uses Rogowski coil to measure weak current (mA ) is chosen to research. Secondly, the paper introduces principle of Rogowski coil and two kinds of working state of differential and integral. It analyses conditions that influence output of Rogowski coil. and response of static state and transient state in power system. The paper puts forward general principle for designing coils. Thirdly, it designs a special kind of coil to measure weak current, and analyse and demonstrate this coil. The paper analyses the back disposal electrocircuit and primarily describes integral electrocircuit. And base on it, it brings forward principle block diagram of inspecting imbalance current and measuring voltage of capacitor by surveying leak current of it to earth. Finally, the paper presents the results of linearity and temperature tests by special framework coil. And base on this coil, it design the whole experimentation of above-mentioned two applications and describe academic analysis of EMC. Giving the test results of the two applications and analyzing the test data. At last giving improvement and idea in future.