Design And Research Of Rogowski Coil Magnetic Shielding Box

As a new type of current transformer,Rogowski coil is widely used in the measurement of high current and high voltage in power system.Compared with the traditional electromagne tic current transformer,it has a series of advantages such as wide measuring range,fast respon se,and no magnetic saturation.However,due to the extremely complex external environment i n which it works,there are often large interfering magnetic fields around the main electrical e quipment of power systems such as power generation terminals,large generator sets,large tra nsformers,and plant busbars,which will cause a great deal of accuracy in the measurement of Rogowski coils.The influence of shielding the external magnetic field is of great significance for improving the accuracy of Rogowski coil measurement.At present,the researches on Rog owski coils mainly focus on improving the design of Rogowski coils and improving the accur acy of transmission.For the design of shielding magnetic field shielding and shielding box sp ecifications,there is still lack of in-depth experimental analysis.Based on the above backgrou nd,this paper designs a Rogowski coil magnetic shielding box based on Rogowski coil magne tic interference analysis and magnetic shielding design points.And through the simulation,test in-depth analysis of its working characteristics,proved the rationality of the magnetic shieldi ng box design.This paper first analyzes the measurement principle of Rogowski coil and the five main factors that cause Rogowski coil measurement error,and then analyzes the electromagnetic field shielding principle and shielding method.Based on the above theoretical analysis of magnetic interference analysis and magnetic shielding design of Rogowski coils,a magnetic shielding box of Rogowski coils with a middle slit is designed,and a semi-shielded box is designed as a comparative analysis.Secondly,using the Ansys Maxwell to simulate and analyze the magnetic shielding box of the Rogowski coil,firstly,the shielding effect of different magnetic shielding materials was simulated and compared;then,when the current frequency is 50Hz and 200kHz,the magneti c shielding box is used to simulate the normal signal.Analysis of the influence of attenuation;Considering that the external disturbance magnetic field is the phase-to-phase power frequenc y interference,the shielding effect of the magnetic shielding box on the external disturbance magnetic field is simulated and analyzed;Finally,the influence of the magnetic shielding box on the normal signal attenuation at di fferent current sizes and frequencies was verified by experiments;and the shielding of the magnetic shielding box from the external disturbance magnetic field when the external distu rbance magnetic field is the phase-to-phase power frequency interference and core resonance i nterference was verified.The test results are consistent with the simulation results,indicating t hat the full shielded box has better performance,the signal attenuation is relatively low after th e shielding box is added under the low-frequency current in obtaining the normal signal.Obvi ously,the attenuation of the signal is smaller after the shielding box is added under high-frequ ency current conditions;at the same time,the anti-magnetic interference capability is greatly i mproved after the shielding box is added.The magnetic shielding box designed in this paper h as certain guiding significance for Rogowski coil field application.