New Current Measuring Technology Based On Hall Effect And Rogowski Coil

The paper is focused on searching for new methods, which can be applied extensively in DC and AC current measurements. According to the research on the method and design of Hall Current Transformer (HCT) and Rogowski Sensor, new transducer modules are presented to take the place of traditional ones with many disadvantages, and new transformers are carried out in practical application and industrialization.HCT is a simple and effective technique in DC or low frequency current measurements. Classical Open-loop HCT has low linearity, limited dynamic range, heavy weight and high price, while Close-loop HCT has complicated structure and increasing price with the increasing of rated current even if zero flux method brings good linearity. In view of transducer module, this paper presents new idea to design HCT, which has no magnetic core with air-gap any more. Circular-Array HCT is based on the magnetic distribution of long-vertical current carrying conductor and can be applied in heavy DC current measurement. On the other hand, Solenoid HCT is based on the magnetic distribution of solenoid conductor and can be used in low current measurement such as leaking current detecting. In point of engineering practice, PCB technology is chosen in the paper to produce Solenoid HCT and Circular-Array HCT. Both new sensors based on PCB and Hall elements have high linearity, exact dynamic range, light weight and low price, which makes them befitting to be mass applied in industry fields.Rogowski Coil has been regarded extremely in alternating magnetic fields measurement and AC current measurement since it was invented. However, low linearity, poor coherence in mass production and temperature instability are the pivotal factors to restrict the vast application and industrialization of Rogowski Coil.In the view of transducer module, it is proved in the paper that Rogowski Coil and Circular-Array HCT are essential consistent. Four basic supposes of perfect Rogowski Coil are summarized, and PCB technology brings chances to develop and extend the existing traditional Rogowski Coil structure. There are three kinds of Rogowski Coil based on PCB technology and long-vertical conductor magnetic distribution called Planar Rogowski Coil, Combined Rogowski Coil and Twin-loops Rogowski Coil. Solenoid Rogowski Coil is based in the magnetic distribution of solenoid current carrying conductor. Different Rogowski Coils are selected as AC current transformer in power system, Plasma current sensor in Tokamak and CT in electronic power energy metering, and new sensors have been used experimentally.Theoretical analysis and actual test indicate that all sensors presented in the paper, including Circular-Array HCT, Solenoid HCT and Rogowski Coils based on PCB, have many advantages and huge potential values to be spread in relevant application fields with different frequency and different scope.