Study On Current Sensor Based On PCB Rogowski Coil

With the micro-electronics technology and computer technology are developing rapidly,the present power system development will be more automatic and intelligentized,it has put forward higher requirements to the power system. Traditional electromagnetic current sensor can no longer meet the requirements of the development of power systems because of its own disadvantage brought about by sensing mechanism.Therefore,the research and development of a new type of electronic current sensor which can have a fast and accurate measurement to the current become a hot issue.Rogowski coil current sensor is one of the electronic current sensor,it has become the ideal sensitive components for the Measurement of different heavy current in high-pressure system Because of its advantages,such as good insulation performance,wide bandwidth,low output power,simple structure,without magnetic saturation and so on.Firstly,This article discusses Rogowski coil's principle of measuring the current,and give a detailed analysis to Rogowski coil's two working states and its frequency characteristics.Through the establishment of Rogowski coil's mathematical model,this paper analyzes influencing factors brought by Wire on the measured position,outside interference magnetic field and temperature,and designs a number of improvement measures according to the analysis results.Secondly,according the general Rogowski coil's disadvantages,Combinating with the designing principles of high precision Rogowski coil and the optimizating methods of parameter,a kind of Rogowski coil based on Printed Circuit Board has been designed.The paper detailed introduces the production method of PCB Rogowski coil.It gives a kind of method which can not only restrain the Electromagnetic Interference but also increase the mutual inductance.By the establishment of PCB Rogowski coil's working mathematical model,Its simulation of the frequency characteristics proved that it has a good performance as a current sensor.Thirdly,the signal processing circuit of the sensor has been analysed and designed,and mainly discusses the integrator in detail.It selects Habitual aspect as the integrator upon request.According to the special working environment,the paper gives a specific electromagnetic shielding measures to enhance the anti-interference ability and improve the measurement accuracy.Finally,the measuring test to the PCB Rogowski coil current sensor is made. The measurement Includs the sensor's sensitivity,linearity,signal to noise ratio at different current,phase changes,Location Changement of the charge wire.Test results show that the sensor has good linearity and measurement accuracy,better anti-interference performance,and it can meet the requirement of power system.