Research On Hall Heavy Current Senor Without Iron Core

In the monitoring of the distribution network,especially in the distribution network fault,the system will generate a large number of instantaneous nonlinear fault current.However,due to the limitation of the core,the traditional electromagnetic current sensor can not accurately reflect the fault current.Therefore,this paper puts forward a kind of Hall current sensor without iron core,which is used to monitor the normal operation of the distribution network and the current in the short circuit fault.Normally,the normal operation of the distribution network is a few kA,shortcircuit fault current is about kA.When the sensor with iron core is used,its volume is large and the measuring range is limited.In addition,there are some limitations in the current measurement.The Hall current sensor without iron core is not only small in size,but also wider in bandwidth of the element.It can also measure the DC and harmonic components.Moreover,it can be achieved without changing the structure of the sensor,only through the programming or replacement of the Hall element to achieve the requirements of different measuring range,different precision requirements of the current.The main limitation of the Hall current sensor without iron core is that: compared with the core of the sensor with the iron core,the core structure of the sensor has low signal noise ratio(SNR).Therefore,this paper focuses on the improvement of the signal to noise ratio of the sensor and the main way to solve the problem.Including the weighted field disturbance decoupling method,decoupling method,Ampere’s law and wire localization algorithm into the sensor design,detailed analysis of the formula and the applicable conditions of the principle,the above algorithm,and simulation method in MATLAB,the method of precision,anti-jamming,measured wire position the measurement error affects the overall evaluation of the performance of the algorithm.In particular,the algorithm proposed in this paper can be used to calculate the current through the measured magnetic field under the relative position of the unknown wire and Hall element.The design and implementation of circular and linear structure of coreless Hall current sensor,calculation method,sensor selection and current resolution relationship,Hall element gives PCB structure from the point of view of theory selection methods,to provide reference for specific application scenarios for sensor design.Finally,the Hall current sensor module is developed,and the performance of the sensor is verified by the measurement of power frequency current and direct current.Among them,the measurement accuracy of the wire positioning algorithm can be up to 1%(DC)and 4.2%(AC)in the experiment.