Modeling Method And Development Technology Of Highfrequency Current Sensor Based On Electromagnetic Induction Principle

With the wide application of high-frequency currents in many fields,accurate measurement of high-frequency currents has become very important,and the demand for highfrequency current sensors in China is becoming more urgent.However,compared with foreign countries that have mature high-frequency current measurement technology and leading international product instruments,the research and development of high-frequency current sensors in China is progressing slowly.Therefore,it is very necessary to realize the independent development of domestic high-frequency current sensor instruments.The main goal of this article is to propose a design scheme for high-frequency current sensors,so that its dynamic response range and operating frequency band meet the needs of most high-frequency current measurements,and explore to solve the problem of high-frequency current measurements.In this paper,iron core coils based on the principle of electromagnetic induction are selected from many common sensors as the research object,and the three major problems that need to be solved in the development of high-frequency current sensors are discussed in depth: the establishment of a true and effective high-frequency equivalent model,the improvement of traditional winding coil sensing accuracy and reducing spurious parameters to increase the high-frequency cutoff frequency.In order to solve the above problems,this paper first uses the mathematical recursion method to establish the frequency characteristic model of the sensor,which truly and accurately reflects the internal transient process of the sensor under the high-frequency signal,and realizes the infinite simulation of its frequency characteristic.Based on this model,the influence of the coil parameters on the frequency characteristics of the sensor is deeply studied.Using the research results of the influencing factors of the sensor's frequency characteristics,a design scheme of high-frequency current sensor based on iron core coil is proposed,and its frequency characteristics are verified by simulation to meet the design requirements.In the development of the sensor,two key technologies were proposed,namely the Core-PCB hybrid structure and the staggered-arrange-secondary winding,which realized the equal and accurate wiring of the secondary winding and improved the measurement accuracy of the sensor.Stray capacitance parameters are also reduced,effectively increasing the high-frequency cutoff frequency of the sensor and widening its operating frequency band.Then,according to the design plan and development technology,a high-frequency current sensor based on the iron core coil was fabricated.Finally,with the support of the Chinese Academy of Metrology,this paper completed the performance test of the high-frequency current sensor.The test results show that when the rated current is 1 A / 10 A,the measurement frequency band is 2.5 k Hz-1 MHz,and the rated current is At 50 A,the measurement frequency band is 2.5 k Hz-75 k Hz,and the above measurement errors are within ± 1%.Both the operating frequency band and the measurement error meet the requirements of the subject.