Research On Pulse High Current Detection Techno Logy Based On Flexible Rogowski Coil

With the progress and development of pulse power technology,pulse high current is widely used in electromagnetic artillery,radar launch,rail transportation,energy and chemical industry and many other fields,the demand for further improvement of pulse high current detection technology will also be more and more.The current domestic needs of high precision current sensors still need a large number of imports from abroad,in order to meet the huge domestic market demand.In addition,the common technical means of current detection field has poor long-term operational stability,low detection accuracy,limited measurement range and other defects,it is difficult to meet the detection needs of high-power pulsed electric energy.The accurate measurement of pulsed electrical energy has become a bottleneck problem that restricts the development of defense weapons and equipment.At the same time,along with the dramatic changes in the international situation,independent research and development is the way to go.Therefore,the study of a set of scientific and effective pulse high current detection system is of great significance to the development of many fields.The thesis analyzes and compares the advantages and disadvantages of several commonly used high-current testing methods,selects a Rogowski coil current sensing probe suitable for pulsed electric energy sources,studies the discharge characteristics and electromagnetic characteristics of high-power pulsed electric energy sources through simulation,and designs and completes a complete pulsed high-current detection system according to the expected index requirements.The main work of the thesis is as follows:(1)By theoretically analyzing the measurement principle of the Rogowski coil,the equivalent circuit model of the coil is established,and the two operating states of the coil with the best sampling resistance of its transfer function are simulated and analyzed.According to the numerical relationship between the electromagnetic and structural parameters of the coil,the factors affecting the dynamic performance of the Rogowski coil are studied.A combination of theory,simulation and experiment is adopted to summarize the optimized design process of Rogowski coils and greatly reduce the errors caused by front-end probe induction by improving the winding method of coils and adding compensation coils.On this basis,the Rogowski coils with reasonable structural parameters and excellent dynamic performance were developed and the performance verification experiments were conducted.(2)Based on the input and output characteristics of the Rogowski coil,the performance differences of several analog integrators are analyzed through theoretical calculations and simulations,and a circuit structure based on inverting active analog integrator is designed to widen the frequency band of the Rogowski coil and reduce the output signal of the Rogowski coil to a small voltage signal proportional to the original side current.After that,a power supply circuit module based on Sepic plus Cuk circuit is designed according to the power supply requirement of the integrator.After verifying the feasibility of the system,the hardware design and physical fabrication of the entire signal processing circuit were completed.(3)Using the self-researched pulsed electrical energy source and the T&M coaxial precision resistor as the main traceability standard,an experimental platform is built to experimentally verify the static noise,sensitivity,error,linearity,bandwidth,peak current and duration of the pulsed high-current measurement sensor.The experimental results show that the designed Rogowski coil pulse high current detection system can achieve a measurement range of 519.12kA,linearity less than 0.22%,relative error less than 0.5%,and 3dB bandwidth up to 138.8kHz,which fully meets the expected performance index.