Research On Adn Design Of A Current Sensor For DC Superimposed Pulse Current

With the development of the times,power electronic equipment and system gradually develop toward the application of high-frequency technology,intelligent,systematic and green direction because society requirements on the environment,energy and efficient are getting higher and higher.Accurate current measurement is the basic requirement of power electronic equipment,in different applications,the current has different waveforms,bandwidth and range.In practical applications,there is a type of current waveform for the DC superimposed pulse current waveform,which contains the DC component and the pulse component,and may has a large bandwidth.So high performance current sensor is required.This paper proposed a new type of current sensor,which can accurately measures the complex current waveforms including the DC,pulse current and DC superimposed pulse current.The prototype and experimental research were performed depending on the analysis in theory and simulation verification.Specific work is as follows:1.The proposed current sensor mainly includes DC component detection,pulse current component detection and DSP signal processing circuit.First of all,the overall structure of the sensor was designed and each structure is analyzed in detail.According to the different current wave forms,different detection methods and signal processing power circuit are designed.2.The principle of high-frequency impulse detection selected the Rogowski coil with a core.This paper analyzed the core materials of the Rogowisk and designed the sensing probe.Further,according to analyzing the working condition of the Rogowski coil,a novel compound integration circuit is designed.Adding the feedback windings is to solve the integration problems of flux-gate and rogowski coil.Finally,High-pass filter is also designed and signal processing circuit is improved.3.The principle of DC and low-frequency impulse detection system is based on fluxgate technology.This paper analyzed closed loop zero flux measurement principle and designed two kinds of cross-winding structures of exciting winding.This paper designed fluxgate sensor probe and external circuit(including the excitation source circuit andfeedback control circuit),while designed low-pass filter to improve the signal processing circuit.4.Simulations and experiments of the proposed current sensor are carried out.Respectively,for high frequency pulse current components,DC and low frequency pulse current component and pulse current with DC are simulated and experimentally verified.The test results are in agreement with the simulation results.The prototype is completed.The measurement error is verified.This paper completes the design of the experimental prototype,and verifies the relative error of the designed current sensor.