| The accuracy of current measurement in modern power network is closely related to the safety and stability of power network.In the trend of rapid development of power network,in order to enhance the degree of interconnection of power network and reduce the line loss,the transmission voltage level and increasing power transmission distance is also rising,while the traditional electromagnetic current sensor because of its complicated insulation mode,large occupied space and inconvenient transportation,easy to be affected by magnetic fields and other issues hinder the process of the intelligent modern power network.The traditional current sensor will be gradually replaced by fiber optic current sensor with excellent characteristics,application of optical fiber sensor in power system has been developed for the measurement of the current hot spots.Magnetic fluid(Magnetic Fluid,MF)as the key component of sensor measurement has the unique optical and magnetic properties of MF,which makes the MF widely used.Therefore,it is of great value to carry out experimental and theoretical research on MF film(Magnetic Fluid Film,MFF)current sensor.The main contents of this paper are as follows:On the base of many on the optical current sensor of Chinese and foreign literature,in-depth study of the physical and optical properties of MF and the characteristic of the MFF transmission characteristics and fiber transmission properties linked,in reference to performance of the existing sensor,we propose and design a current sensor based on MFF.The light transmission characteristics by the method of Monte-Carlo external magnetic field under the action of MFF is analyzed and simulated,and the transmission model of current sensing system based on MFF is established,and then the nonlinear GA algorithm and PSO algorithm are used for parameter identification and optimization of transmission model of current sensor system based on MFF.The error and sensitivity between the nonlinear GA algorithm and the optimized PSO model with the experimental data are analyzed and compared,and an optimal algorithm is determined,and the sensitivity of the optimized model is high and the current can be measured accurately.According to the design of the MFF sensing structure,the experimental platform of the MFF current sensing system is established by selecting the experimental equipment.Inthe course of the experiment,under the influence of the external magnetic field,the transmission characteristics of the MFF will be affected by the adjustment of the particle concentration in the MFF and the thickness of the MFF,and then to explore the changes of these conditions on the MFF current sensing system.The experimental data are analyzed and compared,and then the relationship between the current value of the current sensing model based on MFF and the MFF transmittance is obtained.By comparing the experimental data and the sensing prediction model,the current sensing system based on MFF can be used to accurately reflect the relationship between the transmittance of MFF and the current. |
