| Cable eccentricity detection is an important part of measuring the quality of cables.Cable eccentricity will greatly reduce the effective thickness of cable insulation and cable performance,and even cause safety accidents.Therefore,cable eccentricity detection has very important practical significance.Aiming at this practical problem,a cable eccentricity detection device is researched based on eddy current and laser displacement sensor array in this paper.The device can detect the eccentricity of the cable at any point in the circumferential direction through a single sensor array,and display the eccentricity of the cable graphically through the upper computer,which can more comprehensively observe the eccentricity of the cable.The main research work is as follows:(1)A brand-new cable eccentricity detection device is designed.The slip ring structure is applied to sensor array power supply and signal extraction.The sensor array composed of eddy current sensor,laser displacement sensor,and temperature sensor is used to detect all-directional eccentricity in the circumferential direction of the single core cable by the slip ring structure,which makes up the shortcoming of the traditional four-direction eccentricity detection.(2)In order to realize the design of high-precision eddy current sensor,a three-dimensional finite element model of the cable conductor core and the eddy current sensor coil magnetic field was constructed.The influence of parameters such as inner diameter of coil,number of winding layers,number of winding turns and excitation frequency on sensor performance was analyzed by ANSYS simulation,and the better design parameters of the eddy current sensor probe are obtained.(3)In order to reduce the influence of temperature on the stability of the sensor,a temperature sensor was added to the sensor array to collect ambient temperature,the temperature information and the eddy current sensor information were fused,and the regression model was built by least squares support vector machine(LSSVM),and the sine-cosine algorithm is applied to the parameter optimization of the regression model..Thus,the adverse effect of the ambient temperature on the eddy current sensor is reduced.(4)An experimental platform for single-core cable eccentricity detection is constructed.This system includes upper computer and lower computer.The lower computer is composed of ARM system,which is used for data acquisition,transmission,processing and analysis of the sensor array and transmit the processing results to the upper computer through the serial port.The upper computer can display the eccentricity of each circumferential point of the single core cable in real time through the graphical interface.Experimental results show that the measurement accuracy of the developed high-precision eddy current sensor can reach 0.05mm.After data fusion,the temperature sensitivity coefficient of the system is reduced from 6.61×10-4/℃ to 8.73×10-6/℃,which increased two orders of magnitude,and ensured the stability and reliability of the system.The test results show that the detection system is feasible.The eccentricity of single-core cable can be measured and calculated online in real time,It has broad market application prospects and value. |
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