Research on Static Characteristics of High Sensitivity Built-in Capacitance Control Rod Position Sensor
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摘要: 内置电容式控制棒棒位传感器可应用于控制棒水力驱动系统。针对四螺旋电极电容式控制棒棒位传感器,本文对双电容值方法测量控制棒棒位的静态特性进行了研究。通过开展传感器的原理性实验,建立了传感器的计算模型,并进行了数值模拟结果的实验验证。假定被测杆整体偏心,利用数值模拟方法建立了两组电容值与控制棒棒位的函数关系式,并对该函数关系式进行了误差分析,分析了该关系式对被测杆不同偏转方向和倾斜状态的适用性。研究结果表明,利用双电容值的棒位测量方法,对控制棒棒位的最大测量误差小于±6 mm,传感器灵敏度在0.05 pF/mm量级,能够满足控制棒棒位的实际测量需求。Abstract: The built-in capacitance control rod position sensor can be applied to the control rod hydraulic drive system (CRHDS). Aiming at the four-helix electrode capacitance control rod position sensor, the static characteristics of control rod position measurement by the method of double capacitance values are studied in this paper. Through the principle experiment of the sensor, the calculation model of the sensor is established, and the numerical simulation results are verified by experiments. Assuming that the measured rod is eccentric as a whole, the functional relationship between two groups of capacitance values and rod position of control rod is established by numerical simulation method. The error analysis of the function is conducted, and the applicability of the function to different deflection directions and tilt states of the measured rod is analyzed. The results show that according to the rod position measurement method of double capacitance values, the maximum measuring error of rod positions can be limited within ± 6 mm. The sensitivity of the sensor can be improved to the order of 0.05 pF/mm, which can meet the actual requirements of control rod position measurement.
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表 1 网格无关性分析结果
Table 1. Grid Independence Analysis Results
网格号 域单元数 电容值/pF 前后两套网格的相对变化量/% 1 1381363 85.0168 2 1583350 83.2409 2.1335 3 1786488 83.1599 0.0973 表 2 1号电极对函数拟合的决定系数
Table 2. Determinant Coefficient of Function Fitting for No.1 Electrode Group
L/mm 0 0.2 0.4 0.6 0.8 R2 0.999 1.000 1.000 1.000 1.000 表 3 2号电极对函数拟合的决定系数
Table 3. Determinant Coefficient of Function Fitting for No.2 Electrode Group
L/mm 0 0.2 0.4 0.6 0.8 R2 0.999 1.000 1.000 1.000 0.999 表 4 函数的系数取值
Table 4. Coefficient Values of the Function
P1 P2 P3 P4 P5 P6 1.0000 −127.9261 −4.8637 113.2320 8.7275 0.0160 P7 P8 P9 P10 P11 −151.4021 −0.1792 0.0002 137.9530 0.2006 -
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