Universal contactless converters of monitoring and control systems in water power industry

The paper substantiates the need to use non-contact conversion and measurement of large direct currents using non-destructive magneto modulation non-contact ferromagnetic transducers of increased sensitivity for the needs of land reclamation, irrigation, industry, metallurgy and, in general, agriculture and water management; the results of their design development are presented. It is shown that the developed converter, in contrast to the known ones, has increased accuracy and sensitivity, a technologically advanced design and small weight and dimensions with low material consumption and cost. The issues of reliability of magnetic modulation contactless converters are considered. The results of their research have been obtained. It is shown that the reliability of wide-range magneto modulation contactless converters of large direct currents is equal to 0.998 and taking into account catastrophic failures, their total reliability is 0.9969. The developed converter can be widely used in electrical systems in land reclamation and irrigation, in water supply, industry, railway transport, science, technology and for checking electrical meters at their installation site

High-Accuracy Calibration Based on Linearity Adjustment for Eddy Current Displacement Sensor

High precision position control is essential in the process of parts manufacturing and assembling, where eddy current displacement sensors (ECDSs) are widely used owing to the advantages of non-contact sensing, compact volume, and resistance to harsh conditions. To solve the nonlinear characteristics of the sensors, a high-accuracy calibration method based on linearity adjustment is proposed for ECDSs in this paper, which markedly improves the calibration accuracy and then the measurement accuracy. After matching the displacement value and the output voltage of the sensors, firstly, the sensitivity is adjusted according to the specified output range. Then, the weighted support vector adjustment models with the optimal weight of the zero-scale, mid-scale and full-scale are established respectively to cyclically adjust the linearity of the output characteristic curve. Finally, the final linearity adjustment model is obtained, and both the calibration accuracy and precision are verified by the established calibration system. Experimental results show that the linearity of the output characteristic curve of ECDS adjusted by the calibration method reaches over 99.9%, increasing by 1.9–5.0% more than the one of the original. In addition, the measurement accuracy improves from 11–25 μ m to 1–10 μ m in the range of 6mm, which provides a reliable guarantee for high accuracy displacement measurement