电涡流传感器温度稳定性研究

Research on temperature stability of eddy current sensor

为了提高磁悬浮轴承高频电主轴控制系统中电涡流传感器的温度稳定性，针对恒频调幅式电涡流位移振动传感器，分析了电涡流传感器的基本结构和工作原理，建立了检测电路数学模型，找出了影响其温度稳定性的主要原因，并提出了对激励信号进行稳频、稳幅，尽量减小检测线圈等效损耗电阻以及差动补偿等提高温度稳定性的措施。作者在此基础上研制出的精密差动式电涡流位移振动传感器，在实际运行中温度系数达到２×１０－ ４℃－ １ 以上，长期稳定性优于０．５％ 。

To improve the temperature stability of eddy current sensor in active magnetic bearing controlling system, in allusion to amplitude modulation vibration and displacement eddy current sensor, by the means of mathematical model analysis, the reasons that cause the temperature instability of eddy current sensors are found out and analyzed. A practical design of eddy current sensor is given, with the optimization of the resistance of induction coil and the design of highly frequency and amplitude stabilized oscillatory signal source, and with the method of differential compensation, a high temperature stability is reached. The temperature coefficient is less than 2×10 -4 ℃ -1 , the long term stability is better than 0.5%.