铁心锥形末端对LVDT静态特性影响的研究

Study on the Influence of the Tapered End of Iron Core on the Static Characteristics of LVDT

线性可变差动变压器(LVDT)式位移传感器具有可靠性高和非接触测量的优点,常被应用在闭环控制系统中采集位移信号。内部感应磁场分布不均导致传统LVDT线性度差、灵敏度低,必须配合外部调理电路使用。提出将可动铁心的末端设计成具有一定锥度的结构,使用ANSYS Maxwell建立LVDT有限元模型,通过Maxwell Circuit Editor设计LVDT外部激励电路,进行瞬态磁场耦合仿真。仿真结果表明,将铁心末端设计成具有一定锥度的形式确实能够提高LVDT的线性度和灵敏度。较传统LVDT,新型LVDT的线性度提高了1.5倍,灵敏度提高了10mV/mm。搭建实验平台,验证了该方案的可行性。

The linear variable differential transformer(LVDT)type displacement transducer has the advantages of high reliability and non-contact measurement,and it is widely used in the closed-loop control system to collect the displacement signal.The uneven distribution of internal magnetic field leads to the disadvantage of poor linearity and low sensitivity of traditional LVDT,which must be used with external conditioning circuit.The end of movable iron core was designed with a certain taper,and the LVDT finite element model was established by ANSYS Maxwell.The LVDT external excitation circuit was designed by Simplorer,and the electromagnetic joint simulation of the transient magnetic field was carried out.The simulation results show that the design of the iron core end with a certain taper can improve the linearity and sensitivity of LVDT.Compared with the traditional LVDT,the linearity of new LVDT was increased by 1.5 times and the sensitivity was improved by 10 mV/mm.The feasibility of the scheme was verified by setting up a test platform.