A Novel Analytic Method to Calculate the Equivalent Stray Capacitance of the Low-Speed Maglev Train’s Suspension Electromagnet

Abstract

The suspension electromagnet (SEM) is one of the most critical components of the low-speed maglev train to achieve the stable suspension and non-contact operation with the track. Therefore, it is valuable for optimizing the maglev system to study the characteristics of the SEM. This paper proposes a novel analytic method to calculate the equivalent stray capacitance of the SEM efficiently. It considers the capacitances inside the winding (turn to turn and layer to layer) and between the winding and core. Firstly, utilizing the compensation analytic method (CAM) calculates the static capacitances to reduce the calculation error, and the results of the CAM have significant improvement comparing with that of the traditional analytic method (TAM). Secondly, the analytical formula of the core floating potential is derived based on the partial capacitance theory, which has a 2.1% relative error to the finite element method (FEM). Finally, the experiment results of the SEM of a test rig prove the accuracy and efficiency of the proposed method.