Study of Winding Stray Capacitance in Time Domain

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560347
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Power engineering/Power conversion/Electric machinery
• Research Institution: Toyo University
• Principal Investigator: KATO SHOHEI 東洋大学, 理工学部, 教授 (80103571)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: サージ / コイル / 変圧器 / 数値電磁界解析 / FDTD法 / モーメント法

Outline of Final Research Achievements

Spike-like current appears at the early stage of the step response of coils in addition to the current which increases slowly depending on the resistance and the inductance. It is widely noted the spike-like current to be a charging current that flows to the capacitor between windings, so-called stray capacitor until now. However, in this study, we clear the spike-like current that appears to the step response of the coil and decreases stepwise. The enlarged initial stage of the current peak shows stepwise current decay.
In addition to the experiment, we simulated the response by numerical methods, which are based on method of moment and finite deference time domain method to obtain the current, electric field and magnetic field distributions of the coil. The calculated and measured responses were in good agreement.　We try to explain the current in electrostatic, electromagnetic induction and transmission line theory.

Free Research Field

電力工学