Selection Method of Capacitor Capacity Considering the Influence of Gap Displacement in Self-excited Rail Brakes

The authors proposed a rail brake that does not require a power supply by using capacitor self-excitation. In the case of capacitor self-excitation, the operating state changes passively as the rail brake gap changes. Hence, the capacitor capacity must be selected considering the effect of gap displacement. In this paper, the current-frequency characteristics of the equivalent circuit constants at several gaps are obtained. Using the current-frequency characteristic diagrams, a method for selecting the capacitor capacity is presented. This allows the excitation to continue even when the gap changes and does not cause overvoltage.