Adhesion and Dynamic Phenomena during Slipping of Electrical Rolling Stock : 1st Report, Slipping Phenomena and Improvement of Adhesive Characteristics of Rectifier AC Locomotives

Abstract

For the purpose of improving the adhesive characteristics of rectifier AC locomotives, the slipping phenomena of the standard four-axle locomotive were observed, and a clear picture was obtained of various phenomena which cannot be explained by simplified theories and of conditions of coefficient of adhesion in a range of small wheel-rail relative speeds. Detailed calculative expressions of slipping phenomena were then formulated and these expressions were used for numerical calculation by means of a digital computer. The results of these calculations were found to coincide approximately with actually measured values. The effects of various factors on adhesion were investigated and the following systems were planned : (1) Controlling DC source voltage by feedback of rectifier output DC voltage. (2) Controlling DC source voltage by feedback of maximum difference in armature voltages. The characteristics of these controlling systems and their effects on adhesion were made clear.