Slip control upgrades for light-rail electric traction drives

Many obsolete drives such as a rheostat, contactor or camshaft-contact controlled DC motor drives have often poor dynamic properties in insufficient adhesion conditions. Light-rail vehicles running in many cities already have switched-mode traction drives with thyristor-based or IGBT-based converters that often lack high quality slip, antilock or creep control. Switched-mode converter based multi-motor drives could be partially upgraded to microcontroller-based control. This paper presents and analyses some approaches to be used for performance, efficiency and safety improvement.