Simulation Modelling of an Algorithm for Protection from Skidding and Wheel Locking of Wheel Pairs of Electric Rolling Stock

Abstract

Modern electric rolling stock is equipped with a microprocessor control system of the traction electric drive and smooth contactless voltage regulation on traction motors. It allows implementing a flexible skidding (wheel locking) algorithm of protection. Untimely detection and location of skidding (wheel locking) processes leads to a decrease of the traction (braking) forces, damage to the wheel motor unit, and increased wear of wheels and rails. The simulation model of the electric rolling stock with the rotational-motor electric drive and smooth zone-phase voltage regulation on the traction electric motor was developed. Analysis of the algorithms for protection from skidding and wheel locking in the mode of traction and regenerative braking was made with the help of the above model. The model contains blocks of the MATLAB system and Simulink extension package: traction transformer blocks, traction motor blocks, digital automatic control system of the traction electric drive, current and voltage sensors, and an output module of the modelling results. Skidding (wheel locking) algorithms for protection from skidding (wheel locking) were considered. Their location is a result of the reduction of the armature current of the traction motors with the skidding (wheel–locking) wheel set. In the traction mode, the reduction of the armature current takes place due to the impact on the armature current regulator of the traction electrical motors, and in the mode of the regenerative braking on the exiting current regulator of the traction motors group with the wheel locking wheel set. The considered protective algorithms enable effective localization of the skidding (wheel locking) processes with a minimum loss of the traction (braking) forces.