چكيده به لاتين
Lower fuel consumption, more safety than road transport, relatively low noise pollution, high displacement capacity, greater welfare, low maintenance cost, high cost savings, low power loss and low friction between the wheel and the rail are some of the advantages of using railway and resulting this low friction leads to wheel slip. Maximizing the acceleration/braking of the train is one of the important purpose of traction system designers. The adhesion coefficient value between the wheel and the rail is affected by the wheel slip value. Considering to this issue, finding the best operation point owning the maximum adhesion coefficient in order to maximize acceleration/braking of the train is substantial. Thus, for reaching maximum adhesion coefficient between the wheel and the rail the wheel slip should be controlled in both acceleration and braking modes. Traction motors in the DC trains working together in the coupled system, this point is important in the accelerating and breaking. When the train is accelerating, at first motors are series and after passing some times for reaching to the enough torque and speed they will be parallel. This thesis examines the slip between the wheel and the rail when starting two couplings and transferring them from series to parallel also using a PID controller to control the amount of slip by using a change in rheostat resistance and engine parameters and determining the appropriate transmission time from Series mode is dealt with in parallel. During braking, the slip between the wheel and the rail in mechanical braking conditions, dynamic braking and the condition of two parallel to series coupling engines transmitted, were reviewed to reduce the speed of the train and a slip control strategy was presented.
