چكيده به لاتين
In the railway, both of wheel and the track (rail) are made from iron and they are quite smooth. For this reason comparing to other vehicles, train has the minimum of energy consumption. But, these polished surfaces in the train acceleration cause problems. Therefore the researches of this thesis have been done by aim of controlling wheel slip in the acceleration time of the train. The purpose of the train wheel slip control is attempt to maximum use of the adhesion coefficient between wheel and rail. Because the train acceleration is closely related to the adhesion coefficient between wheel and rail. In line with the research topic which is wheel slip control, after the introduction and introducing basic concepts, is turn of the modeling of train wheel movement on rail. In this thesis after simulation by software modeling, hardware modeling is done. The software model is formed by combining the existing motion models, equations of motion, vector control of induction motor and estimation of the adhesion coefficient. In the hardware modeling, two tangential wheels is used. One of these wheels is as the train driven wheel and is connected to an induction motor. Another wheel is playing the role of the railway and is connected to a synchronous generator. By use of a microprocessor, required algorithms for induction motor speed control are implemented. Synchronous generator role is the train and it is connected to a set of three-phase resistive load. With resistive load, quantity of the generator load is controlled. Generator load is as train load. According to maximum adhesion point, there are three possibilities for the train driving torque; 1- Train driving torque is smaller than the maximum adhesion torque, 2-Train driving torque is greater than the maximum adhesion torque, 3- Train driving torque is equal to the maximum adhesion torque. For the first and second states, by controlling the machine torque amplitude, the target can be achieved. But controlling train wheel slip torque at the point of maximum adhesion is a quite different matter. Adhesion control is performed by help of wheel slip control. Adhesion versus wheel slip curve is function of various factors and is not practically constant available curve. Hence in this thesis a novel method to use of the maximum adhesion coefficient is introduced. As the results of simulation and implementation show, with help of the proposed method wheel slip can be controlled at the point of maximum adhesion torque and by this way the acceleration time of the train can be minimized.
