Electrical railway traction system control and simulation with using direct torque control

In the railway industry, there are four important topic which are safety, comfort, speed and efficiency. For safety, there are many precautions. Some of this precautions are ability of stopping at suitable distance in the international standard, monitoring vehicle doors when vehicle moving and stopping when one of the door open, blocing the moving when doors open etc. For comfort, moving acceleration and braking acceleration should be under the limit which is writing in the international standard. Vehicle traction should work smooth and shouldn't jerk passenger. When getting curve, as traction behavior, vehicle shouldn't jerk passenger. All comfort issues are for passenger. Speed is important for intercity trains on the other hand urban trains have speed limits because of safety issues so speed isn't important for urban rail transportation. This limits can be change for different lines but generally on the underground lines have 80 km/h maximum speed limitation and on the tram lines have 50 km/h maximum speed limitaion. Efficiency comes after safety in railway vehicles. For example when rail vehicle is doing emergency brake, vehicle doesn't send regain energy to catenary line. This energy burn in the brake resistance even if there is lack of energy on the catenary line. Tram vehicles are driven by machinist who controls the energy efficiency. But unattended vehicles doesn't need someone so their energy efficiencies is controled by algorithm which control online catenary line energy and other vehicles location. Thus, energy saving is provided. Energy efficiency is getting important from the beginning of the using electric motors of railway vehicles to this day and it is not hard to guess that it will continue to getting important. Because reaching energy won't find easy in the future. First rail vehicles had steam engine which needed a lot of water and fuel for heating water. Fuel and water were carried separately on tank by vehicle. This load made heavier the vehicle. For this reason, energy efficiency got low. With the introduction of using electrical motors for railway vehicle, energy have been coming direct to vehicle over pantograph. So that, vehicles with electric motor don't need to carring fuel, energy loses decrease and regenerative braking can be use. DC motors mostly had been using from begininig of the using electrical motor in the rail vehicle to 90's. With the evolution of semiconducting technology, AC motors was begun to use for rail vehicles. Especially induction motor can be controled easly by this way using DC motor decrased. There are few things prefering AC motors to DC motors. First of all maintainability of AC motors is easy than DC motor. The other one, AC motors are cheaper than DC motors. Correlation of rail-wheel and resistance which is effect to the vehicle are studied at this thesis for using basic model in the Matlab/Simulink simulation. Resistive effect which can be said as air resistance, roll resistance, curve resistance, grade resistance and accelaration resistance, isn't same all condution. They are changeable for different condutions. Railway construction is important for resistive effects. Traction effort curve have been created for finding suitability of using traction motor and we have comparisoned real motor traction effort curve and simulating motor effort curve. There are many control technique for induction machine. In this thesis, scalar control, direct vector control and direct torque control techniques are studied. Direct torque control technique was choosen to dwell because of some advantages. Rail vehicle simulation was used with direct torque control of induction motor in the Matlab/Simulink. Direct torque control technique was used for simulation because effect of the specific motor parameters were wanted to decrease in the system. The other cause for using direct torque control technique is decreasing to effect of rapid changing torque and flux error. Thus, sudden torque control response is used for induction motor. This can be possible in the inverter switching positions. Real curve and grade parameters were used and shaft with a motor moved in this line in the simulation. High curve and high grade points of line were choosen for moving the shaft because of seeing the performance of induction motor. Creating the reference speed curve comes from rail vehicle drives behavior. All drivers have different drive style but speed limits don't permit this behavior. Reference speed curve was created in general purpose. As a result of simulation, graph of reference rotor speed compared with result of simulation rotor speed. Graph of motor torque-time was studied in a line condition as curve, grade and in a condition of acceleration. Overflow conditions were decreased by tuning the control parameter. Catanery voltage was monitored with changing the front acceleration and braking acceleration. When braking position, regenerative effect can be seen clearly. In addition graph of flux-time was drawn and field weakening place was seen easly. It should be done for reaching high speed in induction motors. The other drawing graph is rotor current – time graph. In simulation, using line modal and using speed reference are like real line and vehicle speed. Therefore we can think that vehicle spent same energy in real life and in simulation. Generally we have to compare with real results and simulation results. Even if simulation not same exactly real, can be closed. If it is close, we can work for simulation like real but it must be acceptable. Rail vehicle traction motors are open for new developing side. Especially energy efficiency of rail vehicle can be improve. Control techniques can be develop for efficiency, different control techniques can be used for same time for efficiency or for different line different control techniques can be used. Like in the other industries, future of railway industry is unattended in an other word driverless system. Driver will be algorithm in unattended systems. In this algorithm will have different control techniques which will work with traction control techniques. For this reasons energy efficiency control will be getting easier rather than with driver system. Our simulation can be developed for different techniques or six car 144 meter metro vehicle and we can use this simulation for developing to unattended rail vehicle algorithm.