Research On Optimization Of Urban Railway Train Control And Dynamic Simulation Of Traction Power Supply System

As the component of traffic transportation industry, urban railway is growing quickly with the rapid development of the social economy. At present, a number of large and medium-sized cities in China are carring out urban rail transit construction projects. The golden age of the development of urban rail transit will arrive in the next few years. Based on the previous research achievement, the optimizations of urban rail train control and traction power supply calculation are discussed in this paper. The optimal train control strategy and realtionship among train position, current and power with respecte to running time are attained by train performance simulator. The traction network voltage and traction substation load process can be achieved by traction power supply calculation. Optimization of train runnig can improve the train control level. It can reduce the power consumption but maintaining the severice quality at the same time. Traction power supply calculation is an important basis of the design of power supply system. Train performance simulator provides the basic data of the traction power supply calculation. Meanwhile, the result of traction power supply calculation can used to examine the rationality of train running scheme. With the combine of train performance simulator and traction power supply calculation, the practical urban railway working procedure can be simulated. At the stage of electrification design of urban railway, line carring capacity can be determined according to the design of power supply facility with these simulated methods presented in this paper. The optimization of the design of traction power supply facility can also be achieved.The paper's research emphasized on several aspected as follow:1. Through constructing the minimum energy consumption model with fixed running time, the urban railway energy saving train control strategies are obtained by Pontryagain minimum principle. An approach for solving train energy saving optimization problem based on variable-length real matrix coded multi-population genetic algorithm is presented. A multi-particle train simulator is adopted to emulating train run. The GA chromosome consists of a variable two dimensional real number representing the train control sequence. A variable operator based on annealing selection is introduced to enhance global search performance. Fitness sharing keeps population's multiplicity. Multi-population parallel search improves convergence rate and evolution stability.2. A four layers'net model including overhead contact line, rail, stray current mat and earth is presented for the simulation of urban railway dc traction power supply system. The traction power supply system is considered as an integrated dynamic net. The polygonal external characteristic is applied to rectifier, whose working state is confirmed by iterative method. The accurate voltages of ocs, rail and stray current mat can be calculated as well as loads of rectifiers.3. Traditional power flow for dc traction power supply system usually carries out at DC traction side or executes separately at AC/DC sides, which simplifies the internal relationship and the calculation precision is not good enough. Through analyzing the model of parallel-connected 12 pulse uncontrolled rectifier, the unified AC/DC power flow for dc traction power system which based on improved Newton-Raphson method and Gauss-Seidel method is discussed and applied in 10 nodes hybrid traction power supply system for practical verification.4. A probability load flow (PLF) method for urban rail traction power supply based on Monte Carlo simulation is presented. The probability distribution of train position is obtained by train running time curve with respect to position. The probability distribution of departing time interval is attained by organization of train operation. With Monte Carlo simulation, the trains'positions which are used to imply power demand are taken as random samples, followed by AC/DC unified power flow calculation to obtain the probability distribution function of nodes'voltage and power. The comprehensive instruction and evaluation for urban rail traction power supply system can be achieved by this method.5. Based on the research presented above, the urban rail traction power supply simulation system UrtSim is implemented. The UML is applied as the software modeling and design method. The simulation system is developed with Visual C++.Net 2005. The UrtSim system has been successfully applied in railway design institute.