| The continuous co-phase power supply technology(CCPST)not only can eliminate the worse power quality of electrified railway effectively,but also can remove the phase splits overall in the feeding section.CCPST is the future development direction of electrified railway.Furthermore,with the "Research on CCPST Engineering Application Technology in Electrified Railway" approved as major project by China Railway Corporation,the research of CCPST has been put on the agenda.Based on this fact,this article has mainly studied the power flow distribution and optimal sizing of the co-phase compensation device(CPD)and the optimal design of continuous co-phase power supply system(CCPSS),which will provide technical support to the railway systems planners and operators for the formulation of CCPSS design plan.The beginning of this paper,based on the topological structure of CCPSS and components,deduced a novel equivalent circuit model of CCPSS,taking into the unified chain model of traction network and the general simulation model of traction substation containing equivalent controlled source of CPD.In the second place,according to the basic principles of train motion and mechanism of train tracking,a multi-train simulator was developed.On this basis,using the restrictive relationship between power supply voltage with locomotive output power at wheel rim,integrating the equivalent circuit model of CCPSS and multi-train simulator,a network-train interaction simulation system was developed specifically for online calculation the traction load and power flow distribution.In the CCPSS,the main power supply facilities,including the electrical substations and CPDs,siting and sizing optimization problem is directly related to the economy and reliability of the system.Based on the principle of negative sequence compensation,a new formulation of the CPDs compensating capacity is proposed.Besides,an improvement particle swarm algorithm is developed and implemented to choose the optimization power supply scheme.The optimization process minimizes the whole capacity supplied by the electrical substations and the average power loss taking into the main design principles constraints in the network-train interaction simulation system.Based on the theoretical calculation and simulation study,a realized new high speed railway in China is used to estimate and compare power supply performance with different power supply systems.Some advantages of CCPSS are included,like the load distribution more balanced and reduction the electrical peak demand.Beyond that,calculations with difference compensation degree of the CPD show that the installation capacity of CPD is strikingly reduced under the satisfactory optimization compensation compared with complete compensation.Finally,the main power supply facilities siting and sizing optimization problem is solved using improvement particle swarm algorithm.In sum,this study demonstrates the superior performance of CCPSS,and shows that the improvement algorithm achieve the objectives efficiently and accurately. |
