Research On The Key Technology Of Cophase Traction Power Supply Device For Electrified Railway

With the rapid progress of high-speed and overloading electric railway, those problems such as seriously-unbalanced three phases, reactive power, and low power factor, harmonic current and crossing neutral sections existing in traction power systems are getting worse, so it is a great meaning to study a novel traction power supply system to solve all these problems. Depends on the deep study of the essence of kind of problems, the theory and practice of cophase power supply system are studid, to validate the built system some simulations and real experiments are performed.According to the existing problem of electrified railway to be solved, a new structure of cophase power supply device was put forward. This structure can not only solve the existing problems of electrified railway, but also can be renewable energy storage braking. And the opological structure, the advantages disadvantages, the realize methods based on this cophase power supply device are all be given.Related problems of ideal traction power supply system are analysed in-depth, and gives the independent power structure, working principle and power distribution, etc.The utilization of the regenerative braking energy is discussed. Combined with the energy storage system, CTPSD can further solve the problem of electrical locomotives’ regenerative braking power-feedback. And the structur of storage unit has been designed.CTPSD has the strong capacity to adapt the exchange of locomotive and the fast dynamic compensation can be realized. CTPSD+ESS have the ability of four quadrants for active and reactive power adjustment, which can achieve locomotive regenerative braking energy. So it can greatly improve the safety and efficiency of traction power supply system. And the calculation, storage and control strategy for regenerative braking capacity were discussed in this paper.The parallel operation measures of CTPSD were studied. Applying the circulation power control measures with scatter logical structure, the problems such as circulation and voltage-sharing can be solved.The composition, feature and communication of multi agent technique, along with the structure of multi-agent system and organization form together, are discussed. Based on BDI model the CTPSD monitoring and control, the management agent and coordinate agent are bulit, and the function modules for different agent are established. And then, the operation mechanism, construction project, correspondence and coordination mechanism for system are discussed. The operating performance and control strategy under emergent conditions are analyzed respectively.Finally, the simulation of the multi-agent-based CTPSD system is made based on the classical Beijing-Shanghai high-speed railway. And the results show that the proposed design structure is very effective. Not only can solve all kinds of problems existing in electrified railway, especially through the mutual cooperation of CTPSD, realize the tide scheduling between substations, and improve the capacity utilization ratio and the load of the traction transforme.Based on the above theory, lots of simulations are finished, and the simulation results show that the proposed system solutions, the control strategies and the regenerative braking energy use are to be true and feasible. The system can realize the balance trasform from single-phase to three-phase, can filter harmonics and compensate reactive power, and makes the single-phase unbalanced loads is only a three-phase symmetric pure resistance load for the power system.