Study On Continuous Co-phase Power Supply Transformation Technology For Existing Heavy Haul Railwany

Heavy haul transportation has the advantages of large volume and low cost,and has been developing rapidly in China in recent years.China’s Heavy haul Railways adopt single-phase power frequency AC system.The traction network has phase splits,which results in the loss of speed and traction force when the electric locomotive passes through the phase splits.With the increase of traction power of electric locomotive,the problem of negative sequence becomes more and more prominent.Continuous co-phase traction power supply technology can fundamentally solve the problem of phase splits and realize the comprehensive management of power quality problems,which is the development direction of the new generation traction power supply system.It has important practical significance to study how to apply continuous co-phase traction power supply technology to the existing heavy haul railway.This paper establishes the traction calculation model based on train kinematics principle and the power flow calculation model based on multi-conductor transmission line theory.The simulation program is compiled by successive linear power flow method and P-Q decomposition method respectively.The comparison between the two methods shows that the P-Q decomposition method converges faster and is more suitable for power flow analysis of continuous co-phase traction power supply system.The power flow calculation shows that the continuous co-phase traction power supply system has better voltage level,smaller system loss and lower installation capacity of traction transformer than the traditional power supply system.Taking a heavy haul railway in China as an example,this paper designs a continuous cophase traction power supply transformation scheme in the original design scheme.Under the initial,near and long-term annual traffic planning,the power supply capacity of the transformation scheme is verified.The results show that the transformation scheme can meet the demand of power supply under three kinds of annual traffic volume modes.Finally,through the cost analysis and benefit analysis of continuous co-phase traction power supply transformation scheme and the original power supply scheme,the investment payback period of the transformation scheme is calculated,and the conclusion that the continuous co-phase traction power supply transformation scheme of heavy haul railway has better economic benefits is drawn.