Study On Reliability Of CO-Phase Traction Power Supply System

Compared with the normal power load, electric railway has a relatively strong volatility. Therefore the capacity utilization of the traction transformer is universally not so high. At present, the Two-part Electricity Price is adopted by the electric railway, while the basic tariff is collected by measuring the capacity of the traction transformer. Another measuring way of the Two-part Electricity Price is the maximum demand method referring that the electricity fee is collected according to the maximum of the average electricity load per unit time during an electricity settlement period. Because of the wildly fluctuating of the traction load, the fee charged through the maximum demand method which counts the traction load electricity may be less than the installed capacity method, which can lower the basic tariff of the electric railway and improve the ability of operating economy.This paper firstly introduces the current electricity price system in our country, after, it’s the diffences between the maximum demand method and installed capacity method. And discussion on the basic way of bills to pay, at the end, according to the measured data to calculate the actual maximum demand to decide the most appropriate contract maximum demand, to make the minimum basic electricity, it is shown that the maximum demand efficiency.In this paper,the traction load of actual measurement is processed by the software of matlab. The paper comparatively analysis the slip method and the interval method to computer the maximum demand. Calculation on the changement of maximum demand under different demand cycles, it’s that the best demand cycle is15minute. The minimum value of basic electricity is analysised and calculated by corresponding to the agreed maximum demand, so that the agreed value could be signed by traction load user and power supply enterprises.The applicability of the maximum demand for the electrified railway is shown in this paper, the maximum demand of high-speed electrified railway, normal-speed electrified railway and freight electrified railway is computered respectively, compared to the installed capacity, the basic electricity of two kinds mode is getted. This article analysises the traction load process under one day (24hours), digital characteristic value such as mean value, the root mean square value, maximum,95%probability are statisticed, to describe the characteristics of traction load fluctuation; Deriving the function between traction load characteristic parameters and maximum demand, to provides the theory basis for the basic electricity metering of new electrified railway.