Research On The Cophase Power Supply Modification Scheme In Existing High Speed Railway

With the rapid development of high-speed railway in China, problems brought by electrical sectioning such as the great loss on electric locomotive’s speed and traction force have become increasingly prominent. The existence of electrical sectioning can also restricts the increase of speed of high-speed railway and brings some security risks at the same time.Cophase power supply technology can cancel the existence of electrical sectioning at the outlet of traction substation, research on how to apply the cophase power supply technology to high-speed railway is fit the needs of the development of high-speed railway in china.The paper researched on using the cophase power supply modification scheme in existing high-speed railway——Beijing-Shanghai High-speed Railway, on based of analyzing the measured data of Beijing-Shanghai High-speed Railway and aiming at solving the negative sequence problem and reducing the installed capacity of traction transformer, the paper proposed two kinds of cophase power supply modification scheme.One of the Beijing-Shanghai High-speed Railway cophase power supply modification scheme is mainly in order to solving the negative sequence problem of Beijing-Shanghai High speed Railway, it is using the Power Flow Controller as the cophase compensation device; the other is using single-three phase combined cophase power supply technology which is more suitable for the existing railway, it is aiming at solving the negative sequence problem and reducing the installed capacity of traction transformer.In this paper, the principle is analyzed and the compensation capacity of the two modification schemes is calculated respectively:if traction substation under the same conditions,scheme two requires a smaller compensation capacity. The economy of the two schemes is analyzed:because of canceling electrical sectioning at the outlet of traction substation,it can save the cost of electrical sectioning;it can save half of the fixed capacity electricity charge in the traction substation without cophase compensation device.Scheme two can also lowering installed capacity of traction transformer and save a fixed capacity electricity charge in traction transformer in the condition that needing cophase compensation device,which brings a great economic benefits.Considering the two kinds of schemes,scheme two is more economical.