Power supply topological structure for split-phase passing of high-speed railway system and control method

Abstract

The invention belongs to power and electronic technology, and particularly relates to a power supply topological structure for split-phase passing of a high-speed railway system and a control method.The structure comprises u, v, w triphase multi-level converter module branches and a capacitance branch, the u, v, w triphase multi-level converter module branches after being parallelly connected areconnected with the capacitance branch parallelly, each phase multi-level converter module branch is divided into an upper bridge arm and a lower bridge arm, and each of the upper bridge arms and thelower bridge arms comprises n multi-level converter modules in sequential serial connection and a buffer inductor in serial connection with the multi-level converter modules, wherein n is a positive integer greater than 1; the capacitance branch is divided into a direct-current bus side upper bridge arm and a lower bridge arm each of which comprises n capacitance modules in sequential serial connection. The power supply topological structure can realize bidirectional current taking according to actual conditions of traction networks on two sides to enable a train to pass split-phase passing without powering off and has the advantage that a transformer does not need to be connected in.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a power supply topology and a control method for over-phase separation of a high-speed railway system. Background technique [0002] In my country's current power grid model, when there is a higher-level power grid, the lower-level power grid is often no longer operated in a loop. Therefore, when 110kV or 220kV is used to supply power to the traction transformer, unilateral power supply or radial power supply is often used. . When using this power supply method, the voltage difference between adjacent power supply arms is very large, and the power supply arms of different voltage phases cannot be directly connected, so there is an isolation section between the two-phase power supply arms, which needs to pass through the isolation link every 20-30km For electrical isolation, it is generally called an electrical phase separation area in the traction power supp...

AI Technical Summary

Problems solved by technology

The problem of electric phase separation and automatic over-phase separation has been seriously restricting the safe and reliable operation of high-speed and heavy-duty trains. In order to eliminate the problems of overvoltage and over-current during the process of over-phase separation, it is necessary to install a complex automatic over-phase separation device

Although this scheme can realize the uninterrupted power splitting of the locomotive, the disadvantage is that the scheme requires that the locomotive must be deloaded to a idling state before entering the neutral section. Therefore, although the locomotive is always charged when passing through the electric split phase, the tractive force and speed are still limited. Loss; Tian Xu of Tsinghua University and others proposed a two-phase MMC uninterruptible power-over-phase-splitting device. Although the scheme uses frequency conversion phase-shifting technology, it can realize the locomotive without power failure and full power through electric phase-splitting, but due to its single-phase current On the one hand, the traction transformer on one side may be overloaded due to insufficient capacity, on the other hand, the load sequence imbalance may be aggravated and the unbalance degree may exceed the standard, resulting in application limitations

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