A railway engine AC traction in-phase power supply device based on YN,vd wiring transformer

Abstract

A kind of railway locomotive AC traction co-phase power supply device based on YN, vd connection transformer, wherein the traction transformer is a three-phase-two-phase balance transformer (T) with YN, vd connection, the line voltage output end of the transformer (T) (T) A rectifier inverter (Z) is connected between b', c') and the phase voltage output terminals (a, x), and the line voltage output terminals (b', c') or the phase voltage output terminals (a, x) are used as The power supply terminals (V1, V2) of the traction locomotive; at the same time, the control device of the rectifier inverter (Z) is connected with the power supply terminals (V1, V2) of the traction locomotive. The device can realize the same-phase power supply for the entire railway line without the need for phase separation, and the power supply voltage of each traction substation section is stable, ensuring the high-speed and heavy-load operation of the locomotive; the power supply system of the railway traction load draws power from the three-phase power grid, eliminating the need for railway Influence of traction load on power quality of utility grid. In addition, the device can be transformed by using the existing traction transformer, with low cost and easy implementation.

Description

technical field [0001] The invention relates to an AC traction in-phase power supply device for a railway locomotive. Background technique [0002] The single-phase system has the advantages of simple structure, low construction cost, convenient operation and maintenance, etc., which determines that single-phase power frequency AC power is generally used to power railway locomotives in electrified railways. The power system hopes that all loads will use the three-phase symmetrical fundamental current from the power grid to make full use of the capacity of equipment and lines and reduce the harm of reactive current and harmonic current to the system. In order to meet this requirement, the electrified railway adopts the scheme of phase sequence rotation and phase-by-phase power supply, that is, every 20-25km along the railway line is regarded as a power supply section, and each section is powered by different phases in the power grid in turn. A phase separation section of abo...

AI Technical Summary

Problems solved by technology

Although there is an automatic over-phase separation device, due to its high voltage and frequent switching actions, there are serious problems in its accuracy and reliability, and it cannot completely solve the adverse effects of electric separation on locomotive operation.

[0007] (2) High-speed and heavy-duty transportation all require large-capacity power supply. In order to meet the national standard for the power system to restrict the power quality of electrified railways, the reactive power compensation technology used in the original single-phase power supply mode has been changed. unable to adapt

If the adjustable symmetrical compensation technology is adopted in the traction substation, even if the AC-DC-AC power supply (regardless of its reactive power and harmonics) is used on the locomotive, the negative sequence is more prominent because of the larger capacity, technically and economically. Difficult to achieve the ideal state

[0008] (3) The high-speed railway to be built in my country may be a mixed operation mode of high and medium speeds. If there is a mixed use of locomotives with AC-DC-AC power supply and locomotives with AC-DC power supply, except for negative sequence, reactive power and harmonics will still remain Existence, power quality cannot be improved, restricting the development of both railways and electric power

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