Single-phase and three-phase combined in-phase power supply and transformation device

Abstract

The invention discloses a single-phase and three-phase combined in-phase power supply and transformation device which comprises a single-phase traction transformer, a three-phase YNd11 grounding compensation transformer and a single-phase in-phase compensation device thereof; the in-phase compensation device comprises an alternating current-direct current-alternating current (AC-DC-AC) converter; the traction transformer and the compensation transformer have equal effect to a three-phase and two-phase balance transformer with the phase of secondary side voltage being vertical; when in a normal state, the traction transformer, the compensation transformer and the in-phase compensation device jointly supply power for a transaction load by a specified proportion; when the compensation transformer or the in-phase compensation device exit the operation, the traction transformer can work independently in a short time; and a backup traction transformer can replace the traction transformer to work and can work on linear voltage different from that of the traction transformer. According to the device, the electric phase at the exit of a traction transformer substation can be canceled, so that the electric energy quality requirements mainly comprising the unbalance of three-phase voltage can be met, and the optimal configuration of traction power supply resources can be realized.

Description

technical field [0001] The invention relates to the field of power supply for electrified railways, in particular to a single-phase three-phase combined in-phase power supply and transformation device. Background technique [0002] The electrified railway in my country generally adopts single-phase power frequency AC system. In order to make the single-phase traction load as balanced as possible in the three-phase power system, the electrified railway often adopts the scheme of alternating phase sequence and split-phase partition power supply. The adjacent power supply intervals at the phase separation partition form a phase separation insulator, which is called electrical phase separation or phase separation. In order to prevent electric locomotives from burning catenary suspension components due to electric split phases due to electric phase separation, and even causing phase-to-phase short circuits and other accidents, as the train speed continues to increase, when the dr...

AI Technical Summary

Problems solved by technology

However, in the case where the three-phase voltage unbalance (negative sequence) does not meet the standard, it is necessary to install the same-phase (symmetrical) compensation device, which needs to be compensated at the three ports on the traction side, and the structure is more complicated. At the same time, compared with the minimum It is necessary to increase 1 / 3 of the same-phase compensation capacity. In addition, when the three-phase voltage unbalance (negative sequence) meets the requirements and does not need the same-phase (symmetrical) compensation, using one of the phases for the same-phase power supply will cause YNd11 wiring traction transformers Large waste of capacity (up to 2 / 3), very uneconomical

Therefore, it is difficult to promote YNd11 wiring traction transformers to implement same-phase power supply on the whole line of new railways

[0007] In addition to the single-phase traction transformer, the same-phase power supply of the line voltage type can come from a three-phase-two-phase balanced wiring transformer, in which one port of most three-phase-two-phase balanced wiring is the line voltage, and the other port is the phase voltage, such as Scott, Leb1anc, (modified) Wood-Bridge and YNvd, etc., the line voltage can cooperate with the traction substation of the single-phase traction transformer to realize the same phase power supply of the whole line, which is an advantage, but the disadvantage is that the three-phase-two-phase balanced wiring traction transformer needs Special manufacturing will increase the cost of standard wiring transformers, and will cause part of the capacity of spare traction transformers to be idle, which will affect the economy, and it will be difficult to promote them on the whole line of new railways

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