Single-phase combined co-phased power supply and transformation structure

Abstract

The invention discloses a single-phase combined in-phase power supply and transformation structure mainly comprising a traction transformer and a CPD. In the CPD, a high-voltage matching transformer primary side and a traction transformer primary side form an SCOTT connected group, a secondary side winding of the CPD is connected to the incoming end of an AC-DC-AC converter, and the outgoing end of the AC-DC-AC converter is connected with the primary side of a traction matching transformer. A secondary side winding of the traction transformer and the secondary side winding of the traction matching transformer are equal in voltage amplitude and phase and both connected with a traction busbar; traction load calculated capacity is equal to the sum of traction transformer calculated capacity and CPD calculated capacity, the traction transformer is responsible for main power supply, and the CPD calculated capacity is determined by the capacity of traction load which caused exceeding three-phase voltage unbalance. The single-phase combined in-phase power supply and transformation structure has the advantages that optima configuration of traction power supply resources is realized and energy conservation is better.

Description

technical field [0001] The invention relates to the field of AC electrified railway power supply, in particular to a single-phase combined in-phase power supply and transformation structure. Background technique [0002] Electrified railways generally adopt the single-phase power frequency AC system powered by the public power system. In order to make the single-phase traction load be distributed as balanced as possible in the three-phase power system, the electrified railway often adopts the scheme of rotating phase sequence and separate phase and partition power supply. The adjacent power supply areas at the phase-splitting partitions are divided by phase-splitting insulators to form electrical split phases, also known as phase splits. In order to prevent electric locomotives from burning out catenary suspension components due to arcing through electric split-phase emission, and even causing phase-to-phase short-circuit and other accidents, as the train speed continues to ...

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 add 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 connection transformer. One port of most three-phase-two-phase balanced connections is the line voltage, and the other port is the phase voltage, such as Scott, Leblanc, (modified) Wood-Bridge and YNvd, etc., among them, 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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