Two-phase-single-phase AC-DC-AC cascade converter system

Abstract

The invention provides a two-phase-single-phase AC-DC-AC cascade converter system, and belongs to the technical field of electrical control. The system comprises a three-phase-two-phase traction transformer, a multi-tap isolation transformer and a two-phase-single-phase AC-DC-AC multi-module cascade converter. The two-phase-single-phase AC-DC-AC cascade converter system of the present invention can be applied to different power supply modes, can be compatible with an existing traditional partition power supply mode, can achieve the connection between an existing two-phase traction transformer and a single-phase traction network, solves the problem of electric energy quality, and meanwhile can achieve the through traction power supply without passing neutral sections of the traction network.

Description

technical field [0001] The invention belongs to the technical field of electric control, and in particular relates to a two-phase-single-phase AC-DC-AC cascaded converter system. Background technique [0002] In the initial stage of electrified railway in my country, power frequency single-phase AC traction system was adopted. The traction substation transforms the three-phase 110kV (or 220kV) high-voltage alternating current into two single-phase 25kV alternating currents, and then supplies power to the catenary in the uplink and downlink directions of the railway. Therefore, the traction transformer has a two-phase output characteristic. [0003] Since the voltage amplitude, frequency and phase of the transformers in different traction substations are not consistent, they cannot be directly connected to each other. Therefore, there are a large number of excessive phases in the traction network. Although the same-phase power supply system replaces the power supply scheme ...

AI Technical Summary

Problems solved by technology

[0003] Since the voltage amplitude, frequency and phase of the transformers between different traction substations are not consistent, they cannot be directly connected to each other, so there are a large number of excessive phase differences in the traction network

Although the same-phase power supply system replaces the power supply scheme of the two bridge arms inside the substation with the power supply of the same phase bridge arm, canceling the excessive phase division inside the substation, but different substations cannot be connected in parallel

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