Single-phase integrated power quality controller for electric railway power supply

Abstract

The invention relates to a single-phase universal electric energy quality controller for power supply for electrified railways, and belongs to the technical field of flexible AC power transmission and distribution; the invention comprises a single-phase multi-coil transformer composed of a primary coil and n secondary coils, so that the secondary coils of the transformer can be connected in parallel with n voltage sources of current transformers; n capacitors are connected with n voltage source current transformers, so as to form a single-phase chain-type H-bridge current transformer with n chains; the AC terminal of the H-bridge current transformer is directly connected with the traction grid through a reactor. The invention has the functions of active power control, reactive power compensation and harmonic compensation, so as to resolve three-phase voltage unbalance, voltage fluctuation, low power factor and harmonic pollution and so on that exist in ER traction transformer stations, effectively lower the capacity of traction transformers, increase ER transport capacity and transportation capability. Moreover, the invention is characterized in small occupied area, little loss and low cost, in order to gain perfect harmonic suppression characteristics and dynamic response features, and provide convenience in industrial production and improve device reliability.

Description

technical field [0001] The invention belongs to the technical field of flexible AC transmission and distribution of power systems and power electronics, and relates to the treatment of large-capacity power electronic devices and user power quality problems, in particular, it provides a multi-winding transformer and chain H-bridge for power supply of electrified railways A unified power quality controller (Unified Power Quality Controller, UPQC) device for structural converters. Background technique [0002] As a large-capacity single-phase load, electric locomotives will inject negative sequence current into the power supply system of electrified railways (referred to as electric railways), and cause power quality problems such as three-phase unbalanced voltage and voltage fluctuations in the power supply system. China's electric railway power supply system is a different-phase power supply mode. The commonly used phase sequence rotation technology and balancing transformer ...

AI Technical Summary

Problems solved by technology

Therefore, the BCD scheme has the disadvantages of large footprint, high cost, and large loss. At the same time, the required passive filter capacity is large, and it is difficult to obtain application in traction substations of electrified railways.

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