Rail traction AC cophase supply apparatus based on three-phase series voltage source type symmetry transformation

Abstract

The invention relates to a dc cophase power supply device of a railway traction based on symmetric transformation of three-phase serial voltage sources. The full three-phase input voltages are divided into a plurality of independent lower voltages to form power units, thereby recombined adjusting resource is formed. A single-phase ac output is formed by serial superposition after the rectification-energy storage filter-inversion transformation of each power unit, a negative sequence current is eliminated, the power factor is improved and the harmonic wave is eliminated by using multiple principles of the input and the output. The device can realize the cophase power supply of a railway traction, make fully use of the capacity of the circuit and device, reduce the damage to the power supply system from the reactive current and harmonic wave, decrease the loss, reduce the pollution to the environment, greatly improve the reliability of train and reduce the operation, management and maintenance cost. The device is convenient to apply, and is suitable for requirement of high speed and overloading development.

Description

technical field [0001] The invention generally relates to railway traction power transformation equipment, and more specifically relates to a railway traction AC in-phase power supply device based on three-phase series voltage source type symmetrical conversion. Background technique [0002] The applicant's prior patent CN1039271C proposed a high-voltage power conversion method and its conversion device, which abandoned the traditional overall conversion method, and converted it into a certain number of circuits, regardless of whether the input of the whole machine is AC or DC. The alternating current (intermediate AC) with independent potential is rectified and filtered separately to form the same number of direct current (intermediate direct current), and then superimposed through the series bridge according to a certain rule, and the required single-phase alternating current, three-phase alternating current or direct current is output. This conversion method is called the...

AI Technical Summary

Problems solved by technology

Because electric locomotives have the characteristics of heavy load, variable load, high speed, long distance, and movement, the three major problems of harmonics, negative sequence, and low power factor have not been ideally resolved.

Although the new AC-DC-AC power supply locomotive and AC-DC power supply locomotive can eliminate the problems of harmonics and low power factor, the negative sequence effect still exists, and the power quality cannot be better improved, which seriously restricts the cooperation between railways and electric power. develop

Images