Four-quadrant converter for frequency multiplication switching

Abstract

The invention belongs to the field of locomotive application, and particularly relates to a four-quadrant converter for frequency doubling switching. The technical problem that harmonic current pollutes a power grid when a locomotive converter is in abnormal operation is solved. According to the method, the four-quadrant converter has good harmonic characteristics in a control software implementation mode, and extra hardware support does not need to be added. Specifically, a control strategy and a carrier switching strategy are adopted in a control algorithm for respective calculation, when switching frequency in the carrier switching strategy is switched, the control frequency is always kept unchanged, that is, the control frequency does not change along with the change of the switching frequency, and a group of control parameters in the control strategy can be suitable for various switching frequencies. According to the invention, when the locomotive converter abnormally operates, the harmonic characteristic of the locomotive converter under the abnormal working condition can be improved; software is adopted to realize self-regulation of the frequency switching control system; real-time and non-stop frequency switching is realized, and the utilization rate of a switching device is maximized.

Description

technical field [0001] The invention belongs to the application field of locomotives, and in particular relates to a four-quadrant converter for frequency multiplication switching. Background technique [0002] Four-quadrant converters are widely used in electric locomotives because of their high power factor and the ability to realize bidirectional flow of energy. The switching frequency of the four-quadrant converter used in the field of locomotives is usually low, and its AC side current has poor harmonic characteristics, which brings harmonic pollution to the power supply network, thereby affecting the power quality of the power supply network and other conditions during the operation of the locomotive. grid environment. [0003] In practical applications, the four-quadrant converter adopts various methods and strategies to comprehensively reduce the pollution caused by current harmonics. For example, a four-quadrant converter adopts a switching frequency switching sch...

AI Technical Summary

Problems solved by technology

[0004] The present invention aims to solve the current technical problem that the harmonic current pollutes the power grid under abnormal operation of the locomotive converter (when there is fault isolation), so as to improve the harmonic characteristics of the locomotive converter under abnormal working conditions, and can Make the switching frequency of the four-quadrant rectifier controller real-time and switch without stopping, maximize the use of the switching frequency of the switching device (IGBT), and improve the utilization efficiency of the device

Images