Capacitor voltage balance control method based on bundling type switching of multiple sub modules

Abstract

The invention provides a capacitor voltage balance control method based on bundling type switching of multiple sub modules. By means of a bundling mode, the quantity level of the sub modules of a modularization multi-level converter valve is degraded for one level, lowering of the capacitor voltage balance control calculated amount is facilitated, and the requirements for control equipment are lowered. After the sub modules are bundled into a module group, switching is conducted overall, the voltage balance of the sub module group is achieved by using a capacitor voltage balance algorithm, voltage-sharing is achieved on the inner portion of the sub module group through self-adaptation, and total voltage-sharing of the sub modules can be achieved. By means of the capacitor voltage balance control method based on bundling type switching of the multiple sub modules, the problem of the control of a high-capacity voltage source converter based high voltage direct current converter valve based on a modularization multi-level converter mode can be effectively solved, and controlling and monitoring of the converter valve with large-scale amount can be achieved.

Description

technical field [0001] The invention belongs to the technical field of flexible alternating current transmission, and in particular relates to a capacitive voltage balance control method based on bundled switching of multiple sub-modules. Background technique [0002] At present, various power electronic circuits based on the fully-controlled power electronic device IGBT have been increasingly used in power systems, locomotive traction, aerospace and other fields. With the development of power electronics technology, materials, and manufacturing processes, the current flow capacity of IGBT devices has become stronger and stronger, making it an important space to play in the field of DC power transmission, which directly promotes the birth and development of flexible DC power transmission technology. Different from the traditional high-voltage direct current transmission technology, the flexible direct current transmission converter replaces the thyristor series converter val...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a capacitive voltage balance control method based on multiple sub-module bundled switching, which can effectively solve the problem of large-capacity flexible DC transmission based on modular multi-level converters. The problem of valve control can realize the operation control and monitoring of a large number of converter valves; through the bundling method, the number of sub-modules of modular multi-level converter valves can be reduced by one level, which is conducive to the reduction of the calculation amount of capacitor voltage balance control. Reduced, reducing the requirements for control equipment

Images