Modularized multi-level converter sub-module control and protection method

Abstract

The invention relates to a modularized multi-level converter sub-module control and protection method. The control and protection method comprises the following processing modes: in four control models of a sub-module, executing different control and protection logics by using a sub-module controller; generating a sub-module internal interface output signal, detecting an input signal and diagnosing a plurality of faults; executing control and protection actions by using the sub-module controller according to an action priority level; detecting the voltage of an energy storage capacitor C by using the sub-module controller; and performing asynchronous serial communication between the sub-module controller and a valve-based controller. In the method, a complete and intelligent control and protection scheme is designed aiming at the structure of the modularized multi-level converter sub-module, the coordinated control and protection of the overall sub-module can be realized, so that the stable and reliable operation of the sub-module in a converter and the coordinated matching with an overall control and protection system of the converter are ensured.

Description

technical field [0001] The invention relates to a control technology of a flexible direct current transmission converter, in particular to a control and protection method for a modular multilevel converter (Modular Multilevel Coverter, MMC) sub-module. 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...

AI Technical Summary

Problems solved by technology

For the two-level converter topology that has been widely used, due to the relatively high voltage and power levels in DC transmission, a single IGBT device is far from meeting the withstand voltage requirements, so it is necessary to connect IGBTs in series to form a valve body to increase the withstand voltage

However, due to the different characteristics of each device, the reliability of the valve body composed of IGBTs in series has become the focus and problem to be solved in this topology.

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