Cascaded communication architecture applicable to modular multilevel converter control system

Abstract

The invention discloses a cascaded communication architecture applicable to a modular multilevel converter control system. According to the cascaded communication architecture, the maximum quantity of sub-modules controlled by one converter control device is Q, and Q is larger than N; N cascaded sub-modules of one bridge arm of a multilevel converter valve are M sub-sections in sequence; the quantity of the converter control devices is M; each converter control device is used for being connected with and controlling the sub-module in one corresponding sub-section; the M converter control devices are further used for cascade of the M sub-sections of the same bridge arm; such a cascade manner that every two adjacent converter control devices are cascaded through optical fiber communication or electric communication. The cascaded communication architecture has the advantages that a single bridge arm is cooperatively controlled by one or more converter control devices; through cascade of the converter control devices, information such as the quantity of faulty modules and the emergency fault state are shared among a plurality of the converter control devices, so as to achieve cooperative control of a plurality of the sub-modules of the single bridge arm, facilitate expansion of the system, and reduce the complexity of software and hardware design for the system.

Description

technical field [0001] The invention relates to the communication field of a converter control system, in particular to a cascade communication architecture suitable for a modular multilevel converter control system. Background technique [0002] High-voltage flexible DC transmission systems are especially suitable for long-distance power transmission, wind power grid integration, submarine power transmission and other applications. Compared with AC transmission and traditional DC transmission, it has its unique advantages. In the high-voltage flexible DC transmission system based on modular multilevel converters, the converter valve is composed of many sub-modules (SM) cascaded, and the number of cascaded sub-modules in one bridge arm can reach hundreds, six for three-phase The number of sub-modules of the bridge arm can reach thousands, and the higher the voltage level, the more the number of sub-modules. Each sub-module has a sub-module control and protection unit (SMC) ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a cascaded communication architecture suitable for a modular multilevel converter control system. A reliable way to solve the expansion problem caused by the number of sub-modules exceeding the maximum control number of a converter control device

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