Control method of modularization multi-level converter based on equivalent circuit model

Abstract

The invention discloses a control method of a modularization multi-level converter based on an equivalent circuit model. The modularization multi-level converter is provided with six alternating current output ends and six converting reactances. It is known that two alternating current output ends of each phase are isoelectric points according to symmetry analysis, and the isoelectric points can be virtualized to be in short circuit in the theoretical analysis, therefore, the two converting reactances of each phase are in a parallel connection relation and can be combined into a reactance so as to obtain the equivalent circuit model of the modularization multi-level converter, wherein the equivalent circuit model has three alternating current output ends and three converting reactances, and is in a structure similar to the traditional voltage source converters of a two-level converter and the like, therefore, the control method of the traditional voltage source converters can be directly applied to the modularization multi-level converter.

Description

technical field The invention relates to the technical field of converter control, in particular to a control method for a modular multilevel converter based on an equivalent circuit model. Background technique The circuit structure of traditional voltage-source converters has certain commonality. Generally, there are only three AC output terminals, and each AC output terminal is connected to the three-phase AC grid through a commutation reactance. Taking a two-level voltage source converter as an example, Figure 1 shows the basic circuit structure of the converter. At present, there are many mature control methods for traditional voltage source converters. The fundamental principle of various control strategies is to control the exchange between the converter and the AC grid by adjusting the terminal voltages of the three AC output terminals of the converter. Active power and reactive power. Modular multilevel converter is a relatively new type of multilevel voltage sour...

AI Technical Summary

Problems solved by technology

It can be seen that the circuit structure of the modular multilevel converter is very different from the traditional voltage source converter with only three AC outputs, which makes the control method of the traditional voltage source converter unable to be directly applied to the modular multilevel converter. In the horizontal converter

Images