Static compensator model prediction control method based on modularized multilevel transverter

Abstract

The invention discloses a static compensator model prediction control method based on a modularized multilevel transverter. A. any one type of switching combination of one phase of the modularized multilevel transverter is selected; B. error values of capacitor voltage of all sub-modules of the phase under the switching combination are calculated; C. the error values of current outputted by a corresponding multilevel transverter AC side are calculated; D. a cost function value is acquired via the error values of the capacitor voltage in the step B and the error values of the current outputted by the multilevel transverter AC side in the step C so that deviation between the output of the corresponding multilevel transverter under the switching combination and a practical control objective is represented; E. another switching combination in the modularized multilevel transverter is selected, and the steps B, C and D are repeated until all the switching combination situations of one phase are completely processed; an F. finally the minimum cost function value and the corresponding switching combination are found, and switch signals are generated according to the switching combination so that switch devices of the sub-modules of the phase are triggered.

Description

technical field [0001] The invention relates to the field of electric power, and more specifically relates to a static compensator model predictive control method based on a modular multilevel converter. Background technique [0002] With the continuous development of the scale of the power system, the requirements for the voltage level and capacity of the flexible alternating current transmission (FACTS) device are also increased. Static compensator (abbreviated as STATCOM) is an important part of FACTS. In order to realize high-voltage and high-power applications, the topology of its converter is divided into two types: low-level number and cascaded multi-level number. The low-level topology adopts the technology of direct series connection of devices, but it brings a series of problems such as dynamic and static voltage equalization and large output harmonics. In the multi-level topology, the multi-level topology using diode or capacitor clamping increases with the numbe...

AI Technical Summary

Problems solved by technology

[0003] Because each sub-module of MMC is independent, the difference in charge and discharge, loss and capacitance value of each sub-module will make the capacitor voltage unbalanced, which will endanger the normal operation of the converter.

Therefore, the problem of DC side capacitor voltage control of each module is a difficult problem for modular multilevel converters

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