Small-Signal Model-Based Control Strategy for Balancing Individual DC Capacitor Voltages in Cascade Multilevel Inverter-Based STATCOM

Author

Liu, Yu ; Huang, Alex Q. ; Song, Wenchao ; Bhattacharya, Subhashish ; Tan, Guojun

Author_Institution

Dept. of Electr. Eng., North Carolina State Univ., Raleigh, NC

Volume

56

Issue

6

fYear

2009

fDate

6/1/2009 12:00:00 AM

Firstpage

2259

Lastpage

2269

Abstract

This paper presents a new feedback control strategy for balancing individual DC capacitor voltages in a three-phase cascade multilevel inverter-based static synchronous compensator. The design of the control strategy is based on the detailed small-signal model. The key part of the proposed controller is a compensator to cancel the variation parts in the model. The controller can balance individual DC capacitor voltages when H-bridges run with different switching patterns and have parameter variations. It has two advantages: 1) the controller can work well in all operation modes (the capacitive mode, the inductive mode, and the standby mode) and 2) the impact of the individual DC voltage controller on the voltage quality is small. Simulation results and experimental results verify the performance of the controller.

Keywords

bridge circuits; control system synthesis; feedback; invertors; power capacitors; static VAr compensators; switching convertors; voltage regulators; DC capacitor voltage; DC voltage controller; H-bridge switch; capacitive mode operation; feedback control strategy; inductive mode operation; small-signal model-based control strategy design; standby mode operation; static synchronous compensator; three-phase cascade multilevel inverter-based STATCOM; Multilevel converters; reactive power; static synchronous compensator (STATCOM); voltage balancing;

fLanguage

English

Journal_Title

Industrial Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0278-0046

Type

jour

DOI

10.1109/TIE.2009.2017101

Filename

4801748