Investigation of modular multilevel converter control methods

Download
index.pdf
2015
Ertürk, Feyzullah
Show full item record
315
views
170
downloads
The thesis focuses on the analysis and control of modular multilevel converter (MMC). The control structures used in the control of MMC are presented. Outer control loops of the converter such as output current, DC-link voltage, and power controls as well as inner control structures unique to the converter such as circulating current control and sorting algorithm based submodule voltage balancing are investigated. In addition, switching methods proposed for MMC are also described. These control and switching methods are examined on a sample DC/AC MMC and their effects are evaluated. In addition, parameters such as circulating current control, sorting algorithm based submodule voltage balancing, modulation methods, used in MMC control, as well as power factor are evaluated on their effects over semiconductor power loss in the system via detailed analysis. Total system loss and individual semiconductor loss are dwelled on. Later, the applicability in HVDC is inspected on a sample back-to-back MMC system and a method to improve dynamic operation is proposed. After the shortcomings of MMC in low-frequency operation are described, the control method that allows MMC to be used in motor drive application is explained and applied in a sample system via simulation. The study is realized by mathematical analysis, topological design, controller design and detailed computer simulation.
Electric current converters., Electric currents, Direct., Electric currents, Alternating., Pulse-duration modulation.
http://etd.lib.metu.edu.tr/upload/12618930/index.pdf
https://hdl.handle.net/11511/24772
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Selection of suitable PWM switching and control methods for modular multilevel converter drives /
Çiftçi, Barış; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2014)
The thesis focuses on the determination of suitable carrier based PWM switching and control method for modular multilevel converter drives. Characterization of various level-shifted and phase-shifted carrier based PWM methods are provided in terms of switching pulse patterns and resultant voltage waveforms both for N+1 and 2N+1 level output phase voltages. Modular multilevel converter PWM based control approaches are evaluated. Performances of different control methods are given for output harmonics distort...
Adaptive control of DC link current in current source converter based STATCOM for improving its power losses
Karaduman, Ferdi; Ermiş, Muammer; Bilgin, Hazım Faruk; Department of Electrical and Electronics Engineering (2012)
In conventional three-phase PWM (Pulse Width Modulation) current source converter based STATCOM (Static Synchronous Compensator) applications, DC link current is kept constant at a predefined value and the reactive power of STATCOM is controlled by varying modulation index. This control strategy causes unnecessary power losses especially when the reactive power of STATCOM is low. For this purpose, in order to reduce the active power drawn by STATCOM, the modulation index can be maximized by adjusting DC lin...
Hierarchical control with partial observations: Sufficient conditions
Boutin, Olivier; Komenda, Jan; Masopust, Tomas; Schmidt, Klaus Verner; Van Schuppen, Jan H. (2011-12-01)
In this paper, hierarchical control of both monolithic and modular discrete-event systems under partial observations is studied. Two new conditions, called observation consistency and local observation consistency, are proposed. These conditions are sufficient for the preservation of observability between the original and the abstracted plant. Moreover, it is shown that both conditions are compositional, that is, they are preserved by the synchronous product. This property makes it possible to use hierarchi...
A High Performance PWM Algorithm for Common Mode Voltage Reduction in Three-phase Voltage Source Inverters
Uen, Emre; Hava, Ahmet Masum (2008-06-19)
A high performance PWM algorithm with reduced common mode voltage (CMV) and satisfactory overall performance is proposed for three-phase PWM inverter drives. The algorithm combines the near state PWM (NSPWM) method which has superior overall performance characteristics at high modulation index and MAZSPWM, a modified form of the active zero state PWM method (AZSPWM1), which is suitable for low modulation index range of operation. Since AZSPWM1 has line-to-line voltage pulse reversals with small zero-voltage...
FPGA implementation of field oriented control forpermanent magnet synchronous motor
Irmak, Gizem; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2019)
The thesis study focuses on the fully operational FPGA implementation for the current/torque control of a Permanent Magnet Synchronous Motor. 3-phase synchronous motors with permanent magnets can be categorized into two categories as Permanent Magnet Synchronous Motor (PMSM) and Brushless Direct Current (BLDC) motor. The main difference between PMSM and BLDC is the shape of the induced back-EMF voltage. While BLDC motors have trapezoidal shaped back-EMF, PMSMs have a sinusoidal back-EMF. In order to take ad...
Citation Formats
F. Ertürk, “Investigation of modular multilevel converter control methods,” M.S. - Master of Science, Middle East Technical University, 2015.
METU IIS - Integrated Information Service open@metu.edu.tr