Design and implementation of variable frequency sine wave output buck-boost inverter

Şener, Yunus
Conventional inverters have pulse-width-modulated output with a fundamental component at the desired frequency and magnitude. These converters are usually buck type and therefore the DC link voltage limits the maximum 3-phase output voltage magnitude. As a consequence, in motor drive applications field weakening is essential after a certain frequency of operation, as it becomes impossible to preserve the rated flux level. In renewable energy applications similar problems arise. When the DC link voltage falls, the rated output voltage at rated frequency is no longer achievable. Therefore, the energy available cannot be extracted from source. Some techniques are used to increase output voltage such as over-modulation. However over-modulation causes harmonics to increase and different problems arise. Thus there are two important issues to be studied for DC to AC conversion; obtaining sinusoidal output and boosting input voltage. Various studies on this topic are searched and analyzed. A method is proposed, implemented and tested. The results show that proposed method enables operation at rated frequency with THD being lower than 5% even if DC-link voltage is %26 lower than nominal voltage.


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...
Design and implementation of advanced pulse width modulation techniques and passive filters for voltage source inverter driven three-phase ac motors
Nebi, Onur Çetin; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2010)
Advanced pulse width modulation (PWM) techniques such as space vector PWM, active zero state PWM, discontinuous PWM, and near state PWM methods are used in three-phase AC motor drives for the purpose of obtaining low PWM current ripple, wide voltage linearity range, and reduced common mode voltage (CMV). In some applications, a filter is inserted between the inverter and the motor for the purpose of reducing the stresses in the motor. The motor current PWM ripple components, terminal voltage overshoots, sha...
On the detection of sinusoidal signals under sinusoidal interference
Balcı, Burak; Candan, Çağatay; Department of Electrical and Electronics Engineering (2010)
A complex exponential waveform embedded in white noise can be optimally detected by matched filtering which is equivalent to Discrete Fourier Transform (DFT). However, if the input includes multiple complex exponentials, the DFT processing is not optimal. The frequency spectrum of the complex exponential signal with finite observation interval is not impulse. The spectrum includes side-lobes called spectral leakage.Because of the strong side-lobes, weak components can be masked, or side-lobes can be interpr...
Series active filter design, control, and implementation with a novel load voltage harmonic extraction method
Şentürk, Osman Selçuk; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2007)
Series Active Filters (SAF) are designed for harmonic isolation and load voltage regulation of single-phase and three-phase voltage harmonic source type nonlinear loads. The novel Absolute Value Method (AVM) for load voltage harmonic extraction is proposed and applied in the control algorithm of SAF. The SAF compensated systems are represented by simplified linear models such that SAF controller gains can be easily determined. Harmonic isolation and load voltage regulation performances of 2.5 kW single-phas...
Design and implementation of Z-source full-bridge DC/DC converter
Uçar, Aycan; Ersak, Aydın; Department of Electrical and Electronics Engineering (2012)
In this work, the operating modes and characteristics of a Z-source full-bridge dc/dc converter are investigated. The mathematical analysis of the converter in continuous conduction mode, CCM and discontinuous conduction mode-2, DCM-2 operations is conducted. The transfer functions are derived for CCM and DCM-2 operation and validated by the simulation. The current mode controller of the converter is designed and its performance is checked in the simulation. The component waveforms in CCM and DCM-2 modes of...
Citation Formats
Y. Şener, “Design and implementation of variable frequency sine wave output buck-boost inverter,” M.S. - Master of Science, Middle East Technical University, 2016.