in order to reduce the volume and size of distribution power transformer, precise and extended controlling of transformer output, the conventional transformers are replaced by intelligent universal transformers (iuts). in this paper, an iut, typical of iran national grid, with the voltage ratio of 20kv:380 v is designed and simulated. regarding the iut implementation, a cascaded h-bridge invert...

In this paper, a new cascaded multilevel inverter by capability of increasing the number of output voltage levels with reduced number of power switches is proposed. The proposed topology consists of series connection of a number of proposed basic multilevel units. In order to generate all voltage levels at the output, five different algorithms are proposed to determine the magnitude of DC volta...

Photovoltaic energy conversion becomes main focus of many researches due to its promising potential as source for future electricity and has many advantages than the other alternative energy sources like wind, solar, ocean, biomass, geothermal etc. In Photovoltaic power generation system multi level inverters can be used as an alternative configuration for the dc to ac inverter. Diode clamped i...

— Recent advances in solid-state semiconductors have led to the development of medium voltage power converters which could obviate the need for the step-up transformers of renewable power generation systems. The modular multilevel cascaded converters have been deemed as strong contenders for the development of medium-voltage converters, but the converters require multiple isolated and balanced ...

This paper presents multicarrier PWM strategies for three phase cascaded seven level Z-source inverter. Multilevel inverters posses the advantage of reduced harmonics, high-power capability and high-voltage level. Impedance network in the cascaded multilevel inverter circuit will perform boost operation. This paper focuses on multicarrier sinusoidal pulse width modulation (MCSPWM) strategy for ...

This paper explains a control strategy SHE-PWM and a closed loop control of the cascaded multilevel inverter based on the modulation index. The modulation index is taken as the feedback to the cascaded multilevel inverter, the proposed system reduces the total harmonic distortion by optimizing the angles of the inverter and the DC voltage sources applied to the cascaded inverter. The specific l...

In this paper, several optimum structures of a cascaded multilevel inverter is proposed. This optimization is based on generation a constant number of output voltage levels by using minimum number of power switches or dc voltage sources or minimum amount of blocked voltage by power switches. In addition, the optimum structure for a constant number of dc voltage sources by using minimum number o...

The MATLAB based simulation on simulink platform is presented for Single Phase Cascaded symmetric Multilevel Inverter for 5 levels. Theoretical study is done for the classification of multilevel inverter. And also the study is done for the classification of modulation scheme for multilevel inverter. Modulation scheme used for single phase symmetric multilevel inverter is fixed frequency multica...

Multilevel voltage source inverter has been recognized as an important alternative to the normal two level voltage source inverter, especially in high power application. Using multilevel technique, the output voltage amplitude is increased, switching devices stress is reduced and the overall harmonics profile is improved. Three presentable topologies can b considered for multilevel inverter (ML...

The emergence of multilevel converters has been in increase since the last decade. These new types of converters are suitable for high voltage and high power application due to their ability to synthesize waveforms with better harmonic spectrum. Numerous topologies have been introduced and widely studied for utility and drive applications. Amongst these topologies, the multilevel cascaded inver...