A power electronic converters are becoming more and more popular for medium voltage & high power applications. To overcome the limitation of semiconductors current and voltage ratings in high power applications, multilevel inverter is often considered an effective solution. In addition, stepped waveform in the output of multilevel inverter has better harmonic spectrum than 2-level inverter in l...

This paper proposes three phase Seven Level Cascaded H-Bridge Multilevel Inverter by using PD, POD, APOD, INVERTED SINEWAVE methods based on Sinusoidal PWM control techniques. There are 3 types of multilevel inverters named as diode clamped multilevel inverter, flying capacitor multilevel inverter and cascaded multilevel inverter. Compared to diode clamped & flying capacitor type multilevel inv...

Multilevel inverter is an effective and practical solution for increasing power demand and reducing harmonics of AC waveforms. Such inverters synthesize a desired output voltage from several levels of dc voltages as inputs. This paper analyzes the performance of cascaded five level inverter using hybrid pulse width modulation technique. It has been found that this technique reduces the switchin...

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 modular three-phase multilevel inverter specially suited for electrical drive applications is proposed. Unlike the cascaded H-bridge inverter, this topology is based on power cells connected in cascade using two inverter legs in series. A detailed analysis of the structure and the development of design equations for the load voltage with n levels are carried out using pulsewidt...

The implementation and analysis strategies plays vital role to minimize THD in Multilevel inverter. The modulation technique regards Selective harmonic Elimination and Space Vector Pulse Width Modulation(SVPWM).Multilevel inverters has tremendous application in the area of high-power and mediumvoltage energy control. In this paper simulation of SVPWM is performed for cascaded H bridge Multileve...

In this study, two types of multilevel convertors, cascaded multilevel inverter with separate DC sources and diode clamped multilevel inverter with common DC source are modeled and compared in the case of feeding of an induction motor. Here, SHEPWM technique is used as the switching strategy. Also a new variable torque feedback control on modulation index is presented, to preserve the induction...

 When utilized at low amplitude modulation indices, existing multilevel carrier-based PWM strategies have no special provisions for this operating region, and several levels of the inverter go unused. This paper proposes some novel multilevel PWM strategies to take advantage of the multiple levels in both a diode-clamped inverter and a cascaded Hbridges inverter by utilizing all of the levels ...

Multilevel voltage source inverter offer several advantages compared to their conventional counterparts. Cascaded H-bridge inverter provides Stepped AC voltage wave form with lesser harmonics at higher levels by combining different ranges of voltage DC sources and the filter components are reduced by increasing Step levels. By increasing the level of the inverter we can get several advantages: ...

1.1 HARMONICS IN ELECTRICAL SYSTEMS ............................................................................................ 1 1.2 CONVENTIONAL TWO-LEVEL AND THREE-LEVEL VOLTAGE SOURCE INVERTER ............................... 2 1.3 MULTILEVEL VOLTAGE SOURCE INVERTER..................................................................................... 5 1.3.1 Diode-Clamped Multilevel Inverter...