A multilevel inverter is implemented for generating the required staircase AC voltage of output from various steps of voltages of DC sources. The multilevel inverter gives a better harmonic spectrum and a compatible quality of output. This article delves into an analytical analysis of the total harmonic distortion (THD) of different multilevel inverters which employ a multicarrier PWM technique. This technique is implemented for operating the switches at their respective angle of conduction. This paper deals with various cascaded H-Bridge multilevel inverters (CMI) with various loads that are modelled by implementing the MATLAB/Simulink platform. The output gives a better result of the proposed model in terms that it is helpful towards reducing the THD and the losses of switching.

A control structure design of a three-phase three-leg four-wire grid-tied Distribution Static Synchronous Compensator (DSTATCOM) based on a combined-step-size real-coefficient improved proportionate affine projection sign algorithm (CSS-RIP-APSA) has been presented. The three-phase four-wire DSTATCOM is used for reactive power compensation along with harmonic current minimization. This strategy also helps in load balancing and neutral current compensation. The affine projection sign algorithm (APSA) is a member of the adaptive filter family, which has a slow convergence rate. The conventional adaptive filter deals with the trade-off between the convergence rate and the steady-state error. In the proposed algorithm, the RIP-APSA adaptive filter with two different step sizes has been designed to decrease the computational burden while achieving the advantages of a fast convergence rate and reduced steady-state error. The proposed controller also makes the inverter function a shunt compensator. The controller primarily evaluates the fundamental weight component of distorted load currents. The aim of the proposed system is to compensate for reactive power and to ensure unity power factor during the faulty conditions as well as for unbalancing grid conditions. The proposed control algorithm of the grid-tied DSTATCOM works effectively on the laboratory prototype as verified from the experimental results.

The maximum power point tracking (MPPT) has been common terminology among the researchers for those who deal with solar energy. A lot of techniques involving MPPTs have been investigated, evolved and proposed by researchers. But those techniques have got some advantages and suffer from limitation to some extent. The gravity of limitations varies from case to case. In current work, it has been investigated the MPPT based Boost Converter without and with MPPT which is perturb and observe (P&O) type. After observing its limitation, this method of MPPT is modified so as to make it suitable for extracting the maximum power from PV unit at all different load conductance’s. In order to validate this concept, the mathematical model is developed using a MATLAB/Simulink environment and this Modified MPPT technique is implemented. The whole model is simulated and compared with conventional method. This concept is quite new and the proposed one exhibits better performance as compared to conventional methods.

The conventional buck converter is the first and foremost member among the family of DC–DC converters. Major drawback of the conventional buck converter is the hard-switching that leads to many shortcomings and finally leads to poor efficiency. So it is the soft-switching (i.e. zero-voltage switching or zero-current switching) mechanism that can alleviate these shortcomings. In past, the researchers have proposed a numerous soft-switching topologies without giving attention to number of active and passive components. Hence it has been focused on optimization of number of active and passive components to be used in proposed topology. This article introduces a novel technique for soft-switching of a DC–DC buck converter, which is independent of snubber resistance and possesses only a snubber capacitor across each switch. The filter parameters of proposed structure are different than those of conventional one. With the inclusion of these filter parameters, the proposed structure is operated under zero-voltage switching or zero-current switching to enable the soft-switching of its devices. The designing technique of this proposed converter is properly narrated. The control strategy is quite simple. The MATLAB/Simulink (MATLAB 6.1 (Version)) model for the proposed topology is developed and its simulation is carried out to analyze its performance.