Power electronic converters are used to transform one form of energy to another. They are classified into four types depending upon the nature of the input and output voltages. The inverter is one among those types; it converts direct electrical current into alternating electrical current at desired frequency. Conventional types of inverters are capable of producing voltage at the output terminal that can only switch between two levels. The range of output voltage generated at the output is low when they are used for high power applications. To improve the voltage profile and efficiency of the overall system, multilevel inverters (MLIs) are introduced. In multilevel inverters the voltage at the output terminal is generated from several DC voltage levels fed at its input. The generated output is more appropriate to a sine wave and the dv/dt rating is also less leading to the reduction in EMI. Though they possess many advantages compared to the conventional inverters, the structural complexity and triggering techniques involved in designing multilevel inverters are high. Many studies are being carried out in defining new topologies of MLI with reduced switch as well as with the implementation of different PWM techniques. This paper will provide an extensive review on variety of MLI configurations based on the parameters such as the number of switches, switching techniques, symmetric, asymmetric, hybrid topologies, configurations based on applications, THD and power quality.

The consumer adoption of electric vehicles (EVs) has become most popular. Numerous studies are being carried out on the usage of EVs, the challenges of EVs, and their benefits. Based on these studies, factors such as battery charging time, charging infrastructure, battery cost, distance per charge, and the capital cost are considered factors in the adoption of electric vehicles and their interconnection with the grid. The large-scale development of electric vehicles has laid the path to Photovoltaic (PV) power for charging and grid support, as the PV panels can be placed at the top of the smart charging stations connected to a grid. By proper scheduling of PV and grid systems, the V2G connections can be made simple. For reliable operation of the grid, the ramifications associated with the PV interconnection must be properly addressed without any violations. To overcome the above issues, certain standards can be imposed on these systems. This paper mainly focuses on the various standards for EV, PV systems and their interconnection with grid-connected systems.

The growth of distributed power generation using renewable energy sources has led to the development of new-generation power electronic converters. This is because DC–DC converters and inverters form the fundamental building blocks in numerous applications, which include renewable integrations, energy harvesting, and transportation. Additionally, they play a vital role in microgrid applications. The deployment of distributed energy resources (DERs) with renewable sources such as solar has paved the way for microgrid support systems, thus forming an efficient electric grid. To enhance the voltage of such sources and to integrate them into the grid, high-gain DC–DC converters and inverter circuits are required. In this paper, a novel single-switch high-gain converter (HG-SIQBC) with quadratic voltage gain and wide controllable range of load is proposed, the output of which is fed to a modified multilevel inverter for conversion of voltage. The overall performance of the newly designed converter and inverter is analyzed and compared with the existing topologies. A prototype of the investigated multilevel inverter is designed and tested in the laboratory. Development and testing of such novel topologies have become the need of the hour as the grid becomes smarter with increased penetration of distributed resources.

Power electronic converters play a major role in wind energy conversion systems (WECS). A typical variable speed WECS includes wind turbine, permanent magnet synchronous generator (PMSG) and power conditioners. In this study, a three‐phase modular boost converter supplied from a PMSG and controlled using a linear quadratic regulator (LQR) is proposed for battery charging applications. Each phase of PMSG is connected to a single phase diode rectifier and a DC–DC boost converter. All boost converters have a common output capacitor and load. The proportional–integral‐based voltage controller provides voltage regulation on the DC side. A fixed frequency LQR‐based current controller applied for the individual phases provides a better three‐phase source utilisation. The instantaneous pq theory is adopted for the reference current calculation. Extensive simulation studies based on the models developed using MATLAB/SIMULINK reveal that the proposed system performs satisfactorily for step variations in wind speed and load. The performance of the low power prototype developed and controlled using a dSPACE 1104 digital signal processor shows good output voltage regulation and better source utilisation for wide variations in load.

Power quality is an important issue in low‐voltage DC (LVDC) grids which drives light‐emitting diode lighting system and many other DC loads in residential applications. The requirement of high‐quality power to the lighting system necessitates power factor correction (PFC). This study presents a three‐phase modular AC‐to‐DC converter with a simple controller for PFC in LVDC grids under balanced and unbalanced supply voltage conditions. The proposed circuit consists of three separate single‐phase boost converter modules. Each module includes a diode rectifier at the front end, followed by a boost converter. The main advantage of this converter is module loss operation where the DC supply given to the lighting system and other DC loads will be continued even in case of failure of one module. The 24 V DC output voltage is regulated using an outer proportional‐integral controller and the input current wave shape in each phase is improved by three individual hysteresis controllers. The controller works successfully in tracking the reference voltage changes in order to vary the regulated DC output voltage. The effectiveness of the controller has been verified by the results obtained through MATLAB/SIMULINK. A prototype model has been developed to validate this system and tested using dSPACE1104 processor.