Solid-state switch mode AC-DC converters having high-frequency transformer isolation are developed in buck, boost, and buck-boost configurations with improved power quality in terms of reduced total harmonic distortion (THD) of input current, power-factor correction (PFC) at AC mains and precisely regulated and isolated DC output voltage feeding to loads from few Watts to several kW. This paper presents a comprehensive study on state of art of power factor corrected single-phase AC-DC converters configurations, control strategies, selection of components and design considerations, performance evaluation, power quality considerations, selection criteria and potential applications, latest trends, and future developments. Simulation results as well as comparative performance are presented and discussed for most of the proposed topologies.

This paper deals with a Cuk dc-dc converter as a single-stage power-factor-correction converter for a permanent-magnet (PM) brushless dc motor (PMBLDCM) fed through a diode bridge rectifier from a single-phase ac mains. A three-phase voltage-source inverter is used as an electronic commutator to operate the PMBLDCM driving an air-conditioner compressor. The speed of the compressor is controlled to achieve optimum air-conditioning using a concept of the voltage control at dc link proportional to the desired speed of the PMBLDCM. The stator currents of the PMBLDCM during step change in the reference speed are controlled within the specified limits by an addition of a rate limiter in the reference dc link voltage. The proposed PMBLDCM drive (PMBLDCMD) is designed and modeled, and its performance is evaluated in Matlab-Simulink environment. Simulated results are presented to demonstrate an improved power quality at ac mains of the PMBLDCMD system in a wide range of speed and input ac voltage. Test results of a developed controller are also presented to validate the design and model of the drive.

This study presents various configurations, control schemes and design of single-phase power factor controller (PFC) topologies for permanent magnet brushless DC motor (PMBLDCM) drives and provides a basis for selection of a suitable PFC topology for a specific application. Several AC–DC converter (buck, boost, buck–boost, Ćuk, SEPIC, Zeta, push–pull, half bridge, full bridge) based PFC topologies are designed, modelled and applied to a 1.5 kW PMBLDCM drive for comparison of performance. Some of bidirectional bridge converter and unipolar inverter topologies are also evaluated to provide a comprehensive comparison of the PFC topologies for PMBLDCM drives. The proposed PFC converter topologies show conformity to international power quality standards with improved performance of PMBLDCM drive, such as reduction of AC mains current harmonics, near unity power factor and reduction of speed and torque ripples. A classified list of more than 200 research publications on the state of art of various PFC topologies and PMBLDCM drives is also given for a quick reference.

This paper deals with a comprehensive study of configurations of microgrid (MG) based on variable speed generators. The selection criteria for these configurations along with the design of required control algorithms, are presented in detail. Simulation results and experimental validation of selected MG configurations are given to demonstrate their suitability. It is aimed to enhance applications of MGs with main emphasis on renewable energy sources to ensure sustainable development in rural and remote areas.

In this paper, a comprehensive controller of a standalone microgrid is implemented, which has three dispersed generation units based on a wind, solar photovoltaic (PV) array, and a diesel generator (DG). The power ratio variable step perturb and observe method is applied to achieve maximum power point tracking of a solar PV array and a variable speed wind turbine coupled a permanent magnet brushless dc generator without rotor/wind speed sensors. Moreover, to ensure perfect synchronization of a DG to the point of common coupling (PCC), a control algorithm is developed, which is based on in-phase and quadrature units. An active power control based on proportional–integral controller with anti-windup, is used for voltage and frequency regulation. The LCL filter based on virtual resistor, is used for power quality improvement at PCC. Simulation and test results are presented for the validation of the proposed system using a prototype of 2 kW in the laboratory.