The present research investigations in power management fraternity are focused towards the realization of smart microgrid (MG) technologies. Due to intrinsic advantages of Direct Current (DC) system in terms of compatibility with power generation sources, modern loads and storage devices, DC MG has becoming popular over Alternate Current (AC) system. A secondary voltage and current control schemes of DC MG system are mainly based on the distributed consensus control of Multi-agent system (MAS) to balance generation and the demand. The basic concern of the cooperative control of MAS is consensus, which is to design a suitable control law such that the output of all agents can achieve synchronization. The distributed consensus algorithm requires much less computational power and information exchange in between the neighbor's agent. Meanwhile the other controllers such as model predictive control (MPC) requires accurate dynamic models with high computational cost and it suffers from lack of flexibility. The hierarchical consensus control technique is classified into three levels according to their features, namely primary, secondary, and tertiary. MAS is a popular distributed platform to efficiently manage the secondary control level for synchronization and communication among the power converters in autonomous MGs. In this article, various primary control techniques for local voltage control, voltage restoration in the secondary control level and tertiary control for energy management techniques are discussed. With this, the key emphasis to reduce the voltage deviation and disturbances in a heterogeneous DC MG network solutions are discussed. Furthermore, to analyze the system response and the charging and discharging characteristics of the battery unit, the developed second order heterogeneous consensus controller is compared with the traditional homogeneous consensus control and droop control methods. Finally a detailed discussion on simulation case study using heterogeneous consensus control method over the traditional methods are provided using MATLAB/Simulink platform.

In this work, a DC microgrid consists of a solar photovoltaic, wind power system and fuel cells as sources interlinked with the utility grid. The appropriate sizing and positioning of electric vehicle charging stations (EVCSs) and renewable energy sources (RESs) are concurrently determined to curtail the negative impact of their placement on the distribution network’s operational parameters. The charging station location problem is presented in a multi-objective context comprising voltage stability, reliability, the power loss (VRP) index and cost as objective functions. RES and EVCS location and capacity are chosen as the objective variables. The objective functions are tested on modified IEEE 33 and 123-bus radial distribution systems. The minimum value of cost obtained is USD 2.0250 × 10⁶ for the proposed case. The minimum value of the VRP index is obtained by innovative scheme 6, i.e., 9.6985 and 17.34 on 33-bus and 123-bus test systems, respectively. The EVCSs on medium- and large-scale networks are optimally placed at bus numbers 2, 19, 20; 16, 43, and 107. There is a substantial rise in the voltage profile and a decline in the VRP index with RESs’ optimal placement at bus numbers 2, 18, 30; 60, 72, and 102. The location and size of an EVCS and RESs are optimized by the modified teaching-learning-based optimization (TLBO) technique, and the results show the effectiveness of RESs in reducing the VRP index using the proposed algorithm.

This study deals with the analysis and implementation of an HPF (high power factor) single‐stage, single switch buck converter‐based power supply design for an LED (light emitting diode) lamp load of 13 W operated at the universal ac mains. In general purpose lighting applications, a buck converter is a good candidate for power factor correction with low component count and reduced cost. In low‐power lighting, it is a tough task to control the THD _i (total harmonic distortion) of ac mains current under the limits of strict international standards such as IEC‐61000‐3‐2 with universal ac mains for class D equipments. In the proposed optocouplerless topology, HPF operation at input ac mains is achieved by operating the buck ac–dc converter in continuous conduction mode. The design, modelling and simulation of the proposed topology are executed using MATLAB‐Simulink and sim‐power system toolboxes. A prototype of the power supply for LED lamp is developed for multiple LEDs connected in series configuration. The efficiency of the proposed LED lamp driver is observed as 83.76% at rated voltage of 220 V and the THD of ac mains current less than 17.27% for a wide range of voltages of 90–270 V.

This paper presents the design, simulation, and implementation of a non-isolated discontinuous conduction mode operated Zeta-converter-based light-emitting diode (LED) driver with the novel wall-switched step-dimming concept to achieve power quality improvement at universal ac mains. The power-factor-corrected Zeta converter maintains constant output current to an LED load of 26 W and conserves the power quality requirements as per IEC 61000-3-2 for class C equipment with high efficiency. Moreover, to obtain cost benefit and size reduction, this converter utilizes reduced control circuitry for general-purpose LED lighting solutions. A cost-effective single-level dimming concept is implemented with current injection technique using a Zeta converter. A prototype is developed using AP1682, which utilizes pulse frequency modulation technique to regulate the output current for improving the input power factor and low total harmonic distortion (THD) of the input current. At full load and rated voltage of 220 V, the measured input power factor is 0.993 and current THD is 2.81% with an efficiency of 90.51%.