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Controlling and conditioning electrical power to be delivered to the critical commercial load is very crucial under non-ideal grid and load conditions. Accordingly, PV-fed UPQC (Photovoltaic fed unified power quality conditioner) is the most suitable alternative to address both voltage and current-related issues under such non-ideal scenarios. Thus, for efficient control and power conditioning, extraction of fundamental grid parameters are the prerequisites. Fundamental frequency estimation, three-phase unit template generation and fundamental active load current component extraction are the most important procedures to carry out the control process efficiently. In the proposed work, an adaptive notch filter cascaded normalized comb filter triggered second order harmonic oscillator (N-CF-SOHO) based control of PV-UPQC is illustrated. The striking feature of this control approach is its ability to generate appropriate reference signals for switching of PV-UPQC by estimating and extracting out fundamental components from highly non-ideal grid voltage and current accurately with faster execution. Notch filters (NF) being the most remarkable digital filter in separating narrow band power signal frequency is used in the proposed work to adaptively estimate the fundamental frequency by iteratively following a variable leaky least mean square (VLLMS) based updating approach. Also, NF is employed in a modified manner to exhibit the behaviour of inverse NF to extract fundamental load current component. Utilising estimated frequency, N-CF-SOHO generates fundamental voltage unit templates necessary for the control of PV-UPQC. The presented method is computationally simple, exhibits lesser run time and is robust against noise of any frequency. The presented work is authenticated both in MATLAB/Simulink platform as well as in the developed experimental prototype justifying the above-mentioned features of the system.

In this letter, an integrated wired/wireless charging topology is proposed to expand the adaptability of the electric vehicle charging stations and further improve the utilization of the charging facilities and venues. By reusing the common structures in the independent wired and wireless charging topologies, on the basis of achieving the wired and wireless charging functions, the integration of charging facilities is improved, and its cost is reduced. Based on the isolated converter in the wired mode, a frequency tuning strategy in the wireless mode is proposed to overcome the frequency detuning problem caused by the parameter fluctuations. The feasibility and practicability of the proposed topology and the frequency tuning strategy are verified by the experiments.

A PV-integrated isolated DC microgrid has the potential to supply the electricity in remote areas with high reliability through greener and cheaper renewable energy resources (RERs). Having in mind the uncertainties in the RERs due to climatic changes, a combined application of battery and supercapacitor as composite energy storage devices (CESDs) in the DC microgrid is presented in this article. The purpose of CESD is to compensate the power imbalance caused by the intermittency of renewable sources and varying load demands. The power allocation in the composite energy storage system is a major concern and also it remains a challenging issue in conventional techniques. Hence, in this article, the problem is resolved by implementing an improved mixed droop technique (IMDT) with optimized steady-state as well as transient performances. With the proposed technique, the supercapacitor compensates all the fast power fluctuations in the system, while the battery supplies only the average power at steady-state. This control strategy advances the consistency of the system, dynamic restoration of the DC bus voltage, and reduces current stress from the battery units. Both MATLAB simulation and experiments are conducted to validate the effectiveness of the proposed strategy. Also, the scheme is verified for a large-scale ${\text{71 kW}}$ PV generating system through simulation.