An increase in demand for renewable energy resources, energy storage technologies, and electric vehicles requires high-power level DC-DC converters. The DC-DC converter that is suitable for high-power conversion applications (i.e., resonant, full-bridge or the dual-active bridge) requires magnetic transformer coupling between input and output stage. However, transformer design in these converters remains a challenging problem, with several non-linear scaling issues that need to be simultaneously optimized to reduce losses and maintain acceptable performance. In this paper, a new transformer-less high step-up boost converter with a charge pump capacitorand capacitor-inductor-diode CLD cell is proposed using dynamic modeling. The experimental and simulation results of the proposed converter are carried out in a laboratory and through Matlab Simulink, where 10 V is given as an input voltage, and at the output, 100 V achieved in the proposed converter. A comparative analysis of the proposed converter has also been done with a conventional quadratic converter that has similar parameters. The results suggest that the proposed converter can obtain high voltage gain without operating at the maximum duty cycle and is more efficient than the conventional converter.

To reduce the allocation of energy storage capacity in wind farms and improve economic benefits, this study is focused on the virtual synchronous generator (synchronverter) technology. A system accompanied by wind power, energy storage, a synchronous generator and load is presented in detail. A brief description of the virtual synchronous generator control strategy is given. The capacity allocation is based on different optimization goals and the optimal energy storage capacity configuration of the coordinated frequency modulation (FM) control strategy. The detail of the dual-loop control strategy is carried out by establishing the grid-connected transfer function model of the synchronverter energy storage and a theoretical model of life cycle cost is established. The optimal control strategy of coordinated FM for wind storage is implemented using MATLAB software. The simulation showed that the proposed strategy provided the energy storage capacity at high wind speed, which is configured to be 5.9% of the installed capacity of the wind turbine, marking a reduction of 26% compared with the 8% capacity required for independent support. In addition, the proposed method has improved the energy storage capacity configuration of the coordinated FM control strategy.

We propose the design principle of a superdirective antenna with needle-like radiation based on multi-layered dielectric cylinder. The electromagnetic fields and far-field directivity of superdirective antenna are calculated. The radiation mechanisms of the superdirective antenna are illustrated by multi-layered asymmetric SPR phenomenon. A nonlinear searching algorithm is utilized to calculate the design parameters of the antenna. A series of constraint conditions on the design parameters are derived from the phenomenon. The constraint conditions restrict the initial values of optimization in a limited solution space, and act as a guidance on the optimizing process and improves the convergence and quality of optimization.

We propose the design of a superdirective antenna based on a multi-layered dielectric cylinder. A novel optimization goal is proposed based on the physical characteristics of the Dirac delta function. The side-lobe properties of superdirective antenna is discussed and treated as the optimization goal for antenna design for the first time. A multi-stage genetic algorithm and trust region reflective algorithm are utilized to shorten the time duration for optimization. The optimizing efficiency is higher and the cost of time is significantly reduced compared with proposed designs. The effect of weight of different algorithms is discussed. Both the dielectric loss and metallic loss are also discussed for practical cases. The optimization is of low computing cost and can be accomplished by personal computers.

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