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This paper first presents an adaptive switching frequency modulation that optimizes the efficiency of the cascaded buck-boost (CBB) converter. Such bidirectional dc–dc CBB topology is typically deployed in PV-battery-device systems. A precise loss-model that accounts for component nonlinearities is developed to determine power-loss distribution. According to the loss model, optimal switching frequencies are selected that correspond to the lowest total loss in both the buck and the boost modes of the operation. Then, a small volume low-profile planar-nanocrystalline inductor is designed to further increase efficiency and power density. Finite element analysis method is used to evaluate the inductor design. A digital control system is designed to periodically adjust the optimal switching frequencies to modulate the pulsewidth modulation duty cycle and to take into account any load and line regulations. The objective of this paper is to achieve ultra-high efficiency (over 99%) for a well-known CBB converter. A 100 W CBB converter prototype was built to verify the proposed algorithm and designed nanocrystalline inductor. A California Energy Commission weighted efficiency of 98.87% with a peak efficiency of 99.31% was achieved for the buck mode and 98.58% with a peak efficiency of 99.25% was achieved for the boost mode, both at nominal voltage. Also, a power density of 3.67 kW/L was reported. [ABSTRACT FROM AUTHOR]

Given the frequency of power outages caused by recent crises, including high-impact natural disasters, power and energy supply must be more resilient and cost effective. Owing to this necessity, this article presents a grid-connected multicarrier energy microgrid, which can provide continuous energy for both electrical and heating load demands at a low cost. The model employs a demand response (DR) scheme based on time of use and integrates with the proposed microgrid. Several energy sources—photovoltaics, batteries, a combined heat and power unit, and associated dispatch strategy—are optimized using the deterministic mixed-integer linear programming algorithm. The proposed model is tested in a hospital of California, USA. The results show the benefits of the DR program in terms of techno-economic output when compared to the system without its implementation. Several simulation results also demonstrate the model’s effectiveness and resiliency in maintaining a continuous energy supply in the midst of power outages at various times of the year while lowering costs. Furthermore, a comparative study with the existing methods is performed, which shows the effectiveness of the proposed technique as well. [ABSTRACT FROM AUTHOR]