Switched-capacitor converter (SCC) features a compact solution due to its magnetic-less structure, which fulfills the high density requirement in low power applications. Compared to other SCC topologies, Fibonacci switched-capacitor converter (FSC) utilizes the least number of flying capacitors to perform any voltage conversion. This paper proposes a monolithic voltage-scalable FSC, which can be used in energy harvesting applications. The challenges to implement on-chip FSC are addressed. The parasitic charge loss is substantial in FSC. Therefore, a charge recycling technique exploiting the presence of parasitic capacitors in each other phase of FSC has been employed resulting in 27% reduction in the power loss, which improves the overall efficiency by 12.7%. For a proof of concept, the proposed converter is implemented in 0.5-μm CMOS technology on 4-mm2die area. The postlayout simulation is carried out using Virtuoso ADE. With 0.3-V input voltage, the system achieves 47.5% peak power efficiency with 5-μW load.

Transmission and distribution (T&D) networks are a critical part of the power grid. As moving towards a smart-grid, it is essential to modernize the T&D networks and make it “Smart-grid ready”. The concept of flexible ac transmission systems (FACTS) has been well-known for three decades. Rapid advancements in power electronics technology in the past decades have led to a new generation of FACTS devices. The Modern FACTS technology helps the transition of transmission networks to “smart”. With increasing penetration of distributed generation, the distribution network is seeing unprecedented variation in terms of its fundamental operation and control, from renewable energy integration to microgrid, from active control of power quality, volt/var and frequency to self-healing and islanding operation. As a key part of smart-grid at the distribution level, we summarize the current efforts as a concept of resilient ac distribution systems (RACDS). The concepts of both FACTS and RACDS for a smart grid are introduced in this paper. Different configurations, key benefits, operating principles and world-wide installations of FACTS and RACDS devices are presented in detail. The ongoing and future direction of R&D leading to newer generations of FACTS and RACDS are also discussed.