Massachusetts Institute of Technology

Arthur Hsu Chen Chang

Steven B Leeb

David J Perreault

Khurram K Afridi

Minjie Chen

Arijit Banerjee

Shahriar Khushrushahi

Al-Thaddeus Avestruz

A stacked switched capacitor (SSC) energy buffer circuit includes a switching network and a plurality of energy storage capacitors. The switching network need operate at only a relatively low switching frequency and can take advantage of soft charging of the energy storage capacitors to reduce loss. Thus, efficiency of the SSC energy buffer circuit can be extremely high compared with the efficiency of other energy buffer circuits. Since circuits utilizing the SSC energy buffer architecture need not utilize electrolytic capacitors, circuits utilizing the SSC energy buffer architecture overcome limitations of energy buffers utilizing electrolytic capacitors. Circuits utilizing the SSC energy buffer architecture (without electrolytic capacitors) can achieve an effective energy density characteristic comparable to energy buffers utilizing electrolytic capacitors. The SSC energy buffer architecture exhibits losses that scale with the amount of energy buffered, such that a relatively high efficiency can be achieved across a desired operating range.

Stacked switched capacitor energy buffer circuit

A system for generating an asymmetric magnetic field. The system includes a drive circuit and a stacked winding structure coupled to the drive circuit. The stacked winding structure includes a plurality of winding layers. The plurality of winding layers includes a first winding layer including a first conductive winding having first turns and a second winding layer including a second conductive winding having second turns ion. The plurality of winding layers is arranged to produce a first magnetic field at a first side of the stacked winding structure and a second magnetic field at a second side of the stacked winding structure when the drive circuit electrically drives the plurality of winding layers. The first magnetic field is greater than the second magnetic field.

Method and apparatus for producing an asymmetric magnetic field

Enhanced stacked switched capacitor energy buffer circuit

Described is a method and apparatus for per-panel photovoltaic energy extraction with integrated converters. Also described are switched-capacitor (SC) converters have been evaluated for many applications because of the possibility for on-chip integration; applications to solar arrays are no exception. Also described is a comprehensive system-level look at solar installations, finding possibilities for optimization at and between all levels of operation in an array. Specifically, novel concepts include new arrangements and options for applying switched-capacitor circuits at 3 levels: for the panel and sub-panel level, as part of the overall control strategy, and for ensuring stable and robust interface to the grid with the possibility of eliminating or reducing the use of electrolytic capacitors.

Systems approach to photovoltaic energy extraction

Described herein is a stacked switched capacitor (SSC) energy buffer circuit architecture and related design and control techniques.

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Irvine, CA, United States of America

Arthur Hsu Chen Chang