An energy buffer for constant power loads

Constant power loads (CPLs) are a class of loads steadily increasing in use. They are present whenever a load is regulated to maintain constant output power, such as with LED drivers in high quality lighting that is impervious to input fluctuations. Because CPLs exhibit a negative incremental input impedance, they pose stability concerns in DC and AC systems. This thesis presents a power converter for a constant power LED bulb that presents a favorable input impedance to the grid. The use of an energy buffer allows the converter to draw variable power in order to resemble a resistive load, while the output consumes constant power. A switched-mode power supply consisting of a cascaded boost and buck converter accomplishes this by storing energy in the boost stage output capacitor. Experimental results demonstrate that the converter exhibits a resistive input impedance at frequencies over 0.5 Hz while maintaining constant power to the LED load.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2017

Author dc:creator

• Gutierrez, Manuel, (Scientist in electrical engineering and computer science) Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Steven B. Leeb, Peter Lindahl and Arijit Banerjee.

• Electrical Engineering and Computer Science.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/111914

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/111914