High efficiency resonant dc/dc converter for solar power applications

This thesis presents a new topology for a high efficiency dc/dc resonant power converter that utilizes a resistance compression network to provide simultaneous zero voltage switching and near zero current switching across a wide range of input voltage, output voltage and power level. The resistance compression network maintains desired current waveforms over a wide range of voltage operating conditions. The use of on/off control in conjunction with narrowband frequency control enables high efficiency to be maintained across a wide range of power levels. The converter implementation provides galvanic isolation and enables large (greater than 1:10) voltage conversion ratios, making the system suitable for large step-up conversion in applications such as distributed photovoltaic converters. Three 200 W prototypes were designed, built and tested. The first prototype was made as a proof of concept and operated at a switching frequency of 100 kHz. It had an efficiency of 93.5% (at 25 V input and 400 V output). The second prototype was operated at a switching frequency of 500 kHz and had an efficiency of 93% (at 25 V input and 400 V output). The high frequency losses caused by the ringing in voltage and current due to the resonating parasitics of the transformer were removed with the help of a matching network in the third prototype. This final prototype operated at a switching frequency of 500 kHz and showed that over 95% efficiency is maintained across an input voltage range of 25 V - 40 V (at 400 V output) and over 93.7 % efficiency across a wide output voltage range of 250 V - 400 V (at 25 V input). These experimental results demonstrated the effectiveness of the proposed design.

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

2013

Author dc:creator

• Inam, Wardah

Advisor dc:contributor.advisor

• David J. Perreault and Khurram K. Afridi.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about 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/1721.1/79153

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/79153