• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.26-32
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• 2012

A current compensation method to reduce the mismatch loss in PV systems is proposed as a way to increase the power generation efficiency. A dc-dc converter is used to supply currents to irregular modules in a PV string and is powered from the string output. The converter's voltage conversion ratio is adjusted so that all the modules in the string are operated at the maximum power point. The power rating and size of the converter can be reduced since only the current difference between the regular and irregular module may be supplied. The compensated string shows very little voltage mismatch compared to other regular strings. The validity of the proposed method is verified through a simulation and experiments in a prototype PV system.

• Proceedings of the KIPE Conference
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• 2009.11a
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• pp.123-125
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• 2009

Mismatch of electrical characteristics of modules in PV string invokes mismatch power loss. The mismatch occurs due to various causes such as shadow, aging, contamination, and module exchange. The concept of mismatch compensation converter(MCC) is presented in this paper to remedy the mismatch loss problem. MCC is connected to irregular modules only. MCC is composed of dc-dc converter and MPPT controller. It is noted that MPPT algorithm is employed to control MCC and is effective for maximum power available from irregular modules. The selection guide of MPPT control period is given based on the period of MPPT in PCU. The effectiveness of the MCC is verified by a prototype experiment.