Use conditions and efficiency measurements of DC power optimizers for photovoltaic systems

Author

Deline, Chris ; MacAlpine, Sara

Author_Institution

Nat. Renewable Energy Lab., Golden, CO, USA

fYear

2013

fDate

15-19 Sept. 2013

Firstpage

4801

Lastpage

4807

Abstract

No consensus standard exists for estimating annual conversion efficiency of DC-DC converters or power optimizers in photovoltaic (PV) applications. The performance benefits of PV power electronics including per-panel DC-DC converters depend in large part on the operating conditions of the PV system, along with the performance characteristics of the power optimizer itself. This work presents a case study of three system configurations that take advantage of the capabilities of DC power optimizers. Measured conversion efficiencies of DC-DC converters are applied to these scenarios to determine the annual weighted operating efficiency. A simplified general method of reporting weighted efficiency is given, based on the California Energy Commission´s CEC efficiency rating and several input/output voltage ratios. Efficiency measurements of commercial power optimizer products are presented using the new performance metric, along with a description of the limitations of the approach.

Keywords

DC-DC power convertors; electric current measurement; energy conservation; photovoltaic power systems; power measurement; power system measurement; CEC; California Energy Commission; DC power optimizer measurement; PV power electronics system; annual conversion efficiency estimation; annual weighted operating efficiency; input-output voltage ratio; per-panel DC-DC converter; photovoltaic system; Histograms; Inverters; Power measurement; Semiconductor device measurement; Voltage measurement; Weight measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Energy Conversion Congress and Exposition (ECCE), 2013 IEEE

Conference_Location

Denver, CO

Type

conf

DOI

10.1109/ECCE.2013.6647346

Filename

6647346