Title :
Decrease in photovoltaic power output from ripple: Simple general calculation and effect of partial shading
Author :
Sullivan, Charles R. ; Awerbuch, Jonathan ; Latham, Alexander M.
Author_Institution :
Thayer Sch. of Eng., Dartmouth Coll., Hanover, NH, USA
Abstract :
The effect of voltage ripple on the power output of a photovoltaic panel is calculated and tested experimentally. Voltage ripple induces a much larger power reduction than would be predicted from a conventional small-signal model of the panels I-V characteristic, even with small ripple amplitude. A simple expression is provided to calculate power reduction from rms ripple voltage, for any ripple waveform shape. The effect of ripple on power output can be much more severe under non-uniform irradiance as can result from partial shading. The results are important for consideration of 120 Hz ripple in single-phase inverters; high-frequency switching ripple with any power converter in a photovoltaic system; and perturbations and tracking errors in maximum-power-point tracking systems.
Keywords :
maximum power point trackers; photovoltaic power systems; I-V characteristic; conventional small-signal model; frequency 120 Hz; high-frequency switching ripple; maximum-power-point tracking systems; nonuniform irradiance; partial shading; photovoltaic panel; photovoltaic power output; photovoltaic system; power converter; power reduction; ripple waveform shape; rms ripple voltage; single-phase inverters; small ripple amplitude; tracking errors; voltage ripple; Approximation methods; Capacitance; Frequency measurement; Noise; Power measurement; Radiation effects; Resistance;
Conference_Titel :
Applied Power Electronics Conference and Exposition (APEC), 2011 Twenty-Sixth Annual IEEE
Conference_Location :
Fort Worth, TX
Print_ISBN :
978-1-4244-8084-5
DOI :
10.1109/APEC.2011.5744864
