Performance of differential power-processing submodule DC-DC converters in recovering inter-row shading losses

Abstract

Large commercial photovoltaic systems suffer a regular and predictable energy loss due to both inter-row shading and reduced diffuse irradiance in tightly spaced arrays. This paper investigates the advantages of replacing bypass diodes with submodule-integrated DC-DC converters (subMICs) to mitigate these losses. Yearly simulations of commercial-scale PV systems were conducted considering two subMIC granularities and a range of row-to-row pitches given either a fixed array size or a fixed land area. Results show subMIC-enhanced systems can recover 35-48% of the total energy loss. In very tightly-spaced arrays, subMICS rated at 100% of maximum substring power can confer a 7% increase in annual energy output while powerlimited subMICs rated at 30% or 15% of maximum substring power still provide a 6% or 3-4% increase, respectively.

Impact of distributed power electronics on the lifetime and reliability of PV systems

“…No partial shading is applied to the scenarios; hence, only the effects of aging of the PV cells and the power converters are taken into account. For previous works related to the long-term performance of PV systems with distributed power electronics in case of partial shading, see [20,21,[30][31][32].…”

“…The advantages of DPP and FPP with respect to the conventional architecture have motivated a number of recent works. These publications have focused on the increased energy yield of PV systems with distributed power electronics and also have discussed the mitigation of hot spots . Nonetheless, the influence of the different distributed power electronics architectures on the reliability and long‐term operation of PV systems has not been addressed.…”