PV cell string optimizer boosts solar panel output up to 30%

September 12, 2016 // By Graham Prophet
Maxim presents its Cell-String Optimizer as the first IC to perform MPPT (maximum power point tracking) at low level in a panel; it allows photovoltaic (PV) panels to harvest significantly more energy and simplifies design complexity for solar installation projects.

Maxim’s cell-string optimizers are highly integrated DC-DC converters that replace the bypass diode and perform maximum power point tracking (MPPT) deep inside the PV module. By replacing each diode with a MPPT device, the on-off response to performance mismatch is eliminated; every cell-string contributes maximum power without interfering with the power production capability of others. This enhanced degree of flexibility leads to increased energy production; eliminating collateral performance loss due to module mismatch, degradation, soiling, localized shading, and row shading loss mechanisms.

The illustration shows the principle; when panel segments are linked by bypass diodes, partial shading or a section takes the output of that group of cells below the point at which the entire section contributes to the total. Using DC/DC converters allows the shaded panel still to feed power to the output, but at a lower level.


A White Paper is here, and a video is here.


Advantages claimed are;

- increases energy harvest: offers optimum shade mitigation, providing 30% additional power over diodes

- extends reliability: eliminates hotspots and minimizes the impact of power degradation mechanisms

- enables flexible design: higher degree of flexibility to incorporate multiple string lengths, multiple orientations, and expanding modules into partially shaded areas

- simplifies operation: fully integrated solution simplifies design by requiring no additional hardware, specialized inverters, or data services


[Ed. Note; package scale is indicated in the picture above by a quarter-dollar, slightly larger in diameter than a 1-euro coin.]


Maxim Integrated; www.maximintegrated.com