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See Power Optimizers for generalities.

Module-level optimizers

The AMPT module-level optimizers are DC-DC buck-boost converters (i.e. full range optimization), that ensure to provide the maximum power from the module (Pmpp), whatever the voltage or current imposed at the output of the device.

This Maximum Power curve (hyperbola  Iout = Pmpp / Uout)  is limited  by pre-defined Voltage and Current limits, characteristics of the optimizer device. Therefore the less power, the more part of the hyperbola within the limits. This ensures that in a string of AMPT optimizers, we have a range of voltages for which the power is optimal (sum of the Pmpp of all modules).

When using an AMPT converter, we have to check that the PV module is compatible with the input specifications  (Voltage, Current, Power) of the device. This is indicated by green devices in the choice listbox.

The sizing should ensure that the maximum possible voltage of the optimizers (a constant value specified for each device) in series doesn't overcome the maximum inverter voltage VAbsMax, nor the maximum system (array) voltage, i.e. 1000 V (IEC) or 600V(UL). It will also check the  maximum voltage * 0.85 is higher than the VmppMin of the inverter.

String-level optimizers

AMPT now proposes  Dual String optimizers. These devices are current-Boost DC-DC converters. They include 2 channels, each one able to accept a string of modules with a high number of modules in series (much more than the inverter input capabilities), thus reducing the wiring needs on the field.

This architecture doesn't provide the optimizing effects (on mismatch in a string) of module-level optimizers.