SMA SUNNY ISLAND 4548-US Operating Manual page 237

SMA Solar Technology America LLC 23 Glossary
MPP Tracker
Regulation of the power drawn so that a PV field remains as close as possible to the MPP. This
operating point varies with the solar irradiation and the temperature conditions of the modules. MPP
tracking optimizes the extraction of electrical power and is a feature of inverters and charge
controllers.
Multi-String Inverter
An inverter that combines the advantages of several string inverters (separate MPP tracking of
individual strings) and a central inverter (lower performance specific costs).
Nominal Energy Throughput of the Battery
A nominal energy throughput is the calculated result of one full charge and discharge of the battery.
Grid-Tie Plant
A PV system that is connected to the utility grid, such as the power company.
NiCd
Nickel cadmium battery, contains nickel, cadmium and potassium hydroxide as electrolytes. They
require a significantly higher charging voltage, have a lower level of efficiency and are significantly
more expensive than lead-acid batteries. Their robustness, cycle resistance and low temperature
capabilities allow them to be used in certain special applications.
Parallel Connection
Parallel connection of the batteries (all positive terminals connected and all negative terminals
connected) increases the capacity of the battery storage system while keeping the voltage constant.
Example: Two 24 V/100 Ah batteries connected in parallel still have a voltage of 24 V, however, a
capacity of 100 Ah + 100 Ah = 200 Ah.
Piggy-Back (Printed Circuit Board)
A printed circuit board that is plugged into another assembly to increase performance. A Piggy-Back
can also replace an individual chip. In this case, the chip is removed and the Piggy-Back is plugged
into the empty base.
Photovoltaics
Photovoltaics (PV) is the conversion of solar irradiation into electrical energy using special
semiconductors called PV cells.
PV System
Describes the totality of devices required for the exploitation and utilization of solar energy. In grid-tie
systems, this includes not only the PV array, but also the inverter, e.g. Sunny Boy or
Sunny Mini Central.
Operating Manual SI4548-6048-US-BE-en-21 237