PHOTON International The Photovoltaic Magazine

SMA's second inverter for multiple strings

One year after the introduction of its first inverter for several module strings, the German company SMA Regelsysteme GmbH will present a smaller version of its transformerless device, the Sunny Boy Multistring 5000, in June.

	© SMA Regelsysteme GmbH
The second coming: In June, SMA Regelsysteme GmbH will introduce its second inverter for multiple strings, the Sunny Boy 4200 TL.

The new inverter, which is called the Sunny Boy 4200 TL, has a nominal power of 4 kW - just 600 W less than its predecessor. The device's MPP range of 125 to 750 V is quite extensive, and its European efficiency of 94.5 percent is also fairly impressive for a transformerless inverter in this power class.

According to this inverter's design, modules suited for similar irradiation conditions are connected to a string. Since an integrated DC/DC-converter with a separate MPP regulator ensures that each string operates at maximum power, the values of the MMP points of the strings can differ - which has an advantageous effect on the yield of solar modules placed in varying orientations or operating under shadowy conditions.

Whereas the Sunny Boy 5000 has three separated MPP-regulated DC-inputs, the new device has just two such inputs, each of which can withstand a maximum of 7.5 A of electricity. The 2-year standard guarantee can be extended to 10 years at an additional cost. The inverter is available worldwide. The price for the Sunny Boy 4200 TL had not been set when we went to print.