DH Test of a Femtogrid Power Optimizer and Microinverter under Operation

Introduction The market share of Module Level Power Electronics (MLPE) such as Power Optimizers (PO) and Micro-Inverters (MI) is growing fast. Advantages of MLPE compared with string inverter systems are the freedom in installation of systems and the higher yield, especially in case of shadow and/or different orientation of the PV modules. A disadvantage is that the MLPE have to be connected close to the PV module, by which it suffers from high temperatures and/or high humidity. High temperatures and high humidity can limit the lifetime of the MLPE. A second disadvantage is the high number of connections needed for this “add-on” product. To simplify the system installation, reduction of the cost and improvement of the reliability, it is expected that newer generations of MLPE will be integrated in for instance the junction box. So far there is no IEC standard for certifying PV modules with integrated MLPE. In the future it is likely that PV modules with integrated MLPE have to be tested at the same conditions as PV modules, such as DH (85/85) and TC in accordance with IEC 61215. For this reason, we tested a PO and MI in DH of which the results will be shown.