Abstract: A method of converting a direct voltage generated by a decentralized power supply system into three-phase alternating voltage by means of a plurality of single-phase inverters (WR1-WR3), said alternating voltage being provided for supplying an electric mains, is intended to avoid inadmissible load unbalances using single-phase inverters. This is achieved in that, upon failure of one inverter (WR1-WR3), an asymmetrical power supply distribution is reduced by limiting the output of the other inverters. The method makes it possible to simplify three-phase voltage monitoring.

Abstract: A method of finding a power maximum of a photovoltaic generator using an MPP regulator of a photovoltaic current converter by means of which a maximum generator power is set at an operating point of the generator's characteristic curve is intended to supply improved efficiency when the generator is partially shadowed. This is achieved by switching the MPP regulator off in order to next load and/or unload the generator to allow a new operating point of the generator's characteristic curve to set and by next switching the MPP regulator on again.

Abstract: A buried grid structure is produced in a semiconductor material particularly a silicon wafer, while using a metallic grid mask. The buried grid is formed directly within the semiconductor material by contradoping ion implantation by means of a high energy accelerator through the metallic grid mask. The bars or ribs of the metallic grid mask stop the ions passing therethrough so that two vertically separated and laterally offset buried grid structures are produced. By beveling the periphery of the wafer, buried conductive structures are formed at the same time as connections between the buried grid structures and a control electrode provided on the back side of the wafer.