Sma Solar Technology Ag

Guenther Cramer

Frank Greizer

Bernd Engel

Joachim Ralf Laschinski

Sven Bremicker

Matthias Victor

Wilfried Groote

Torben Westphal

Thorsten Dingel

Ralf Joachim Laschinski

Holger Becker

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 (WR-WR), 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 (WR-WR), 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.

Method for converting direct voltage into three phase alternating voltage

A solar power plant includes at least one photovoltaic module for generating power to be fed in a multi-phase grid. At least one inverter is provided for converting a direct voltage generated by the at least one photovoltaic module into an alternating mains voltage. A mains transformer is coupled to receive the alternating mains voltage from the inverter. The inverter is coupled to a primary side of the mains transformer. A direct voltage source coupled between an output of the at least one inverter and an input of the mains transformer such that a potential of the at least one photovoltaic module is displaced and that a bias voltage is set which is different from zero volts.

Device and method for generating alternating current

A solar power plant with a plurality of photovoltaic modules for generating a power to be fed in a multi-phase grid, several photovoltaic strings, which are allocated to different phases, being connected to a primary side of a mains transformer and at least one inverter for converting the direct voltage generated by the photovoltaic modules into an alternating mains voltage conforming to the grid being provided and said mains transformer being provided with a neutral conductor and with a grounded terminal, is intended to be improved in such a manner that the life of the photovoltaic modules, in particular in case of thin-film modules, is increased, allowing for high conversion efficiency of the inverters at low wiring costs. This is achieved in that an additional direct voltage source is inserted between the neutral conductor and ground in such a manner that the potential of the photovoltaic strings is displaced and that a bias voltage is set, which is different from zero volt.

Solar power plant

Growing community of inventors

Kassel, Germany

Guenther Cramer