Abstract: An apparatus and a method for preparing connection of a photovoltaic system (Q1) as a first energy source to a power grid (13) by way of a motor generator set (5, 6, 7) is presented. The DC motor (5) is coupled to a three-phase generator (7) by way of a shaft (6), wherein the three-phase generator (7) can be connected to the power grid (13). It has been observed that connecting this type of apparatus to the small or varying power output of the photovoltaic system (Q1) can be difficult and time-consuming. To enable a clean and quick connection, the DC motor (5) is powered with electric DC current from a second DC current source (Q2), wherein the operation of the three-phase generator (7) is matched to the conditions in the power grid (13) with the help of the second DC current source (Q2), and wherein the photovoltaic system (Q1) is connected to the DC motor (5) and the second DC current source (Q2) is disconnected from the DC motor (5) only after a complete match has been attained.

Abstract: An apparatus and a method for preparing connection of a photovoltaic system (Q1) as a first energy source to a power grid (13) by way of a motor generator set (5, 6, 7) is presented. The DC motor (5) is coupled to a three-phase generator (7) by way of a shaft (6), wherein the three-phase generator (7) can be connected to the power grid (13). It has been observed that connecting this type of apparatus to the small or varying power output of the photovoltaic system (Q1) can be difficult and time-consuming. To enable a clean and quick connection, the DC motor (5) is powered with electric DC current from a second DC current source (Q2), wherein the operation of the three-phase generator (7) is matched to the conditions in the power grid (13) with the help of the second DC current source (Q2), and wherein the photovoltaic system (Q1) is connected to the DC motor (5) and the second DC current source (Q2) is disconnected from the DC motor (5) only after a complete match has been attained.

Abstract: A photovoltaic system includes a plurality of photovoltaic modules and a DC motor connected to a three-phase generator driven by a shaft. The three-phase generator is connected to a power mains. The electric power supplied to the DC motor by the plurality of photovoltaic modules is repeatedly measured and adjusted, by changing an external excitation current of the DC motor, to the peak power attainable at the current ambient temperature and the current incident solar radiation intensity. The peak power is preferably determined by incrementally changing the excitation current in predetermined time intervals, until the supplied electric power produces a power level which can be regarded as the peak power.

Abstract: A photovoltaic system includes a plurality of photovoltaic modules and a DC motor connected to a three-phase generator driven by a shaft. The three-phase generator is connected to a power mains. The electric power supplied to the DC motor by the plurality of photovoltaic modules is repeatedly measured and adjusted, by changing an external excitation current of the DC motor, to the peak power attainable at the current ambient temperature and the current incident solar radiation intensity. The peak power is preferably determined by incrementally changing the excitation current in predetermined time intervals, until the supplied electric power produces a power level which can be regarded as the peak power.