Abstract: A method in a power inverter system (100) is disclosed, wherein the power inverter system comprises a central unit (130) and a plurality of switching units (110) operable in an inverter mode in which they are individually switched so as to produce a combined output voltage waveform and AC (VOUT) transmitted in a common line (120), and operable in a communication mode in which the switching units are switched so as to produce a communication signal, the communication signal being transmitted in the common line to the central unit. The method comprises operating at least some of the switching units in the inverter mode such that they are switched in response to switching commands of a command signal produced by the central unit, and between two consecutive switching commands of the command signal, operating at least one of the switching units in the communication mode.

Abstract: A method for generating a combined output waveform (VOUT) in a power inverter system (100) is disclosed. The power inverter system comprises a voltage equaliser (120) having an energy storage element adapted to be charged by a combined output voltage from a plurality of switching units and to add an adjustable voltage to the combined output waveform. A voltage of the combined output waveform is measured, a difference (?) between the measured voltage of the output waveform and a voltage of a target waveform (UT) is determined, and a voltage (UCORR) corresponding to the determined difference is added, by the voltage equaliser, to the combined output waveform so as to improve the matching of the combined output power waveform and the target power waveform.

Abstract: A common mode inductor (10) for suppression of common mode noise and transmission of a differential signal is disclosed. The inductor comprises a core (15) with a first and second winding (11, 12), wherein the first winding and the second winding forms a pair of conductors arranged to convey a differential communication signal. Further, a third and fourth winding (13, 14) is arranged to extend along at least a portion of the first and second winding, respectively. The third winding and the fourth winding may be locally inductively coupled to the first winding and the second winding, respectively. Moreover, the third winding and the fourth winding are connected in series with each other so that differential signal on the first and second windings transformed to the third and fourth winding maybe added to each other. The third and fourth winding may hence provide a sensor signal induced by the differential communication signal in the first winding and the second winding.

Abstract: A method for generating a combined output waveform (VOUT) in a power inverter system (100) is disclosed. The power inverter system comprises a voltage equaliser (120) having an energy storage element adapted to be charged by a combined output voltage from a plurality of switching units and to add an adjustable voltage to the combined output waveform. A voltage of the combined output waveform is measured, a difference (?) between the measured voltage of the output waveform and a voltage of a target waveform (UT) is determined, and a voltage (UCORR) corresponding to the determined difference is added, by the voltage equaliser, to the combined output waveform so as to improve the matching of the combined output power waveform and the target power waveform.

Abstract: A common mode inductor (10) for suppression of common mode noise and transmission of a differential signal is disclosed. The inductor comprises a core (15) with a first and second winding (11, 12), wherein the first winding and the second winding forms a pair of conductors arranged to convey a differential communication signal. Further, a third and fourth winding (13, 14) is arranged to extend along at least a portion of the first and second winding, respectively. The third winding and the fourth winding may be locally inductively coupled to the first winding and the second winding, respectively. Moreover, the third winding and the fourth winding are connected in series with each other so that differential signal on the first and second windings transformed to the third and fourth winding maybe added to each other. The third and fourth winding may hence provide a sensor signal induced by the differential communication signal in the first winding and the second winding.

Abstract: A method in a power inverter system (100) is disclosed, wherein the power inverter system comprises a central unit (130) and a plurality of switching units (110) operable in an inverter mode in which they are individually switched so as to produce a combined output voltage waveform and AC (VOUT) transmitted in a common line (120), and operable in a communication mode in which the switching units are switched so as to produce a communication signal, the communication signal being transmitted in the common line to the central unit. The method comprises operating at least some of the switching units in the inverter mode such that they are switched in response to switching commands of a command signal produced by the central unit,and between two consecutive switching commands of the command signal, operating at least one of the switching units in the communication mode.

Abstract: A method of controlling a plurality of DC/AC converters in cascade configuration, each being arranged to receive an input direct current and voltage from a respective photovoltaic panel and to deliver an electric output. The method includes receiving information representing at least one of frequency, phase, amplitude and harmonics of a required AC, and receiving information on the input direct current and voltage to each one of the plurality of DC/AC converters. Based on the received information, each one of the plurality of DC/AC converters is individually controlled in such manner that the combined output from the plurality of DC/AC converters produces an AC matching the required AC.

Abstract: A method of controlling a plurality of DC/AC converters in cascade configuration, each being arranged to receive an input direct current and voltage from a respective photovoltaic panel and to deliver an electric output. The method includes receiving information representing at least one of frequency, phase, amplitude and harmonics of a required AC, and receiving information on the input direct current and voltage to each one of the plurality of DC/AC converters. Based on the received information, each one of the plurality of DC/AC converters is individually controlled in such manner that the combined output from the plurality of DC/AC converters produces an AC matching the required AC.