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AssigneeFronius International GmbH
InventorsFriedrich Oberzaucher, Joachim Danmayr
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The invention relates to a method for checking a separation point (14) between a photovoltaic inverter (1) and a power supply network (7) having multiple phases (L1, L2, L3) and a neutral conductor (N), wherein multiple switching contacts of the separation point (14) are controlled by the photovoltaic inverter (1), and to a photovoltaic inverter (1). To allow a simple and quick check of the functionality of the separation point (14), the switching contacts of the separation point (14) are each formed by single-pole relays (15-22) and switched in steps according to a switching pattern. For checking switching contacts, a voltage (26, 27, 28) is measured at at least one phase (L1, L2, L3) with respect to the neutral conductor (N), upstream of the separation point (14), and compared to voltage values assigned in accordance with the switching pattern, thereby to deduce the functionality of the switching contacts.
A method for checking a separation point between a photovoltaic inverter and a power supply network having a plurality of phases and a neutral conductor, wherein a plurality of switching contacts of the separation point are controlled by the photovoltaic inverter, wherein the switching contacts of the separation point are each formed by respective single-pole relays and switched in steps according to a switching pattern, and a voltage is measured at at least one phase with respect to the neutral conductor, upstream of the separation point, for checking several switching contacts, and compared to values of the voltage assigned in accordance with the switching pattern from which the functionality of the switching contacts is deduced, and wherein the switching pattern is implemented by a stepwise switchover of the switching contacts of the separation point from one switching state to another switching state, wherein the functionality of the individual switching contacts of the separation point is deduced from the different switching states or the switchover of the switching states.
A photovoltaic inverter for converting a DC voltage to an AC voltage, having a plurality of phases and a neutral conductor, and for supplying the AC voltage to a power supply network having at least first, second, and third phases and a neutral conductor, comprising a separation point formed by at least first, second, third, fourth, fifth, and sixth relays having switching contacts for a galvanic separation from the at least first, second, and third phases and the neutral conductor of the power supply network, wherein the separation point is composed of the at least first, second, third, fourth, fifth, and sixth relays with one switching contact each, and the first and fourth relays, the second and fifth relays, and the third and sixth relays are respectively connected in series for connecting the first, second, and third phases, respectively, wherein devices for measuring the voltages of the phases with respect to the neutral conductor are provided upstream of the separation point, and further comprising first and second controllers respectively upstream and downstream of the separation point, wherein the first and second controllers are independent from each other and connected to each other by a data bus.
Dependencies are inferred from the claim text.