Abstract: A power converter between an AC side and DC of the power converter is disclosed. The AC side is connected to an AC supply grid and the DC side is connected to a DC grid. The power converter includes a bridge circuit connected to the AC side of the power converter via AC switches and connected to the DC side of the power converter via circuit breakers, wherein a DC link circuit of the power converter is chargeable from the AC supply grid via an AC precharging circuit. The power converter has an insulation monitor to measure the insulation resistance of the DC side when the AC precharging circuit is connected to the DC link circuit. The disclosure also includes a related method.

Abstract: The application describes a method for balancing voltages on a first and a second DC conductor in a DC grid using a balancing circuit with a first and second semiconductor switch connected in series between the first and second DC conductors, and a connection to a ground potential that is arranged between the first and second semiconductor switches. In the presence of an asymmetry in the voltages of the first and second DC conductors to ground potential, a compensation current is generated between at least one of the DC conductors ground potential via at least one of the semiconductor switches, with the asymmetry in the voltages being reduced by the compensation current (IA), with the voltages of the DC conductors to ground potential being balanced.

Abstract: The disclosure relates to an inverter including a first bridge branch with a first phase output, a second bridge branch with a second phase output, a third bridge branch with a third phase output, wherein the phase outputs of the bridge branches can each be connected to a phase conductor of a three-phase power distribution network.

Abstract: An inverter includes a DC/AC converter connectable to a DC power grid, at least one DC/DC converter arranged upstream of the DC/AC converter and providing a galvanic isolation, and a DC voltage link at the input of the at least one DC/DC converter and connectable to at least one DC power source. The inverter also includes at least one further DC voltage link which is galvanically isolated from the first DC voltage link by the DC/DC converter, on-board voltage rails supplying a controller and other auxiliary devices of the inverter with electric energy; and an on-board supply unit. The on-board supply unit is configured and adapted to feed the electric energy into the on-board voltage rails both out of the first DC voltage link and out of the at least one further DC voltage link.

Abstract: An inverter includes a DC/AC converter connectable to a DC power grid, at least one DC/DC converter arranged upstream of the DC/AC converter and providing a galvanic isolation, and a DC voltage link at the input of the at least one DC/DC converter and connectable to at least one DC power source. The inverter also includes at least one further DC voltage link which is galvanically isolated from the first DC voltage link by the DC/DC converter, on-board voltage rails supplying a controller and other auxiliary devices of the inverter with electric energy; and an on-board supply unit. The on-board supply unit is configured and adapted to feed the electric energy into the on-board voltage rails both out of the first DC voltage link and out of the at least one further DC voltage link.

Abstract: The invention is directed to a circuit array with a relay (K1; K12) incorporating a field coil (E) as well as a switch contact (1a, 1b), said switch contact (1a, 1b) being provided as a switch point between a grid, in particular a mains supply (N), and an inverter (WR) fed by a direct voltage source, in particular by a photovoltaic generator (PVG), said relay (K1; K12) being configured to be a bistable relay.

Abstract: The subject matter of the invention is an inverter (3), more specifically for use in a photovoltaic plant (1) with a direct voltage input (connection terminals 4; 5) for connection to a generator (2) and an alternating voltage output (connection terminals 7; 8) for feeding into an energy supply network (6) as well as with a DC-AC converter (12) with semiconductor switch elements (15) and an intermediate circuit (11), at least one short-circuit switch element (18) being connected in parallel to the generator (2), so that the voltage will not exceed a maximum voltage value neither at the connection terminals (4; 5) of the generator (2) nor between the connection terminals (9; 10) of the inverter.

Abstract: The invention relates to a measuring array with an earth connection point (5) for determining the insulation resistance (Riso) of an energized electrical apparatus or of an installation with a supply voltage UB with a positive pole (6) and a negative pole (7), two switches (S1, S2) or a corresponding two-way switch being provided for creating a current path between one of the two poles and said earth connection point (5) in order to determine the insulation resistance (Riso) generally obtained when one or a plurality of insulation faults occur at any potential reference, two measurements being performed one after the other for determining the insulation resistance, the first switch (S1) being closed and the second switch (S2) open during the first of these two measurements and the first switch (S1) being open and the second switch (S2) closed during the second of these measurements.