Abstract: The present invention provides a method for operation of an offline uninterrupted power supplyfor providing power to a load in case of failure of a power source, the uninterrupted power supply comprising at least one disconnect switch, which is arranged between the power source and the load, at least one energy storage, at least one power converter, which is arranged between the at least one energy storage and the load at a load side of the disconnect switch, and a control device for controlling the at least one power converter to provide power from the at least one energy storage to the load in case of failure of the power source, comprising the steps of identifying a power quality event, differentiating the identified power quality events to separate load side events from power supply side quality events, and upon identification of a power supply side power quality event from an identified power quality event, providing power from the at least one energy storage to the load.

Abstract: A protection arrangement for an uninterruptible power supply system including at least one vacuum circuit breaker connected in series with an inductive element, the protection arrangement including a first bypass branch and a first grounding branch, the first bypass branch being connected in parallel with the inductive element and including two series-connected protective components of a first type and a bypass branch midpoint between them, where the first grounding branch is connected between the bypass branch midpoint and ground and includes a first grounding surge arrester.

Abstract: A protection arrangement for an uninterruptible power supply system including at least one vacuum circuit breaker connected in series with an inductive element, the protection arrangement including a first bypass branch and a first grounding branch, the first bypass branch being connected in parallel with the inductive element and including two series-connected protective components of a first type and a bypass branch midpoint between them, where the first grounding branch is connected between the bypass branch midpoint and ground and includes a first grounding surge arrester.

Abstract: The present invention provides a method for operation of an offline uninterrupted power supply (100), in particular a medium-voltage uninterrupted power supply, for providing power to a load in case of failure of a power source, the uninterrupted power supply (100) comprising at least one disconnect switch (112), which is arranged between the power source and the load, at least one energy storage (114), at least one power converter (116), which is arranged between the at least one energy storage (114) and the load at a load side of the disconnect switch (112), and a control device (120) for controlling the at least one power converter (116) to provide power from the at least one energy storage (114) to the load in case of failure of the power source, comprising the steps of identifying a power quality event, differentiating the identified power quality events to separate load side events from power supply side quality events, and upon identification of a power supply side power quality event from an identifie