Patent ID: 11949280
Assignee: ABB SCHWEIZ AG
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. An uninterruptable power supply device comprising:
a grid connection;
a grid switch connected to the grid connection, wherein the grid switch is a mechanical switch, and wherein the grid switch comprises a confirmation device configured to generate a confirmation signal in response to the uninterruptible power supply being disconnected from the grid connection;
a rectifier and an inverter interconnected via a DC link;
an energy storage connected to the DC link;
a load connection, to which the inverter is connected;
a monitoring device configured to generate a fault signal in response to detecting an electrical fault at a grid or at a load;
a bypass switch, which is connected in parallel to the rectifier, the DC link and the inverter between the grid switch and the load connection, wherein the bypass switch is a semiconductor switch; and
a control device configured to:
in a normal operation mode in which the bypass switch is opened, the grid switch is closed, the uninterruptable power supply device is connected to the grid via the grid connection and connected to the load via the load connection, operate the rectifier in a rectifying mode, in which an AC current from the grid is converted to a DC current supplied to the DC link and operating the inverter to convert the DC current from the DC link into an AC current supplied to the load;
upon receiving the fault signal from the monitoring device, which signals an electrical fault concerning at least one of the load and the grid, send a disconnect signal to the grid switch to open the grid switch and disconnect the uninterruptable power supply device from the grid; and
upon receiving the confirmation signal from the grid switch, which confirms disconnection from the grid, send a closing signal to the bypass switch and sending a mode change signal to the rectifier to operate the rectifier in an inverting mode, in which a DC current from the energy storage is converted into an AC current, such that the load is supplied by the inverter and the rectifier.