| 摘要 |
The present invention relates to an Uninterruptible Power Supply and a method for operating an Uninterruptible Power Supply, where the UPS is connected between a grid and a consumer, where the UPS is rectifying the power from the grid for generating DC, which DC is used as source for an inverter, which inverter generates power for the consumer. The main object of the invention is to achieve UPS to bridge the grid voltage drops by supplying power for one-phase or multi-phase consumer in a short period after a grid failure. The object can be achieved if the preamble to claim 1 is modified so that the DC link comprises a boost device, which boost device has at least one an input line, which input line is connected through rectifier means to the grid, which boost device has at least one output line, which output line is connected to the power conversion means. Hereby can be achieved that a power supply to a load can be maintained in a period of a few seconds where a grid failure will force mostly all consumers to a full or partly shut down. Most power failures on the grid have duration of a few seconds, but they can be of duration long enough for computerised consumers to get into an unwanted power down situation. Such a power down can be extremely dangerous for computer systems, e.g. if a hard disk is in a writing situation when a power failure occurs. If an UPS-device in connection with computer means could keep uninterrupted power for only 10-20 seconds that would be sufficient for many computer systems to shut down at least in a way of operation where the hard disks are been sent into a parking mode before the shut down. The use of the boost device instead of a battery will make this UPS-system much smaller simply because are typically lead accumulators which are very heavy and which have to be under continuous service management in order to be operational when power is needed. |
