| 摘要 |
The present invention provides an uninterruptable power supply system (100) comprising a first AC source (108) providing three-phase AC power via a four-wire AC-power supply line (112); a DC source (110) providing DC power via a DC power supply line (114), and a power converter (102) receiving AC power from the first AC source (108) and/or DC power from the DC source (110) and delivering two wire DC power to a load (118) via a DC output line (116), whereby one pole of the DC output line (116) is connected to the neutral reference of the four-wire AC-power supply line (112), the uninterruptable power supply system (100) further comprises a bypass device (142) for passing power from its output side (106) to the DC output line (116), whereby the bypass device (142) and the power converter (102) are connected in parallel to the DC output line (116), and the bypass device (142) comprises at least one switching unit (144), which receives AC power at its input side, and a control unit (138), whereby the switching unit (144) is controlled by the control unit (138) to supply pulsed power from an AC power supply with essentially the same polarity as the DC output line (116). The present invention also provides a method for realizing a bypass in the above uninterruptable power supply system (100). |
