| 摘要 |
<p>To avoid transient frequency changes in the output power signal of an uninterruptible power supply during the transfer of the load from the primary (41, 42) to the reserve power source (14), which frequency changes can be disruptive of the load, the period of the output signal of the reserve source is momentarily shortened at the time of load transfer. Such shortening creates a phase differential between the reserve output signal and the power supply output signal, whereupon the reserve source supplies power to the load. No phase interruption is required in the output signal of the power supply to generate the phase differential necessary for the load transfer, hence transient frequency changes are avoided. </p> |
