| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an uninterruptible power supply system where a new inverter can be turned on in parallel during operation of at least one or more inverters in a parallel redundant system. <P>SOLUTION: A plurality of inverter circuits 12-1, 12-2, 12-3 is connected in parallel via the reactor L22 for parallel of a reactor panel 13. The inverter circuit 12-3 to be switched on later can not detect the bus voltage V0 from another reactor panel 13. Accordingly, it performs the control of making the phase of the inverter voltage Va3 of the inverter circuit 12-3 follow the phase of a corrected bus voltage, with the corrected bus voltage, where the amount of voltage drop of a current (a circulating current) Iloop for inverter sharing control by the reactor L22 for parallel is added to the pseudo bus voltage Vn3 of the power switch 23-3, as the reference voltage. Therefore, the inverter voltage Va3 becomes the same phase as the inverter voltage of the inverter circuit 12-1, and a cross current does not flow at parallel connection. <P>COPYRIGHT: (C)2008,JPO&INPIT |
