| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a control method wherein stable voltage is supplied to a load on an uninterruptible power supply system. <P>SOLUTION: The uninterruptible power supply system is constructed of uninterruptible power supply units 10a and 20a, a change-over switch circuit 41, CT 61 that detects a current to a load 60, and the like. A shunting resistor 16 and an auxiliary CT 17 are connected in series with the secondary winding of the CT 61. The secondary current of the auxiliary CT 17 is inputted as a load current command value (i<SB>L</SB><SP>*</SP>) to the uninterruptible power supply unit 10a. Further, a shunting resistor 26 and an auxiliary CT 27 are connected in series with the secondary winding. The secondary current of the auxiliary CT 27 is inputted as a load current command value (i<SB>L</SB><SP>*</SP>) to the uninterruptible power supply unit 20a. Thus, when operation is performed to change power supply to the load 60 from a UPS feeding bus bar 30 to a power system 50, the current of the UPS feeding bus bar 30 and the current of the power system bus bar 50 are brought into burden sharing state in which they vary in the shape of first-order lag waveform. Depression in the voltage across the load 60 is thereby eliminated. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
