| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and a circuit for correcting voltage of a parallel operation inverter suitable for controlling cross current when a plurality of inverters are connected in parallel to a bus bar and AC power is supplied from the bus bar to a load. <P>SOLUTION: The voltage correcting circuit is formed of a subtraction computing element 16a, a reactive power computing unit 16b, a subtraction computing element 16c, an integrator 16d, a restricted computing unit 16e, a rectification/smoothing circuit 16f, a multiplier 16g and an addition computing unit 16h. In UPS, an output voltage value of the UPS is corrected by a voltage correction value as an output value of the addition computing unit 16h. Thus, current for controlling cross current flowing in UPS is set to be less than about 3% of rated output current. Deterioration of a power supply margin to the load of UPS is prevented. The voltage correcting circuit can set an assigned current value of respective UPS to the rated output current value of the corresponding UPS even if wiring impedance of a load path is unknown. <P>COPYRIGHT: (C)2008,JPO&INPIT |
