| 摘要 |
PURPOSE:To attain the parallel operation between a solar battery and an AC power supply by controlling the output frequency of an inverter device so that the deviation is set at zero between the DC input voltage of the inverter device and the set voltage and setting the deviation at zero between the load bus of the inverter device and the reactive power. CONSTITUTION:A switch 18 is always kept on excepting in a fault mode of a commercial power supply 9. Under such conditions, the output frequency of an inverter device 4 is controlled so that the deviation is set at zero between the DC input voltage of the device 4 and the set voltage. At the same time, the output voltage of the edevice 4 is controlled so that the deviation DELTAQ (output of an amplifier 33) is set at zero between the reactive power Q1 of the output of the device 4 and the reactive power Q2 of a load bus 7. In such a way, both power supplies can be operated in parallel to each other. When the power supply 9 has a fault, it is cut off together with the switch 18 turned off. Under such conditions, a controller 10 has a control so as to keep the output frequency of the device 4 at a fixed level in response to the set value of a frequency setter 17. |
