| 摘要 |
PURPOSE: To reduce the number of components and to make a quick response by detecting the variation direction of a current frequency and the variation direction of power consumption, and determining the next time variation direction of a inverter frequency according to the detection results and performing control. CONSTITUTION: The DC output of the solar battery is converted by an inverter 3 into an AC output, which is fed to a solar battery pump 7. Here, a controller 10 multiplies the current signal and voltage signal, detected by an ammeter 5 and a voltmeter 6, through an amplifier 11 and the multiplication result is differentiated by a differentiating circuit 12b to generate a power consumption variation signal. A frequency command value commanded from the controller 10 to the inverter 3, on the other hand, is differentiated by a differentiating circuit 12a to generate the frequency variation signal of the inverter, which is compared by comparators 13a and 13b with reference values, and their output binary signals are exclusively ORed; and the exclusive OR output is counted and integrated by an up/down counter 16. Thus, the controller 10 detects the variation directions of the current frequency and power consumption and determines the next-time frequency variation direction. |
