| 摘要 |
PURPOSE:To prevent the generation of system down and to improve the using efficiency of a solar battery. CONSTITUTION:When the power of the solar battery is dropped like a graph (B) in a VVVF inverter for driving a motor at a variable speed by using the solar battery as a power supply, the frequency command value of the inverter is suddenly reduced like fb in a graph (A), its frequency f0 is stored and then the frequency command value is gradually increased from the fb up to a value immediately before the f0 under a condition that the power is not dropped, so that the generation of system down can be prevented. |
