| 摘要 |
PURPOSE:To avoid the useless consumption of capacitors by deciding whether a light load current is less than a light load level or not and cutting off all applied capacitors at the light load to inhibit the automatic power factor control. CONSTITUTION:A CPU 102 calculates an application level, a cut-off level and a light load level from the synthetic regeneration ratios of a transformer 2 and a current transformer 3 as well as the load capacities of capacitors 62a, 62b... to be applied and cut off. Then the CPU 102 decides whether a load current is less than the light load level or not. If so, a light load state is decided. Thus the CPU 102 transmits the cut-off signals to a relay control part 107 to cut off all applied capacitors. If not, the normal automatic power factor control is carried out. Thus it is possible to avoid such an inconvenient case where the automatic power factor control is uniformly carried out even at the light load. |
