| 摘要 |
PURPOSE:To perform secure control to a constant power factor by using the absolute value of a reactive power component calculated on the bais of the voltage and current of an AC power source system as the command value of the control, and using the reactive power component as a detection value. CONSTITUTION:A power detector 7' finds reactive power EIsinpsi and active power EIcospsi from the voltage and current of an AC power source respectively, and an absolute value arithmetic device 9 performs arithmetic to obtain a command value for a power factor regulator 8'. On the other hand, the EIsinpsi is used as a detection value. In this case, E is a voltage value, and I is a current value; and psi is a power factor angle, and 1/K is the gain of the arithmetic device 9. Then, the power factor is set nearly to 1 by decreasing the gain 1/K of the device 9 as much as possible, and when the gain is increased, the output of the device 9 reaches zero. The output is the command value of the regulator 8', so the reactive power component EIsinpsi is controlled to 0 and the power factor of the system becomes 1. For this purpose, said K is selected adequately to obtain an optional power factor. |
