| 摘要 |
PURPOSE:To conduct reclosing positively with high precision by uniting motor revolution detected by the residual voltage of a motor on instantaneous-stoppage reclosing and output frequency from an inverter and performing reclosing. CONSTITUTION:An output voltage-frequency command circuit 1 brings a switch SW1 to an OFF state on instantaneous-stoppage reclosing, turns a switch SW2 ON, and outputs the signal of command voltage corresponding to the number of revolution of a motor IM. A micro-computer 3 computes the actual number of revolution of the motor IM from a zero-cross detecting signal from a zero- cross detector 2, conducts necessary correction or the decision of erroneous pulses or the like, and sets the value of command voltage corresponding to the number of revolution of the motor to a D/A converter. |
