| 摘要 |
PURPOSE:To enable a control unit to detect the slipping condition precisely and to control the slip to a proper value, by detecting the DC current flowing to an inverter portion linearly and by comparing its variation with the output frequency component to detect the slip. CONSTITUTION:A core 19 detects the DC current linearly which flows between a converter portion and an inverter portion, and also detects it as the voltage quantity and changes it over into the magnetic charge. A Hall element 20 converts the magnetic charge into the quantity of electricity again. A compara tor 22 compares the variation of the DC current detected by the core 19 with the frequency component of the pseudo AC current outputted from the inverter portion. The slip of an induction motor is detected by this comparator 22 and a microcomputer 7. |
