| 摘要 |
PURPOSE:To rotatably drive an induction motor at an arbitrary speed by controlling an inverter on the basis of a torque signal corresponding to the rotating speed of the motor. CONSTITUTION:Magnetic flux detecting means 15 calculates a primary crossing vector at the time of rotatably driving an induction motor 1, and a comparator 3 outputs a magnetic flux signal on the basis of the result, and a region discriminator 6 outputs a region signal to a controller 19. As the motor 1 rotates, an encoder 20 detects the angle speed of the motor 1. The signal is analog- converted by an f/v converter 21, compared by a subtractor 22 with a target speed output from a speed instructing circuit 23, its deviation is proportionally integrated by a Pl controller 24, and input to a comparator 26. The comparator 26 compares it with a sawtooth wave W, and a rectangular wavelike torque signal is output to the controller 19. A switching signal corresponding to a primary voltage vector selected by the controller 19 is output to an inverter 2. |
