| 摘要 |
PURPOSE:To obtain an inverter device, which can control an induction motor so as to obtain its output torque stable even in a low speed region, by constituting the device so as to output a torque component voltage command and an excitation component voltage command of the induction motor. CONSTITUTION:A 3-phase/2-phase converter 1 detects three-phase currents iv, iu, iw of an induction motor (not shown) and outputs a two-phase current signal corresponding to a torque component current Igamma and to an excitation component current Idelta by using an integral value of an inverter operation angle frequency command omega1*. A setter 20 outputs a value resulting from multiplying a difference between the command omega1* and a signal corresponding to the excitation component current Idelta by a positive constant K to a multiplier 3. An adder 28 adds an output signal R1Igamma of a setter 24 to an output signal L1omega1*Idelta* of a setter 27 to output, and an adder 29 outputs a signal corresponding to torque component voltage Vgamma, obtained by adding output signals of a divider 23 and the adder 28, as a torque component voltage command Vgamma* by an expression I. On the other hand, an excitation component voltage command Vdelta* is obtained by an expression II from an output signal Vdelta of a setter 25. |
