| 摘要 |
PROBLEM TO BE SOLVED: To provide a conjecturing method in which the position of a rotor in a synchronous motor, having a salient-pole property is estimated precisely on the basis of an observable amount. SOLUTION: An induced-voltage estimation and shaft-deviation computing part 61 is installed at a control system, which adjusts the output frequency ω1 of an inverter 13, on the basis of the value of the shaft deviation Δθ of a synchronous motor 2, and which operates the motor 2 in synchronization with the output frequency. Currents Idc, Iqc which convert detection currents iu, iw into a control shaft, voltage commands Vdc*, Vqc* which are to be outputted to an opposite converter 44 and a speed command ωr* are input. The induced voltage of the motor 2 is estimated, and the shaft deviation Δθ is found on the basis of its phase. When the voltage of an inductance is to be dropped, an electrical constant Lq of the inductance is used, the Lq is set as the product of a motor-speed command by the magnitude of a motor current, and the Lq is set as a virtual amount which does not depend on the position of a rotor in the motor. The vector of the virtual amount is derived, in such a way that the phase of an intrinsic induced voltage will not change. |
