ELECTRIC POWER CONVERSION DEVICE, ELECTRIC MOTOR DRIVE SYSTEM, TRANSPORT MACHINE, AND LIFTING DEVICE

摘要

In the present invention, the detection sensitivity at a magnetic-pole position is estimated on the basis of the saliency of an electric motor. In an electric motor control device (100a), a superimposed voltage phase adjustment means (7) outputs a high-frequency voltage phase command value (thetavh*) on the basis of a high-frequency current vector (Ih) extracted from a current vector (I) by a current extraction means (6). A current control means (5) estimates a magnetic pole position (thetad) on the basis of this high-frequency voltage phase command value (thetavh*) and outputs a fundamental voltage vector command (V1*). A superimposed voltage phase shifting means (8) adjusts the high-frequency voltage phase command value (thetavh*) and outputs a shifted high-frequency voltage phase command value (thetavh**). On the basis of the foregoing, a voltage superimposition means (9) superimposes an alternating voltage onto the fundamental voltage vector command (V1*) and outputs the result to a voltage conversion means (3). A sensitivity computation means (10) computes the sensitivity (KDeltatheta) with respect to the estimation of the magnetic pole position (thetad) on the basis of the high-frequency current vector (Ih) and the shifted high-frequency voltage phase command value (thetavh**).