Abstract: Identification of electrical equivalent circuit parameters (15) of a three-phase asynchronous motor (09) without a shaft encoder. The method comprises—Assumption of a standstill position of the rotor (11);—Equidirectional test signal infeed U1?, U1? in ? and ? in the stator axis direction of the asynchronous motor (09);—Measuring of a measuring signal I1?, I1? of the ? and ? axial direction of the asynchronous motor (09); and—Identification of equivalent circuit parameters of the asynchronous motor (09) on the basis of the test signal voltages U1?, U1? and of the measuring signal currents I1?, I1?; whereby the test signal feed allows the rotor (11) to remain torque-free. Determination of equivalent circuit parameters (15) of an asynchronous motor (09) as well relates to a motor control device (35), whereby the identified equivalent circuit parameters (15) can be used for the determination, optimization and monitoring of a motor control and for control of electrical drives.

Abstract: The present invention provides a wireless power feeding system which achieves a configuration enabling effective reception of electrical energy wirelessly transmitted from a wireless power feeding device, and which contributes to the improvement of the power reception efficiency. For the above purpose, the wireless power feeding system includes a power transmitting coil for wirelessly transmitting the electrical energy, a power supply connected to the power transmitting coil, a control unit for controlling the power supply, a power receiving coil portion for receiving the electrical energy transmitted from the power transmitting coil, a power receiving circuit for supplying a load member with the electrical energy received by a power receiving coil, and a magnetic member for collecting a magnetic flux generated by the power transmitting operation of the power transmitting coil to the power receiving coil.

Abstract: The present invention relates to a control method and a control device for a position sensorless motor which has position sensorless operation and synchronized operation, wherein a rotation position of a rotor is detected on the basis of counter electromotive forces generated in stator coils in the position sensorless operation, the stator coils are excited in synchronization with the detected rotation position of the rotor to rotate the rotor and a deviation between a target position and the present position is determined from a target rotation position according to the position command signal and the detected rotation position, position sensorless close loop drive is made on the basis of the determined deviation, and when the synchronized operation is made, the stator coils of the motor are excited in synchronization with the position command signal to rotate the rotor.

Abstract: A dynamolectric machine stator has a primary winding for single phase alternating current input and a secondary winding for polyphase alternating current to be supplied from output terminals. The secondary winding is connected such that at least two frequencies are provided at the terminals. The rotor has two windings thereon for excitation, one being excitable for one frequency output and the other rotor winding being excitable for another frequency output at the secondary terminals. Another secondary winding may be provided on the stator to obtain a desired output terminal voltage at one of the selected frequencies.