| 摘要 |
PROBLEM TO BE SOLVED: To provide a method, which can simply and surely detect the position of a magnetic pole, making use of harmonic currents such as inverter output higher harmonics, carrier frequency components, etc. SOLUTION: In a voltage-type PWM inverter, arbitrary frequency excluding the output frequency of an inverter 7 is generated in the input voltage or current of a motor by a means 6, which makes it possess optional phase differences among the two phases of UV, VW, and WU, and it is converted into a two-phase static coordinate system where U-phase of the motor is an axis α and an axis crossing it at 90 deg. is an axis β, and the current of optional higher-frequency components is detected at the axis α and the axis β; and further it is transformed into a two-phase static coordinate system, where an axis α' is shifted by 45 deg. from the axis α of the original coordinate system, with its phase being shifted by 45 deg. from that of the two-phase static coordinate system and an axis crossing it at 90 deg. is an axis β', and the current of optional high-frequency components is detected at the axis α' and the axis β', and the magnetic pole position of the motor is detected 12, using the high-frequency current components detected with the four axes. |
