| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a sensorless measuring method for position/speed/voltage amplitude of a synchronous motor capable of precisely measuring the position/speed, and the voltage amplitude of a rotor, even if the rotor ends up rotating at 180°or larger in an electric angle by measuring the position/speed from the time difference and the phase difference of a short-circuit pulsed current. <P>SOLUTION: A controller 2 generates short-circuit pulsed currents at times t0, t1, and t2 at varying time intervals by gate-controlling by an inverter 1 while the rotor of the motor 5 is in idling. A current phase detecting part 6 detects short-circuit pulsed current phases θ0, θ1 and θ2. A speed calculating part 7 acquires time differences Ta and Tb and phase differences θa and θb for measurement periods, and a speed ω<SB>est</SB>is found from the difference result. An integrating part 8 formed by integrating the speed ω<SB>est</SB>detects the phase. A phase difference correcting part 9 calculates and estimates a phase lead angle for each measurement period from the speed measuring result, and based on this, corrects the phase difference when it undergoes the multi-rotation of a measurement phase. The amplitude component of an induced electromotive force can also be obtained, based on the difference component of an increase in the short-circuit pulse current and a difference component of a current decrease, immediately after the short-circuit ends. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
