| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inverter, a brushless DC motor controlling method, and a compressor driving system that allow accurate detection of the rotational position of a rotor and stable operation with high efficiency and high output, unaffected by the change of motor temperatures. <P>SOLUTION: A current deviation operator 21 obtains current deviations ΔIdm, ΔIqm between presumed currents Idm, Iqm based on the equivalent model equation of a motor and detected currents Id, Iq. An integral adjuster 24 operates the integration of the current deviation ΔIqm to obtain presumed speed electromotive force em. A proportional adjuster 26 and another integral adjuster 27 operate the proportion/integration of the current deviation ΔIdm to obtain a correction term. Based on the presumed speed electromotive force em and the correction term, presumed rotational speed ωm and presumed rotational position θm are obtained. Furthermore, based on the presumed speed electromotive force em and the presumed rotational speed ωm, magnetic flux ψ is obtained, and based on the output values of the integral adjusters 24, 27, the rate of change Dψ of the magnetic flux ψis obtained. The use of this magnetic flux ψ makes a target current be held always under maximum torque control conditions. <P>COPYRIGHT: (C)2004,JPO |
