Patent ID: 9048778
Filing Date: 2015-06-02
Classification: H02P

Abstract:
1. A rotor phase/speed estimating device for an AC motor in which a rotor shows a salient pole characteristic with respect to a high-frequency current having a frequency higher than a drive frequency, the estimating device being arranged to perform a stator voltage application function and a stator current detection function, the estimating device comprising: a high-frequency voltage injection unit arranged to superimpose a high-frequency voltage having a zero DC component and using a high frequency ω a high-frequency current amplitude detection unit of a fundamental wave component arranged to detect a primary Fourier coefficient equivalent value by obtaining a stator current from the drive control device and then subjecting the stator current or the γ axis and δ axis components of a high-frequency current equivalent value obtained by processing the stator current, to Fourier series development equivalent processing in which a high frequency ω a correlation signal generation unit arranged to generate a correlation signal having correlation with a rotor phase evaluated on the γ-δ semi-synchronous coordinate system, using the Fourier coefficient equivalent value detected from the γ axis and δ axis components; and a rotor phase generation unit arranged to generate a phase of the γ-δ semi-synchronous coordinate system and at least one of an estimated value of the rotor phase and an estimated value of a rotor speed remaining in a calculus relationship with the rotor phase.