Patent ID: 11929695
Assignee: KABUSHIKI KAISHA YASKAWA DENKI
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 11:
12. A magnetic flux estimation method comprising:
determining whether an operating speed of the electric motor is less than a predetermined level or exceeds the predetermined level,
performing, when the operating speed of the electric motor is less than a predetermined level, a first estimation of estimating a primary magnetic flux appearing in the electric motor on the basis of an output current from a power conversion circuit to the electric motor and an inductance of the electric motor; and
performing, when the operating speed exceeds the predetermined level, a second estimation of estimating the primary magnetic flux by estimating a magnetic flux differential value on the basis of an output voltage from the power conversion circuit to the electric motor and integrating the magnetic flux differential value using, as an initial value, an estimation result of the primary magnetic flux by the first estimation.