| 摘要 |
PROBLEM TO BE SOLVED: To prevent the generation of strange sounds, when an electric angle is measured. SOLUTION: A measuring voltage is applied to a specified winding combination (Steps S205, S225, S245), and the variation of a current flowing in each winding is detected (Steps S215, S235, S255), by utilizing the fact that the electric angle of a three-phase synchronous motor corresponds to the inductance between windings. When a driving current is flowing in the three-phase synchronous motor, a current flowing between each winding and the next winding attenuates, compared to the case where the driving current is zero, so the current value is corrected (Step S260), referring to a table on the basis of the variation of the current. An electric angle is found (Step S270), referring to the table, on the basis of the corrected current value. As the result of this, it becomes unnecessary to perform measurement after always having returned the driving correct to zero, and it enables shortening of the measuring time, thus preventing the generation of strange sounds. |
