| 摘要 |
PROBLEM TO BE SOLVED: To obtain a constant V/f controller for permanent magnet synchronous motor having no positional detector in which energy can be saved while reducing the loss and enhancing the efficiency by performing Id=0 control and reduction control of reactive power attributed to Id. SOLUTION: A controller performing constant V/f control of a permanent magnet synchronous motor 7 through an inverter 6 comprises means 9 for detecting at least two phases of current in a winding, a coordinate conversion means 10 for separating a detected current into two axial current components, i.e., a current component parallel with a voltage vector being applied to the motor 7 and a current component orthogonal thereto, and a voltage command regulating means 8 for operating a quantity proportional only to a current component parallel with the flux vector produced from a field permanent magnet based on the two axial current components, the voltage being applied to the motor, inductance of the winding, and the angular frequency and generating a correction amount Δv* for bringing the amount thus operated to zero to feed back the voltage command v* of the motor 7. |
