| 摘要 |
PROBLEM TO BE SOLVED: To accurately obtain the primary resistance of an electric motor. SOLUTION: When the value of a primary current I1 reaches Ia, an induction motor constant arithmetic means 410 further increases the value of a voltage command signal Vd* of a d axis to be outputted by an amount of change ΔV of the minimum voltage command that can be set (step S103). The induction motor constant arithmetic means 410 checks to see if the value of the primary current I1 has been updated or not (step S104), and returns to the step S103 if the value has not been updated. When the value of the primary current I1 has been updated in the step S104, the induction motor constant arithmetic means 410 reads a voltage detection value (e) at that point, and the value of the primary current I1 (step s105). The induction motor constant arithmetic means 410 obtains the value of primary resistance r1 according to the value of the voltage detection value (e) and the primary current I1 (step S106). |
