Control device for rotary machine and inductance measurement method for rotary machine

An inductance measurement method for rotary machine using a control device for rotary machine including:

• a voltage instruction generation section for generating a voltage instruction;
• a voltage application section for applying voltage to a rotary machine based on the voltage instruction;
• a current detection section for detecting rotary machine current of the rotary machine;
• and an inductance calculation section for calculating an inductance of the rotary machine from the voltage instruction and the rotary machine current, the inductance measurement method for rotary machine comprising:
• a step of the voltage instruction generation section generating voltage instructions of constant DC voltages which are a first voltage instruction for inductance measurement preparation and a second voltage instruction for measurement;
• a step of the voltage application section sequentially applying voltages to the rotary machine based on the first and second voltage instructions;
• a step of the current detection section detecting the rotary machine current;
• and
• a step of the inductance calculation section calculating the inductance from the voltage instruction for measurement arbitrarily selected from the voltage instructions, and the rotary machine currents detected by the current detection section before and after application of the voltage instruction for measurement.