Patent ID: 8736206

Claim:
A power converting apparatus including: a power converter that converts a DC voltage into an AC voltage and applies the AC voltage to an AC rotating machine; and a control unit that controls the power converter based on an operation command from an outside, the power converting apparatus comprising: a first calculating unit that calculates and outputs, from current information detected by the AC rotating machine and a current command value based on the operation command, a first voltage command value to the power converter, a magnetic flux of the AC rotating machine, and first speed, which is free-run speed of the AC rotating machine; a second calculating unit that sets, as an initial value, at least one of the first speed and the magnetic flux of the AC rotating machine input from the first calculating unit and calculates and outputs a second voltage command value to the power converter and second speed, which is driving speed of the AC rotating machine; a control switching unit that generates and outputs a first control signal when the operation command is input and generates and outputs a second control signal instead of the first control signal after a predetermined time from the input of the operation command; and a speed switching unit that switches the first speed to the second speed at a point when the first control signal is switched to the second control signal.