Inverter controller and on-vehicle fluid machine

An inverter controller used to control an inverter circuit, the inverter circuit being configured to drive an electric motor arranged in an on-vehicle fluid machine, the inverter controller comprising a processing circuitry configured to:

• obtain a command rotation speed transmitted repeatedly from outside of the inverter controller;
• count a command obtaining interval that is a period from a point in time where an old command rotation speed was obtained to a point in time where a new command rotation speed is obtained, the old command rotation speed being the command rotation speed that was precedingly obtained, the new command rotation speed being the command rotation speed that is presently obtained;
• set a target acceleration of the electric motor when the command rotation speed has been obtained;
• and
• control the inverter circuit such that the electric motor rotates at the set target acceleration,
• wherein the processing circuitry is configured to calculate a command acceleration based on the counted command obtaining interval and the new command rotation speed, the command acceleration being set as the target acceleration.