Controller for motor-driven oil pump and method for controlling motor-driven oil pump

A controller for a motor-driven oil pump of a vehicle, wherein the vehicle includes an engine, a mechanical oil pump configured to be driven by a crankshaft of the engine, a battery configured to be recharged by a rotational force of the crankshaft, a motor-driven oil pump configured to be driven by a driving voltage applied by the battery, and a hydraulic device configured to be driven when supplied with oil from the mechanical oil pump and the motor-driven oil pump,

• the controller comprising processing circuitry, wherein
• the processing circuitry includes a voltage control unit configured to control the driving voltage in a stop period during which the engine automatically stops and automatically restarts,
• the stop period includes a first period starting when the engine automatically stops and continuing until cranking starts and a second period starting when the cranking starts and continuing until the engine automatically restarts, and
• the voltage control unit is configured to control the driving voltage so that the driving voltage in the first period is less than the driving voltage in the second period.