Motor device, wiper device, and motor control method

A motor control method for a motor device comprising a motor that has windings of three phases and is rotationally driven, and an inverter that supplies an alternating current to the windings of three phases based on a drive signal, the motor control method comprising:

• rotation speed detecting in which a rotation speed detector detects a rotation speed of the motor;
• and
• drive signal generating in which a drive signal generator controls a duty ratio indicating a drive output of the motor so as not to exceed a duty ratio upper limit value, and performs control for an energization angle of each phase of the three phases and performs advance angle control for shifting the phase from a reference position to generate the drive signal corresponding to the duty ratio, wherein
• in the drive signal generating, the motor control method further comprises:
• advance angle/energization angle controlling in which an advance angle/energization angle controller of the drive signal generator changes the energization angle to 120 degrees or less while performing the advance angle control in response to the duty ratio being equal to or greater than the duty ratio upper limit value and the rotation speed of the motor being equal to or less than a predetermined threshold value in a state where the energization angle is greater than 120 degrees.