Motor control device and brake control device

A brake control device, comprising:

• a brake;
• and
• a motor control device that drives the brake,
• wherein the motor control device includes
• a three-phase synchronous motor that includes a three-phase winding,
• an inverter that is connected to the three-phase winding,
• a control unit that controls the inverter based on a rotor position of the three-phase synchronous motor, and
• a rotational position estimation unit that estimates the rotor position based on a neutral point potential of the three-phase winding, and
• the rotational position estimation unit estimates the rotor position selectively using one or more of a plurality of detected values of the neutral point potential according to a pre-estimated value of the rotor position and a voltage application state to the three-phase winding, wherein
• the plurality of detected values of the neutral point potential are obtained in a plurality of the voltage application states, and
• the rotational position estimation unit estimates the rotor position using a detected value in a voltage application state in which the neutral point potential changes more with respect to the rotor position near the pre-estimated value among the plurality of voltage application states.

A motor control device, comprising:

• a three-phase synchronous motor that includes a three-phase winding;
• an inverter that is connected to the three-phase winding;
• and
• a control unit that controls the inverter based on a rotor position of the three-phase synchronous motor,
• wherein the control unit controls the inverter based on the rotor position sensed by a rotational position detector,
• the motor control device, further comprising:
• a rotational position estimation unit that estimates the rotor position based on a neutral point potential of the three-phase winding;
• and
• a determination unit that determines abnormality of the rotational position detector based on the rotor position estimated by the rotational position estimation unit, wherein
• the rotational position estimation unit estimates the rotor position selectively using one or more of a plurality of detected values of the neutral point potential according to a pre-estimated value of the rotor position and a voltage application state to the three-phase winding,
• the plurality of detected values of the neutral point potential are obtained in a plurality of the voltage application states, and
• the rotational position estimation unit estimates the rotor position using a detected value in a voltage application state in which the neutral point potential changes more with respect to the rotor position near the pre-estimated value among the plurality of voltage application states.