Motor control device

A motor control device implemented in an electric power steering apparatus that generates a steering assist torque by a motor by interchangeably converting a direct current electric power of a power source and an alternating current electric power of the motor with a power conversion circuit according to a power running operation and a regeneration operation of the motor for controlling energization of the motor, the motor control device comprising:

• a voltage instruction value calculation unit configured to calculate a q-axis voltage instruction value and a d-axis voltage instruction value by feedback control of dq-axis currents;
• and
• a voltage instruction value limit unit configured to limit at least one of the q-axis voltage instruction value and the d-axis voltage instruction value, wherein
• during the regenerative operation of the motor, the voltage instruction value limit unit performs
• a q-axis voltage limit prioritize process for limiting the q-axis voltage instruction value over the d-axis voltage instruction value, or
• a d-axis voltage limit prioritize process for limiting the d-axis voltage instruction value over the q-axis voltage instruction value.