Electric power steering apparatus

An electric power steering apparatus of a vector control system that calculates steering assist command values of dq-axes based on at least a steering torque, calculates dq-axes current command values from said steering assist command values, converts said dq-axes current command values into 3-phase duty command values, driving-controls a 3-phase brushless motor by an inverter of a pulse width modulation (PWM) control, and applies an assist torque to a steering system of a vehicle, comprising:

• a dead time compensating section A that calculates first dq-axes compensation values relating to said dq-axes of said inverter based on 3-phase terminal voltages of said 3-phase brushless motor;
• a dead time compensating section B that calculates second dq-axes compensation values relating to said dq-axes of said inverter based on a motor rotational angle;
• and
• a compensation-value switching section that gradually and mutually switches while mixing said first dq-axes compensation values and said second dq-axes compensation values based on said steering assist command value of said q-axis, and outputs dq-axes dead time compensation values,
• wherein a dead time compensation of said inverter is performed by a correction of said dq-axes current command values with said dq-axes dead time compensation values.