In a current control system for a cylindrical permanent magnet synchronous
motor as the drive source of an electric power steering apparatus,
proportional gain Kdp and integral gain Kdi of a d-axis current PI
control portion 126 are respectively set to K1Ld and K1Rd on the basis of
d-axis inductance Ld and d-axis resistance Rd of the motor. Further,
proportional gain Kqp and integral gain Kqi of a q-axis current PI
control portion 128 are respectively set to K2Lq and K2Rq on the basis of
q-axis inductance Lq and q-axis resistance Rq of the motor (K1 and K2 are
optional coefficients). In this case, both of the d-axis resistance Rd
and the q-axis resistance Rq have values resulting from adding the
external resistance R' including wiring resistance to the internal
resistance R of the motor.