CONTROLLER FOR ELECTRIC MOTOR CAR

摘要

PURPOSE:To charge a battery efficiently by making field-weakening control at the time of regenerative braking weaker than that at the time of power running at the time of partial load. CONSTITUTION:The rotation of a rotor is converted into a binary signal by an interface 52 through a rotary encoder 50, and changed into the angle of rotation theta on the basis of a conversion table stored in a ROM 54. The binary signal is converted into voltage V proportional to rotational speed by an F/V converter 56. Two phase currents iu, iw in the three-phase armature windings of a motor 12 are inputted to a three-phase two-phase converter 60 through an A/D converter 58. The three-phase two-phase converter 60 feeds back flux currents id and torque currents iq to a current amplifier 62. The current amplifier 62 obtains a d-axis voltage command Vd* and a q-axis voltage command Vq* on the basis of a torque command iq* and a field current command id*. Field-weakening control characteristics making a field weaker than field weakening at the time of power running when control starts regenerative braking after the time of power running in partial load are stored in a field command generating circuit 74.