Patent ID: 8080957
Filing Date: 2011-12-20
Classification: B62D,H02P

Abstract:
1. A motor control device, comprising: phase current detection means for detecting phase currents in a three-phase brushless motor; rotor rotational position detection means for detecting a rotational position of a rotor in the three-phase brushless motor; target current setting means for setting a target current for the three-phase brushless motor, and outputting motor phase current command values based on the target current and the rotor rotational position detected by the rotor rotational position detection means; drive voltage control means for controlling drive voltages based on the motor phase current command values output from the target current setting means and the phase currents detected by the phase current detection means; and a motor drive circuit that supplies phase currents to the three-phase brushless motor based on the drive voltages of the drive voltage control means, wherein the target current setting means is configured to output phase current command values that do not cause torque fluctuation, and provide an absolute value of a composite vector of the drive voltages of the respective phases that is substantially constant and corresponds to a value in the neighborhood of a value √3/2 times a power supply voltage including the value √3/2 times the power supply voltage.