×

Motor controller and electric power steering apparatus

  • US 7,126,304 B2
  • Filed: 09/06/2005
  • Issued: 10/24/2006
  • Est. Priority Date: 09/08/2004
  • Status: Active Grant
First Claim
Patent Images

1. A motor controller comprising a DUTY instruction value generation section, a PWM output section, and a PWM inverter, the DUTY instruction value generation section generating a DUTY instruction value through a feedback control based on a deviation of an actual current value from a current command value, the PWM output section outputting a gate ON/OFF signal according to comparison between the DUTY instruction value and a carrier wave, the PWM inverter being formed of a plurality of switching element circuits connected in parallel, each switching element circuit being formed of a pair of switching elements connected in series, wherein, when each switching element is turned on and off based on the gate ON/OFF signal, the PWM inverter converts a direct-current power supply to three-phase drive power, and supplies the three-phase drive power to a brushless motor, wherein dead time is set to prevent arm short circuits due to ON/OFF switching of each switching element, and wherein the gate ON/OFF signal is renewed at every predetermined cycle, the motor controller, further comprising:

  • a current direction determination section that determines the direction of current of each phase;

    a rotation angular velocity computation section that computes a rotation angular velocity of the brushless motor;

    a compensation amount determination section that determines a compensation amount for correcting the DUTY instruction value based on the rotation angular velocity, wherein the greater the absolute value of the rotation angular velocity, the smaller the compensation amount determined by the compensation amount determination section becomes,a dead time compensation section that selectively adds the compensation amount to and subtracts the compensation amount from the DUTY instruction value according to the current direction of each phase; and

    a gain determination section that determines a feedback gain of the feedback control based on the rotation angular velocity, wherein the gain determination section changes the feedback gain such that the greater the absolute value of the rotation angular velocity, the higher the responsivity of the feedback control becomes.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×