4 3 APPARATUS AND METHOD FOR REDUCING TORQUE RIPPLE IN THREE PHASE MOTOR CONTROLLER USING FOUR SWITCHING ELEMENTS

摘要

The present invention relates to an apparatus and method for reducing torque ripple in a three-phase motor controller using four switching elements. In particular, a three-phase motor is rotated using four switching elements to generate voltage generated by charging and discharging an input DC voltage. The upper and lower DC link capacitors to be supplied to the inverter, a current detector for detecting a current at which one phase of the three-phase motor is connected to the DC link neutral terminal, and the upper and lower ends by integrating the detected currents. Compensation for switching A and B phase switch elements of the inverter using the integrator that indirectly obtains the voltage difference of the DC link capacitor, the voltage difference obtained above, the speed difference between the actual speed and the command speed of the motor, and the rotor position. Calculate the component and provide a voltage command generator that provides a switching time with this compensation component to control the speed of the motor. And, phase, and detecting the voltage difference between the bottom of the direct current link terminal indirectly, to one by adjusting the switching times according to the detected voltage difference so as to reduce the ripple in the generated torque.