PWM CONTROL SYSTEM FOR THREE-PHASE VOLTAGE TYPE INVERTER

摘要

PURPOSE:To reduce current ripples and eliminate torque ripples, electromagnetic noise and the like by changing the distributing ratio of the output times of two zero voltage vectors in the period of one sampling. CONSTITUTION:The distributing ratio (k) of the output times of zero voltage vectors V0, V7, which minimize current ripples with respect to a multitude of objective output voltage vectors V*, are obtained by k=T01/T0 (where; T01 is the output time of the zero voltage vector V0) while the tip ends of the objective output voltage vectors V*, whose distributing ratios (k) are equal, are connected as an equal distributing ratio diagram. When the objective output voltage vector is VA*, output current ripple may be minimized by outputting respective zero voltage vectors V0, V7 with the time ratio of k=0.525 or T01=0.525T0, T02=0.475T0 (where; T02 is the output time of the zero voltage vector V7).