| 摘要 |
PURPOSE:To operate a voltage pattern having a small output-voltage phase error arithmetically even when output voltage is saturated by computing a value obtained by adding a voltage-vector applying time having different phase of 60 deg. and arithmetically operating and acquiring each voltage component ratio for a suynthetic-voltage vector applying time obtained. CONSTITUTION:The added value (t1+t2) of voltage-vector applying time t1 and t2 is acquired. When output voltage is saturated as shown in (t1+t2)>T/2, (t1+t2) is limited in T/2. (t1+t2) is limited in (t1+t2)=T/2, and t1/(t1+t2) is obtained. Formula acquired is changed into a table, and the speed of arithmetic processing is increased. t1 is obtained from the following formulae. t2 is acquired from t1=t1/(t1+t2) and t2=(t1+t2)-t1. Lastly, the time t0 of a zero-voltage vector period is obtained from t0=[T/2-(t1+t2)]/2. The amplitude of output voltage is limited by conducting such arithmetic operation, but a phase error can be eliminated. |
