| 摘要 |
PURPOSE:To facilitate the integration of a pulse width modulation inverter by employing as firing angle instruction values electric angle information of the level varying point of a pulse width modulation pattern and the integer times sum of the electric angles corresponding to the phase difference of an inverter fundamental firing sequence. CONSTITUTION:The firing angle instruction value of thyristors S1-S6 in a 3- pulse type 3-phase current type PWM inverter is obtained from the electric angle information when the pulse width modulation pattern varies between ''1'' and ''0'' and the sum of the integer times of the prescirbed electric angle of 60 deg. corresponding to the firing phase difference of the inverter fundamental firing sequence. The fundamental firing sequence is advanced by the interrupt operation at every 60 deg. of the electric angle, the interrupt operation is waited to flow the PWM pattern firing sequence, thereby computing the firing angle insturction value. Accordingly, the firing angle instruction can be performed by the less number of bit length data, and the capacity of the memory can be reduced, thereby facilitating the integration of the inverter. |
