| 摘要 |
PROBLEM TO BE SOLVED: To completely eliminate the necessity of a gain adjustment by determining a switching command signal to turn each of main circuit switching power element on or off by a renewal timing and a timing when the current comparison result changes from a small value to a large one. SOLUTION: A current command signal iT is compared with a first, a second, and a third line current detection result iFU, iFV, iFW by a current comparing means 11. A current level R1, being H level when one of these line current detection results iFU, iFV, iFW is larger than the current command signal iT and L level in the other cases, is output to a switching command signal generating means 12. Then, the switching command signal generating means 12 determines whether each main circuit switching power element should be turned on or off by a time of the rise of a renewal timing signal T1 from a timing generating means 10 and a timing when the current comparison result changes its level. |
