| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide the technology which, while protecting a lower arm side switch from an overcurrent, avoids regeneration from a voltage inverter to a DC bus bar. <P>SOLUTION: The timing with which a converter commutates is when a carrier C1 takes on a value drt. A carrier C3 comes in the same form as the carrier C1 and is 180 degrees out of phase with it. Switching of an inverter takes place when the carrier C3 assumes a signal waveform dst+drt(d7+d6+d4), dst+drt(1-d4), dst+drt×(1-d4-d6), dst(1-d7-d6-d4), dst×d4, or dst(d4+d6). These signal waveforms can be properly set, so that even when this switching takes place, any one of upper arm side switches conducts a current. Therefore, even when all of lower arm switches are turned off at any point of time, a reflux operation occurs in the inverter, whereby regeneration is avoided. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
