| 摘要 |
<P>PROBLEM TO BE SOLVED: To greatly enhance control precision for an inverter while making the best use of advantages of two-phase PWM control for the inverter. <P>SOLUTION: The inverter controller comprises a section 9a, 9b, 9c for judging whether the signal level D of each two-phase reference voltage signal V<SB>U2</SB>, V<SB>V2</SB>, V<SB>W2</SB>falls within a dead zone predetermined in the vicinity of the amplitude value of a triangular carrier signal V<SB>C</SB>or not. In a period where the signal level D of each two-phase reference voltage signal V<SB>U2</SB>, V<SB>V2</SB>, V<SB>W2</SB>does not fall within the dead zone (V<SB>H</SB>, V<SB>L</SB>-V<SB>A</SB>), an inverter 4 is subjected to "two-phase PWM control" using the each two-phase reference voltage signal V<SB>U2</SB>, V<SB>V2</SB>, V<SB>W2</SB>. In a period where the signal level D of each two-phase reference voltage signal V<SB>U2</SB>, V<SB>V2</SB>, V<SB>W2</SB>falls within the dead zone (V<SB>H</SB>, V<SB>L</SB>-V<SB>A</SB>), the inverter 4 is subjected to "three-phase PWM control" using a three-phase reference voltage signal V<SB>U3</SB>, V<SB>V3</SB>, V<SB>W3</SB>. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
