| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain a common-mode leakage current resulting from a switch parasitic capacity, while restraining a common mode leakage current resulting from a load parasitic capacity in various types of power conversion apparatuses. <P>SOLUTION: A PWM inverter 1 associated with a first invention includes a detection part 4 for detecting an average output voltage; a voltage generation part 5 for generating superposed voltage equal to the average output voltage; and an overlap part 6 for overlapping the voltage, with a polarity opposite to that of an overlapped voltage on upper and lower arm power source lines E<SB>U</SB>, E<SB>D</SB>of the inverter, to restrain the common mode leakage current, resulting from the load parasitic capacity and the lower arm side switch parasitic capacity. Furthermore, a PWM inverter 1', associated with a second invention, includes a compensation current generator 7 for generating a compensation current equivalent to the leakage current of the upper arm side switch parasitic capacity, causing the leakage current flowing into the upper arm side switch parasitic capacity to circulate within the inverter and to restrain the common-mode current resulting from the upper arm side switch parasitic capacity. <P>COPYRIGHT: (C)2008,JPO&INPIT |
