| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a power converter for setting the reference level of a pro tecting function to a value suitable for a load device including an objective induction motor driven at a variable speed and a cable connecting the power converter and the induction motor. <P>SOLUTION: This power converter has a current detection circuit 14 detecting an output current Iout outputted from a switching circuit 13 for converting DC power into AC power of a prescribed frequency and a prescribed AC voltage, and a protection means 3 protecting the switching circuit 13 and an induction motor 23 by adding the maximum value IR<SB>max</SB>of a ripple component of the output current to the initial value I<SB>c</SB>of the reference level, set in accordance with a rated current of the power converter 1 or a rated current of the induction motor 23, to obtain the reference level I<SB>a</SB>of a protecting function compared with the detected output current I<SB>out</SB>, and by comparing it with the reference level I<SB>a</SB>of the protecting function. <P>COPYRIGHT: (C)2004,JPO |
