| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively perform thermal protection of an element by estimating a temperature that exceeds a maximum value of pulsation temperature at least during a transient state of average temperature. <P>SOLUTION: A control device of a power converter includes an average loss calculation part 202 which calculates an average loss of a semiconductor element at a cycle for estimation calculation of the temperature of the semiconductor element, and a partial temperature change estimating part 240 which takes a semiconductor element as a thermal circuit network that contains at least one set among sets 205 of single thermal resistance and thermal time constant, and estimates a change of partial temperature of a set based on loss of a semiconductor element and the set 205 of thermal resistance of a semiconductor element and thermal time constant. The partial temperature change estimating part 240 includes a gain 206 and a primary low-pass filter 207, to estimate a partial temperature that pulsates according to pulsation frequency of loss based on the average loss. The time constant of the primary low-pass filter 207 is set to be closer to a thermal time constant 205 as the pulsation frequency rises, and is set smaller than the thermal time constant 205 as the pulsation frequency becomes lower. <P>COPYRIGHT: (C)2012,JPO&INPIT |
