| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately detect open failure of a semiconductor switching element for power which constitutes an inverter for driving an AC motor that is controlled by switching two or more control modes, even when its control mode is frequently switched, within a short interval. <P>SOLUTION: A controller gets a filter current value regarding each phase which is obtained by low-pass filtering of phase currents, separately for each control mode (S120). When the absolute value of the filter current value exceeds a determined value, open failure of the switching element of a relevant phase is detected (S200). With respect to switching of the control mode, the filter current value is kept, when a mode other than the target control mode is selected (S160); and at switching to the target control mode, offset modification is carried out on the filter current value so as to prevent misdetection of the open failure (S140). <P>COPYRIGHT: (C)2011,JPO&INPIT |
