摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a specific switching element constituting an inverter from generating heat excessively when a motor generator is operating at an extremely low rotational speed. <P>SOLUTION: Based on a switching mode set temporarily by a mode setting unit 31, a prediction unit 33 calculates prediction currents ide, iqe. A mode determination unit 34 increases the evaluation of a switching mode where the degree of divergence of the prediction currents ide, iqe and command currents id*, iq*is small, and determines the switching mode having a high evaluation as an actual switching mode. In the extremely low rotational speed region of a motor generator 10, the number of switching times of each switching state is 1 during the period where the switching mode corresponds again to the reactive voltage vector after corresponding to the reactive voltage vector. <P>COPYRIGHT: (C)2013,JPO&INPIT |