摘要 |
A motor driving control device that achieves as high as possible phase coil energization level while preventing thermal destruction of the power switching element by using precise thermal detection of a portion of the power switching element inside a switching module of the control device. An electric power loss Lt at the switching element is used for calculating a saturation temperature Tjgoal. On the basis of the saturation temperature, Tjgoal, and a time constantτof temperature rise, an instant junction temperature Tjnow is calculated. A difference Error between the instant junction temperature Tjnow and an upper temperature limit value Tjmax is calculated. In a motor locked condition, a coefficient Kt is calculated for the target torque, the target torque being equal to the required torque multiplied by Kt. Kt is based on the Error for calculating the target torque. If Error is greater than or equal to a predetermined value, K3, Kt is set to be 1, even if Kt is in excess of 1. If Error is less than or equal to 0 , Kt is set to be zero.
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