| 摘要 |
PROBLEM TO BE SOLVED: To control a motor into the condition corresponding to an acceleration sensor, by estimating the current load torque from the value of an armature current and the value of a field current, and also, estimating the revolution of the motor from the voltage of the armature, through keeping the field current constant. SOLUTION: The current load torque is estimated from the current value Ia of an armature current Ia and the value If of a field current, and the proper command value of a field current is decided, based on the estimated value of the load torque. Then, based on the command value, a switching element 21 and field switching elements 312 and 314 are chopper-controlled so that the field current If and the armature voltage Va may come to the specified values. At this time, the magnitude of the armature current Ia is limitted to under a certain value. That is, the revolution of the motor 81 is estimated from the voltage Va of the armature by keeping the field current If constant. As a result, the motor can be controlled into the condition corresponding to an acceleration sensor without using a speed sensor. |
