| 摘要 |
PURPOSE:To prevent a vector control system from possibly running away due to a positive feedback by judging a feedback polarity, and inverting the detected phase when the feedback polarity is positive. CONSTITUTION:When a phase difference delta0 falls within a range of pi/2<delta0<=3pi/ 2 in the correction when a torque disturbance DELTAT is applied by a torque disturbance generator 20, a vector control system becomes a positive feedback to run away. In this case, the polarity of the signal DELTAT and the polarity of a torque command T are monitored, and if both have the same polarity, it is judges as that the vector control system runs away. After the runaway is thus detected, the phase is shifted by pi from the phase difference delta0, i.e., inverted to be corrected. |
