| 摘要 |
<p>PURPOSE:To check rise of a voltage to impress on a motor and thus to improve an adhesion performance when the motor current decreases regardless of a current command due to racing by providing a limit voltage command circuit. CONSTITUTION:A three-phase induction motor 5 to drive a wheel 6 has a power supplied from a variable voltage and variable frequency of inverter 1. A pulse sensor 8 is mounted on a wheel 7, and a frequency fG according to a car speed is obtainable. A constant frequency fS and car speed fG are added to be in a frequency controlling circuit 4 and impressed on a limit voltage command circuit 11. Then, a motor current IM is detected on a detector 9, compared with a command value IP, and the deviation signal is impressed on a voltage controlling circuit 3. Limit voltage EP of a voltage limiter 10 is set slightly higher than inverter output voltage EO, and if a slip frequency is minimized by an occurrence of idling and thus the voltage controlling circuit 3 is about to generate output, the voltage limiter 10 operates to limit the voltage EO, torque is decreased and thus the wheel is kept readhesive.</p> |
