| 摘要 |
PROBLEM TO BE SOLVED: To avoid an operation in the rotative direction different from the commanded rotative direction which is caused by malfunctioning. SOLUTION: The rotative direction detection signal obtained from a pulse encoder 16 and the rotative direction command signal set separately are inputted to a limiting operation discriminator 41. A disagreement signal, which is outputted by the limiting operation discriminator 41 when both the input signals do not agree with each other, makes a speed detection value ωr , given to a rotor frequency calculator 20 by a culated speed value limiter 42, zero. An electrical angle limiter 43 comprising a previous value holding device 44 and a changeover device 45 changes an electrical angle Γ2 calculation value, given to a second coordinate converter 10 and a first coordinate converter 11 from an integrator 15, to the previous value held by the previous value holding device 44 corresponding to the disagreement signal. |
