| 摘要 |
1. Start device (8, 9, 11, 25, 26, 29) for a controlled or regulated asynchronous machine (1) wherein the stator winding is fed by a controllable rectifier (2) and the field orientated control or regulation unit contains : a) a flux detective device (3, 4, 5) which forms output values (cosphi, sinphi) corresponding to the particular position of the magnetic main flux vector (Fr, Fj) of the asynchronous machine relative to a stationary reference vector in the stator and b) a co-ordinate converter (6) which is supplied with the output values from the flux detection device (3, 4, 5) and which converts two input values (b, w) which correspond to the components of a predetermined vector relative to the particular position of the main flux vector into control values (I*R , I*S , I*T ) for the rectifier which are such that in the event of a change in one component (b) of the predetermined vector, only that component (Ib) of the stator current which is parallel to the main flux vector is influenced, and in the case of the other component (w) only that component (Iw) of the stator current which is perpendicular thereto is influenced, characterized by a swither-over device (8, 9, 11) by means of which, prior to the start of the asynchronous machine, the co-ordinate converted (6) is supplied temporarily not with the output values (cos phi, sin phi) of the flux detection device (3, 4, 5), but with values (Va, Vb) which correspond to a predetermined position of the main flux vector and which moreover keep that input value (w) which influences the component (Iw) of the stator current which is perpendicular to the main flux vector at a value (w' = 0) which serves to limit to zero the component of the stator current which is perpendicular to the main flux vector. |
