| 摘要 |
A method and a device for controlling the magnetic flux of asynchronous machine (11) are proposed. The asynchronous machine (11) is used for driving a diesel-electric prime mover and is supplied with a variable voltage and frequency via a rectifier (1), a DC-voltage intermediate circuit (2) and an invertor (10). The magnetic flux is controlled by specifying suitable values for the stator frequency (f1) and the stator voltage (U1), and hence for the slip frequency (f2v) and the stator current (I1*) by means of two-dimensional characteristic transmitters (21, 22), as a function of a reference variable (W) which determines the power or the torque, and as a function of the rotation frequency (fn). When the diesel-electric prime mover is braking, braking resistors (4, 5, 6) are connected in the DC voltage intermediate circuit (2), which results in a change in the intermediate-circuit voltage (Ud). In order to keep the torque (braking torque) constant despite a falling intermediate-circuit voltage (Ud), the slip frequency is varied in inverse proportion to the square of the intermediate-circuit voltage (f2v x k1/Ud2), but limited at a maximum to the value of the pull-out slip frequency (f2k). The stator frequency (f1) is formed by adding the slip frequency to the rotation frequency (fn). The method is universally suitable for driving and braking operation. <IMAGE> |
