Method and apparatus for speed control of a sensorless, field-oriented operated asynchronous machine

摘要

A method for speed regulation (revs) of a sensorless field orientated driven asynchronous machine, in which a voltage space vector is generated by means of a two-component current regulation with an e.M.f computer (8), in which a stator frequency (ws) is calculated by means of a device with a e.M.f controller (38) in which control signals (S1---S6) are determined by means of a space vector modulation method in dependence of a voltage-space vector and this stator frequency (ws), and in which the e.M.f controller (38) is deactivated at a stator frequency (ws) less than a first threshold frequency (f1) and the integral component of the controller is set to zero with delay, in which the first threshold frequency is very much smaller than a nominal slip (sn) of the sensorless field orientated async machine. An output signal (w') of the e.M.f regulation (14) is unilaterally limited to zero at a stator frequency greater than the first threshold frequency (f1) in dependence on a nominal direction of rotation (S' dir).