Method for controlling and regulating a synchronous machine

For a method for controlling and regulating a synchronous machine which is operated from a converter and has indirect flux orientation, that is to say the flux position which is required for control is calculated from the rotor position and the reference variables for the currents and an additional determination of the components of the actual voltage value with respect to the precalculated position of the flux, it is intended that no rotor position transmitter be required and no integrators be provided, which drift and tend to damp oscillations when this drift is compensated for. This is achieved in that the deviation of the I component of the voltage vector is supplied from the reference value, which is precalculated in the machine model, to a first flux regulator (11a) whose output signal is added to the reference value for the excitation current, in that either a tachogenerator (4) with a downstream-connected sine/cosine generator (12) or only one of the latter is used to determine the rotor position (cos lambda , sin lambda ), a suitable, controlled preset for the angular velocity ( omega 0) being made for said generator during starting from the rotation speed of zero, in that the deviation of the m component of the voltage is supplied to a second flux regulator (orientation regulator) (11b) whose output signal is likewise supplied to the sine/cosine generator (12), additively to the tachogenerator and/or the angular velocity preset value.