Circuit for forming the phase position of a stator voltage vector or of a stator current vector of an asynchronous machine fed by a converter

摘要

For forming the phase position psi 1 of the stator voltage vector or of the stator current vector for controlling an asynchronous machine (14) supplied via a three-phase converter (13), the angular value psi 2, obtained from the torque-dependent slip frequency f2 by means of an integrator (16), the angular value psi n, obtained from the rotor frequency of rotation fn by means of an integrator (18) and the torque-dependent load angle DELTA psi , are added together. The sum psi 1 = psi 2 + psi n + DELTA psi is passed to sine function generators (7, 8, 9) to produce a three-phase rotating system. The output signals of the sine function generators (7, 8, 9) are multiplied by a torque-dependent amplitude value of the stator voltage (¦U¦) or of the stator current (¦I¦), in multipliers (10, 11, 12), and supplied to the converter (13) as the required value of the instantaneous values of the stator voltage or stator current. IMAGE