Method and circuit arrangement for controlling an asynchronous motor supplied from a static frequency changer

摘要

Method for controlling the speed and torque of an asynchronous machine fed through a static frequency changer with impressed intermediate current link, a control variable for the frequency of the current delivered by the frequency changer being formed from an electrical variable corresponding to a slip frequency value and an electrical variable corresponding to actual value of a frequency proportional to the rotor speed of the asynchronous machine which includes operating the asynchronous machine with constant flux in a region of constant maximal torque, and adjusting the flux in the machine, in a region of constant maximal power, as a function both of voltage at commutating capacitors of a self-commutating inverter and of a respective load condition of the asynchronous machine.