CIRCUIT FOR THE CONTROL OF STATOR CURRENT AND ROTOR FREQUENCY OF A THREE-PHASE ASYNCHRONOUS MOTOR BEING FED BY A FREQUENCY CONVERTER

摘要

The circuit is formed of a non-linearity block (11) connected to whose input is a terminal (1) of the required magnitude of the motor and whose first output is connected to the plus input of the current comparator (2). That is connected by its output through a current regulator (3) to the first input of the modulator (5), whose output is connected with the input of the frequency converter (8) of the asynchronous motor (9). The output of the speed sensor (10) of the motor (9) is connected through a transformer (7) to the second input of the summing element (6), whose first input is connected with the second output of the non-linearity block (11) and whose output is connected to the second input of the modulator (5). Outputs from the current sensors of individual phases of the asynchronous motor (9) are connected through the current size evaluation circuit (4) to the minus input of the current comparator (2).<IMAGE>