The AC Motor Rotational Speed Control with the Programmable Dynamics

Abstract

The digital control of the AC motor enables the programmable dynamics of the rotation speed transient. There are two problems - motor control and measurement of the instant rotor angle (connected with the rotational speed calculation). It is necessity to check if the controlled motor follows the assigned curve of the motor voltage/current supply frequency and amplitude. The only solution in the high power supply range is to use the PWM waveforms. The presented multi-package system enables 3-phase motor PWM U/f control and the measurement of the instant rotor angle together with the rotational speed. The PWM generator enables the programmable dynamics of the motor rotation start and the “soft” change of the rotational speed between 2 steady values. The presented controller can operate as a part of the whole complex DMC system or in the stand-alone mode, can receive orders using RS bus or by mean of the system bus or from the local keyboard.