A Torque Regulated Induction Motor Drive With A Tiny DC Link Using Active Front-End Control

Variable Frequency Drives are commonly used in industries to control an induction machine for air compressors, fans, pumps, or other applications that demand speed or torque regulation. The topology of the drive comprises cascaded power converter systems with bulky DC link storage. The commonly used aluminium electrolytic DC link capacitors are the second most failed electrical component in a drive. This work proposes a suitable pulse width modulation technique in the input power converter to replace the troublesome electrolytic capacitors with more reliable and tiny film capacitors. A 1.5 kW active frontend converter cascaded with a tiny DC link and a field-oriented controlled induction motor is proposed for a torque regulation application. A dynamic current control using hysteresis PWM is implemented in the front-end converter, reducing the DC link capacitor to just 16$\mu$ F. The front-end converter control strategy is verified in both Software in Loop and Processor in Loop simulation using Texas Instruments C2000 LaunchpadXL F28069M Microcontroller.