Capacitor Sizing of High Resolution Converter for Induction Machine Driven Fan Load

The capacitor requirement of any power electronic converter plays a vital role in determining the converter's cost, weight and volume. In recent days several multilevel inverters have been reported in the literature for different applications. A high-resolution multilevel converter can offer several advantages w.r.t PWM converters with limited levels. This paper investigates the potential of double Level Doubling Network (LDN) based multilevel converter topology for fan and similar (for e.g., pump and compressor) applications using induction machines. The torque ripple and capacitor requirement of the converter is investigated in detail. Load current (along with reactive power demand), frequency change, and torque requirement in a given speed for such load are considered to assess the worst-case capacitor requirement. To validate the concept, a simulation model is developed in MATLAB/Simulink.