Study on Energy efficiency and Harmonics mitigation in a HVAC AHU Blower/Fan Application using Electronically Commutated BLDC Motors

Abstract

Usage of solid state devices for speed control is a widely used method in industrial energy efficiency projects. This method has a disadvantage of injecting harmonics in the system. Here, a novel idea of mitigating harmonics in energy efficient way is proposed. In this case study a comparison of the harmonic and energy parameters of an induction motor with AC (alternating current) to DC (direct current) to Pulse With Modulated (PWM) AC Variable Frequency Drive (VFD) and an electronically commutated brushless direct current motor (EC BLDC) with AC to DC to variable DC VSD for an air handling unit fan application is carried out. Simulation and theoretical analysis of this idea is done using Matlab/Simulink. The results of the pilot real time installation are highly encouraging with a reduction of current Total Harmonic Distortion (THD) by 15 percent and energy consumption by 45 percent with the proposed system. Future scope for harmonic reduction with BLDC EC fan and improving the overall system efficiency further to this retrofit are also discussed briefly.