Harmonic Emission by Smart LED Systems under Phase Unbalanced Conditions

Light emitting diode (LED) lighting systems are widely used in dimming and color-changing applications. When an automated lighting control system is in use, there can be several combinations of dimming levels and colors of lighting fixtures in a given installation. The power consumption of an LED depends on the level of dimming and the color. Even though the lighting system is designed to be balanced over three phases at the full load condition, the system unbalanced conditions are created when the automated lighting control systems are in operation. This paper evaluates the standards applicable to LED systems with control, and phase balancing requirements in lighting systems, followed by an investigation on power quality impact created by mass-scale LED lighting installations in dynamic operation based on several field studies on dimmable LED lighting systems.