Power Quality Impact of Residential LED Lighting Systems with Integrated TRIAC-Based Dimmer

LED lamps are superior alternatives to fluorescent lamps, often used in conjunction with residential dimmers for additional energy savings. The market-dominant TRIAC-based dimmers induce line voltage and current disturbances at the TRIAC turn-on instant which can seriously degrade the electric power quality (P.Q.). The impact on key power quality indicators such as line voltage distortion, dimmer current transient, and common-mode current transient during TRIAC turn-on instant can be magnified with an increased TRIAC firing angle i.e., dimmed LED output. These dimmer-induced effects threaten the operation of other sensitive electronics connected at the point of common coupling (PCC). This paper provides in-depth analysis and modeling for the residential LED lighting systems equipped with TRIAC-based dimmer. The model explains the cause of the P.Q. degradation in TRIAC dimmer-based LED lamp systems. It is revealed that certain operating modes and component interactions lead to undesired disturbances. System-level impact on sensitive electronics at the PCC such as PFCs adapters are discussed. The simulation results from the established model are consistent with measured experimental line voltage and current spikes.