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 current total harmonic distortion (THDi) and power factor (PF) can be magnified with a decreased TRIAC conduction 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 digest provides in-depth analysis and modelling 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 the operating modes and component interactions lead to the undesired disturbances. The simulation results from the established model are shown to be consistent with measured experimental line voltage and current spikes. System level impact at the PCC will be provided in the final paper.
