Analysis of the current harmonics injected into the power grid by dimmable LED lamps

In recent years, the world has experienced a new revolution in the lighting technology with the advent of LED lamps, which are based on the use of the light-emitting diodes (LEDs). The LED technology is a viable solution for lighting together to the compact fluorescent lamp (CFL) technology, and it is steadily in development. Accordingly, the quality of the LED lamps is going to improve since lately LED devices are more powerful and brighter. The two types of lamps in many fields of applications work with dimmer devices, which allow adjusting the flux. However, the CFL lamps are subject to many problems related to compatibility with the dimmers, which in turn considerably limit their flux control. The two technologies introduce a high harmonic content in the power line, which perhaps increases in case of the flux control with dimmers. In this paper, the harmonic content introduced by dimmable LED lamps of different brands is experimentally investigated and analyzed. The experimental tests aim to evaluate the variations of the performances, according to the Standard IEC 61000-3-2.