摘要：Harmonics reduce power quality and increase inefficiency. Although light emitting diode (LED) bulb has been considered more efficient than previous bulb technologies; its internal circuits potentially generate additional problems. This paper has surveyed 6 LED bulb samples and measured the harmonics generated by the internal circuits. As a result. 7 Watt type B LED bulb produces the highest 3rd order harmonics current which is incompatible with IEC61000-3-2 Class C. A prototype of LC filter is designed to decrease the harmonic level. The measurement shows that the designed passive filter is able to reduce at least 81.3% of harmonics.
