Power quality of energy saving lamps under wide voltage variations

PLN, State-owned Electricity Company in Indonesia has been promoting energy saving lamps (ESLs) through demand-side management (DSM) program since 2005. As a result, those lamps are widely used in Indonesia. To avoid outages on the customers, a brownout strategy (voltage reduction) is sometimes used. The lamps are in this case operated at a lower voltage than their rating. The paper aims to investigate the effect on power quality of those voltage variations through a laboratory test. Value of harmonics, power factor and waveform of ESLs were analyzed. The test relates to 16 sample lamps commonly used in residential and commercial area, divided in 11 LED lamps and 5 CFLs covering different manufacturers and different power ratings. The experiment uses power meter to obtain the electrical characteristics. The supply voltage applied during testing was generated by an ideal power source without voltage harmonics to avoid effects linked to device non-linear behavior. The test results show that 4 types of LEDs and 2 types of CFLs can be identified based upon the input current waveform. However, their responses under voltage amplitude variation differ. This paper focuses on this specific electrical property, which is not readily documented. It was observed that only a few ESLs have low level of harmonic currents and high power factor, in concordance with low sensitivity to amplitude variations. Moreover, the experimental results are compared with the standard harmonic limit allowable for lighting load as per IEC 61000-3-2.