تاثیر فناوری های لامپ بر کیفیت توان شبکه توزیع برق Effect of Lamp Technologies on the Power Quality of Electrical Distribution Network

Lighting plays a vital role in regular human activities which may be artificial (lamps) or naturally (sunlight). Artificial lightings is adjudged to be one of the component of electrical system that affect the quality of life of people[1]. Adequate lighting system is required in work places, classrooms, offices etc. to achieve a given task comfortably. Hence, it should be functionally suitable for people working inside the task area. However, most recent light technologies are classified as non-linear load which may impact negatively on the power quality of the surrounding distribution network. Moreover, lighting accounts for 21% of the total electrical energy consumption in the world [1]. Therefore, reducing the electrical energy consumption by using energy efficient lamps is generally believed to be one of the important solutions to reducing electrical energy consumption. In an attempt to provide this solution, so many companies sprang-up to manufacture different lamps. Hence, different lighting technologies have found their ways into the market. As such, it is paramount to evaluate the performance characteristics of these lighting technology and the possible effects they might have on the power network. Various lamp technologies have emerged since the invention of the incandescent, one of the most recent being the LED technology. The new lighting technologies have taken energy savings into serious considerations. The demand for energy-efficient lamps is on the increase not only because of its energy-saving benefits, but also for the laws applied in different countries to ban the use of incandescent bulbs[2]. Such lamps offer benefits as access to electricity is hampered by inadequate generation. One major benefit which is reduction in electricity cost has made them particularly attractive. Although these modern lighting technologies offer these huge benefits, there is a tendency that they produce harmonics since they are non-linear load. Harmonics in power system poses negative consequences on the power system; it increases line losses and cause excessive heating of equipment which decreases their lifetime [3, 4]. Sub-harmonics could cause flickers that result in an uncomfortable visual effect on the eyes, imbalance and core saturation of transformers and thermal aging of induction motors[5, 6]. It is therefore necessary to evaluate the impact of these modern lamp technologies on the power system. Considerable work has been done regarding the effect of several lighting technologies on a distribution network. The basic problem arising in the mass usage of CFLs and LEDs is the problem with the network voltage distortion that arises due to their distorted current which contains a high level of harmonic components. Moreover mitigation of harmonic distortion caused by CFLs is very difficult once they are widely distributed over the large power system network [7]. Increased harmonic distortion can cause excessive winding losses and hence abnormal temperature rise in transformers. So when non-linear loads such as LEDs and CFLs are the major energy consumers in a distribution network, early fatigue of transformer insulation and reduction of the useful life of transformer are some of the issues that could arise [8]. In this paper, three different lamp technologies i.e. Light Emitting Diode (LED) lamps, Incandescent Lamps (IC) and Compact-fluorescent lamps (CFL) are analysed to check the impact of their usage on the power quality of a distribution system through a laboratory experiment. The rest of the paper is organised as follows: section 2 described the effect of harmonic on the distribution network using the laboratory experimental set-up, section 3 compares the voltage and current characteristics of different lighting technologies, section 4 presents harmonic generation levels of the technologies, section 5 compares other performance characteristics of the technologies while section 6 concludes the paper