Evaluation of impact assessment of non-linear lighting loads on power quality in distribution network

Abstract

Because of increased unit cost and lack of adequate power supply there is a trend worldwide to use lesser electricity without hampering comfort and production. But most of the energy saving elec- trical equipments used by residential and commercial users produce huge harmonics. High levels of harmonics in a power system can create voltage distortion resulting in power quality problems. Environmental concern on electrical power generation and electrical energy cost have diverted users to have more energy efficient systems rather than focussing on power quality. However, power quality indices are required by power utilities to ensure safe operation of the power sup- ply network that essentially include generators, transmission lines and transformers. To address the adverse affects of harmonics generated by energy efficient gadgets, a comprehensive study is conducted in this research to assess the impacts of loads of different combination on the overall power quality of a distributed network. Different loads have been modeled using current wave- form templates. A setup has been developed to acquire current waveforms of the different loads. These waveforms are processed and stored as templates for the specified load. These templates are later used in different combinations to determine the overall current waveform of a network. The overall waveform is analyzed for extracting the power quality parameters. A generalized approach is adopted in this work so that users can choose the load combinations and see the load impact on power quality. Few case studies have been conducted utilizing the proposed load models. It is observed that the impact of lighting loads where lamps and tube lights are completely replaced by CFL and Electronic Ballasts, do not significantly affect the power quality. This is because of the lesser share of the lighting loads of the total power in a network.