Pollution impact of residential loads on distribution system and prospects of DC distribution

Unlike in the previous decades, the recent past saw the advent of many modern appliances in residential buildings. The unique feature in most of these appliances is that they use direct current (dc) in their internal circuits. With an already established alternating current (ac) distribution system in the present scenario, this situation calls for an in-depth analysis for a suitable dc distribution scheme to improve power quality and efficiency. In this paper an extensive survey of loads is conducted in various residential buildings supplied by different distribution transformers and their harmonic pollution impact on the system is investigated. To improve the efficiency and power quality of the traditional domestic distribution system, a dc distribution scheme is proposed which reduces harmonics and neutral loading of distribution transformers. The scheme can be made effective by shifting the harmonic inducing loads to the dc network side. This system also eliminates redundant power conversion stages involved in the integration of renewable energy sources in the conventional distribution system. The effectiveness of the system is validated by simulating a prototype distribution system and the results are verified experimentally.