Abstract: Long term load forecasting have important role in generation, transmission, and distribution network planning in a power system. A good forecasting reflects current and future trends, tempered with good judgment. The present paper is devoted to study the long term load forecasting of Amritsar city using fuzzy logic methodology along with various mathematical equations i.e. Straight line, Parabola, Exponential and S-Curve equations. Electric load and population data of Amritsar City for last 18 years (from 1997 to 2014) is taken and load is calculated for next nine years (from 2015 to 2023). To obtain the results from Fuzzy Logic methodology error corrections are applied individually and which type of mathematical equation gives least error for load calculations is also taken into consideration. MATLAB programming is used for all the computational work. The same methodology can also be applied for short term and medium term load forecasting, by doing so load shedding in particular area can be reduced. This study is important for an electric utility so that they have an idea about the maximum required power well in advance so that it can be made available as and when required.

Keywords: Long term load forecasting, DDF(Data Dependent Factor), MDF(Model Dependent Factor), ES(Expert System), Straight line(SL), Parabola(P), Exponential(E), S-curve(SC), Fuzzy logic.