Transmission System Usage Amount Planning by Brazilian Distribution Utilities

The increase of distributed generators and energy storage devices in modern distribution systems impacts the demand provided by the distribution utility and, hence, the techniques employed to determine the Transmission System Usage Amount at the border with the transmission system. If the contracted demand is violated, the utility must pay inefficiency charges. The complexity of this new reality is the stochastic characteristics associated with the new devices installed at medium and low voltage levels. In this context, this work proposes a methodology composed of a linear programming model to determine the demand to be contracted by the distribution utility. This work incorporates the problem uncertainties by integrating historical data and demand forecasting from the distribution utility and the Brazilian Energy Research Company. The developed methodology obtained a 1.5% error compared to the contracted demand which would lead to the minimum annual demand cost when applied to a Brazilian system.