Improving gradient constraint of complex energy orders on power exchanges

The unification of the day-ahead power exchanges resulted in a varying set of order types, which leads to challenges in the formalization of mathematical models and clearing procedures. In our paper, we have focused on complex orders. Complex orders have been in use in the Iberian power markets for many years, and they have been involved in the EUPHEMIA [1] as well, which is the clearing algorithm of the Pan-European market coupling. Complex orders are generally a set of traditional hourly supply orders with additional conditions. In this paper, a new gradient constraint is proposed which takes into consideration the fact that the gradient limit of the generation units relates to the supplied power. We show the mathematical model of the constraint and the effects of the different gradient constraints on the variables of the market analyzing test cases.