Aluminum plant. Load modeling for stability studies

The “Sistema Electrico Patagonico Interconectado (SEPI)” is an electric system that involves the southern Argentina region. This electric system is isolated from the other one in the north of the country. 60% of its load is consumed by an aluminum production plant consisting of two 160 MW series of 200 electrolytic cells. Dynamic and transient stability studies carried out over this system taking into account present and future situations, with load and generation growing at the aluminum plant and in the remaining system, require adequate modeling of this particular load. Tests and simulations carried out to obtain the electrolytic process load model are described. Statistical behavior of the aluminum plant load variations is analyzed, to estimate the spinning reserve in the system. Available load shedding mechanisms at the aluminum plant, as a system control element were tested and the results are analyzed