Frequency control by aluminum smelter load response in an isolated wind power system: A study for an industrial case

Reducing fossil consumptions of aluminum smelting productions, which consumes around 8% electricity annually in China, is of significantly meaningful for China´s energy section. One possible solution is by integrating wind power to supply for part of aluminum smelter loads. Based on this background, the paper studies an actual industrial case which is an isolated power system with as high as 30% wind penetration level integrated for aluminum production. After the integration of wind power, frequency stability issues become critical in such a system. This paper hence proposes a demand-side frequency control scheme, which uses self-saturable reactors to control load power of aluminum smelters responding to frequency deviations of this system. The scheme is designed based on the relationship between the input DC voltage of smelting loads and the commutation voltage drop which can be adjusted by self-saturable reactors. A numerical case study demonstrates the effectiveness of the proposed control scheme under the scenario considering with wind power outputs.