Unit Commitment with Nonconvex Cost Model in Deep Peak Regulation

Abstract

In recent years, China witnessed a dramatic growth of renewable energy generation, but the integration of renewable energy like wind power and solar power will bring some disturbance to the power system, thus the demand for deep peak regulation has continued to rise. In this context, more coal-fired units need to participate in deep peak regulation to absorb renewable energy, deep peak regulation of coal-fired power plants requires coal-fired power plants to adjust the output of the unit below the minimum technical output of the unit. Therefore, it is necessary to carry out deep peak regulation adaptation transformation for traditional coal-fired power plants and put oil into the boiler, so that coal-fired power plants can operate safely below the minimum generating output. After the unit is adapted and put into oil, it will bring about the cost of transformation and the cost of oil investment. The increase in these costs will make the total cost curve of the unit become a non-convex cost curve. Aiming at the difficulty in solving unit commitment optimization with non-convex cost curve. This paper introduces an unit commitment (UC) optimization method considering the non-convexity of power generation cost caused by deep peak regulation. Taking the 118-node system [17] as the research object, the simulation results in the UC of all units participating in peak regulation and all units not participating in peak regulation are given. The results show that when the non-convex cost curve is linearized, the increase in 0/1 variables will lead to slower solution speed of the unit combination program.