Wasserstein-metric-based distributionally robust optimization method for
unit commitment considering wind turbine uncertainty
Abstract
Abstract The penetration of wind turbines in the power grid is
increasing rapidly. Still, the wind turbine output power has
uncertainty, leading to poor grid reliability, affecting the grid’s
dispatching plan, and increasing the total cost. Thus, a
distributionally robust optimization (DRO) method for thermal power unit
commitment considering the uncertainty of wind power is proposed. For
this method, energy storage and interruptible load are added to simulate
increasingly complex electricity consumption scenarios. Furthermore, the
amount of load cutting reflects the satisfaction level of electricity
consumption on the user side. Based on Wasserstein metric, an ambiguity
set is established to reflect the probabilistic distribution information
of the wind power uncertainty. An ambiguity set preprocessing method is
proposed to depict the probability distribution of ambiguity set more
clearly, to minimize the operation cost under the condition that the
uncertainty of wind turbine output power obeys the extreme probabilistic
distribution of the ambiguity set. The test case in a modified version
of the IEEE 6-bus system shows that the proposed method can flexibly
adjust the robustness and economy of optimization decisions by
controlling the sample size and the confidence of Wasserstein ambiguity
set radius. In addition, the proposed ambiguity set preprocessing method
can obtain more economical dispatching decisions with a smaller sample
size.