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Center for Nonlinear Studies |
In this presentation, we will discuss tightly interwoven challenges that power system operators face in their day-ahead planning: reliability, cost-efficiency, and tractability of decision-making tools in the presence of renewable generation. These challenges will then be put in context of the state-of-the-art scenario-based, interval-based, and robust optimization frameworks, which have been shown to outperform the traditional deterministic paradigm (still the industry standard, though).
Next, we will present a new hybrid approach to the day-ahead unit commitment problem, which combines scenario-based and interval-based optimization frameworks and aims to minimize the operating cost subject to the expected electricity demand conditions and constraints on generation and transmission resources. The scenario-based unit commitment minimizes the expected operating cost over a set of scenarios (forecasts) and produces the most cost-efficient solution at the expense of reliability and tractability issues. On the other hand, the solution obtained with the interval-based unit commitment minimizes the cost of meeting the deterministic forecast while guaranteeing feasibility of worst-case capacity and ramp scenarios, which leads to a more expensive, but robust and tractable schedule.
The proposed hybrid unit commitment enforces the scenario-based formulation to the initial operating hours of the optimization horizon, characterized by more accurate forecasts, and then switches to the interval formulation for the remainder. The optimal switching hour balances the cost of unhedged uncertainty from the scenario-based unit commitment against the security premium inherent in the interval-based unit commitment formulation.
Host: Misha Chertkov