Fast Constraint Screening for Multi-Interval Unit Commitment

TL;DR

This paper introduces a fast constraint screening method for multi-interval unit commitment problems in power systems, significantly reducing problem size while maintaining solution feasibility, especially under high renewable penetration.

Contribution

It proposes a novel pre-screening scheme based on load distribution and physical feasibility, improving constraint elimination efficiency over existing methods.

Findings

Can screen out over 80% of constraints

Maintains problem feasibility after screening

Effective under high renewable penetration

Abstract

Power systems Unit Commitment (UC) problem determines the generator commitment schedule and dispatch decisions for power networks based on forecasted electricity demand. However, with the increasing penetration of renewables and stochastic demand behaviors, it becomes challenging to solve the large-scale, multi-interval UC problem in an efficient manner. The main objective of this paper is to propose a fast and reliable scheme to eliminate a set of redundant or inactive physical constraints in the high-dimensional, multi-interval, mixed-integer UC problem, while the reduced problem is equivalent to the original full problem in terms of commitment decisions. Our key insights lie on pre-screening the constraints based on the load distribution and considering the physical feasibility regions of multi-interval UC problem. For the multistep UC formulation, we overcome screening conservativeness by utilizing the multi-step ramping relationships, and can reliably screen out more constraints compared to current practice. Extensive simulations on both specific load samples and load regions validate the proposed technique can screen out more than 80% constraints while preserving the feasibility of multi-interval UC problem.