  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.
