Evaluating the impact of sub-hourly unit commitment method on spinning reserve in presence of intermittent generators

• Proposing Dynamic Programming integrating Priority Listing order for unit commitment.
• Considering physical and operational constraints.
• Cost saving can be achieved while satisfying the system's reliability.

This paper presents an algorithm to deal with thermal Unit Commitment which takes into account the intermittency and volatility of the renewable energies such as wind and solar energies. Dynamic Programming (DP) integrating Priority Listing order (PL) based on Best Per Unit Cost (BP) was applied to commit the thermal units in an isolated island with generators based on renewable sources. In this work, the effects of a high time resolutions such as 60, 30, 15, 10 and 5 min on production costs, reserves and intermittent generators are investigated. In order to demonstrate the capability of the proposed algorithm, two cases were studied. Firstly, a test system composed of ten diesel generators, three wind turbines and one Photovoltaic (PV) power plant is examined and then the IEEE 118-bus test system, integrating wind and PV power plants, is considered. The presented simulation results show that a proper schedule for each generation unit can be reached at a time resolution closer to real time unit commitment and economic dispatch while a high level of reliability can be guaranteed by assuring practical constraints fulfillment.