Optimal Energy Reserve Scheduling in Integrated Electricity and Gas Systems Considering Reliability Requirements

Abstract

With the growing interdependence between the electricity system and the natural gas system, the operation uncertainties in either subsystem, such as wind fluctuations or component failures, could have a magnified impact on the reliability of the whole system due to energy interactions. A joint reserve scheduling model considering the cross-sectorial impacts of operation uncertainties is essential but still insufficient to guarantee the reliable operation of the integrated electricity and natural gas system (IEGS). Therefore, this paper proposes a day-ahead security-constrained unit commitment (SCUC) model for the IEGS to schedule the operation and reserve simultaneously considering reliability requirements. Firstly, the multi-state models for generating units and gas wells are established. Based on the multi-state models, the expected unserved energy cost (EUEC) and the expected wind curtailment cost (EWC) criteria are proposed based on probabilistic methods considering wind fluctuation and random failures of components in IEGS. Furthermore, the EUEC and EWC criteria are incorporated into the day-ahead SCUC model, which is nonconvex and mathematically reformulated into a solvable mixed-integer second-order cone programming (MISOCP) problem. The proposed model is validated using an IEEE 30-bus system and Belgium 20-node natural gas system. Numerical results demonstrate that the proposed model can effectively schedule the energy reserve to guarantee the reliable operation of the IEGS considering the multiple uncertainties in different subsystems and the cross-sectorial failure propagation. Index Terms--Integrated electricity and natural gas system (IEGS), natural gas reserve, electric reserve, expected unserved energy cost, expected wind curtailment, multi-state model, operational reliability.

Segmented Real-time Dispatch Model and Stochastic Robust Optimization for Power-gas Integrated Systems with Wind Power Uncertainty

“…In this paper, the AGC resources mainly include the AGC units and P2Gs. With regard to the current inadequate conversion efficiency and high cost of P2Gs (water electrolysis and methanation) [2], [16], the PGIS will tend to make less use of the P2Gs in the real-time adjustment. Therefore, we propose a segmented real-time dispatch model for the PGIS, which sets different dispatch strategies of the AGC units and the P2Gs when the wind power uncertainty falls into different segments.…”

“…P OWER-GAS integrated system (PGIS) can utilize the electricity and natural gas energy synergistically and interactively, which improves the energy efficiency and operation flexibility of the total system [1]. Recently, with the emerging power-to-gas (P2G) technology [2], it becomes possible to co-optimize traditional units and P2G devices to maintain the energy balance and address uncertainty issues from the increasing penetration of the renewable power integration, e.g., wind power [3]. By dynamically converting ex-cess power from the power system into natural gas, P2Gs can fast respond to the dispatch signals and participate in the real-time dispatch [4] - [6], which is typically undertaken by traditional automatic generation control (AGC) units.…”

“…In another sentence, the adjustment task will be assigned to these resources based on the fixed participation factors regardless of the real-time degree of the wind power uncertainty. As we know, the efficiency of converting power to natural gas is comparatively lower (50%-60%) [16], and thus it is expensive to keep the P2G operation all over the time [2]. In fact, it is costly and unnecessary for P2Gs to always participate in leveling off the wind power fluctuations.…”

Optimal Stochastic Scheduling Strategy of Multi-vector Energy Complex Integrated with Full-blown Power-to-biomethane Model

“…R ECENTLY, the global crisis of natural gas supply has intensified owing to the interweaving of global geopolitical risks and various adverse circumstances [1]. The natural gas consumption in 2021 was 4.0 trillion cubic meters worldwide, with a yearly growth rate of approximately 5.3%.…”