Two-Stage Distributionally Robust Optimization for Energy Hub Systems

Xiang

et al. 2021

IEEE Systems Journal

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Volt/VAR optimization (VVO) is one important operation in distribution systems to maintain acceptable voltage profiles. However, the high penetration of renewable generation poses severe challenges to VVO, leading to voltage deviation and fluctuation. This is further complicated by the growing coupling between electricity and natural gas systems. To resolve unacceptable voltage deviation under energy system interdependency, this paper proposes a co-optimization of VVO for an integrated electricity and gas system (IEGS) with uncertain renewable generation. A two-stage data-driven distributionally robust optimization (DRO) is developed to model the coordinated optimization problem, which determines two-stage VVO and operation schemes with dispatch and corrective adjustment through active power regulation and reactive power support in both dayahead and real-time stage. A semidefinite programming is reformulated to ensure the tractability and the proposed problem is solved by a constraint generation framework. Simulation studies are conducted on a 33-bus-6-node IEGS. Case studies demonstrate that the interdependency between electricity and gas systems reduces siginificant operation cost and voltage rise. It thus can benefit integrated system operators with a powerful operation tool to manage systems with fewer costs but integrate more renewable energy while maintaining high supply quality.

Section: System Modellingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Reactive Power Optimization in Integrated Electricity and Gas Systems

Xiang

et al. 2021

IEEE Systems Journal

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“…CHPs have a range of advantages over their traditional counterparts: (a) an efficiency over 80%; (b) saving up to 30% on energy bills; (c) saving up to 30% on carbon emissions; (d) reduction in transmission and distribution losses; and (e) increasing supply security. 15,16,35 2.2 | Power to gas by electrolysis…”

Section: Combined Heat and Powermentioning

confidence: 99%

“…[45][46][47] For the sake of simplicity, the subscript {Á} representing {hs, b} is used. The charging and discharging power/heat are limited in (15) and (16). Equation 17ensures that charging and discharging do not occur simultaneously.…”

Section: Energy Storage Systemmentioning

confidence: 99%

Robust energy hub optimization with cross‐vector demand response

Zhu

Int Trans Electr Energ Syst

et al. 2020

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The integration of multi-energy systems increases renewable penetration and efficiency of energy use, and reduces costs. This integration is further reinforced by new technologies, such as cross-vector demand response and power-togas technologies, bringing big flexibility to system operation. This paper studies the optimal operation of multi-vector energy systems, considering cross-vector demand response with power-togas technology by using robust optimization. An energy hub system (EHS) is considered as the realization of a multi-vector energy system, which consists of (a) the two-way multienergy converters between electricity and gas, (b) an energy storage system and (c) renewable energy resources. The demand response to energy price variations in both electricity and heat is considered, where customers can change their energy consumption behaviors motivated by pricing mechanisms. In the EHS, energy conversion, storage, production and consumption are all modeled. To handle the uncertainty from renewable power generation, robust optimization is used with a hybrid box-polyhedral uncertainty set for solving the built model. Case studies demonstrate that the proposed method can

“…Much effort has been focused on the optimization of IES, mainly achieving economic and environmental targets [14,15]. A RO model is proposed for an integrated power-gas-heat system in smart districts [16].…”

Section: Introductionmentioning

confidence: 99%

Economic-Effective Multi-Energy Management Considering Voltage Regulation Networked With Energy Hubs

IEEE Trans. Power Syst.

Cao

et al. 2021

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This paper develops a novel two-stage coordinated volt-pressure optimization (VPO) for integrated energy systems (IES) networked with energy hubs considering renewable energy sources. The promising power-togas (P2G) facilities are used for improving the interdependency of the IES. The proposed VPO contains the traditional volt-VAR optimization functionality to mitigate the voltage deviation while ensuring a satisfying gas quality due to the hydrogen mixture. In addition to the conventional voltage regulating devices, i.e., on-load tap changers and capacitor banks, P2G converter and gas storage are used to address the voltage fluctuation problem caused by renewable penetration. Moreover, an effective two-stage distributionally robust optimization (DRO) based on Wasserstein metric is utilized to capture the renewable uncertainty with tractable robust counterpart reformulations. The Wasserstein-metric based ambiguity set enables to provide additional flexibility hedging against renewable uncertainty. Extensive case studies are conducted in a modified IEEE 33-bus system connected with a 20-node gas system. The proposed VPO provides a voltage-regulated economic operation scheme with gas quality ensured that contributes to high-quality but low-cost multienergy supply to customers.