Energy Management And Trading Strategy For Cloud Data Centers Considering Interaction With Power Grids

Cloud data centers that handle the explosive demands from cloud users are critical information infrastructures in the digitalized world.In consequence,the electricity demands of cloud data centers are increasing rapidly,enabling them to act as significant consumers in power grids.Backboned by cloud computing and energy management technologies,cloud data centers can not only schedule their power consumptions temporally but also dispatch cloud requests and the associated electricity demands across geo-distributed regions via the Internet,showing temporal-spatial energy management flexibility that is distinguished from other conventional power loads.In the context of electricity markets,power grids can utilize market tools to facilitate the flexibility of cloud data centers to fully release their values.Meanwhile,cloud data centers can obtain corresponding economic incentives,which can upgrade their operational management.Therefore,it is meaningful to investigate “Cloud Data Center-to-Grid(CDC2G)” in the context of electricity markets.Considering the temporal-spatial energy management flexibility,cloud data centers can arbitrage across multiple markets in temporal-spatial dimensions and can develop complicated coupling relationships with power grids under different market scenarios,bringing huge challenges to decision-makers.However,CDC2 G scenarios have not yet been fully discussed in current studies.The complicated coupling relationships of cloud data centers and power grids have not been further analyzed and considered in decision-making.The above limitations have hindered the development of this promising research.Aiming at establishing a proactive and win-win CDC2 G framework,this paper firstly investigates the energy management strategies and the temporal-spatial energy management flexibility of cloud data centers and then analyzes the dimensional coupling relationships between cloud data centers and power grids.Further,this paper studies the integrated planning of cloud data centers and power grids,as well as the energy management and trading strategy of cloud data centers.The major contributions of this paper are summarized as follows:(1)An energy management model is proposed after investigating the fundamental components and energy management strategies of cloud data centers.The proposed model includes mathematical equations and constraints of the net-power consumption and energy management flexibility of a cloud data center.The foundations and interaction scenarios of CDC2 G are analyzed.For two interaction modes,i.e.individual and coordination,generalized optimization models are proposed.Based on the above energy management and interaction models,the dimensional coupling relationships between cloud data centers and power grids are analyzed.(2)Regarding the CDC2 G issue in the planning stage,a multi-objective integrated planning model for cloud data centers and battery energy storage systems is proposed.In the proposed model,the coupling relationships and operational characteristics of cloud data centers and power grids in the planning and operation time scales are considered.The model aims to simultaneously optimize three objectives,including the cloud data centers’ quality-of-service,the system’s total cost,and the peak-to-average ratio of the coupled system’s power load profile.Multi-Objective Natural Aggregation Algorithm is adopted to solve the proposed model.Numerical case studies show that by coordinately planning the cloud data centers and grid-side energy storage resources,the system’s quality-of-service,economics,and reliability can be efficiently enhanced.Also,the economic benefit of the integrated planning scheme is verified.(3)Regarding the decision-making of cloud data centers in the context of geo-distributed local energy markets,a two-stage energy management and market strategy model is proposed,which includes a day-ahead bidding stage and a real-time energy balancing stage.In the proposed model,the coupling relationships between the local energy market mechanism and cloud data center flexibilities are considered.Natural Aggregation Algorithm is adopted to solve the day-ahead bidding model while linearization methods are proposed to transform the real-time energy balancing model into a mixed-integer linear programming.The simulation results have verified that the proposed framework can achieve a win-win result for both cloud data centers and market operators in terms of economic profit.(4)Regarding the decision-making of cloud data centers in the context of hybrid cloud and electricity markets,a three-level portfolio optimization model is proposed,which considers the coupling relationships between cloud and electricity markets as well as the gaming between multiple market participants.In the proposed framework,the lower-level model indicates the leader-follower gaming between the cloud service provider and on-demand cloud users;the upper-level model indicates the bidding and clearing inside a cloud federation,and the middle-level model investigates the decision-making of cloud data centers in wholesale electricity markets and local energy markets.Karush–Kuhn–Tucker optimal constraints and some linearization approaches are utilized to transform the initial nonlinear three-level problem into a single-level linear programing.Extensive case studies are conducted to verify the effectiveness of the proposed framework,which show that the proposed framework can achieve a trade-off optimal decision of cloud data centers in combined cloud and electricity markets,and fully exploit their energy management flexibilities and intellectual decision-making abilities.This work is supported by the China Scholarship Council,National Natural Science Foundation of China(51577073),Chinese Academy of Engineering(Consulting Project2018-ZD-02-05),and Guangdong Provincial Key R&D Program(2019B111109002).Part of the research achievements has won the first prize in China Electrical Technology and the first prize in Science and Technology Progress of China Southern Power Grid.Some research achievements have been applied in the engineering projects of China Southern Power Grid and have gained satisfactory technical and economic profits,which verify the effectiveness of this work.