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CSEE Journal of Power and Energy Systems 2024年第1期10卷 162-174页

作者： Yu Zeng Yinliang Xu Xinwei Shen hongbin sun Tsinghua-Berkeley Shenzhen Institute.Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China

While price schedules can help improve the economic efficiency of renewable energy-powered microgrids,timeof-use(TOU)pricing has been identified as an effective way for microgrid development,which is presently limited by its high costs.In this study,we propose an evolutionary game theoretic model to explore optimal TOU pricing for development of renewable energy-powered microgrids by applying a multi-agent system,that comprises a government agent,local utility company agent,and different types of consumer agents.In the proposed model,we design objective functions for the company and the consumers and obtain a Nash equilibrium using backward induction.Two pricing strategies,namely,the TOU seasonal pricing and TOU monthly pricing,are evaluated and compared with traditional fixed pricing.The numerical results demonstrate that TOU schedules have significant potential for development of renewable energy-powered microgrids and are recommended for an electric company to replace traditional fixed pricing.Additionally,TOU monthly pricing is more suitable than TOU seasonal pricing for microgrid development.

关键词： Game theory microgrid multi-agent system renewable energy time-of-use pricing

Energy Management of Price-maker Community Energy Storage by Stochastic Dynamic Programming

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 492-503页

作者： Lirong Deng Xuan Zhang Tianshu Yang hongbin sun Yang Fu Qinglai Guo Shmuel S.Oren Department of Electrical Engineering Shanghai University of Electric PowerShanghai 200000China Tsinghua-Berkeley Shenzhen Institute Tsinghua UniversityShenzhen 518055China Department of Industrial Engineering and Operations Research University of California BerkeleyBerkeleyCAUSA Risk Analytics and Optimization Chair EPFLSwitzerlandand also with Power Systems LaboratoryETH Zurich8092 ZurichSwitzerland State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

In this paper,we propose an analytical stochastic dynamic programming(SDP)algorithm to address the optimal management problem of price-maker community energy storage.As a price-maker,energy storage smooths price differences,thus decreasing energy arbitrage value.However,this price-smoothing effect can result in significant external welfare changes by reduc-ing consumer costs and producer revenues,which is not negligible for the community with energy storage systems.As such,we formulate community storage management as an SDP that aims to maximize both energy arbitrage and community welfare.To incorporate market interaction into the SDP format,we propose a framework that derives partial but sufficient market information to approximate impact of storage operations on market prices.Then we present an analytical SDP algorithm that does not require state discretization.Apart from computational efficiency,another advantage of the analytical algorithm is to guide energy storage to charge/discharge by directly comparing its current marginal value with expected future marginal value.Case studies indicate community-owned energy storage that maximizes both arbitrage and welfare value gains more benefits than storage that maximizes only arbitrage.The proposed algorithm ensures optimality and largely reduces the computational complexity of the standard SDP.Index Terms-Analytical stochastic dynamic programming,energy management,energy storage,price-maker,social welfare.

关键词： Analytical stochastic dynamic programming energy management energy storage price-maker social welfare

A projected Newton algorithm based on chemically allowed interval for chemical equilibrium computations

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Frontiers of Chemical Science and Engineering 2024年第3期18卷 25-37页

作者： hongbin Lu Shaohui Tao Xiaoyan sun Li Xia Shuguang Xiang Institute of Process Systems Engineering College of Chemical EngineeringQingdao University of Science and TechnologyQingdao266042China

The chemical equilibrium equations utilized in reactive transport modeling are complex and nonlinear,and are typically solved using the Newton-Raphson method.Although this algorithm is known for its quadratic convergence near the solution,it is less effective far from the solution,especially for ill-conditioned problems.In such cases,the algorithm may fail to converge or require excessive iterations.To address these limitations,a projected Newton method is introduced to incorporate the concept of projection.This method constrains the Newton step by utilizing a chemically allowed interval that generates feasible descending iterations.Moreover,we utilize the positive continuous fraction method as a preconditioning technique,providing reliable initial values for solving the algorithms.The numerical results are compared with those derived using the regular Newton-Raphson method,the Newton-Raphson method based on chemically allowed interval updating rules,and the bounded variable least squares method in six different test cases.The numerical results highlight the robustness and efficacy of the proposed algorithm.

关键词： chemical equilibrium reactive transport modeling numerical methods projected Newton method

New roles of tumor-derived exosomes in tumor microenvironment

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Chinese Journal of Cancer Research 2024年第2期36卷 151-166页

作者： Shiqian Chen Jinzhe sun Huan Zhou hongbin Lei Dan Zang Jun Chen Department of Oncology the Second Hospital of Dalian Medical UniversityDalian 116023China Department of Radiotherapy the Second Hospital of Dalian Medical UniversityDalian 116023China

Throughout tumorigenesis, the co-evolution of tumor cells and their surrounding microenvironment leads to the development of malignant phenotypes. Cellular communication within the tumor microenvironment(TME) plays a critical role in influencing various aspects of tumor progression, including invasion and metastasis. The release of exosomes, a type of extracellular vesicle, by most cell types in the body, is an essential mediator of intercellular communication. A growing body of research indicates that tumor-derived exosomes(TDEs) significantly expedite tumor progression through multiple mechanisms, inducing epithelial-mesenchymal transition and macrophage polarization, enhancing angiogenesis, and aiding in the immune evasion of tumor cells. Herein, we describe the formation and characteristics of the TME, and summarize the contents of TDEs and their diverse functions in modulating tumor development. Furthermore, we explore potential applications of TDEs in tumor diagnosis and treatment.

关键词： Tumor-derived exosomes tumorigenesis tumor microenvironment diagnosis treatment

Deep Reinforcement Learning-Based Task Offloading and Service Migrating Policies in Service Caching-Assisted Mobile Edge Computing

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China Communications 2024年第4期21卷 88-103页

作者： Ke Hongchang Wang Hui sun hongbin Halvin Yang School of Computer Technology and Engineering Changchun Institute of TechnologyChangchun 130012China College of Computer Science and Engineering Changchun University of TechnologyChangchun 130012China Department of Electronic and Electrical Engineering University College LondonLondonUK

Emerging mobile edge computing(MEC)is considered a feasible solution for offloading the computation-intensive request tasks generated from mobile wireless equipment(MWE)with limited computational resources and energy.Due to the homogeneity of request tasks from one MWE during a longterm time period,it is vital to predeploy the particular service cachings required by the request tasks at the MEC server.In this paper,we model a service caching-assisted MEC framework that takes into account the constraint on the number of service cachings hosted by each edge server and the migration of request tasks from the current edge server to another edge server with service caching required by tasks.Furthermore,we propose a multiagent deep reinforcement learning-based computation offloading and task migrating decision-making scheme(MBOMS)to minimize the long-term average weighted cost.The proposed MBOMS can learn the near-optimal offloading and migrating decision-making policy by centralized training and decentralized execution.Systematic and comprehensive simulation results reveal that our proposed MBOMS can converge well after training and outperforms the other five baseline algorithms.

关键词： deep reinforcement learning mobile edge computing service caching service migrating

Minimal Euler characteristics of 4-manifolds with 3-manifold groups

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Science China Mathematics 2023年第10期66卷 2325-2336页

作者： hongbin sun Zhongzi Wang Department of Mathematics Rutgers University-New BrunswickPiscatawayNJ 08854USA Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China

Letπ=π_(1)(M)for a compact 3-manifold M,andχ_(4),p and q^(*)be the invariants of Hausmann and Weinberger(1985),Kotschick(1994)and Hillman(2002),respectively.For a certain class of compact 3-manifolds M,including all those not containing two-sided RP2’s,we determineχ_(4)(π).We address when p(π)equalsχ_(4)(π)and when q^(*)(π)equalsχ_(4)(π),and answer a question raised by Hillman(2002).

关键词： 3-manifold 4-manifold fundamental group Euler characteristic

Distributed Real-time Temperature and Energy Control of Energy Efficient Buildings via Geothermal Heat Pumps

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CSEE Journal of Power and Energy Systems 2023年第6期9卷 2289-2300页

作者： Xiaotian Wang Lei Liang Xuan Zhang hongbin sun Tsinghua-Berkeley Shenzhen Institute Tsinghua UniversityShenzhenChina Department of Electrical Engineering Tsinghua UniversityBeijingChina

Geothermal heat pumps(GHPs)are a type of heating ventilation and air conditioning(HVAC)systems that use low-temperature resources from soil and groundwater for heating/cooling.In recent years,there has been an increasing interest in GHP systems due to their high energy efficiency and abundant geothermal resources.Thus,the optimization and control design of the GHP system has become a hot topic.On the other hand,as the GHP system is an ideal respon-sive load,mechanism design for the GHP system to realize demand response(DR)in a virtual power plant(VPP)without affecting user comfort is particularly essential.In this paper,we propose a distributed real-time temperature and energy management method via GHP systems for multi-buildings,where both floor and radiator heating/cooling distribution subsystems in multiple thermal zones are considered.We design an energy demand response mechanism for a single GHP to track the given energy consumption command for participating in VPP aggregation/disaggregation.Besides,a coordination mechanism for multiple GHPs is designed for the community-level oper-ator in joining VPP aggregation/disaggregation.Both designed schemes are scalable and do not need to measure or predict any exogenous disturbances such as outdoor temperature and heating disturbances from external sources,e.g.,user activity and device operation.Finally,four numerical examples for the simulation of two different scenarios demonstrate the effectiveness of the proposed methods.

关键词： Building temperature and energy management disaggregation distributed control GHP HVAC VPP

Online Frequency Security Assessment Based on Analytical Model Considering Limiting Modules

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CSEE Journal of Power and Energy Systems 2022年第5期8卷 1363-1372页

作者： Yuqian Zhang Qinglai Guo Yanzhen Zhou hongbin sun State Key Laboratory of Power Systems Department of Electrical EngineeringTsinghua UniversityBeijing 100084China

Due to the increasing implementation of high voltage direct current(HVDC)and the integration of renewable resources,frequency stability problems in power systems are drawing greater attention in recent years.It has become necessary to carry out online frequency security assessments to ensure the safe operation of power systems.Considering the low time-efficiency of simulation-based methods,analytical models,such as the frequency nadir prediction(FNP)model,are more suitable for online assessment,which requires calculating the worst frequency deviation under various contingencies.Based on the FNP model,the FNP-L model for online frequency security assessment is proposed in this paper.The proposed model implements security assessment by calculating and checking the frequency features,including the nadir time and frequency,followed by contingencies.The effect of the governor,including nonlinear constraints,is approximated into polynomial functions so that the results are obtained by solving multiple polynomial equations.Case studies are carried out using the New-England 39-bus system and a regional power grid,which shows that the proposed model could achieve both high speed and high accuracy,and can therefore be applied in online security assessment.

关键词： Frequency response frequency stability power system security

Convex Reformulation for Two-sided Distributionally Robust Chance Constraints with Inexact Moment Information

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Journal of Modern Power Systems and Clean Energy 2022年第4期10卷 1060-1065页

作者： Lun Yang Yinliang Xu Zheng Xu hongbin sun TsinghuaBerkeley Shenzhen Institute Tsinghua Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055China Department of Electrical Engineering State Key Laboratory of Power SystemsTsinghua UniversityBeijing 100084China

Constraints on each node and line in power systems generally have upper and lower bounds,denoted as twosided constraints.Most existing power system optimization methods with the distributionally robust(DR)chance-constrained program treat the two-sided DR chance constraint separately,which is an inexact approximation.This letter derives an equivalent reformulation for the generic two-sided DR chance constraint under the interval moment based ambiguity set,which does not require the exact moment information.The derived reformulation is a second-order cone program(SOCP)formulation and is then applied to the optimal power flow(OPF)problem under uncertainty.Numerical results on several IEEE systems demonstrate the effectiveness of the proposed SOCP formulation and show the differences with other DR chance-constrained OPF approaches.

关键词： Two-sided chance constraint distributionally robust conic reformulation interval moment optimal power flow

Attack-resilient Distributed Control for Islanded Single-/three-phase Microgrids Based on Distributed Adaptive Observers

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Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 109-119页

作者： Jianguo Zhou Yinliang Xu Lun Yang hongbin sun Tsinghua-Berkeley Shenzhen Institute(TBSI) Tsinghua Shenzhen International Graduate School(TsinghuaSIGS)Tsinghua UniversityShenzhen 518055China Department of Electrical Engineering State Key Laboratory of Power SystemsTsinghua UniversityBeijing 100084China

This paper investigates the power sharing and voltage regulation issues of islanded single-/three-phase microgrids(S/T-MGs)where both sources and loads are unbalanced and the presence of adversarial cyber-attacks against sensors of distributed generator(DG)units is considered.Firstly,each DG unit is modeled as a heterogeneous linear dynamic agent with disturbances caused by sources and loads,then the problem is formulated as a distributed containment control problem.After that,to guarantee satisfactory power sharing and voltage control performance asymptotically achieved for the S/T-MGs,an attack-resilient distributed secondary control approach is developed by designing a distributed adaptive observer.With this approach,the effect of the cyber-attacks can be neutralized to ensure system stability and preserve bounded voltage synchronization.Simulation results are presented to demonstrate the effectiveness of the proposed control approach.

关键词： Single-/three-phase microgrid cyber-attack resilient distributed control distributed observer power sharing