publications
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2025
- Dynamics-incorporated Modeling Framework for Stability Constrained Scheduling Under High-penetration of Renewable EnergyIEEE Transactions on Sustainable Energy, 2025
In this paper, a modularized modeling framework is designed to enable a dynamics-incorporated power system scheduling under high-penetration of renewable energy. This unique framework incorporates an adapted hybrid symbolic-numeric approach to scheduling models, effectively bridging the gap between device- and system-level optimization models and streamlining the scheduling modeling effort. The adaptability of the proposed framework stems from four key aspects: extensible scheduling formulations through modeling blocks, scalable performance via effective vectorization and sparsity-aware techniques, compatible data structure aligned with dynamic simulators by common power flow data, and interoperable dynamic interface for bi-direction data exchange between steady-state generation scheduling and time-domain dynamic simulation. Through extensive benchmarks with various usage scenarios, the framework’s accuracy and scalability are validated. The case studies also demonstrate the efficient interoperation of generation scheduling and dynamics, significantly reducing the modeling conversion work in stability-constrained grid operation towards high-penetration of renewable energy.
@article{10836855, author = {Wang, Jinning and Li, Fangxing and Fang, Xin and Cui, Hantao and She, Buxin and Shuai, Hang and Zhang, Qiwei and Tomsovic, Kevin}, journal = {IEEE Transactions on Sustainable Energy}, title = {Dynamics-incorporated Modeling Framework for Stability Constrained Scheduling Under High-penetration of Renewable Energy}, year = {2025}, volume = {}, number = {}, pages = {1-13}, doi = {10.1109/TSTE.2025.3528027}, } - Safe Reinforcement Learning for Grid-Forming Inverter Based Frequency Regulation with Stability GuaranteeJournal of Modern Power Systems and Clean Energy, 2025
This letter investigates a safe reinforcement learning strategy for grid-forming (GFM) inverter based frequency regulation. To guarantee stability of the inverter based resource (IBR) system under the learned control policy, a model based reinforcement learning (MBRL) technique is combined with Lyapunov approach which determines safe region of states and actions. To obtain near optimal control strategy, the control performance is safely improved by approximate dynamic programming (ADP) using data sampled from the region of attraction (ROA). Moreover, to enhance the control robustness against parameter uncertainty in the inverter, a Gaussian process (GP) model is adopted by the proposed MBRL to effectively learn system dynamics from measurements. Numerical simulations validate the effectiveness of the proposed method.
@article{10495852, author = {Shuai, Hang and She, Buxin and Wang, Jinning and Li, Fangxing}, journal = {Journal of Modern Power Systems and Clean Energy}, title = {Safe Reinforcement Learning for Grid-Forming Inverter Based Frequency Regulation with Stability Guarantee}, year = {2025}, volume = {13}, number = {1}, pages = {79-86}, doi = {10.35833/MPCE.2023.000882}, issn = {2196-5420}, }
2024
- Modeling and Validating System Dynamics in Saudi Synthetic Electric GridMishal Alonize, Jinning Wang, Zackery Malkmus, and 1 more authorIn 2024 56th North American Power Symposium (NAPS), Oct 2024
This paper introduces a modeling approach for creating a synthetic Saudi power grid, designed to simulate the transient dynamics of a real power grid. This synthetic grid model, created from open-source data, is available for open sharing and can be utilized for educational, and research purposes. The cases are built to match a detailed model of Saudi power system elements, Saudi code requirements, and statistical characteristics found in actual power grids. First, we describe how we built, tested, tuned, and validated this synthetic Saudi grid model by using statistics from currently available data. The CURENT Large-scale Testbed (LTB) and its ANDES package enabled power flow calculations, simulations of transient stability, and analysis of small-signal stability in transmission systems. Second, we describe our use of the ANDES package for dynamic simulation and testing, and our use of the LTB’s AGVis package for grid visualization. This Saudi synthetic grid model has 223 buses that have been tested, tuned and validated to ensure that they are realistic and are practical for various studies. Also, it greatly enhances the diversity of existing collections of synthetic grids in the current literature.
@inproceedings{10741657, author = {Alonize, Mishal and Wang, Jinning and Malkmus, Zackery and Li, Fangxing Fran}, booktitle = {2024 56th North American Power Symposium (NAPS)}, title = {Modeling and Validating System Dynamics in Saudi Synthetic Electric Grid}, year = {2024}, volume = {}, number = {}, pages = {1-6}, doi = {10.1109/NAPS61145.2024.10741657}, issn = {2833-003X}, month = oct, } - Virtual Inertia Scheduling (VIS) for Microgrids with Static and Dynamic Security ConstraintsIEEE Transactions on Sustainable Energy, 2024
Microgrids feature a high penetration of inverter-interfaced distributed energy resources (DERs). The low inertia characteristic and fast dynamics of DERs pose challenges to conventional decoupled static economic operation and dynamic control design within microgrids. Hence, this paper proposed virtual inertia scheduling (VIS) for microgrids, aiming to ensure both economy and security. First, a unified framework for device-level control and grid-level operation is introduced, with VIS serving as a key application to address low inertia issues. VIS actively harnesses the controllability and flexibility of DERs to effectively manage microgrid inertia. It updates the conventional economic operation framework by incorporating the virtual inertia/damping cost, transient performance constraints, and stability constraints. Control parameters for DERs are formulated as additional decision variables. Then, VIS is specified in microgrids, followed by explication and linearization of dynamic constraints. An efficient workflow is developed to facilitate the integration of data-driven methods into microgrid-VIS, involving data generation, cleaning, and labeling to alleviate computational burdens. Time-domain simulations are further integrated for correction, validation, and performance guarantee. Finally, VIS is verified in an islanded microgrid modified from the IEEE 123-bus system. Results demonstrate that VIS effectively addresses the low inertia challenges in DER-penetrated microgrids, balancing economic considerations and dynamic performance.
@article{10729702, author = {She, Buxin and Li, Fangxing and Wang, Jinning and Cui, Hantao and Wang, Xiaofei and Bo, Rui}, journal = {IEEE Transactions on Sustainable Energy}, title = {Virtual Inertia Scheduling (VIS) for Microgrids with Static and Dynamic Security Constraints}, year = {2024}, volume = {}, number = {}, pages = {1-12}, doi = {10.1109/TSTE.2024.3481239}, issn = {1949-3037}, month = {}, } - Time-Delay Correction Control Strategy for HVDC Frequency Regulation ServicesYuqing Dong, Kaiqi Sun, Jinning Wang, and 4 more authorsCSEE Journal of Power and Energy Systems, 2024
With the advancements in voltage source converter (VSC) technology, VSC based high voltage direct current (VSC-HVDC) systems provide system operators with a prospective approach to enhance system operating stability and resilience. In addition to long-distance transmission, the VSC-HVDC system can also provide multiple ancillary services, such as frequency regulation, due to its power controllability. However, if a time delay exists in the control signal, the VSC-HVDC system may bring destabilizing influences to the system, which will decrease the system resilience under the disturbance. In order to reduce control deviation caused by time delay, in this paper, a small signal model is first conducted to analyze the impact of time delay on system stability. Then a time-delay correction control strategy for HVDC frequency regulation control is developed to reduce the influence of the time delay. The control performance of the proposed time-delay correction control is verified both in the established small signal model and the runtime simulation in a modified IEEE 39 bus system. The results indicate that the proposed time-delay correction control strategy shows significant improvement in system stability.
@article{9770530, author = {Dong, Yuqing and Sun, Kaiqi and Wang, Jinning and Wang, Shunliang and Huang, He and Liu, Tianqi and Liu, Yilu}, journal = {CSEE Journal of Power and Energy Systems}, title = {Time-Delay Correction Control Strategy for HVDC Frequency Regulation Services}, year = {2024}, volume = {10}, number = {5}, pages = {2027-2037}, doi = {10.17775/CSEEJPES.2021.02770}, } - Electric Vehicles Charging Time Constrained Deliverable Provision of Secondary Frequency RegulationIEEE Transactions on Smart Grid, 2024
Aggregation of electric vehicles (EVs) is a promising technique for providing secondary frequency regulation (SFR) in highly renewable energy-penetrated power systems. Equipped with energy storage devices, EV aggregation can provide reliable SFR. However, the main challenge is to guarantee reliable intra-interval SFR capacities and inter-interval delivery following the automatic generation control (AGC) signal. Furthermore, aggregated EV SFR provision will be further complicated by the EV charging time anxiety because SFR provision might extend EV’s charging time. This paper proposes a deliverable EV SFR provision with a charging-time-constrained control strategy. First, a charging-time-constrained EV aggregation is proposed to address the uncertainty of EV capacity based on the state-space model considering the charging-time restriction of EV owners. Second, a real-time economic dispatch and time domain simulation (RTED-TDS) cosimulation framework is proposed to verify financial results and the dynamic performance of the EV SFR provision. Last, the proposed charging time-constrained EV aggregation is validated on the IEEE 39-bus system. The results demonstrate that with charging time-constrained EV aggregation, the dynamic performance of the system can be improved with a marginal increase in total cost. More importantly, the charging time constraint can be respected in the proposed SFR provision of the EV aggregation.
@article{10411057, title = {Electric Vehicles Charging Time Constrained Deliverable Provision of Secondary Frequency Regulation}, issn = {1949-3053, 1949-3061}, url = {https://ieeexplore.ieee.org/document/10411057/}, doi = {10.1109/TSG.2024.3356948}, urldate = {2024-01-23}, journal = {IEEE Transactions on Smart Grid}, author = {Wang, Jinning and Li, Fangxing and Fang, Xin and Wang, Wenbo and Cui, Hantao and Zhang, Qiwei and She, Buxin}, year = {2024}, volume = {15}, number = {4}, pages = {3892-3903}, } - Distributed cooperation optimization of multi-microgrids under grid tariff uncertainty: A nash bargaining game approach with cheating behaviorsJianan Du, Xiaoqing Han, and Jinning WangInternational Journal of Electrical Power & Energy Systems, Jan 2024
Multi-microgrid system (MMGs) has drawn extensive attention recently because of its high energy efficiency. However, MMGs’ operational efficiency can be affected by market price fluctuations and intermittent renewable energy. This paper proposes an energy-sharing model based on the Nash bargaining game between multi-microgrids. The proposed model provides a robust energy trading schedule to deal with uncertainties brought by grid tariffs and renewable energy. To ensure the model is tractable, the original game problem is equivalently converted into a system benefit maximization subproblem and an additional profit distribution subproblem to get optimal energy sharing power and prices. In addition, microgrid has the motivation to cheat for maximizing its benefits which may lead to the breakdown of cooperation. Furthermore, cheating behaviors in energy transaction are analyzed; the energy sharing scheme based on cheating equilibrium is derived by proposing an intermediary transaction mode. Finally, the alternating direction method of multipliers (ADMM) is used to protect the players’ privacies in a distributed way. Simulation results show that the proposed model can realize stable cooperation, effectively reduce operating costs and immunize against multiple uncertainties and cheating behaviors.
@article{S0142061523007019, title = {Distributed cooperation optimization of multi-microgrids under grid tariff uncertainty: A nash bargaining game approach with cheating behaviors}, volume = {155}, issn = {01420615}, shorttitle = {Distributed cooperation optimization of multi-microgrids under grid tariff uncertainty}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0142061523007019}, doi = {10.1016/j.ijepes.2023.109644}, language = {en}, urldate = {2024-01-23}, journal = {International Journal of Electrical Power \& Energy Systems}, author = {Du, Jianan and Han, Xiaoqing and Wang, Jinning}, month = jan, year = {2024}, pages = {109644}, } - Siting and Sizing of DG Units Considering Energy Equity: Model, Solution, and GuidelinesChenchen Li, Fangxing Li, Sufan Jiang, and 2 more authorsIEEE Transactions on Smart Grid, Jan 2024
Low-income communities have challenges obtaining equal access to electricity, so it is important to implement energy justice. Meanwhile, increasing installations of distributed generators (DGs) in distribution systems is a viable means to promote energy equity. Therefore, this work explores a new planning method for a DG units’ siting and sizing problem with an energy equity constraint embedded in the model, and concluding guidelines can be used as a rule of thumb for future DG planning considering energy equity. In this paper, first, the DG siting and sizing problem is formulated as a stochastic bi-level model, where energy equity is considered as an energy burden constraint. The upper level determines the optimal sites and sizes of DGs under investment and energy burden constraints, while the lower level optimizes the distribution operation. Next, a solution method is proposed by applying the Karush-Kuhn-Tucker optimality conditions to convert the stochastic bi-level model to a single-level model. A decomposition approach and Progressive Hedging Algorithm are used to further simplify the single-level model into multiple easy-to-solve subproblems. Finally, numerical studies are performed on two systems to verify the effectiveness of the proposed model. Technical rule-of-thumb guidelines are presented for siting and sizing DGs considering energy equity.
@article{10382640, title = {Siting and Sizing of DG Units Considering Energy Equity: Model, Solution, and Guidelines}, issn = {1949-3053, 1949-3061}, shorttitle = {Siting and {Sizing} of {DG} {Units} {Considering} {Energy} {Equity}}, url = {https://ieeexplore.ieee.org/document/10382640/}, doi = {10.1109/TSG.2024.3350914}, urldate = {2024-01-18}, journal = {IEEE Transactions on Smart Grid}, author = {Li, Chenchen and Li, Fangxing and Jiang, Sufan and Wang, Xiaofei and Wang, Jinning}, year = {2024}, volume = {15}, number = {4}, pages = {3681-3693}, } - Virtual Inertia Scheduling (VIS) for Real-Time Economic Dispatch of IBR-Penetrated Power SystemsIEEE Transactions on Sustainable Energy, Jan 2024
A new concept called virtual inertia scheduling (VIS) is proposed to efficiently handle the increasing penetration of inverter-based resources (IBRs) in power systems. VIS is an inertia management framework that targets security-constrained and economy-oriented inertia scheduling and generation dispatch with a large scale of renewable generations. Specifically, it determines the appropriate power setting points and reserved capacities of synchronous generators and IBRs, as well as the control modes and control parameters of IBRs to provide secure and cost-effective inertia support. First, a uniform system model is employed to quantify the frequency dynamics of the IBRs-penetrated power systems after disturbances. Leveraging this model, the s -domain and time-domain analytical responses of IBRs with inertia support capability are derived. Then, VIS-based real-time economic dispatch (VIS-RTED) is formulated to minimize generation and reserve costs, with full consideration of dynamic frequency constraints and derived inertia support reserve constraints. The virtual inertia and damping of IBRs are formulated as decision variables. A deep learning-assisted linearization approach is further employed to address the non-linearity of dynamic constraints. Finally, VIS-RTED is demonstrated on a two-machine system and a modified IEEE 39-bus system. A full-order time-domain simulation is performed to verify the scheduling results and ensure their feasibility.
@article{10264213, title = {Virtual Inertia Scheduling (VIS) for Real-Time Economic Dispatch of IBR-Penetrated Power Systems}, year = {2024}, volume = {15}, number = {2}, pages = {938-951}, issn = {1949-3029, 1949-3037}, url = {https://ieeexplore.ieee.org/document/10264213/}, doi = {10.1109/TSTE.2023.3319307}, urldate = {2023-10-20}, journal = {IEEE Transactions on Sustainable Energy}, author = {She, Buxin and Li, Fangxing and Cui, Hantao and Wang, Jinning and Zhang, Qiwei and Bo, Rui}, } - METHODS AND APPARATUS FOR CONTROLLING AN INVERTERDec 2024
In examples, provided are decentralized control methods and apparatus for controlling an output of an inverter. Also provided are decentralized control methods and apparatus for controlling demand in islanded microgrids operating with an insufficient distributed energy resource system (DER) power supply. The provided control methods and apparatus can include a power regulator and a voltage-frequency regulator configured to generate supplementary inputs to control the inverter. The power regulator can control an output of the inverter according to a real-time capacity constraint of the DER. The voltage-frequency regulator can control the output of the inverter in a manner that mitigates a voltage-frequency deviation, such as by leveraging load sensitivity.
@patent{20240421599, title = {METHODS AND APPARATUS FOR CONTROLLING AN INVERTER}, number = {20240421599}, author = {Li, Fangxing and She, Buxin and Wang, Jinning and Cui, Hantao and Bo, Rui}, year = {2024}, month = dec, }
2023
- DiME and AGVis: A Distributed Messaging Environment and Geographical Visualizer for Large-Scale Power System SimulationNicholas Parsly, Jinning Wang, Nick West, and 3 more authorsIn 2023 North American Power Symposium (NAPS), Oct 2023
This paper introduces the messaging environment and the geographical visualization tools of the CURENT Large-scale Testbed (LTB) that can be used for large-scale power system closed-loop simulation. First, Distributed Messaging Environment (DiME) is presented as an asynchronous shared workspace to enable high-concurrent data exchange. Second, Another Grid Visualizer (AGVis) is presented as a geovisualization tool that facilitates the visualization of real-time power system simulation. Third, case studies show the use of DiME and AGVis in power system research. The results demonstrate that, with the modular structure of DiME and AGVis, the LTB is capable of not only federal use for real-time, large-scale power system simulation, but also independent use for customized power system research.
@inproceedings{10318583, address = {Asheville, NC, USA}, title = {DiME and AGVis: A Distributed Messaging Environment and Geographical Visualizer for Large-Scale Power System Simulation}, isbn = {9798350315097}, shorttitle = {{DiME} and {AGVis}}, url = {https://ieeexplore.ieee.org/document/10318583/}, doi = {10.1109/NAPS58826.2023.10318583}, urldate = {2023-11-22}, booktitle = {2023 {North} {American} {Power} {Symposium} ({NAPS})}, publisher = {IEEE}, author = {Parsly, Nicholas and Wang, Jinning and West, Nick and Zhang, Qiwei and Cui, Hantao and Li, Fangxing}, month = oct, year = {2023}, pages = {1--5}, } - Disturbance Propagation in Power Grids With High Converter PenetrationHantao Cui, Stavros Konstantinopoulos, Denis Osipov, and 4 more authorsProceedings of the IEEE, Oct 2023
High penetration of converter-interfaced renewable energy resources will significantly change the swing dynamics between synchronous generators (SGs) in future power systems. This article examines the impact of high converter penetration on wave-like disturbance propagation arising from sudden generator and load losses in radial (1-D) and meshed (2-D) power systems. To keep the uniformity assumption as converters are introduced, the rating of each SG is decreased with a converter resource making up for the reduction. Numerical simulations demonstrate that as the penetration level of constant-power grid-following (GFL) converters increases, the speed of disturbance propagation increases due to the reduced system inertia. Naturally, converters with the capabilities to positively respond to disturbances would in turn reduce the propagation speed. Analytical studies based on continuum models are presented for the 2-D system with SGs and constant-power GFL converters in order to visualize the disturbance propagation and validate numerical simulations based on differential-algebraic equations. In addition, fast active power control of converters can slow down the electromechanical wave (EMW) propagation and even contain it. These concepts are illustrated on the idealized radial and meshed systems and a reduced model of the U.S. eastern interconnection.
@article{9777891, title = {Disturbance Propagation in Power Grids With High Converter Penetration}, issn = {0018-9219, 1558-2256}, url = {https://ieeexplore.ieee.org/document/9777891/}, doi = {10.1109/JPROC.2022.3173813}, urldate = {2022-05-25}, journal = {Proceedings of the IEEE}, author = {Cui, Hantao and Konstantinopoulos, Stavros and Osipov, Denis and Wang, Jinning and Li, Fangxing and Tomsovic, Kevin L. and Chow, Joe H.}, year = {2023}, volume = {111}, number = {7}, pages = {873-890}, } - Decentralized and Coordinated V-f Control for Islanded Microgrids Considering DER Inadequacy and Demand ControlIEEE Transactions on Energy Conversion, Sep 2023
This paper proposes a decentralized and coordinated voltage and frequency (V-f) control framework for islanded microgrids, with full consideration of the limited capacity of distributed energy resources (DERs) and V-f dependent load. First, the concept of DER inadequacy is illustrated with the challenges it poses. Then, a decentralized and coordinated control framework is proposed to regulate the output of inverter-based generations and reallocate limited DER capacity for V-f control. The control framework is composed of a power regulator and a V-f regulator, which generates the supplementary signals for the primary controller. The power regulator regulates the output of grid-forming inverters according to the real-time capacity constraints of DERs, while the V-f regulator improves the V-f deviation by leveraging the load sensitivity to V-f. Next, the static feasibility and small signal stability of the proposed method are rigorously proven through mathematical formulation and eigenvalue analysis. Finally, a MATLAB-Simulink simulation demonstrates the functionalities of the control framework. A few goals are fulfilled within the decentralized and coordinated framework, such as making the best use of limited DERs’ capacity, enhancing the DC side stability of inverter-based generations, and reducing involuntary load shedding.
@article{10078029, title = {Decentralized and Coordinated V-f Control for Islanded Microgrids Considering DER Inadequacy and Demand Control}, volume = {38}, issn = {0885-8969, 1558-0059}, url = {https://ieeexplore.ieee.org/document/10078029/}, doi = {10.1109/TEC.2023.3258919}, number = {3}, urldate = {2023-10-20}, journal = {IEEE Transactions on Energy Conversion}, author = {She, Buxin and Li, Fangxing and Cui, Hantao and Wang, Jinning and Min, Liang and Oboreh-Snapps, Oroghene and Bo, Rui}, month = sep, year = {2023}, pages = {1868--1880}, } - Profit-Oriented BESS Siting and Sizing in Deregulated Distribution SystemsXiaofei Wang, Fangxing Li, Qiwei Zhang, and 2 more authorsIEEE Transactions on Smart Grid, Sep 2023
Within the deregulation process of distribution systems, the distribution locational marginal price (DLMP) provides effective market signals for future unit investment. In that context, this paper proposes a two-stage stochastic bilevel programming (TS-SBP) model for investors to best allocate battery energy storage systems (BESSs). The first stage obtains the optimal siting and sizing of BESSs on a limited budget. The second stage, a bilevel BESS arbitrage model, maximizes the arbitrage revenue in the upper level and clears the distribution market in the lower level. Karush-Kuhn-Tucker (KKT) optimality conditions, strong duality theory, and the big-M method are utilized to transform the TS-SBP model into a tractable two-stage stochastic mixed-integer linear programming (TS-SMILP) model. A novel statistics-based scenario extraction algorithm is proposed to generate a series of typical operating scenarios. Then, scale reduction strategies for BESS candidate buses and inactive voltage constraints are proposed to reduce the scale of the TS-SMILP model. Finally, case studies on the IEEE 33-bus and 123-bus systems validate the effectiveness of the DLMP in incentivizing BESS planning and the efficiency of the two proposed scale reduction strategies.
@article{9711558, title = {Profit-Oriented BESS Siting and Sizing in Deregulated Distribution Systems}, issn = {1949-3053, 1949-3061}, url = {https://ieeexplore.ieee.org/document/9711558/}, doi = {10.1109/TSG.2022.3150768}, urldate = {2022-06-08}, journal = {IEEE Transactions on Smart Grid}, author = {Wang, Xiaofei and Li, Fangxing and Zhang, Qiwei and Shi, Qingxin and Wang, Jinning}, year = {2023}, volume = {14}, number = {2}, pages = {1528-1540}, } - Modeling A Notional Carbon-Free Power Grid with 24-hour Dispatch and Power FlowHongyu Li, Melanie Bennett, Jinning Wang, and 9 more authorsIn 2023 International Conference on Future Energy Solutions (FES), Sep 2023
This paper proposes methods of DC and AC power flow development and the battery configuration for a notional carbon-free power grid. Facing climate change, many governments are seeking carbon-free generation technologies, so there is a great need for carbon-free grid modeling. In this paper, a public synthetic ERCOT model is used as a base case. Also, the actual renewable generation and load profiles in a summer heavy load day from EIA are utilized in the modeling. First, all loads are scaled to project the actual EIA load profile. Second, all fossil-fuel generators in the base case are replaced by the combinations of renewables and batteries, while hydro and nuclear remain unchanged. Third, the PV and wind power are scaled according to the actual EIA generation profile, with the consideration of battery energy balance and reasonable PV/capacity ratio in the future. Finally, AC power flow results of the developed dispatches are obtained by PSS/E. Meanwhile, necessary battery capacity and initial SoC are estimated based on the dispatches. Even though achieving carbon-free power grid is very challenging, the developed cases in this paper can provide insights for the related research. Also, the methods to develop dispatches and conFigure batteries can benefit the researchers who need to build the carbon-free model in a different grid.
@inproceedings{10183308, author = {Li, Hongyu and Bennett, Melanie and Wang, Jinning and Okhuegbe, Samuel N. and Ademola, Adedasola A. and Alshuaibi, Khaled M. and Chen, Chang and Jia, Xinlan and Lin, Min and Albukhari, Waleed M. and Dong, Yuqing and Liu, Yilu}, booktitle = {2023 International Conference on Future Energy Solutions (FES)}, title = {Modeling A Notional Carbon-Free Power Grid with 24-hour Dispatch and Power Flow}, year = {2023}, volume = {}, number = {}, pages = {1-5}, doi = {10.1109/FES57669.2023.10183308}, }
2022
- Transmission-Distribution Dynamic Co-simulation of Electric Vehicles Providing Grid Frequency ResponseYijing Liu, Thomas J. Overbye, Wenbo Wang, and 4 more authorsIn 2022 IEEE Power & Energy Society General Meeting (PESGM), Jul 2022
This paper investigates the impacts of electric vehicles (EVs) on power system frequency regulation based on an open-source transmission-and-distribution (T&D) dynamic cosimulation framework. The development of an EV dynamic model based on an Western Electricity Coordinating Council dynamic model is introduced first, then the T&D dynamic co-simulation platform is described. The advantage of the overall platform is that distributed energy resources, such as distributed photovoltaics and EVs, are modeled explicitly in both transmission and distribution simulators for frequency and voltage dynamics, respectively. The case studies simulate the frequency responses (i.e., primary and/or secondary) of the EVs after the system is exposed to an N-1 contingency, such as a generation trip. Various EV frequency regulation participation strategies are also investigated to study their impacts on system frequency response. The studies shows that EVs have the potential capability to provide effective frequency regulation services.
@inproceedings{9917027, address = {Denver, CO, USA}, title = {Transmission-Distribution Dynamic Co-simulation of Electric Vehicles Providing Grid Frequency Response}, isbn = {978-1-66540-823-3}, url = {https://ieeexplore.ieee.org/document/9917027/}, doi = {10.1109/PESGM48719.2022.9917027}, language = {en}, urldate = {2023-01-09}, booktitle = {2022 {IEEE} {Power} \& {Energy} {Society} {General} {Meeting} ({PESGM})}, publisher = {IEEE}, author = {Liu, Yijing and Overbye, Thomas J. and Wang, Wenbo and Fang, Xin and Wang, Jinning and Cui, Hantao and Li, Fangxing}, month = jul, year = {2022}, pages = {1--5}, } - Cyber-Physical Dynamic System (CPDS) Modeling for Frequency Regulation and AGC Services of Distributed Energy ResourcesAug 2022
The substantial integration of renewable energy brings significant challenges to balance the system in real time because of the variability and intermittency of renewable power. For the reliable system operation, the frequency regulation service is used to stabilize the system frequency through automatically balancing the system generation and load. On one hand, with the substantially increasing deployment of renewable energy in electricity system, the requirement of frequency regulation (FR) services increases significantly. On the other hand, the current main resource of FR services, the controllable conventional generation, is continuously decreasing in the system generation mix. This means that in the future high renewable penetration power system, additional and alternative reliable FR services providers such as distributed energy storage (DES) resources should be explored. Although the capability of utility-scale energy storage to provide FR services has been demonstrated, the integrated control and dynamic modeling of distributed energy resource (DER) providing frequency regulation grid services has been rarely explored. There are several challenges to adopt DERs to provide reliable grid services as illustrated in FERC 755. First, the distributed installation of DES requires a comprehensive cyber-physical dynamic system (CPDS) modeling to fully consider the impacts of the communication latency variability on its real time FR provision capability. Unlike the conventional generators, there are two-layer communication between DERs and system operators which increase the communication delay. Second, unlike the conventional generators whose dynamic models have been comprehensively studied, the difference among individual DER components’ power-dynamic characteristic brings challenges in the accurate dynamic AGC modeling of its power-frequency relationship. Third, the temporal dependent state of charge uncertainty of DERs challenges DERs’ power and frequency regulation capacities scheduling in the look-ahead generation scheduling. Therefore, the aggregator should optimize the frequency regulation provision from individual DER in real time. To overcome these challenges, this project proposes a cyber-physical dynamic system (CPDS) model to handle the uncertainty of DERs two-layer communication latency and power dynamics. The variability of DERs’ communication delay and dynamic constraints will be comprehensively modeled. The DERs’ AGC model with communication delay is designed to validate DESs’ frequency regulation services. Like current performance-based frequency regulation evaluation, the delivery of DERs’ frequency regulation will be assessed through post-analysis of the actual AGC response with respect to the AGC control signal from system operators. Consequently, the reliability improvement with DERs providing reliable frequency regulation services can be evaluated from a comprehensive perspective considering all the dynamics of communication and power.
@techreport{1882191, title = {Cyber-Physical Dynamic System (CPDS) Modeling for Frequency Regulation and AGC Services of Distributed Energy Resources}, url = {https://www.osti.gov/servlets/purl/1882191/}, language = {en}, number = {NREL/TP-6A40-82644, 1882191, MainId:83417}, urldate = {2023-01-09}, author = {Wang, Wenbo and Fang, Xin and Cui, Hantao and Wang, Jinning and Li, Fangxing and Liu, Yijing and Overbye, Thomas and Cai, Mengmeng and Irwin, Chris}, month = aug, year = {2022}, doi = {10.2172/1882191}, pages = {NREL/TP--6A40--82644, 1882191, MainId:83417}, } - Electricity consumption variation versus economic structure during COVID-19 on metropolitan statistical areas in the USNature Communications, Nov 2022
The outbreak of novel coronavirus disease (COVID-19) has resulted in changes in productivity and daily life patterns, and as a result electricity consumption (EC) has also shifted. In this paper, we construct estimates of EC changes at the metropolitan level across the continental U.S., including total EC and residential EC during the initial two months of the pandemic. The total and residential data on the state level were broken down into the county level, and then metropolitan level EC estimates were aggregated from the counties included in each metropolitan statistical area (MSA). This work shows that the reduction in total EC is related to the shares of certain industries in an MSA, whereas regardless of the incidence level or economic structure, the residential sector shows a trend of increasing EC across the continental U.S. Since the MSAs account for 86% of the total population and 87% of the total EC of the continental U.S., the analytical result in this paper can provide important guidelines for future social-economic crises.
@article{wang_electricity_2022, title = {Electricity consumption variation versus economic structure during COVID-19 on metropolitan statistical areas in the US}, volume = {13}, issn = {2041-1723}, url = {https://www.nature.com/articles/s41467-022-34447-7}, doi = {10.1038/s41467-022-34447-7}, language = {en}, number = {1}, urldate = {2023-01-09}, journal = {Nature Communications}, author = {Wang, Jinning and Li, Fangxing and Cui, Hantao and Shi, Qingxin and Mingee, Trey}, month = nov, year = {2022}, pages = {7122}, }
2021
- Impacts of VSG Control on Frequency Response in Power Systems with High-Penetration RenewablesIn 2021 IEEE 5th Conference on Energy Internet and Energy System Integration (EI2), Oct 2021
With the increase of renewable energy into power systems, the system inertia continuously decreases, which poses challenges to the existing frequency regulating strategy. To improve system frequency response in the low-inertia system, Virtual Synchronous Generator (VSG) has been proposed in the literature. This paper investigates the VSG frequency response model and verifies the implementation at large scale. First, the frequency response model of VSC is investigated. In addition, the frequency response performance of the conventional synchronous generator (SG), the renewable power plant, and the renewable power plant with VSG are compared under different penetration levels of renewable energy. The simulation results show the capability of the CURENT Large-scale Testbed (LTB) for real-world, large-scale power system simulation in future scenarios and indicate that VSG-configured renewable power plants can provide the power grid with adequate frequency regulation ability under high renewable energy penetration.
@inproceedings{9712880, address = {Taiyuan, China}, title = {Impacts of VSG Control on Frequency Response in Power Systems with High-Penetration Renewables}, isbn = {978-1-66543-425-6}, url = {https://ieeexplore.ieee.org/document/9712880/}, doi = {10.1109/EI252483.2021.9712880}, urldate = {2023-10-30}, booktitle = {2021 {IEEE} 5th {Conference} on {Energy} {Internet} and {Energy} {System} {Integration} ({EI2})}, publisher = {IEEE}, author = {Wang, Jinning and Li, Fangxing and Cui, Hantao and Zhang, Qiwei}, month = oct, year = {2021}, pages = {171--176}, }
2020
- 基于谐波状态空间建模的变换器交直流谐波耦合特性分析 Analysis on AC/DC Harmonic Coupling Characteristics of Converter Based on Harmonic State Space ModelingJinning Wang, Lei Wang, Xiaoqing Han, and 2 more authors电力系统自动化 Automation of Electric Power Systems, Oct 2020
基于谐波状态空间(HSS)理论对变换器进行建模，深入分析了变换器交直流谐波耦合特性。 首先，通过数学推导，采用HSS理论对三相AC/DC变换器拓扑进行建模。HSS模型将交直流侧的各次 谐波包括在内，反映了各频次谐波变量的作用关系。其次，通过该模型推导变换器的谐波传递函数，建立耦合阻抗图，分析交直流谐波翘合特性。该模型根据微电网中常用的电压源型三相AC/DC变换器建 立，给出了变换器交直流谐波耦合阻抗的全局关系，可探究变换器两侧各个频次的谐波特性，并用于变换器并联、级联等结构的谐波分析。最后，在PLECS平台中搭建电压源型三相AC/DC变换器模型，与HS S模型计算结果进行对比，并通过实验验证了所提模型与谐波耦合特性分析的准确性。 A model of the AC/DC converter based on the harmonic state space (HSS) theory is developed, and the AC/DC harmonic coupling characteristics of the converter have been analyzed in depth. Firstly, through the mathematical derivation, the three-phase AC/DC converter is modeled based on the HSS theory. The HSS model includes each harmonic on the AC and DC sides, which reflects the relationship between the harmonic variables of each frequency. Secondly, the harmonic transfer function of the converter is deduced by the model, and the diagram of harmonic coupling impedance is established to analyze the AC/DC harmonic coupling characteristics. The model is built according to the voltage source three-phase AC/DC converter which is commonly used in microgrids. The full range of coupling characteristics between AC and DC side is illustrated, and can be used to explore the harmonic characteristics at all frequencies, and can also be applied in harmonic analysis of converter with parallel and cascaded structures. Finally, the simulation of the voltage source three-phase AC/DC converter is performed in PLECS, and it is compared with the HSS calculation results to verify the proposed model and the study of harmonic coupling characteristics.Furthermore, the proposed model and the conclusion of harmonic coupling characteristics are verified by experiments.
@article{wang2020analysis, title = {基于谐波状态空间建模的变换器交直流谐波耦合特性分析 Analysis on AC/DC Harmonic Coupling Characteristics of Converter Based on Harmonic State Space Modeling}, author = {Wang, Jinning and Wang, Lei and Han, Xiaoqing and Meng, Runquan and Guo, Haixia}, journal = {电力系统自动化 Automation of Electric Power Systems}, volume = {44}, number = {4}, pages = {159--167}, year = {2020}, doi = {10.7500/AEPS20190409002}, } - 采用一致性算法的自治微电网群分布式储能优化控制策略 Optimization Control Strategy of Distributed Energy Storage in Autonomous Microgrid Cluster on Consensus AlgorithmBuyun Zhang, Jinning Wang, Dingkang Liang, and 1 more author电网技术 Power System Technology, Oct 2020
针对多个自治微电网互联合作运行时，由于分布式电池储能的充放电损耗与线路损耗，所造成的系统高运行成本问题，提出了一种以经济性为目标的分布式储能控制策略。该方法通过构建考虑 线路损耗的电池储能运行成本模型，采用一致性算法进行迭代求解，以优化各储能单元间输出功率的经济分配。所提一致性控制策略仅需与相邻节点进行信息交互，无需装置中央控制器，通信拓扑灵活简 单，可靠性高。在实时数字仿真仪RTDS中搭建了 4 个自治微电网形成的微电网群模型，利用不同场景下仿真结果验证了所提控制策略的有效性和经济性。 Aiming at the problem of high operating cost caused by the charging/discharging loss of distributed battery energy storage and the transmission loss, this paper proposes a distributed energy storage control strategy concerning the economic purpose in the microgrid cluster. In this method, the operating cost model of the battery energy storage system is constructed with the transmission losses. This operating cost model obtain the solution with the consensus algorithm in order to optimize the proper power allocation between the battery energy storage systems. The proposed strategy utilizes a distributed controller to exchange information between the neighboring agents, which obtains fast response, flexible communication network and high robustness. An microgrid cluster model is built with four autonomous microgrids in the real-time digital simulator RTDS. The effectiveness and economics of the proposed control strategy were verified under the different simulation scenarios.
@article{zhang2020optimization, title = {采用一致性算法的自治微电网群分布式储能优化控制策略 Optimization Control Strategy of Distributed Energy Storage in Autonomous Microgrid Cluster on Consensus Algorithm}, author = {Zhang, Buyun and Wang, Jinning and Liang, Dingkang and Han, Xiaoqing}, journal = {电网技术 Power System Technology}, volume = {44}, number = {5}, pages = {1705--1713}, year = {2020}, doi = {10.13335/j.1000-3673.pst.2019.1968}, } - 基于谐波状态空间建模的AC/DC变换器交直流谐波耦合特性分析 Analysis on AC/DC Harmonic Coupling Characteristics of Converter Based on Harmonic State Space ModelingJinning WangTaiyuan University of Technology, Oct 2020
随着分布式能源、微电网、以及电动汽车的大量应用，电力电子变换器在电力系统中的渗透率不断提高，对电网的电能质量以及稳定性提出了新的挑战。变换器通过开关网络将交直流网 络连接在一起，使得两侧的交直流谐波发生耦合，进而导致变换器两侧的电压电流波动相互影响、恶化电能质量。然而，变换器运行时具有非线性特性的特性，这给两侧的谐波交互特性分析带来了 挑战。因此，对变换器建立精确的谐波传输模型，准确分析其谐波交互特性显得尤为关键。本文针对微电网中常用的三相 AC/DC 变换器，采用谐波状态空间理论进行建模，提出了基于谐波耦合阻抗 的交直流谐波分析方法，分析了变换器在两种工作模式下交直流两侧的谐波作用规律，对于微电网的电能质量问题研究具有重要价值。首先，从传统的 AC/DC 变换器建模方法出发，建立了变换 器 dq 域模型，设计了变换器在不同工作模式下的控制策略。从变换器的 dq 域模型建模机理上分析了该模型在交直流谐波交互分析中的局限性，阐明了本文采用谐波状态空间建模方法的必要性。 其次，重点研究了谐波状态空间理论的建模过程，在变换器小信号模型的基础上，通过数学推导建立了 AC/DC 变换器的谐波状态空间模型。谐波状态空间模型将变换器交直流侧的各次谐波包括在 内，反映了各频次谐波变量的作用关系。根据所建模型，设计了相应的计算程序，实现了在频域内对变换器交直流谐波耦合扰动的计算。然后，提出了基于变换器交直流耦合阻抗的谐波特性分析方法。 通过 AC/DC 变换器的谐波状态空间模型，计算了变换器系统的谐波传递函数。利用该函数建立变换器的交直流谐波耦合阻抗，对变换器的交直流谐波耦合特性进行分析。分析表明，变换器交直流耦 合现象会改变谐波的频次，而且在不同的工作模式下其谐波耦合特性也会发生改变。在变换器中，不仅存在交直流侧的谐波耦合，也存在同侧的电压与电流的跨频次的耦合现象。变换器工作在逆变模 式时直流侧的低频波动影响更为严重，而整流模式下交流侧的正序畸变导致的谐波含量更高。最后，搭建了三相并网 AC/DC 变换器实验平台，通过硬件实验完成了变换器谐波状态空间建模以及变 换器谐波耦合特性分析的验证。实验结果表明，本文建立的谐波状态空间模型以及对于谐波耦合特性分析的结论基本准确，能够有效地反映出变换器交直流侧谐波耦合的内在作用规律。 With the widespread application of distributed energy sources,microgrids,and electric vehicles,the penetration of power electronic converters in power systems continues to increase,which poses new challenges to the power quality and stability of power grids.The converter connects the AC and DC networks together through a switching network,so that the AC and DC harmonics on both sides are coupled,which in turn causes the voltage and current fluctuations on both sides of the converter to affect each other and deteriorate the power quality.However,the converter has nonlinear characteristics during operation,which brings challenges to the analysis of harmonic interaction characteristics on both sides.Therefore,it is especially critical to establish an accurate harmonic transmission model for the converter and accurately analyze its harmonic interaction characteristics.In this paper,for the three-phase AC/DC converters commonly used in microgrids,the harmonic state space theory is used for modeling, an analysis method of AC and DC harmonics based on harmonic coupling impedance is proposed,and the AC and DC harmonic funtional rules of the converter in two working modes are analyzed.This research is of great value on power quality issues.First,starting from the onventional AC/DC converter modeling method,the dq domain model of the converter is established,and the control strategy of the converter in different working modes is designed.The limitations of the dqdomain modeling used for the interactive analysis of AC and DC harmonics are analyzed,and the necessity of adopting the harmonic state space modeling method in this paper is clarified.Secondly,it focuses on the modeling precedures of harmonic state space theory.Based on the small signal model of the converter,the harmonic state space model of the AC/DC converter is established through mathematical derivation.The harmonic state space model includes the harmonics of the AC and DC sides of the converter,and reflects the function relationship of the harmonic variables of each frequency.According to the propoed model,the corresponding calculation program is designed to realize the calculation of the AC/DC harmonic coupling disturbance of the converter in the frequency domain.Then,a harmonic characteristic analysis method based on the AC-DC coupling impedance of the converter is proposed.Through the harmonic state space model of the AC/DC converter,the harmonic transfer function of the converter system is calculated.The converter harmonic coupling resistance is estalished,and the AC-DC harmonic coupling characteristics of the converter are analyzed.The analysis shows that the AC-DC coupling phenomenon of the converter will change the frequency of harmonics,and its harmonic coupling characteristics will also change under different working modes.In the converter,not only there is harmonic coupling on the AC and DC sides,but also there is a cross-frequency coupling phenomenon of voltage and current on the same side.When the converter works in invert mode,the low-frequency fluctuation of the DC side is more serious.In contrast,working in convert mode the harmonic caused by the positive sequence distortion on the AC side is higher.Finally,a three-phase grid-connected AC/DC converter experimental platform was built,and the hardware harmonic experiment space modelling and converter harmonic coupling characteristics analysis verification were completed.The experimental results show that the harmonic state space model established in this paper and the conclusions on the analysis of the harmonic coupling characteristics are basically accurate,and can effectively reflect the internal action law of the harmonic coupling of the AC and DC sides of the converter.
@mastersthesis{wang2020analysit, title = {基于谐波状态空间建模的AC/DC变换器交直流谐波耦合特性分析 Analysis on AC/DC Harmonic Coupling Characteristics of Converter Based on Harmonic State Space Modeling}, author = {Wang, Jinning}, year = {2020}, school = {Taiyuan University of Technology}, doi = {10.27352/d.cnki.gylgu.2020.000136}, }