For the implementation of power market in China,medium-and Iong-term security checks are essential for bilateral transactions,of which the electricity quantity that constitutes the generation feasible region(GFR)is th...For the implementation of power market in China,medium-and Iong-term security checks are essential for bilateral transactions,of which the electricity quantity that constitutes the generation feasible region(GFR)is the target.However,uncertainties from load forecasting errors and transmission contingencies are threats to medium-and Iong-term electricity tradi ng in terms of their in flue nces on the GFR.In this paper,we prese nt a graphic distortio n pattern in a typical threegenerator system using the Monte Carlo method and projection theory based on security constrained economic dispatch.The underlying potential risk to GFR from uncertainties is clearly visualized,and their impact characteristics are discussed.A case study on detailed GFR distortion was included to dem on strate the effectiveness of this visualization model.The result implies that a small uncertainty could distort the GFR to a remarkable extent and that different line-contingency precipitates disparate the GFR distortion patterns,thereby eliciting great emphasis on load forecasting and line reliability in electricity transacti ons.展开更多
The National Electricity Market(NEM)in Australia was suspended during June 15-23,2022,with a primary attribution to the lack of available generation capacity.This incident is noteworthy because it was the first market...The National Electricity Market(NEM)in Australia was suspended during June 15-23,2022,with a primary attribution to the lack of available generation capacity.This incident is noteworthy because it was the first market suspension in NEM’s history and took place in a major energy exporting country.In this letter,we review the outline and impacts of the incident.From the perspectives of market regulation,electricity supply,and electricity demand,we identify three underlying causes of the market suspension and offer four recommendations for the market mechanism evolution to ensure power supply security.展开更多
Multi-energy integrations provide great opportunities for economic and efficient resource utilization. In the meantime, power system operation requires enough flexible resources to deal with contingencies such as tran...Multi-energy integrations provide great opportunities for economic and efficient resource utilization. In the meantime, power system operation requires enough flexible resources to deal with contingencies such as transmission line tripping. Besides economic benefits, this paper focuses on the security benefits that can be provided by multi-energy integrations. This paper first proposes an operation scheme to coordinate multiple energy production and local system consumption considering transmission networks. The integrated flexibility model, constructed by the feasible region of integrated demand response(IDR), is then formulated to aggregate and describe local flexibility. Combined with system security constraints, a multi-energy system operation model is formulated to schedule multiple energy production, transmission, and consumption. The effects of local system flexibility on alleviating power flow violations during N-1 line tripping contingencies are then analyzed through a multi-energy system case. The results show that local system flexibility can not only reduce the system operation costs, but also reduce the probability of power flow congestion or violations by approximately 68.8% during N-1 line tripping contingencies.展开更多
To incorporate the operating constraints of a virtual power plant(VPP)in transmission-level operation and market clearing,the concept of the VPP capability curve(VPP-CC)is proposed which explicitly characterizes the a...To incorporate the operating constraints of a virtual power plant(VPP)in transmission-level operation and market clearing,the concept of the VPP capability curve(VPP-CC)is proposed which explicitly characterizes the allowable range of active and reactive power outputs of a VPP.A two-step projection-based calculation framework is proposed to approximate the VPP-CC by the convex hull of critical points on its perimeter.The output of the proposed algorithm is concise and can be easily incorporated in the existing system operation and market clearing.Case studies based on the IEEE 33 and 123 test feeders show the computational efficiency of the proposed method outperforms existing methods by 4~7 times.Additionally,many fewer inequalities are needed to depict the VPP-CC while achieving the comparative approximation accuracy compared to sampling-based methods,which will relieve the communication and computation burden.展开更多
The Texas electric power crisis that occurred in February 2021 has drawn great attention internationally due to its severity and for not having been foreseen.In this rapid communication,we classify the 2021 Texas elec...The Texas electric power crisis that occurred in February 2021 has drawn great attention internationally due to its severity and for not having been foreseen.In this rapid communication,we classify the 2021 Texas electric power crisis as an energy insufficiency-caused power crisis,which alerts of a new blackout mechanism.Different from capacity insufficiencycaused power crises in the past,the Texas electric power crisis of 2021 directly resulted from the long-duration extreme cold weather as well as fundamentally from the insufficiency of sustainable supply capability of energy.We begin this paper with a brief retrospect of the event and its consequences.Definitions of energy/capacity insufficiency-caused power crises are given,as well as an overview of the supply and demand during the event,based on realistic operation data.Quantitative simulations are then conducted to reveal the underlying reasons for the power crisis and reveal how to better prepare for the future.Finally,several insights and suggestions on handling the new mode of blackout in the future are proposed and discussed.展开更多
As COVID-19 sweeps through the whole world,human activities have been changed significantly.Under such circumstances,the electricity sector is deeply affected and faced with great challenges.This paper provides a comp...As COVID-19 sweeps through the whole world,human activities have been changed significantly.Under such circumstances,the electricity sector is deeply affected and faced with great challenges.This paper provides a comprehensive review of the impacts that the pandemic has caused on the electricity sector.Electricity demand has dropped sharply as governments around the world executed lockdown restrictions,while the load composition and daily load profile have also changed.The share of renewable generation has increased against the decline of the total electricity generation.Changed power balance situation and increased uncertainty of demand have posed higher pressure on system operators,along with voltage violation issue and challenges for system maintenance and management.The electricity market is also substantially influenced,while longterm investment in clean energy is expected to be stable.The externality such as emission reduction is also discussed.展开更多
基金the National Key R&D Program of China under Grant No.2020YFB0905900in part by the State Grid Corporation of China project“Research on inter-provincial price coupling mechanism of national unified electricity spot market”.
文摘For the implementation of power market in China,medium-and Iong-term security checks are essential for bilateral transactions,of which the electricity quantity that constitutes the generation feasible region(GFR)is the target.However,uncertainties from load forecasting errors and transmission contingencies are threats to medium-and Iong-term electricity tradi ng in terms of their in flue nces on the GFR.In this paper,we prese nt a graphic distortio n pattern in a typical threegenerator system using the Monte Carlo method and projection theory based on security constrained economic dispatch.The underlying potential risk to GFR from uncertainties is clearly visualized,and their impact characteristics are discussed.A case study on detailed GFR distortion was included to dem on strate the effectiveness of this visualization model.The result implies that a small uncertainty could distort the GFR to a remarkable extent and that different line-contingency precipitates disparate the GFR distortion patterns,thereby eliciting great emphasis on load forecasting and line reliability in electricity transacti ons.
基金supported by the National Natural Science Foundation of China (No.U2166201)China Postdoctoral Science Foundation (No.2022TQ0206)。
文摘The National Electricity Market(NEM)in Australia was suspended during June 15-23,2022,with a primary attribution to the lack of available generation capacity.This incident is noteworthy because it was the first market suspension in NEM’s history and took place in a major energy exporting country.In this letter,we review the outline and impacts of the incident.From the perspectives of market regulation,electricity supply,and electricity demand,we identify three underlying causes of the market suspension and offer four recommendations for the market mechanism evolution to ensure power supply security.
基金supported by State Grid Corporation of China “Research on Multi-energy System Energy Conversion Simulation and Energy Efficiency Evaluation”(No.SGTYHT/18-JS-206)。
文摘Multi-energy integrations provide great opportunities for economic and efficient resource utilization. In the meantime, power system operation requires enough flexible resources to deal with contingencies such as transmission line tripping. Besides economic benefits, this paper focuses on the security benefits that can be provided by multi-energy integrations. This paper first proposes an operation scheme to coordinate multiple energy production and local system consumption considering transmission networks. The integrated flexibility model, constructed by the feasible region of integrated demand response(IDR), is then formulated to aggregate and describe local flexibility. Combined with system security constraints, a multi-energy system operation model is formulated to schedule multiple energy production, transmission, and consumption. The effects of local system flexibility on alleviating power flow violations during N-1 line tripping contingencies are then analyzed through a multi-energy system case. The results show that local system flexibility can not only reduce the system operation costs, but also reduce the probability of power flow congestion or violations by approximately 68.8% during N-1 line tripping contingencies.
基金supported in part by National Natural Science Foundation of China under Grant No.51777102in part by Beijing Natural Science Foundation under Grant No.3182017in part by the Science and Technology Project of State Grid Corporation of China‘Research on the electricity market mechanism design and application to promote the accommodation of renewable energy’.
文摘To incorporate the operating constraints of a virtual power plant(VPP)in transmission-level operation and market clearing,the concept of the VPP capability curve(VPP-CC)is proposed which explicitly characterizes the allowable range of active and reactive power outputs of a VPP.A two-step projection-based calculation framework is proposed to approximate the VPP-CC by the convex hull of critical points on its perimeter.The output of the proposed algorithm is concise and can be easily incorporated in the existing system operation and market clearing.Case studies based on the IEEE 33 and 123 test feeders show the computational efficiency of the proposed method outperforms existing methods by 4~7 times.Additionally,many fewer inequalities are needed to depict the VPP-CC while achieving the comparative approximation accuracy compared to sampling-based methods,which will relieve the communication and computation burden.
基金This work was supported by the National Natural Science Foundation of China(No.U1966204).
文摘The Texas electric power crisis that occurred in February 2021 has drawn great attention internationally due to its severity and for not having been foreseen.In this rapid communication,we classify the 2021 Texas electric power crisis as an energy insufficiency-caused power crisis,which alerts of a new blackout mechanism.Different from capacity insufficiencycaused power crises in the past,the Texas electric power crisis of 2021 directly resulted from the long-duration extreme cold weather as well as fundamentally from the insufficiency of sustainable supply capability of energy.We begin this paper with a brief retrospect of the event and its consequences.Definitions of energy/capacity insufficiency-caused power crises are given,as well as an overview of the supply and demand during the event,based on realistic operation data.Quantitative simulations are then conducted to reveal the underlying reasons for the power crisis and reveal how to better prepare for the future.Finally,several insights and suggestions on handling the new mode of blackout in the future are proposed and discussed.
基金This work was supported by the Science and Technology Project of State Grid Corporation of China(1200-201999526A-0-0-00)National High-End Think Tank Construction Project of National Governance and Global Governance Institute of Tsinghua University(2020WTF044).
文摘As COVID-19 sweeps through the whole world,human activities have been changed significantly.Under such circumstances,the electricity sector is deeply affected and faced with great challenges.This paper provides a comprehensive review of the impacts that the pandemic has caused on the electricity sector.Electricity demand has dropped sharply as governments around the world executed lockdown restrictions,while the load composition and daily load profile have also changed.The share of renewable generation has increased against the decline of the total electricity generation.Changed power balance situation and increased uncertainty of demand have posed higher pressure on system operators,along with voltage violation issue and challenges for system maintenance and management.The electricity market is also substantially influenced,while longterm investment in clean energy is expected to be stable.The externality such as emission reduction is also discussed.