The current status of wind power and the energy infrastructure in Denmark is reviewed in this paper.The reasons for why Denmark is a world leader in wind power are outlined.The Danish government is aiming to achieve 1...The current status of wind power and the energy infrastructure in Denmark is reviewed in this paper.The reasons for why Denmark is a world leader in wind power are outlined.The Danish government is aiming to achieve 100%renewable energy generation by 2050.A major challenge is balancing load and generation.In addition,the current and future solutions of enhancing wind power penetration through optimal use of cross-energy sector flexibility,so-called indirect electric energy storage options,are investigated.A conclusion is drawn with a summary of experiences and lessons learned in Denmark related to wind power development.展开更多
Gallium nitride(GaN)-based power conversion systems exhibit striking competitiveness in realizing compact and high-efficiency power management modules.Recently emerging GaN-based p-channel field-effect transistors(FET...Gallium nitride(GaN)-based power conversion systems exhibit striking competitiveness in realizing compact and high-efficiency power management modules.Recently emerging GaN-based p-channel field-effect transistors(FETs)and monolithic integration techniques enable the implementation of GaN-based complementary logic(CL)circuits and thereby offer an additional pathway to improving the system-level energy efficiency and functional-ity.In this article,holistic analyses are conducted to evaluate the potential benefits of introducing GaN CL circuits into the integrated power systems,based on the material limit of GaN and state-of-the-art experimental results.It is revealed that the propagation delay of a single-stage CL gate based on the commercial p-GaN gate power HEMT(high-electron-mobility transistor)platform could be as short as sub-nanosecond,which sufficiently satis-fies the requirement of power conversion systems typically with operating frequencies less than 10 MHz.With the currently adopted n-FET-based logic gates(e.g.,directly coupled FET logic)replaced by CL gates,the power consumption of peripheral logic circuits could be substantially suppressed by more than 10^(3) times,mainly due to the elimination of the pronounced static power loss.Consequently,the energy efficiency of the entire system could be substantially improved.展开更多
An integrated energy system with multiple types of energy can support power shortages caused by the uncertainty of renewable energy.With full consideration of gas network constraints,this paper proposes a multi-energy...An integrated energy system with multiple types of energy can support power shortages caused by the uncertainty of renewable energy.With full consideration of gas network constraints,this paper proposes a multi-energy inertia-based power support strategy.The definition and modelling of gas inertia are given first to demonstrate its ability to mitigate power fluctuations.Since partial utilization of gas inertia can influence overall gas network parameters,the gas network is modelled with an analysis of network dynamic changes.A multi-energy inertia-based power support model and strategy are then proposed for fully using gas-thermal inertia resources in integrated energy systems.The influence of gas network constraints on strategy,economy and power outputs is analyzed.Special circumstances where the gas network can be simplified are introduced.This improves the response speed and application value.The feasibility and effectiveness of the proposed strategy are assessed using a real scenario.展开更多
With the wide application of integrated energy systems(IES),the degree of coupling between different types of energy sources is further strengthened,and the mechanism of fault development tends to be complicated.There...With the wide application of integrated energy systems(IES),the degree of coupling between different types of energy sources is further strengthened,and the mechanism of fault development tends to be complicated.Therefore,in order to improve the accuracy and practicability of the reliability assessment of IESs,a sequential simulation reliability assessment method considering multi-energy flow and thermal inertia is proposed in this paper.In this method,the IES structure model is constructed with the combined cooling,heating and power(CCHP)unit as the core equipment,combining with the new energy source to realize the comprehensive energy power flow calculation considering any loss.Then,a load reduction optimization model is established,considering the importance of load and operational economy,in the system status analysis.Furthermore,the heat supply reliability index is corrected taking into account the transmission delay characteristics and terminal thermal inertia.A case study based on the 20-node and the analysis of the influence factors demonstrates the validity of the proposed method.展开更多
考虑到风光出力的随机性与各能源负荷的波动性对综合能源系统(integrated energy system,IES)的影响,构建出在基于多时间尺度下的IES能量优化调度模型。该模型以平抑系统功率波动为主要目标,建立起日前与日内两种时间尺度的优化调度模型...考虑到风光出力的随机性与各能源负荷的波动性对综合能源系统(integrated energy system,IES)的影响,构建出在基于多时间尺度下的IES能量优化调度模型。该模型以平抑系统功率波动为主要目标,建立起日前与日内两种时间尺度的优化调度模型,通过所建立的多时间尺度上层与下层约束条件确定系统的能量流动与功率平衡,同时根据运行方式完成在不同时间尺度下对IES系统的优化调度。仿真结果表明:多时间尺度下的优化调度有助于减轻IES的功率负担,降低外界不确定性对系统运行的干扰,提高系统稳定性。展开更多
The depletion of fossil energy and the deterioration of the ecological environment have severely restricted the development of the power industry.Therefore,it is extremely urgent to transform energy production methods...The depletion of fossil energy and the deterioration of the ecological environment have severely restricted the development of the power industry.Therefore,it is extremely urgent to transform energy production methods and vigorously develop renewable energy sources.It is therefore important to ensure the stability and operation of a large multi-energy complementary system,and provide theoretical support for the world’s largest single complementary demonstration project with hydro-wind-PV power-battery storage in Qinghai Province.Considering all the multiple power supply constraints,an optimization scheduling model is established with the objective of minimizing the volatility of output power.As particle swarm optimization(PSO)has a problem of premature convergence and slow convergence in the latter half,combined with niche technology in evolution,a niche particle swarm optimization(NPSO)is proposed to determine the optimal solution of the model.Finally,the multiple stations’coordinated operation is analyzed taking the example of 10 million kilowatt complementary power stations with hydropower,wind power,PV power,and battery storage in the Yellow River Company Hainan prefecture.The case verifies the rationality and feasibility of the model.It shows that complementary operations can improve the utilization rate of renewable energy and reduce the impact of wind and PV power’s volatility on the power grid.展开更多
文摘The current status of wind power and the energy infrastructure in Denmark is reviewed in this paper.The reasons for why Denmark is a world leader in wind power are outlined.The Danish government is aiming to achieve 100%renewable energy generation by 2050.A major challenge is balancing load and generation.In addition,the current and future solutions of enhancing wind power penetration through optimal use of cross-energy sector flexibility,so-called indirect electric energy storage options,are investigated.A conclusion is drawn with a summary of experiences and lessons learned in Denmark related to wind power development.
基金supported in part by the Hong Kong Research Impact Fund(Grant No.R6008-18)the Shen-zhen Science and Technology Innovation Commission(Grant No.SGDX2020110309460101).
文摘Gallium nitride(GaN)-based power conversion systems exhibit striking competitiveness in realizing compact and high-efficiency power management modules.Recently emerging GaN-based p-channel field-effect transistors(FETs)and monolithic integration techniques enable the implementation of GaN-based complementary logic(CL)circuits and thereby offer an additional pathway to improving the system-level energy efficiency and functional-ity.In this article,holistic analyses are conducted to evaluate the potential benefits of introducing GaN CL circuits into the integrated power systems,based on the material limit of GaN and state-of-the-art experimental results.It is revealed that the propagation delay of a single-stage CL gate based on the commercial p-GaN gate power HEMT(high-electron-mobility transistor)platform could be as short as sub-nanosecond,which sufficiently satis-fies the requirement of power conversion systems typically with operating frequencies less than 10 MHz.With the currently adopted n-FET-based logic gates(e.g.,directly coupled FET logic)replaced by CL gates,the power consumption of peripheral logic circuits could be substantially suppressed by more than 10^(3) times,mainly due to the elimination of the pronounced static power loss.Consequently,the energy efficiency of the entire system could be substantially improved.
基金supported by National Key R&D Program of China(No.2019YFE0118000).
文摘An integrated energy system with multiple types of energy can support power shortages caused by the uncertainty of renewable energy.With full consideration of gas network constraints,this paper proposes a multi-energy inertia-based power support strategy.The definition and modelling of gas inertia are given first to demonstrate its ability to mitigate power fluctuations.Since partial utilization of gas inertia can influence overall gas network parameters,the gas network is modelled with an analysis of network dynamic changes.A multi-energy inertia-based power support model and strategy are then proposed for fully using gas-thermal inertia resources in integrated energy systems.The influence of gas network constraints on strategy,economy and power outputs is analyzed.Special circumstances where the gas network can be simplified are introduced.This improves the response speed and application value.The feasibility and effectiveness of the proposed strategy are assessed using a real scenario.
文摘With the wide application of integrated energy systems(IES),the degree of coupling between different types of energy sources is further strengthened,and the mechanism of fault development tends to be complicated.Therefore,in order to improve the accuracy and practicability of the reliability assessment of IESs,a sequential simulation reliability assessment method considering multi-energy flow and thermal inertia is proposed in this paper.In this method,the IES structure model is constructed with the combined cooling,heating and power(CCHP)unit as the core equipment,combining with the new energy source to realize the comprehensive energy power flow calculation considering any loss.Then,a load reduction optimization model is established,considering the importance of load and operational economy,in the system status analysis.Furthermore,the heat supply reliability index is corrected taking into account the transmission delay characteristics and terminal thermal inertia.A case study based on the 20-node and the analysis of the influence factors demonstrates the validity of the proposed method.
文摘考虑到风光出力的随机性与各能源负荷的波动性对综合能源系统(integrated energy system,IES)的影响,构建出在基于多时间尺度下的IES能量优化调度模型。该模型以平抑系统功率波动为主要目标,建立起日前与日内两种时间尺度的优化调度模型,通过所建立的多时间尺度上层与下层约束条件确定系统的能量流动与功率平衡,同时根据运行方式完成在不同时间尺度下对IES系统的优化调度。仿真结果表明:多时间尺度下的优化调度有助于减轻IES的功率负担,降低外界不确定性对系统运行的干扰,提高系统稳定性。
文摘The depletion of fossil energy and the deterioration of the ecological environment have severely restricted the development of the power industry.Therefore,it is extremely urgent to transform energy production methods and vigorously develop renewable energy sources.It is therefore important to ensure the stability and operation of a large multi-energy complementary system,and provide theoretical support for the world’s largest single complementary demonstration project with hydro-wind-PV power-battery storage in Qinghai Province.Considering all the multiple power supply constraints,an optimization scheduling model is established with the objective of minimizing the volatility of output power.As particle swarm optimization(PSO)has a problem of premature convergence and slow convergence in the latter half,combined with niche technology in evolution,a niche particle swarm optimization(NPSO)is proposed to determine the optimal solution of the model.Finally,the multiple stations’coordinated operation is analyzed taking the example of 10 million kilowatt complementary power stations with hydropower,wind power,PV power,and battery storage in the Yellow River Company Hainan prefecture.The case verifies the rationality and feasibility of the model.It shows that complementary operations can improve the utilization rate of renewable energy and reduce the impact of wind and PV power’s volatility on the power grid.