According to the US Energy Information Administration, about 4118 billion kilowatt-hours (kWh) electricity was generated at large-scale generation facilities in 2019. About 63% of this was from fossil fuels, e.g., coa...According to the US Energy Information Administration, about 4118 billion kilowatt-hours (kWh) electricity was generated at large-scale generation facilities in 2019. About 63% of this was from fossil fuels, e.g., coal, natural gas, petroleum, and other gases. Environmental exposure to particulates, sulfur dioxide, nitrogen oxides, mercury, arsenic, radioactive fly ash, and other pollutants are extremely detrimental to the human cardiovascular, respiratory, and nervous systems. Such exposure increases the risk of lung cancer, stroke, heart disease, chronic respiratory diseases, respiratory infections, and other illnesses. In light of the challenges associated with renewables providing large quantities of base load power, as well as other factors, the benefits offered by nuclear power should be reexamined by policy makers to move the country towards a more ecological and ethical method of electric power production. This paper offers a concise analysis of many of the salient issues, comparing electricity generation from coal plants and light water nuclear reactors.展开更多
A new electrical power generation device based on high-frequency dynamic piezoelectric shear deformation under friction is developed.During the operation of a moving plate compressed and sliding on the top of a piezoe...A new electrical power generation device based on high-frequency dynamic piezoelectric shear deformation under friction is developed.During the operation of a moving plate compressed and sliding on the top of a piezoelectric patch with constant velocity,dynamic shear deformation of the elastic piezoelectric patch is excited by periodic friction force and status(sliding and stick)variation.The dynamic piezoelectric shear strain can then generate continuous electrical power for energy absorbing and harvesting applications.The design of the piezoelectric couple device is first provided,and its mechanism,dynamic response and electric power generation under friction are described by a detailed iteration model.By comparing with previous experimental results,the accuracy of the proposed model is proven.Through numerical studies,the influences of the equivalent mass of the system,the velocity of the sliding object,the static friction coefficient and its lower limit,as well as the friction force delay rate on the power generation are obtained and discussed.The numerical results show that with the proposed design,up to 50-Watt maximum electrical power could be generated by a piezoelectric patch with a dimension of 20×2×6 cm under continuous friction with the moving plate at the velocity of 15 m/s.The possible bi-linear elastic stiffness variation of the system is also introduced,and the threshold of bi-linear elastic deformation,where the system stiffness changes,can be optimized for obtaining the highest power generation.展开更多
This paper discusses the potential and prospect of building-integrated photovoltaics (BIPV) for solar electrical power generation in China.The BIPV technology has been identified as the most economical renewable energ...This paper discusses the potential and prospect of building-integrated photovoltaics (BIPV) for solar electrical power generation in China.The BIPV technology has been identified as the most economical renewable energy resource to contribute to world electrical energy demand for protecting environment from reduced fossil fuel consumption.The available solar energy resource of 14 cities and the potential power generation from PV claddings in buildings in China were estimated.The economical analysis of BIPV application is discussed.It is found that the potential is significant and the government should play an important role in its development.展开更多
To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surfa...To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surface solar collectors, so working at low temperature (i.e., below 100°C). This power plant is aimed at warm countries, i.e., the ones mainly located between -40° and 40° latitude, having available space along their coast. This land based plant, to install on the seashore, is technologically similar to the one used for OTEC (Ocean Thermal Energy Conversion). This plant, apart from supplying electricity with a much better thermodynamic efficiency than OTEC plants, has the main advantage of providing desalinated water for drinking and irrigation. This plant is designed to generate electricity (and desalinated water) night and day and all year round, by means of hot water storage, with just a variation of the power delivered depending on the season.展开更多
Load shedding is usually the last resort to balance generation and demand to maintain stable operation of the electric grid after major disturbances,such as generation trips.Current load-shedding optimisation practice...Load shedding is usually the last resort to balance generation and demand to maintain stable operation of the electric grid after major disturbances,such as generation trips.Current load-shedding optimisation practices focus mainly on the physical optimality of the network power flow to re-dispatch generation after the contingencies.This might lead to an uneven allocation of load curtailment,hence disadvantaging some loads more than others due to the network properties.Addressing this over-sight,this article introduces an innovative equity-aware load-shedding optimisation model emphasising a fair allocation of load curtailment across the network.First,a novel equity indicator for load shedding is proposed based on the concept of the Gini coefficient.Then,the equity constraint is integrated into an alternating-current optimal power flow(ACOPF)-based optimi-sation framework.Case studies performed on the IEEE 14-bus and 118-bus systems highlight the importance of equity con-siderations in determining optimal load curtailment between buses.The proposed equity-aware load-shedding model offers grid operators a potential alternative strategy to select alternatives.展开更多
The doubly fed induction generator(DFIG)shows multi-time-scale and strong nonlinearity,making its stability analysis difficult.This paper conducts small perturbation stability analysis for the single-DFIG infinite-bus...The doubly fed induction generator(DFIG)shows multi-time-scale and strong nonlinearity,making its stability analysis difficult.This paper conducts small perturbation stability analysis for the single-DFIG infinite-bus system with additional inertia control(AIC).First,the full-order electromagnetic transient model is constructed based on its topology and control structure.Then,the original model is reduced by using the singular perturbation method,and the validity of the simplified sixth-order model is verified by simulation.After linearising the sixth-order model based on the root locus and frequency response diagrams,it is found that increasing the gain coefficient K_(f) of the AIC could improve the inertia response characteristics but weaken the system's small disturbance stability.Furthermore,a complex torque model is constructed,which reveals that the system's negative damping originates from the terminal voltage control loop.Moreover,as K_(f) increases,the inherent damping continuously decreases,leading to further deterioration of the negative damping.As T_(f) increases,the stability of the system initially weakens and then strengthens.This study could help understand the DFIG grid-tied system dynamics.展开更多
In September 2025,the world's first buoyant megawatt-scale high-altitude wind energy system(HAWES)successfully completed its initial field deployment and structural validation in Hami,China.The prototype is a buoy...In September 2025,the world's first buoyant megawatt-scale high-altitude wind energy system(HAWES)successfully completed its initial field deployment and structural validation in Hami,China.The prototype is a buoyant aerostat operating at 1500 m,equipped with 12 turbine-generators to harness the stronger and more consistent winds found at that altitude.The HAWES concept offers compelling advantages:higher wind-power density allows for significantly lighter components(1.16 tonnes vs.over 10 tonnes for conventional turbines),whereas steadier winds improve the capacity factor,benefiting grid integration.Key technical challenges for the system include the design of a deeply integrated,lightweight electrical topology and the management of wind speed heterogeneity caused by the aerostat's operational tilt.To validate its core functionality,the system's power generation capability was evaluated through off-grid load tests conducted in a PSCAD/EMTDC simulation environment.The simulation,which successfully modelled the nonuniform wind conditions,confirmed the design's feasibility by demonstrating a stable start-up process and a steady-state power output of 1.135 MW.展开更多
文摘According to the US Energy Information Administration, about 4118 billion kilowatt-hours (kWh) electricity was generated at large-scale generation facilities in 2019. About 63% of this was from fossil fuels, e.g., coal, natural gas, petroleum, and other gases. Environmental exposure to particulates, sulfur dioxide, nitrogen oxides, mercury, arsenic, radioactive fly ash, and other pollutants are extremely detrimental to the human cardiovascular, respiratory, and nervous systems. Such exposure increases the risk of lung cancer, stroke, heart disease, chronic respiratory diseases, respiratory infections, and other illnesses. In light of the challenges associated with renewables providing large quantities of base load power, as well as other factors, the benefits offered by nuclear power should be reexamined by policy makers to move the country towards a more ecological and ethical method of electric power production. This paper offers a concise analysis of many of the salient issues, comparing electricity generation from coal plants and light water nuclear reactors.
文摘A new electrical power generation device based on high-frequency dynamic piezoelectric shear deformation under friction is developed.During the operation of a moving plate compressed and sliding on the top of a piezoelectric patch with constant velocity,dynamic shear deformation of the elastic piezoelectric patch is excited by periodic friction force and status(sliding and stick)variation.The dynamic piezoelectric shear strain can then generate continuous electrical power for energy absorbing and harvesting applications.The design of the piezoelectric couple device is first provided,and its mechanism,dynamic response and electric power generation under friction are described by a detailed iteration model.By comparing with previous experimental results,the accuracy of the proposed model is proven.Through numerical studies,the influences of the equivalent mass of the system,the velocity of the sliding object,the static friction coefficient and its lower limit,as well as the friction force delay rate on the power generation are obtained and discussed.The numerical results show that with the proposed design,up to 50-Watt maximum electrical power could be generated by a piezoelectric patch with a dimension of 20×2×6 cm under continuous friction with the moving plate at the velocity of 15 m/s.The possible bi-linear elastic stiffness variation of the system is also introduced,and the threshold of bi-linear elastic deformation,where the system stiffness changes,can be optimized for obtaining the highest power generation.
文摘This paper discusses the potential and prospect of building-integrated photovoltaics (BIPV) for solar electrical power generation in China.The BIPV technology has been identified as the most economical renewable energy resource to contribute to world electrical energy demand for protecting environment from reduced fossil fuel consumption.The available solar energy resource of 14 cities and the potential power generation from PV claddings in buildings in China were estimated.The economical analysis of BIPV application is discussed.It is found that the potential is significant and the government should play an important role in its development.
文摘To this day, only two types of solar power plants have been proposed and built: high temperature thermal solar one and photovoltaic one. It is here proposed a new type of solar thermal plant using glass-top flat surface solar collectors, so working at low temperature (i.e., below 100°C). This power plant is aimed at warm countries, i.e., the ones mainly located between -40° and 40° latitude, having available space along their coast. This land based plant, to install on the seashore, is technologically similar to the one used for OTEC (Ocean Thermal Energy Conversion). This plant, apart from supplying electricity with a much better thermodynamic efficiency than OTEC plants, has the main advantage of providing desalinated water for drinking and irrigation. This plant is designed to generate electricity (and desalinated water) night and day and all year round, by means of hot water storage, with just a variation of the power delivered depending on the season.
文摘Load shedding is usually the last resort to balance generation and demand to maintain stable operation of the electric grid after major disturbances,such as generation trips.Current load-shedding optimisation practices focus mainly on the physical optimality of the network power flow to re-dispatch generation after the contingencies.This might lead to an uneven allocation of load curtailment,hence disadvantaging some loads more than others due to the network properties.Addressing this over-sight,this article introduces an innovative equity-aware load-shedding optimisation model emphasising a fair allocation of load curtailment across the network.First,a novel equity indicator for load shedding is proposed based on the concept of the Gini coefficient.Then,the equity constraint is integrated into an alternating-current optimal power flow(ACOPF)-based optimi-sation framework.Case studies performed on the IEEE 14-bus and 118-bus systems highlight the importance of equity con-siderations in determining optimal load curtailment between buses.The proposed equity-aware load-shedding model offers grid operators a potential alternative strategy to select alternatives.
基金Innovation Project of China Southern Power Grid,Grant/Award Number:YN-KJXM20222153.
文摘The doubly fed induction generator(DFIG)shows multi-time-scale and strong nonlinearity,making its stability analysis difficult.This paper conducts small perturbation stability analysis for the single-DFIG infinite-bus system with additional inertia control(AIC).First,the full-order electromagnetic transient model is constructed based on its topology and control structure.Then,the original model is reduced by using the singular perturbation method,and the validity of the simplified sixth-order model is verified by simulation.After linearising the sixth-order model based on the root locus and frequency response diagrams,it is found that increasing the gain coefficient K_(f) of the AIC could improve the inertia response characteristics but weaken the system's small disturbance stability.Furthermore,a complex torque model is constructed,which reveals that the system's negative damping originates from the terminal voltage control loop.Moreover,as K_(f) increases,the inherent damping continuously decreases,leading to further deterioration of the negative damping.As T_(f) increases,the stability of the system initially weakens and then strengthens.This study could help understand the DFIG grid-tied system dynamics.
基金supported by Smart Grid-National Science and Technology Major Project(Grant 2025ZD0805800).
文摘In September 2025,the world's first buoyant megawatt-scale high-altitude wind energy system(HAWES)successfully completed its initial field deployment and structural validation in Hami,China.The prototype is a buoyant aerostat operating at 1500 m,equipped with 12 turbine-generators to harness the stronger and more consistent winds found at that altitude.The HAWES concept offers compelling advantages:higher wind-power density allows for significantly lighter components(1.16 tonnes vs.over 10 tonnes for conventional turbines),whereas steadier winds improve the capacity factor,benefiting grid integration.Key technical challenges for the system include the design of a deeply integrated,lightweight electrical topology and the management of wind speed heterogeneity caused by the aerostat's operational tilt.To validate its core functionality,the system's power generation capability was evaluated through off-grid load tests conducted in a PSCAD/EMTDC simulation environment.The simulation,which successfully modelled the nonuniform wind conditions,confirmed the design's feasibility by demonstrating a stable start-up process and a steady-state power output of 1.135 MW.
