There is a general concern that the increasing penetration of electric vehicles(EVs)will result in higher aging failure probability of equipment and reduced network reliability.The electricity costs may also increase,...There is a general concern that the increasing penetration of electric vehicles(EVs)will result in higher aging failure probability of equipment and reduced network reliability.The electricity costs may also increase,due to the exacerbation of peak load led by uncontrolled EV charging.This paper proposes a linear optimization model for the assessment of the benefits of EV smart charging on both network reliability improvement and electricity cost reduction.The objective of the proposed model is the cost minimization,including the loss of load,repair costs due to aging failures,and EV charging expenses.The proposed model incorporates a piecewise linear model representation for the failure probability distributions and utilizes a machine learning approach to represent the EV charging load.Considering two different test systems(a 5-bus network and the IEEE 33-bus network),this paper compares aging failure probabilities,service unavailability,expected energy not supplied,and total costs in various scenarios with and without the implementation of EV smart charging.展开更多
This paper proposes an adaptive segmentation method as a market clearing mechanism for peer-to-peer(P2P)energy trading scheme with large number of market players.In the proposed method,market players participate in th...This paper proposes an adaptive segmentation method as a market clearing mechanism for peer-to-peer(P2P)energy trading scheme with large number of market players.In the proposed method,market players participate in the market by announcing their bids.In the first step,players are assigned to different segments based on their features,where the balanced k-means clustering method is implemented to form segments.These segments are formed based on the similarity between players,where the amount of energy for trade and its corresponding price are considered as features of players.In the next step,a distributed method is employed to clear the market in each segment without any need to private information of players.The novelty of this paper relies on developing an adaptive algorithm for dividing large number of market players into multiple segments to enhance scalability of the P2P trading by reducing data exchange and communication overheads.The proposed approach can be used along with any distributed method for market clearing.In this paper,two different structures including community-based market and decentralized bilateral trading market are used to demonstrate the efficacy of the proposed method.Simulation results show the beneficial properties of the proposed segmentation method.展开更多
The integration of large amount of wind power into a power system imposes a new challenge for the secure and economic operation of the system.It is necessary to investigate the impacts of wind power generation on the ...The integration of large amount of wind power into a power system imposes a new challenge for the secure and economic operation of the system.It is necessary to investigate the impacts of wind power generation on the dynamic behavior of the power system concerned.This paper investigates the impacts of large amount of wind power on small signal stability and the corresponding control strategies to mitigate the negative effects.The concepts of different types of wind turbine generators(WTGs)and the principles of the grid-connected structures of wind power generation systems are first briefly introduced.Then,the state-of-the-art of the studies on the impacts of WTGs on small signal stability as well as potential problems to be studied are clarified.Finally,the control strategies on WTGs to enhance power system damping characteristics are presented.展开更多
This paper presents a series of operating schedules for Battery Energy Storage Companies(BESC)to provide peak shaving and spinning reserve services in the electricity markets under increasing wind penetration.As indiv...This paper presents a series of operating schedules for Battery Energy Storage Companies(BESC)to provide peak shaving and spinning reserve services in the electricity markets under increasing wind penetration.As individual market participants,BESC can bid in ancillary services markets in an Independent System Operator(ISO)and contribute towards frequency and voltage support in the grid.Recent development in batteries technologies and availability of the day-ahead spot market prices would make BESC economically feasible.Profit maximization of BESC is achieved by determining the optimum capacity of Energy Storage Systems(ESS)required for meeting spinning reserve requirements as well as peak shaving.Historic spot market prices and frequency deviations from Australia Energy Market Operator(AEMO)are used for numerical simulations and the economic benefits of BESC is considered reflecting various aspects in Australia’s National Electricity Markets(NEM).展开更多
Distribution state estimation(DSE)is an essential part of an active distribution network with high level of distributed energy resources.The challenges of accurate DSE with limited measurement data is a well-known pro...Distribution state estimation(DSE)is an essential part of an active distribution network with high level of distributed energy resources.The challenges of accurate DSE with limited measurement data is a well-known problem.In practice,the operation and usability of DSE depend on not only the estimation accuracy but also the ability to predict error variance.This paper investigates the application of error covariance in DSE by using the augmented complex Kalman filter(ACKF).The Kalman filter method inherently provides state error covariance prediction.It can be utilized to accurately infer the error covariance of other parameters and provide a method to determine optimal measurement locations based on the sensitivity of error covariance to measurement noise covariance.This paper also proposes a generalized formulation of ACKF to allow scalar measurements to be incorporated into the complex-valued estimator.The proposed method is simulated by using modified IEEE 34-bus and IEEE 123-bus test feeders,and randomly generates the load data of complex-valued Wiener process.The ACKF method is compared with an equivalent formulation using the traditional weighted least squares(WLS)method and iterated extended Kalman filter(IEKF)method,which shows improved accuracy and computation performance.展开更多
Congestions are becoming a significant issue with an increasing number of occurrences in distribution networks due to the growing penetration of distributed generation and the expected development of electric mobility...Congestions are becoming a significant issue with an increasing number of occurrences in distribution networks due to the growing penetration of distributed generation and the expected development of electric mobility.Fair congestion management(CM)policies and prices require proper indices of congested areas and contributions of customer to congestions.This paper presents spatial and temporal indices for rapidly recognizing the seriousness of congestions from the perspectives of both magnitude violation and duration to prioritize the affected areas where CM procedures should be primarily activated.Besides,indices are presented which describe the contributions of customers to the congestions.Simulation tests on IEEE 123-bus and Australian 23-bus low-voltage distribution test feeders illustrate the calculation and capabilities of the proposed indices in balanced and unbalanced systems.展开更多
The continuum model is a key paradigm describing the behavior of electromechanical transients in power systems.In the past two decades,much research work has been done on applying the continuum model to analyze the el...The continuum model is a key paradigm describing the behavior of electromechanical transients in power systems.In the past two decades,much research work has been done on applying the continuum model to analyze the electromechanical wave in power systems.In this work,the uniform and non-uniform continuum models are first briefly described,and some explanations borrowing concepts and tools from other fields are given.Then,the existing approaches of investigating the resulting wave equations are summarized.An application named the zero reflection controller based on the idea of the wave equations is next presented.展开更多
More customers are tending to install batteries with photovoltaic(PV), so they can better control their electricity bills. In this context, customers may be tempted to go offgrid at a substantial up-front cost, leadin...More customers are tending to install batteries with photovoltaic(PV), so they can better control their electricity bills. In this context, customers may be tempted to go offgrid at a substantial up-front cost, leading electricity companies into a death spiral, thereby raising electricity price further on those remaining on grid. Neighborhood energy markets can promote the sharing of locally generated renewable energy and encourage prosumers to stay on grid with financial incentives. A novel neighborhood energy trading(NET) mechanism is developed using the topology of existing radial distribution network to encourage sustainable energy sharing in neighborhood and encourage prosumers to stay on grid. This mechanism considers loss, congestion management, and voltage regulation, and it is scalable with low computation and communication overhead.An IEEE test system is used to validate the NET mechanism.The simulation shows that the price and flow results are obtained with fast computation speed(within 10 iterations) and with loss reflected, flow limit reinforced, and voltage regulated.This study proves that the economic demand-supply-based pricing mechanism can be applied effectively in distribution networks to help encourage more renewable energy sharing in sustainable neighborhood and avoid energy network death spiral.展开更多
文摘There is a general concern that the increasing penetration of electric vehicles(EVs)will result in higher aging failure probability of equipment and reduced network reliability.The electricity costs may also increase,due to the exacerbation of peak load led by uncontrolled EV charging.This paper proposes a linear optimization model for the assessment of the benefits of EV smart charging on both network reliability improvement and electricity cost reduction.The objective of the proposed model is the cost minimization,including the loss of load,repair costs due to aging failures,and EV charging expenses.The proposed model incorporates a piecewise linear model representation for the failure probability distributions and utilizes a machine learning approach to represent the EV charging load.Considering two different test systems(a 5-bus network and the IEEE 33-bus network),this paper compares aging failure probabilities,service unavailability,expected energy not supplied,and total costs in various scenarios with and without the implementation of EV smart charging.
文摘This paper proposes an adaptive segmentation method as a market clearing mechanism for peer-to-peer(P2P)energy trading scheme with large number of market players.In the proposed method,market players participate in the market by announcing their bids.In the first step,players are assigned to different segments based on their features,where the balanced k-means clustering method is implemented to form segments.These segments are formed based on the similarity between players,where the amount of energy for trade and its corresponding price are considered as features of players.In the next step,a distributed method is employed to clear the market in each segment without any need to private information of players.The novelty of this paper relies on developing an adaptive algorithm for dividing large number of market players into multiple segments to enhance scalability of the P2P trading by reducing data exchange and communication overheads.The proposed approach can be used along with any distributed method for market clearing.In this paper,two different structures including community-based market and decentralized bilateral trading market are used to demonstrate the efficacy of the proposed method.Simulation results show the beneficial properties of the proposed segmentation method.
基金This work is supported by a discovery project of Australia Research Council(No.DP120101345)National Key Technology Research and Development Program of China(No.2011BAA07B02).
文摘The integration of large amount of wind power into a power system imposes a new challenge for the secure and economic operation of the system.It is necessary to investigate the impacts of wind power generation on the dynamic behavior of the power system concerned.This paper investigates the impacts of large amount of wind power on small signal stability and the corresponding control strategies to mitigate the negative effects.The concepts of different types of wind turbine generators(WTGs)and the principles of the grid-connected structures of wind power generation systems are first briefly introduced.Then,the state-of-the-art of the studies on the impacts of WTGs on small signal stability as well as potential problems to be studied are clarified.Finally,the control strategies on WTGs to enhance power system damping characteristics are presented.
文摘This paper presents a series of operating schedules for Battery Energy Storage Companies(BESC)to provide peak shaving and spinning reserve services in the electricity markets under increasing wind penetration.As individual market participants,BESC can bid in ancillary services markets in an Independent System Operator(ISO)and contribute towards frequency and voltage support in the grid.Recent development in batteries technologies and availability of the day-ahead spot market prices would make BESC economically feasible.Profit maximization of BESC is achieved by determining the optimum capacity of Energy Storage Systems(ESS)required for meeting spinning reserve requirements as well as peak shaving.Historic spot market prices and frequency deviations from Australia Energy Market Operator(AEMO)are used for numerical simulations and the economic benefits of BESC is considered reflecting various aspects in Australia’s National Electricity Markets(NEM).
文摘Distribution state estimation(DSE)is an essential part of an active distribution network with high level of distributed energy resources.The challenges of accurate DSE with limited measurement data is a well-known problem.In practice,the operation and usability of DSE depend on not only the estimation accuracy but also the ability to predict error variance.This paper investigates the application of error covariance in DSE by using the augmented complex Kalman filter(ACKF).The Kalman filter method inherently provides state error covariance prediction.It can be utilized to accurately infer the error covariance of other parameters and provide a method to determine optimal measurement locations based on the sensitivity of error covariance to measurement noise covariance.This paper also proposes a generalized formulation of ACKF to allow scalar measurements to be incorporated into the complex-valued estimator.The proposed method is simulated by using modified IEEE 34-bus and IEEE 123-bus test feeders,and randomly generates the load data of complex-valued Wiener process.The ACKF method is compared with an equivalent formulation using the traditional weighted least squares(WLS)method and iterated extended Kalman filter(IEKF)method,which shows improved accuracy and computation performance.
文摘Congestions are becoming a significant issue with an increasing number of occurrences in distribution networks due to the growing penetration of distributed generation and the expected development of electric mobility.Fair congestion management(CM)policies and prices require proper indices of congested areas and contributions of customer to congestions.This paper presents spatial and temporal indices for rapidly recognizing the seriousness of congestions from the perspectives of both magnitude violation and duration to prioritize the affected areas where CM procedures should be primarily activated.Besides,indices are presented which describe the contributions of customers to the congestions.Simulation tests on IEEE 123-bus and Australian 23-bus low-voltage distribution test feeders illustrate the calculation and capabilities of the proposed indices in balanced and unbalanced systems.
基金This work is jointly supported by a discovery project of Australia Research Council(No.DP120101345)National High Technology Research and Development Program of China(863 Program)(No.2011AA05A105).
文摘The continuum model is a key paradigm describing the behavior of electromechanical transients in power systems.In the past two decades,much research work has been done on applying the continuum model to analyze the electromechanical wave in power systems.In this work,the uniform and non-uniform continuum models are first briefly described,and some explanations borrowing concepts and tools from other fields are given.Then,the existing approaches of investigating the resulting wave equations are summarized.An application named the zero reflection controller based on the idea of the wave equations is next presented.
基金supported in part by the Australian Research Council Discovery Project (No. 160102570)。
文摘More customers are tending to install batteries with photovoltaic(PV), so they can better control their electricity bills. In this context, customers may be tempted to go offgrid at a substantial up-front cost, leading electricity companies into a death spiral, thereby raising electricity price further on those remaining on grid. Neighborhood energy markets can promote the sharing of locally generated renewable energy and encourage prosumers to stay on grid with financial incentives. A novel neighborhood energy trading(NET) mechanism is developed using the topology of existing radial distribution network to encourage sustainable energy sharing in neighborhood and encourage prosumers to stay on grid. This mechanism considers loss, congestion management, and voltage regulation, and it is scalable with low computation and communication overhead.An IEEE test system is used to validate the NET mechanism.The simulation shows that the price and flow results are obtained with fast computation speed(within 10 iterations) and with loss reflected, flow limit reinforced, and voltage regulated.This study proves that the economic demand-supply-based pricing mechanism can be applied effectively in distribution networks to help encourage more renewable energy sharing in sustainable neighborhood and avoid energy network death spiral.
