Hong Ming Yang

Optimal Dispatch of Power System with Stochastic Wind Generation

Large-scale wind power incorporated into power grid brings new challenges to optimal dispatch of power system. Especially, wind power at different locations may has a significant degree of correlation. A copula function was used to characterize the Joint Probability Distribution (JPD) of wind power from multiple wind farms considering their correlation. An optimal dispatch model based on Chance Constrained Programming (CCP) for power system with multiple wind farms was set up. And Sample Average Approximation (SAA) was proposed to transform the chance constrains. Finally Genetic Algorithm (GA) was employed to solve the optimal model. Simulation results indicate that copula function can well express the correlation of wind power from multiple wind farms and SAA has been a dramatic increase and improvement on the search of solution.

Impact Analysis of Electric Vehicles Charging/Discharging

The penetration of a large number of plug-in hybrid electric vehicles (PHEVs) has introduced severe challenges to power grid operation. In this paper, the grid-connected PHEV model is first proposed to reflect the charge/discharge property of PHEV. Then, a simulation approach is developed to study the probability distributions of the aggregate load and available vehicle to grid (V2G). capacity of PHEVs. Simulation results show that the charging and discharging capacities have the characteristic of normal distribution．

Generation Strategy Optimization Based on Peak Regulation Right Transaction Mechanism

A bidding system of peak regulation right based on multi-agent is proposed according to the property of the peak regulation right. Then, the biggest goals of social benefits of all power generation companies are developed based on bidding system. Simultaneously bidding strategy of peak regulation right of the biggest goals of social benefits of all power generation company agents and internal cost optimization strategy of electricity generation companies are respectively raised for the goals. Example analysis shows that the proposed Bidding system takes on better viability and effectiveness.

Stochastic Optimal Dispatch Model Considering Security Risk Constraint

Due to the natural disasters, the transmission line fault has randomness. In order to describe the uncertainty of the transmission line fault, the conditional value-at-risk (CVaR) theory is introduced to quantify the uncertainty risk caused by transmission line failure. A stochastic optimal dispatch model of the power system considering the security risk constraint is proposed in this paper, using the sample average approximation (SAA) method and the analytic method to solve the model. The influence on the result of stochastic optimization dispatching is analysed by different conditional value at risk and confidence levels. The simulations demonstrate that the stochastic optimal dispatch model considering the security risk constraint is reasonable and provides a theoretical basis for the stochastic optimization dispatching of the power system considering line failure.

Stochastic optimal dispatch of power system under extreme weather disaster

Several large scale failures of power system took place due to extreme weather disaster recent years, which aroused the consideration of power network security operation. Considering that the line failure events caused by natural disaster presented random characteristic, using Poisson distribution theory to depict the probability of line failure, a stochastic power system optimal dispatch model based on chance constraints theory was also proposed. We adopted the Differential Evolution algorithm to calculate the total loss based on Monte-Carlo simulation. The results of IEEE 9-bus case study imply that the dispatch model will give full consideration of weather effects, and provide a more reasonable dispatch plan for power system disaster prevention and reduction.

Simulation and Analysis of Dynamic Evolution of Electricity Market Based on Bidding Decisions with Heterogeneous Expectations

Based on different bidding decisions with heterogeneous expectations of market participants, a dynamic model of electricity market considering power network constraints is proposed. This model is represented by a discrete difference equations embedded with the optimization problem of market clearing. By using the nonlinear complementarity function, the complex dynamic behaviors of electricity market are simulated and analyzed. The Nash equilibrium and its stability, the periodic and even chaotic dynamic behaviors beyond the stability region of Nash equilibrium are investigated.

The Probabilistic Method of Failure Analysis to Transmission Facilities under Ice Storms

Based on Extreme Value Theory (EVT), the Generalized Pareto Distributions (GPDs) of meteorological variables wind speed and freezing precipitation is simulated. Considering the dependence of them, a joint probability distribution is calculated by the Copula function. Further more, the probability distributions of ice loads and wind loads on transmission lines are analyzed, and the failure probability of broken lines and collapsed towers under ice storms is calculated. The accuracy and validity of this analytical method is demonstrated with comparison between numerical results and the historical datas of Chen Zhou power transmission systems.

Research on Optimization and Debugging Simulation Model of Logistics Center Based on Neural Network

An important aspect of simulation modeling of the logistics center is the optimization and debugging. Usually it takes lengthy time to debug the logistics center simulation model by the traditional method. This paper presented a new method to debug simulation model. Through analyzing the data streams of the simulation model, the dominant sets of model parameters were identified to modify the model. The results show that this method can enhance the debug efficiency of model simulation.

Stochastic Optimal Dispatch of Power System with Multiple Wind Farms

Wind power at different locations may has a significant degree of correlation. A copula function, in this paper, is employed to characterize the Joint Probability Distribution (JPD) of wind power from multiple wind farms considering their correlation. Based on this, an optimal dispatch model of power system with multiple wind farms is proposed based on Chance Constrained Programming (CCP) to describe the randomness of wind power. And a new method named Sample Average Approximation (SAA) is used to transform the chance constrians in CCP. Finally the Particle Swarm Optimization (PSO) is used to solve the dispatch model. Simulation results show the affectivity of this model and method, which will be highly useful for optimal dispatch of power system with multiple wind farms.

The Insulator’s Pollution Raining Flashover Forecast under GARCH-Based Forecast of Rainstorm Disasters1

In this paper,it proposes insulator flashover probability prediction model based on Markov chain and ARMA-GARCH. It provides a foundation for risk evaluation of rainstorm of power system. First,this model daily precipitation forecasting model which combined Markov chain with ARMA-GARCH based on self-dependency and time-varying of atmosphere factor; and then according to rainfall’s impact on insulator’s pollution raining flashover,the paper raises the probability prediction model of insulator flashover;Ultimately, we can predict the insulator flashover’s probability. Through Historical data of Hunan Grid to calculate the probability of flashover, and compares with the actual situation it shows that the method can achieve rapid, accurate prediction of power insulator flashover probability.