Research On Optimal Economic Operation Model Of Microgrid Considering Randomness

Microgrid is a single controllable independent power generation system composed of distributed generations,loads,energy storage devices and control devices.How to increase the penetration of renewable energy and optimize the regulation of distributed generations are essential to achieve economy and clean operations of micro-grid.However,wind turbines,photo-voltaic generated power in distributed manner,as well as the strong randomness of loads,which pose great challenges to the micro-grid economic and optimal operation.In order to solve these problems,this thesis studies the economic optimized operation of microgrid considering system randomness;we establish a two-stage stochastic programming model of microgrid,and use the model predictive control to solve the optimal dispatch problem.The simulation results show effectiveness of the proposed model and algorithm.First of all,this thesis introduces the concept of micro-grid and the current research scope in our country and abroad,analyzing the working principles and developed model of the main distributed power supplies in detail.Based on this,by taking into account the randomness of wind powers,photo-voltaic and load requirements,the thesis proposes a two-stage stochastic programming model of the microgrid based on the economic operational cost as the objective function to meet the balance between demands and supplies.Secondly,since the two-stage stochastic programming model of micro-grid contains non-linearity and multiple constraints,we use the model predictive control algorithm to get the optimal power dispatch of each power sources.The Monte Carlo simulation and the scene analysis is employed to deal with the randomness in the model.The economic and environmental operation of microgrid can be realized by controlling the scheduled power output of each distributed generation,charging and discharging in the energy storage system,power interaction between the microgrid and main grid,and determining the amount of load shedding.Finally,this thesis verifies the performance of the stochastic programming model,compared to the traditional deterministic model through the MATLAB simulation.And the effectiveness of the model predictive control algorithm in the microgrid energy optimization problem is verified.