Multi-time Scale Optimal Dispatch And Design Of Electricity Transaction Mechanism In Isolated Microgrid With High Penetration Of Renewable Energy Generation

With the increasing penetration of distributed generators and the development of storage technology,isolated microgrid and microgrid cluster have become a new trend of power grid construction in area with low population density or area without electricity.On one hand,isolated microgrid provides a flexible networking mode for renewable energy integration,reducing construction cost,maintenance cost and power loss.On the other hand,it realizes electrification in the area without electricity rapidly,so it is encouraged by governments all around the world.Besides,electricity market in the isolated microgrid will also evolve,including many stakeholders.Based on multi-time scale optimal dispatch and design of electricity transaction mechanism in the isolated microgrid,main researches are as follows:(1)Considering uncertainty of renewable energy generation and loads,a framework for day-ahead optimal dispatch in the isolated microgrid is established.A demand management mechanism with different types of the loads is proposed,and then a multi-objective day-ahead optimal dispatch model is built,involving high renewable energy penetration.This passage uses an approximate dynamic programming algorithm with adaptive weighted-sum to solve the optimal model.Case study builds a Pakistani isolated microgrid model with 100% renewable energy penetration and analyzes day-ahead dispatch results under different daily operation modes.(2)A framework for hourly rolling optimal dispatch in the isolated microgrid is applied,and a corresponding optimal model considering multiple storages is proposed.An improved approximate dynamic programming algorithm is developed to solve it.This passage analyzes rolling dispatch results under different real-time operation modes,as well as compares two different dispatch methods.(3)According to the characteristics of stakeholders in the isolated microgrid or the microgrid cluster,an architecture for electricity trading in the isolated microgrid is established.Based on it,this passage designs a mechanism of marketized dispatch and electricity transaction.In the transaction mechanism,a punishment mechanism is set to limit the monopolized activities of some stakeholders.Besides,a deviation penalty mechanism is designed for the uncertainty of wind power,solar power and load power.Some transaction simulations are carried out to analyze revenue and cost of microgrid generation companies as well as market settlement results.The research of this paper shows that building the demand management mechanism and installing the storages can promote power balance in the isolated microgrid effectively.The day-ahead and rolling dispatch schemes resulted from the proposed models and algorithms are very adaptive to the uncertainty.Furthermore,the transaction simulations verify the effectiveness of the proposed electricity transaction mechanism.It can reduce user's electricity cost and encourage the microgrid generation companies to increase investment of generation capacity,which gets a win-win result among the stakeholders as well as supports long-term development of the isolated microgrid.