Research On Predictive Optimal Dispatch And Distributed Secondary Coordinated Control Of Microgrid

With the rapid development of renewable energy sources,the penetration rate of distributed power sources with strong randomness and volatility in the power grid continues to increase,which has a significant impact on the stable and economic operation of the power grid.Microgrids,as an effective means of connecting distributed power sources to the distribution network,can maximize the utilization of distributed power sources,improve power supply reliability and power quality,and achieve diversified energy utilization.Microgrids not only need to construct energy optimization scheduling strategies according to the characteristics of distributed power sources,to achieve the optimal distribution of distributed power generation,but also need to control the physical quantities such as voltage,frequency,active power,and reactive power outputted by the power electronics interface devices of distributed power sources,to achieve efficient tracking of power generation and ensure good power quality.This paper proposes a layered optimization structure and control method for microgrids,focusing on solving the power prediction of distributed power sources in microgrids,microgrid optimization scheduling problems,and distributed power source secondary coordination control problems.The main research results are as follows:1.In order to solve the problem of the economic and stable operation of microgrids affected by the fluctuation and uncertainty of renewable energy output and load demand power in microgrids,a multi-objective optimization scheduling decision for microgrids is proposed.Firstly,considering the impact of the fluctuation and uncertainty of the renewable energy output and load demand power,a Variational Mode Decomposition(VMD)combined with an Adaptive Differential Evolution algorithm is used to achieve accurate power prediction of renewable energy output and load demand;based on this,a multi-objective optimization scheduling model for microgrid operation cost optimization and pollutant emission minimization is constructed;finally,the Imperialist Competition Algorithm with fast convergence speed,high convergence accuracy,and strong global convergence is used to achieve the Pareto optimality of microgrid operation cost and pollutant emission cost.2.In order to solve the problem of the impact of the disorderly charging of electric vehicles on power quality and economic operation of microgrids,which is increasing in scale,a microgrid optimization scheduling decision based on demand-side response of electric vehicles is proposed.Firstly,based on the situation of electric vehicle ownership in Qinhuangdao Economic and Technological Development Zone,a Monte Carlo simulation method based on electric vehicle travel chain and different functional zones is proposed to predict the charging load demand of electric vehicles;based on this,a source-load interactive microgrid optimization scheduling strategy for electric vehicles and distributed power sources is constructed considering electric vehicle charging as demand-side response to achieve the optimal operation cost of microgrids.3.In order to ensure the coordinated response of distributed power sources to the above microgrid optimization scheduling decisions,a finite-time consensus control strategy based on event-triggered mechanism is proposed.Firstly,a consensus control model for distributed power sources is constructed;in order to improve the transient performance of secondary control,improve convergence speed,and reduce the network resource occupancy rate of consensus control protocol,a new event-triggered condition and rules are designed,and a finite-time consensus control strategy based on event-triggered mechanism is proposed,so that the intelligent agents of distributed power sources not only update data at their own trigger time,but also update data at the trigger time of neighboring nodes,which can reduce the number of control task executions,improve the quick recovery of microgrid system voltage and frequency,achieve equal distribution of active and reactive power,and prevent the occurrence of Zeno phenomenon.4.For islanded microgrids,in order to ensure that distributed power sources can respond in a coordinated manner to the above microgrid optimization scheduling decisions under sudden interruption of communication networks,a finite-time consensus control strategy is proposed.Firstly,a prediction algorithm for network interruption in isolated microgrids is designed;based on this,a distributed finite-time secondary control protocol is proposed,and the secondary control problem in multiple scenarios is analyzed to achieve the consistent and coordinated control of microgrid voltage and frequency with fast recovery,as well as the equal distribution of active and reactive power,and improve the response speed and robustness of microgrid secondary control.