Research On Microgrid Control Strategy Based On Islanded Mode

Microgrid is a small autonomous system of power generation,electricity and power distribution which is made up of distributed power,energy storage system,the control and inverter equipment,monitoring,load.In order to solve the problem of the electricity difficulties in remote areas such as islands and border,The paper designs an islanded microgrid system which can make full use of renewable energy sources such as solar and wind energy.And the paper designs a stable control system for islanded microgrid emphatically.The paper firstly analyses the existing typical microgrid architecture and designs the islanded three-phase AC microgrid system architecture combined with the island's actual demand.Then the paper builds the platform of islanded three-phase AC microgrid system.Taking into consideration of economic factors and geographical location,the paper optimizes the capacity configuration and ultimately determines the system total capacity of 5.5KW.The thesis researches on the performance and output characteristics of power generation equipment,energy storage equipment,control and inverter equipment and load,then determines their models and parameters.Then the paper analyses the coordination control method of microgrid system and compares their advantages and disadvantages,and designs the hierarchical control algorithm combined with the characteristics of island type power supply.The thesis designs the stability controller in the centralized control layer.The stability controller achieves homeostatic control of system by adjusting the distributed power supply,the load and energy storage.The thesis implements the power-balancing algorithm of the islanded microgrid within the stability controller emphatically.The algorithm includes control algorithm for the normal operation and emergency handling algorithm.In view of the communication with the SCADA monitoring,the paper realizes the related communication protocol in the controller.For the design of the stability controller,this paper uses DSP TMS320F28335 of TI as the core MCU.Hardware circuit of stability controller includes power supply module,AD sampling module,serial communication module,control system and human-computer interaction module,etc.The software of stability controller includes the main framework design,data acquisition,serial communication,control strategy and human-computer interaction subroutine,etc.And then the thesis debugs the function of stability controller's modules and the software program.The results of the debugging show that the intended goal is achieved.At last the thesis runs stability controller to the system platform,and carries out relevant tests.And the effectiveness and the feasibility of the power-balancing algorithm of islanded microgrid are proved by a large number of experimental data.