Research On Decentralized Control Strategy And Energy Management System Of Microgrid

With the gradual depletion of traditional fossil energy and the increasingly serious energy problem,the development and utilization of clean and renewable energy has become very important.As a system that can effectively integrate renewable distributed generation units,microgrid has received more and more attention and development.The coordinated control strategy and corresponding energy management system of microgrid are the key to ensure the stable and economic operation of microgrid.This paper mainly studies the decentralized control strategy and the engineering implementation of energy management system of the microgrid.(1)For single AC or DC microgrid,based on the fuzzy logic control method,a decentralized control strategy for microgrid is proposed,which can take into account the SOC and charging/discharging power of the storage battery.The adaptive power controller for photovoltaic system and demand side control strategy are also designed.Through the coordination of the designed control parts,the source-storage-load coordination in the microgrid without communication lines can be realized,while ensuring the safe and stable operation of the system,and the SOC and charging/discharging power of the storage battery can be limited to their maximum allowable range,so as to prolong the service life of the battery as far as possible.(2)A decentralized control strategy for hybrid AC/DC microgrid is proposed.Firstly,based on the proposed control strategy for a single AC or DC microgrid,the corresponding decentralized control strategies are designed for the AC subgrid and DC subgrid in the hybrid microgrid to ensure that SOC and charging/discharging power of energy storage units in each subgrid are limited to their maximum allowable ranges.Then,based on fuzzy logic control,a control strategy of bidirectional power converter is designed.This strategy can effectively deal with various complex operation scenarios of hybrid microgrid,realize reasonable power interaction control between AC subgrid and DC subgrid,maximize the output power of renewable energy such as photovoltaic in hybrid microgrid,and ensure the stability and reliability of hybrid microgrid.Finally,a charging and discharging control strategy based on fuzzy logic control is designed for energy storage unit of each subgrid in the grid-connected operation mode of hybrid microgrid,which can ensure the safe and reasonable use of energy storage units in the grid-connected mode,maximize the service life of energy storage units,and also ensure the security of hybrid microgrid operation.(3)Taking an energy optimization management strategy of microgrid based on model predictive control as an example,based on the actual microgrid system,a set of related software of energy management system and central controller of microgrid is developed,and the corresponding experimental tests are carried out.The relevant experimental results are in line with expectations,which verifies the effectiveness and practicability of the developed energy management system.