Research On The Control Technology And Optimizing The Allocation Of Energy Storage In The Micro Power Grid

As a controlled power source,the energy storage device can make the energy balance in the micro grid,guaranteeing the normal operation of the micro power grid.For example,the power energy fluctuation needs to be eased by energy storage device when the micro power grid is working.And the micro power,such as photovoltaic or wind power,needs to be supported by energy storage device as reference voltage source.In view of the importance of energy storage device in the network running procedure,the paper studied some key technologies which is encountered in the process of application:Firstly,the paper introduced the Active Disturbance Rejection Control Technique(ADRC).Then the paper introduced and analyzed the related working principle and function of each part of the ADRC.On this basis,the paper concluded that there were some questions in terms of parameters.Then according to the new research about the ADRC,the paper introduced the Liner Active Disturbance Rejection control(LADRC)with the characteristics of less parameter to be tuned.Second,the paper studied the control of the energy converter in the energy storage device.After introducing the structure and working principle of the energy converter,it set up mathematical model of the energy converter.At the same time,the paper analyzed the control strategy mathematical modeling.Then the paper analyzed respectively the control strategy used in the energy storage device,which are PQ decoupling control strategy and V/f control strategy,when the micro-grid works in the condition of parallel operation and isolated network operation.On this basis,the paper controls the energy converter with the LADRC in PQ decoupling control strategy and V/f control strategy.And in the same conditions,compared with PID control technology,the results show that the LADRC has better control effect.Finally,the paper studied the problem about energy storage configuration.In the micro grid,there is the difference between power generation and load of power demand,so the micro grid need energy storage device to decrease the difference.Based on analyzing the load characteristics,considering the single energy storage can not meet the requirement of the project,so the paper used the hybrid energy storage including lithium battery and super capacitor to solve this problem,and put forward the way of solving the hybrid energy storage capacity.The total cost of the hybrid energy storage system was the objective function,the paper gave the ratio of the capacity and power of the supercapacitor and lithium batteries.