Research On Power Grid Voltage Monitoring Strategy For MEA

Due to the ecological and economic sustainable development,More Electric Aircraft(MEA)has become the trend of future advanced aircraft.Replacing mechanical energy,hydraulic energy and pressure energy by electric energy is one of the most important technologies in MEA.In order to ensure the safety of flight and the comfortbal of passengers,more and more power load is added on the airplane network.The load is variety,the main load is linear load and nonlinear load,some nonlinear loads such as constant power load with energy feedback characteristics,when it will cause the pulse wave voltage to the energy feedback power grid,the voltage fluctuation may damage the power grid connected with some electronic devices,the impact on the aircraft flight.So it is very important to monitor and adjust the grid voltage in real time to reduce the impact of voltage fluctuation on the grid.In this paper,a hybrid energy storage system consisting of a battery and a super capacitor connected in parallel by a bi-directional DC / DC converter is added to the DC power grid.A three-level monitoring strategy is developed and different monitoring strategies are proposed at different monitoring stages.The fuzzy logic controller Current,DC bus voltage,SOC(state of charge),lead-acid battery SOC as input variables,according to different grid conditions to develop fuzzy control rules,in the constant power load power consumption and feedback power.The hybrid energy storage system can quickly absorb and store the excess power in the grid.When the grid voltage is undervoltage,the hybrid energy storage system is quickly provide power,to improve the power grid voltage.