In order to solve the problem of the traditional fuzzy controller without considering the interaction between all electric parameters leading to the problem of insufficient accuracy and harmony

we comprehensively considered the relations of micro source’s output

load demand

and energy storage state in the DC microgrid so as to put forward hybrid energy scheduling schemes based on DC bus voltage fluctuation

the flywheel and the battery’s energy storage state.Moreover

on the basis of the scheduling schemes

a multivariable fuzzy controller was designed after considering the mutual influence between electric parameters.A multiplication fuzzy relationship matrix was created through weighted value which considered the influence of electric parameters to modify the fuzzy input

then a fuzzy rule base was established to logically judge the results of the defuzzification and to generate control signals.In order to optimize the charging and discharging power of energy storage system

a hybrid energy storage charge and discharge optimization method was put forward which set the minimum DC bus voltage fluctuation as the goal

with the constraints of instantaneous power balance and storage device charge or discharge limiting condition.The simulation results showed that when the DC microgrid’s DC bus voltage fluctuation is more than 5%

according to the state of flywheel and battery storage

the energy storage system can choose the right way to run quickly

so as to maintain the stability of the DC bus voltage; furthermore

the results also verify the feasibility and effectiveness of the multivariable fuzzy controller and hybrid energy storage charge and discharge of the optimization method

and the study for the engineering practice and theoretical research has certain reference value.