Research on power coordinated control strategy of wind turbine-based DC microgrid under various modes

Power balance of a DC microgrid is an important guarantee for the safety and stability of power network. To have an integrative consideration of DC microgrid and capacity of converters, the operation of DC microgrid is divided into four modes, which contains the full rated converter induction generator, storage batteries and AC/DC loads. The four modes include grid-connected operation, current-limited operation, short-time failure operation and island operation. According to the four modes, a power coordination control strategy based on multivariable is proposed. The working operation of each converter can be automatically coordinated by the proposed control strategy, according to the DC voltage variation, the state of charge of battery and the current of grid connected converter. Then, the active power of DC microgrid can be balanced under any working condition to maintain the voltage stability of DC bus. Finally, MATLAB/Simulink simulation results are presented to validate the effectiveness and feasibility of the proposed control strategy.