基于多储能调节的直流微电网电压波动分层协调控制策略

The Hierarchical Coordinating Control Strategy of Fluctuating Voltage in DC Microgrid Based on Multi-energy Storage Regulation

针对直流微电网独立运行的状态,本文提出了一种依托于多储能调节的直流微电网电压波动分层协调控制策略。充分发挥混合储能系统功率密度和能量密度互补的优点,设计超级电容超前蓄电池的储能结构,并引入储能飞轮辅助混合储能系统的调节作用。根据直流母线电压阈值和蓄电池的荷电状态,对系统的工作模式进行详细分层,并建立对应模式的改进下垂控制模型。结合混合储能系统和储能飞轮对系统进行单元级和系统级控制,实现均衡母线电压,减少蓄电池的充放电频率,延长蓄电池的使用寿命,提高了微电网的灵活性和稳定性。最后采用PSCAD/EMTDC仿真验证该控制策略的适用性和合理性。

Aiming at characteristics of the DC microgrid running independently,a hierarchical and coordinated control strategy used for inhibiting voltage fluctuation and based on multi energy storage system was proposed.In order to make full use of complementary advantage between power density and energy density of the dual energy storage system,the hardware circuit on which super capacitor and battery can work coordinately was designed.Further,flywheel storage as auxiliary device was introduced to regulate voltage fluctuation and its control process was given in a detail.Taking the DC-bus voltage for research object and considering respective constraints of the energy storage system,working mode of the system was planned on the basis of voltage fluctuation amplitude and optimized droop control model was created.The DC-bus voltage fluctuation was inhibited well by the hierarchical control strategy at unit and system level.The PSCAD/EMTDC simulation results show that the control strategy proposed in the thesis is reasonable and feasible and so it has popularization value in practical engineering application.