交直流混合微电网互联变流器微分平坦控制

为提高交直流混合微电网在发生功率波动、电源缺失等情况下的动态和鲁棒性能，提出了一种基于微分平坦（flatness-based control，FBC）理论的互联变流器（interlinking converter，ILC）控制策略。首先分析了孤岛模式下子网内分布式电源采用下垂控制策略解决各自网内的功率分配问题；其次建立dq坐标轴下ILC数学模型，并证明了ILC系统满足微分平坦性；接着，根据微分平坦理论设计了ILC的功率控制器，其结构包括前馈控制和误差补偿两部分，系统采用串级控制结构，由功率外环产生平坦输出的参考轨迹，电流内环产生ILC期望输出的dq轴电压分量；最后，在Matlab/Simulink中建立FBC和PI控制的ILC仿真系统，在3种工况下仿真结果验证了FBC控制系统具有更好的动态性与鲁棒性。

Flatness-Based Control of AC / DC Hybrid Microgrid Interconnected Converter

An Interlinking Converter (ILC) control strategy based on the differential Flatness-Based Control (FBC) theory is proposed to improve the dynamic and robust performance of the hybrid AC-DC microgrid in the presence of power fluctuations and power loss. First analyzes the distributed power supply in the sub-network under the island mode. It uses the droop control strategy to solve the power distribution problem in the respective network. Secondly, it establishes the ILC mathematical model under the DQ axis and proves that the ILC system satisfies the differential flatness. Then, according to the differential flatness theory, the power controller of ILC is designed, which consists of feedforward control and error compensation. The cascade control structure is adopted in the system. The outer power loop generates the reference trajectory of balanced output, and the current inner loop generates the DQ axis voltage component of the ILC expected output. Finally, the ILC simulation system of FBC and PI control is established in Matlab / Simulink. Under three working conditions, the simulation results verify that the FBC control system has better dynamics and robustness.