基于集中逆向解耦结构的制冷系统内模控制

Internal Model Control in Refrigeration System Based on Centralized Inverted Decoupling Structure

针对制冷系统具有大滞后、强耦合和扰动复杂等特点,设计了采用集中逆向解耦结构的内模控制方法。上述方法采用集中逆向解耦控制实现蒸发温度和过热度的独立控制,同时在反馈通道上加入滤波器提升制冷系统对负荷扰动的抗扰性。由于制冷系统中存在大的不确定性,采用μ分析的方法分析了控制系统鲁棒性的充要条件。通过对比仿真结果表明,上述控制方法与模型动态逆解耦的内模控制方法相比具有更好的解耦效果和较强的抗扰性,且利用仿真得到的结构奇异值幅频曲线验证了改进方法具有较强的鲁棒性。

To deal with large delay time, strong coupling and complicated disturbances presented in the refrigeration system, an internal model control based on centralized inverted decoupling structure （CIDIMC） was proposed in this paper. We used centralized inverted decoupling controller to achieve the independent control of superheat and evaporation temperature. The filter was added to the feedback path to improve disturbance rejection. Meanwhile, for the uncertainty of the refrigeration system, μanalysis method was used to analyze the necessary and sufficient conditions of the robustness. Through the simulation, it is found that this method has better decoupling effect and stronger disturbance rejection, compared with the internal model control based on model dynamic inverted decoupling. At last, the robustness of the control system was verified by the amplitude-frequency curve of the structure singular value by simulation.