分置式斯特林制冷机的自耦PI温度控制

Autocoupling PI temperature control for a split Stirling cryocooler

分置式微型斯特林制冷机是一种多变量强耦合的非线性系统。针对分置式微型斯特林制冷机的温度控制存在超调量大和抗负载扰动能力不佳的问题,提出了分置式斯特林制冷机自耦PI的温度控制方法。该方法使用斯特林制冷过程近似温度模型,运用递推最小二乘法辨识温度模型参数,设计二阶观测器获取平滑微分信号,进而构造误差函数,最后应用自耦PI控制器实现系统的有效控制。仿真和实验结果表明该控制方法的有效性,具有良好的动态特性和稳态性能。

The split-type mini-Stirling cryocooler is a highly complex nonlinear system with multiple variables.To address the issues of excessive overshoot and poor load disturbance resistance,this study proposed a temperature control method based on auto-coupling PI(ACPI)for the split Stirling cryocooler.This method utilized an approximate temperature model of the Stirling refrigeration process,identified the parameters of the temperature model using recursive least square method,designed a second-order observer to obtain smooth differential signals,constructed an error function,and finally employed an auto-coupling PI controller to achieve effective system control.Simulation and experimental results demonstrate that this proposed control method is effective with excellent dynamic and steady performance.