工业感应加热电源的H∞控制算法设计与仿真

Design and simulation of H∞ controller for industrial induction heating power supply

感应加热由于其环保和热效率高等优势一直是国内外学者研究的热点。由于感应加热电路中普遍存在扰动,电气元件参数不易准确估计,传统的基于确定性模型设计的PI控制器性能难以提升,有必要进一步改进。以感应加热系统为研究对象,建立了具有等效串联谐振负载的系统状态空间模型,并对模型进行了线性化解耦,基于解耦之后的模型设计了双闭环PI控制器以及改进的电流内环H∞控制器。为验证结果,分别对PI控制器与H∞控制器在两种启动条件下进行仿真,通过对比进一步证实了改进之后的系统具有更好的抗干扰能力与动态特性。

Induction heating has always been a hot topic for scholars domestic and overseas because of its advantages of environmental protection and high thermal efficiency. The disturbance which exists in the power and control circuits brings the difficulty of estimating the parameters of electrical components accurately. The performance of traditional PI controller based on deterministic model is difficult to improve. Therefore, it is necessary to consider the influence of the disturbance on the induction heating control system. In this paper, a system state space model with equivalent series resonant load was established, and the model was decoupled by linearization method. Based on the decoupled model, a double closed loop PI controller and an improved current inner loop H∞ controller were designed. Finally, the PI controller and the H∞ controller were simulated under two starting conditions respectively. It is further confirmed by comparison that the improved system has better anti-interference ability and dynamic characteristics.