中频感应加热智能控制器的研究

发布时间：2019-04-08 16:15

【摘要】：随着“工业4.0”概念的提出,我国积极参与并加快发展工业科学技术,感应加热技术在工业冶炼行业中得到广泛应用。当前传统感应加热控制器多采用模拟器件结合经典控制策略的系统模式,该模式在控制过程及输出效果上,存在着诸多不足之处。因此,设计一款数字化、智能化的控制器,对提高感应加热控制器的控制效果及工作效率是具有价值的。针对传统感应加热控制器存在的温度漂移、电路复杂、稳定性差等缺陷,以及加热过程中普通控制方法,无法有效改善的温度非线性时变问题,本文以90kW/1kHz中频感应加热半桥串联主拓扑电路为研究对象,并对其工作特性进行分析,提出了一种基于FPGA的复合调功算法,并在Simulink中进行了可行性验证及样机的设计与测试。具体工作如下:首先,分析了串联半桥主拓扑电路的工作模式及负载特性,提出了一种脉冲宽度与脉冲频率结合的复合调功策略;其次在Simulink环境下搭建了感应加热系统模型,采用锁相环与模糊-P[多模态控制算法实现感应加热调功策略,并对比了传统PI算法和模糊-PI多模态算法在本系统中的控制效果。仿真结果表明,基于模糊-PI多模态算法的复合调功策略是可行的,且在稳、快、准以及抗干扰方面具有一定的优越性;在此基础上,计算了主回路各器件的参数,并设计了以FPGA为核心的触发控制系统,主要设计与测试的模块有:FPGA最小系统、反馈信号A/D采集模块、它激转自激启动模块、反馈信号调理模块、隔离驱动及保护模块;最后在软件上采用纯逻辑器件实现了锁相环的信号跟踪功能。搭建了Qsys系统并利用N1OS II实现功率闭环调节。基于上述软硬件设计搭建了实验样机,完成了对中频感应加热串联半桥智能控制器的调节与测试。实验结果表明,利用复合调功策略的半桥串联拓扑电路,实现了频率的跟踪与恒功率输出控制,提高了功率因数,减少了开关管的功率损耗,使系统具有更强的鲁棒性和适应能力,对中频感应加热冶炼行业的发展具有一定的参考意义。
[Abstract]:With the concept of "Industrial 4.0" put forward, our country actively participates in and accelerates the development of industrial science and technology, induction heating technology has been widely used in industrial smelting industry. At present, the traditional induction heating controller mostly adopts the system mode of analog device combined with classical control strategy. There are many shortcomings in the control process and output effect of this mode. Therefore, it is valuable to design a digital and intelligent controller to improve the control effect and working efficiency of induction heating controller. Aiming at the defects of traditional induction heating controller, such as temperature drift, complex circuit, poor stability and so on, as well as the non-linear time-varying problem of temperature which can not be improved effectively by ordinary control methods in heating process. In this paper, the 90kW/1kHz mid-frequency induction heating half-bridge series main topology circuit is studied, and its working characteristics are analyzed. A hybrid power regulation algorithm based on FPGA is proposed, and the feasibility verification and prototype design and test in Simulink are carried out. The concrete work is as follows: firstly, the working mode and load characteristics of the series half-bridge main topology circuit are analyzed, and a hybrid power regulation strategy combining pulse width and pulse frequency is proposed. Secondly, the induction heating system model is built in the environment of Simulink, and the phase-locked loop and fuzzy-P [multi-modal control algorithm] are used to realize the power regulation strategy of induction heating. The control effects of traditional PI algorithm and fuzzy-PI multimodal algorithm in this system are compared. The simulation results show that the hybrid power regulation strategy based on fuzzy-PI multi-mode algorithm is feasible and has some advantages in stability, fast, accurate and anti-jamming. On this basis, the parameters of each device in the main loop are calculated, and the trigger control system based on FPGA is designed. The main modules of design and test are: FPGA minimum system, feedback signal A / D acquisition module, which activates self-excited start-up module. Feedback signal conditioning module, isolation drive and protection module; Finally, the signal tracking function of PLL is realized by using pure logic device in the software. The Qsys system is built and the power closed loop regulation is realized by using N1OS II. Based on the above-mentioned hardware and software design, an experimental prototype is built, and the regulation and test of the intelligent controller for mid-frequency induction heating series half-bridge is completed. The experimental results show that the frequency tracking and constant power output control are realized by using the half-bridge series topology circuit based on the compound power regulation strategy, the power factor is improved and the power loss of the switch tube is reduced. The system has stronger robustness and adaptability, and has certain reference significance for the development of intermediate frequency induction heating smelting industry.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP273

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