【作者】 王斌；

【导师】 钟彦儒； 李金刚；

【作者基本信息】 西安理工大学 ， 电力电子与电力传动， 2007， 硕士

【摘要】 感应加热电源以其具有加热效率高、速度快、可控性好及自动化程度高等优点，已在熔炼、铸造、弯管、热锻、焊接和表面热处理等行业得到广泛的应用。目前国内的超音频感应加热电源比较缺乏，尤其是控制技术的研究水平较低，因而对其频率跟踪及功率调节的数字化控制的研究具有一定实际意义。 本论文的研究内容主要是串联谐振式超音频感应加热电源的数字化控制技术。论文首先简要介绍了感应加热的基本原理及感应加热技术的发展方向，分析了超音频感应加热电源主电路工作原理。并对以往的频率跟踪技术和功率调节技术进行了分析比较，在此基础上研究了一种新的数字化控制方案，使其在对负载频率进行无相差频率跟踪的前提下，对逆变器的输出功率进行移相式PWM调节，实现了数字锁相环DPLL与移相式PWM的有机结合。用MATLAB／SIMULINK进行了仿真，并给出相应结果验证了其可行性。编制了控制系统的程序，并在TMS320F240 DSP平台上进行调试，实验证明了该算法可以实现频率跟踪，并可产生移相角可调的基准臂和移相臂的驱动信号。更多还原

【Abstract】 Induction heating power supply has been used extensively in the industrial process such as melting, foundry, siphon, forging, welding and surface heat treating wherewith its advantage of high heating efficiency, good controllability, and easy to mechanize and automate, etc. With an absence of domestic ultra-audio-frequency induction heating power supply at present, especially the low level of research for control technique, the research therefore makes good practical sense on digital control for frequency-tracking and power modulation.The digital control of ultra-audio-frequency serial resonant induction heating power supply is mainly researched in this paper. Firstly the basic principle and developing actuality of induction heating is introduced briefly, and then the working principium of the ultra-audio-frequency induction heating power supply main circuit is analyzed. Based on analysis and comparison of previous frequency-tracking and power modulation technique, a novel digital control method is researched, which can implement the digital phase-shifted PWM control of output power with the precondition that the load frequency is tracked without phase error. Consequently the organic combination of digital phase locked loop (DPLL) and phase-shifted PWM is realized. Simulation results used MATLAB/SIMULINK verify the feasibility of the digital control method. The procedure of control system is compiled and debugged based on the TMS320F240 DSP. Experimental results indicated the arithmetic can implement frequency-tracking and generate the drive signals of norm-arm and shift-arm with an adjustable phase-shift degree.更多还原