【作者】 张智娟；

【导师】 李和明； 彭咏龙；

【作者基本信息】 华北电力大学（河北） ， 电机与电器， 2010， 博士

【摘要】 感应加热电源以其高效、无污染、控制灵活、加热速度快等诸多优点,在工业热处理领域中得到广泛应用。在对不同工件进行加热时,必须根据负载的变化,对感应加热电源的输出功率进行灵活控制,以满足工件的加热工艺要求。针对目前高频感应加热电源中逆变器功率调节方式,本文对高频感应加热电压型逆变器的相移控制、脉冲密度控制以及通过负载匹配进行功率控制等方法进行了深入研究,论文完成的主要工作和取得的创新性成果如下:1.提出了一种相移控制多相LLC电压型逆变器的并联方法。通过控制各相逆变器间的相移来控制各个并联的电压型逆变器的输出功率,同时利用LLC谐振电路特点,采用多个LLC电压型逆变器并联的形式提高电源容量。应用基波稳态分析法,推导出了相移控制下各相逆变器输出电流、输出功率、负载电流和效率的计算公式。设计了相移0~360°的控制电路,并进行了仿真和实验验证。2.研究了LCCL负载匹配电路的拓扑结构、输出功率、输出电流比和电压比,提出了一种利用LCCL负载匹配进行功率控制的方法,并进行了仿真和实验验证。研究结果表明,LCCL电路不仅具有CCL负载匹配电路电流变换的特性,而且通过串联电容的改变可以控制逆变器的输出功率。3.提出了一种改进型均匀脉冲密度控制方法。分析了品质因数对负载电流的影响以及品质因数与最小脉冲密度的理论关系。与均匀脉冲密度控制LC串联负载谐振电路相比,该方法可以使控制脉冲分布更加均匀,降低负载电流波动性;在深度功率控制时,也能够实现对负载谐振频率的可靠跟踪,提高了谐振逆变器的功率控制精度。4.研制了高频感应加热电源试验系统。针对以上各种控制方法,采用不同负载形式,进行了试验研究。验证了理论推导的正确性和方法的可行性。更多还原

【Abstract】 Induction heating power supply has been widely applied in the areas of industrial heating on account of its advantages, such as high efficiency, no pollution, flexible control and fast heating speed. To satisfy the different requirements for heating various work-pieces, the output power of an induction heating power supply must be regulated and controlled flexibly according to the load changing. Focusing on the existing power regulation modes of induction heating power supply inverter, this paper makes an intensive research on power control for the voltage-fed inverter of high-frequency induction heating power supply using the phase shift control, pulse density mode control, and through load matching. The main works and innovative achievements are as following:1. A kind of phase shift control multi-phase LLC voltage-fed inverter parallel method is proposed. The output power of the parallel inverters is modulated by controlling the phase shift between multi-inverters, and the inverter capacity is enhanced by the parallel connection of multi-phase LLC voltage-fed resonant inverters. The equations of each phase inverter output current, output power, load current and efficiency are derived using the analysis of fundamental steady state. A 0~360°phase shift control circuit is designed. In addition, the simulation and prototype experiments are carried out and verified.2. The topology, output power, output current ratio and output voltage ratio of LCCL load matching circuit are explored, a kind of power control approach employing LCCL load matching is proposed and the simulation and prototype experiments are verified. The results presented that the LCCL circuit not only has the characteristics of the circuit current transformation of CCL load matching circuit, but also can regulate the inverter’s output power by changing the series capacitor.3. An improved symmetrical pulse density control approach is proposed. The impact of quality factor to load current and the relationship between quality factor and the minimum pulse density are analyzed. Compared with symmetrical pulse density control approach for LC series load resonant circuit, using this method can make the control pulse distribute more evenly and reduce the fluctuation of the load current, implement reliable load resonant frequency tracking, and improve the resonant inverter precision of power control when the voltage-fed inverter is in the condition of deep power control.4. High frequency induction heating power supply test system is established. The experiments were accomplished using the above mentioned control methods and different load forms. The correctness of theoretical analysis and the feasibility of the approaches are validated.更多还原