大功率高频高压电源控制系统研究

发布时间：2018-03-30 05:31

本文选题：大功率高频高压电源　切入点：全桥LCC谐振变换器　出处：《北方工业大学》2017年硕士论文

【摘要】：随着科技发展,电子束焊接技术向着工件高精度加工和汽车制造等领域发展,且不断扩展应用领域。尽管国外对于大功率电子束焊机产品比较成熟,但是国内研究比较落后,普遍缺乏对于大功率高频高压电源控制系统研究,尚未涉及到大功率谐振变换器的特性分析及其控制环路设计。本文简述了大功率高压电源国内外发展现状和技术创新,确定LCC谐振变换器作为本课题电源系统的主电路拓扑,选择数字控制技术来实现电源系统闭环控制。进一步,分析了大功率LCC谐振变换器的电压增益特性、电流传输特性和谐振腔阻抗特性等固有特性,提出了适用于大功率电源的全桥LCC谐振变换器设计方案。通过Saber软件仿真,验证设计参数的准确性。借助大功率LCC谐振变换器仿真波形分析,明确了传统脉宽调制(PWM)控制策略与频率调制(PFM)控制策略对大功率电源系统控制的优势与缺陷,提出PFM与PWM相结合的混合控制策略。借助等效电路模型法和扩展函数建模法,推导出全桥LCC谐振变换器的小信号模型,并给出了电流模式控制环传递函数。利用环路增益法,实现增益裕度、相位裕度和控制带宽之间的平衡,设计出单独的PWM和PFM相结合的线性PI闭环控制器。最后,文章详细解析了电源样机的硬件平台和软件程序的设计原理,并详细分析了实验波形,验证大功率LCC谐振变换器及其闭环控制器设计的正确性与可行性。
[Abstract]:With the development of science and technology, electron beam welding (EBW) technology has been developed in the fields of high precision workpiece machining and automobile manufacturing, and the application fields have been continuously expanded. Although the products of high power electron beam welding machine are relatively mature in foreign countries, the domestic research is relatively backward. There is a general lack of research on the control system of high-power high-frequency and high-voltage power supply, and the characteristic analysis and control loop design of high-power resonant converter have not been involved. This paper briefly describes the development status and technological innovation of high-power high-voltage power supply at home and abroad. The LCC resonant converter is determined as the main circuit topology of the power supply system in this paper. The digital control technology is selected to realize the closed-loop control of the power supply system. Furthermore, the voltage gain characteristics of the high-power LCC resonant converter are analyzed. The design scheme of full-bridge LCC resonant converter suitable for high-power power supply is proposed. The design of full-bridge LCC resonant converter is simulated by Saber software. The accuracy of design parameters is verified. With the aid of simulation waveform analysis of high-power LCC resonant converter, the advantages and disadvantages of traditional PWM control strategy and frequency-modulated LCC control strategy for high-power power system control are determined. A hybrid control strategy combining PFM and PWM is proposed. The small-signal model of full-bridge LCC resonant converter is derived by using the equivalent circuit model method and the extended function modeling method, and the current-mode control loop transfer function is given. To achieve the balance between gain margin, phase margin and control bandwidth, a single linear Pi closed-loop controller combining PWM and PFM is designed. Finally, the hardware platform and software design principle of the power supply prototype are analyzed in detail. The experimental waveform is analyzed in detail to verify the correctness and feasibility of the design of high power LCC resonant converter and its closed-loop controller.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM46

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