可变负载的电磁热激励电源控制器研究

发布时间：2018-10-04 20:49

【摘要】：对产品质量要求的提高使得无损检测日渐重要,基于红外热成像的无损检测方法已成为研究热点。红外热成像检测时要求激励电源加热时间较短,需更换不同材料负载,负载电感、电阻参数可能变化较大,导致负载固有谐振频率会发生变化。常规使用频率跟踪来实现激励电源的最大化功率输出,但是在高频或频率变化较大时,尤其电源启动时,有可能跟踪速度较慢甚至跟踪不上,存在跟踪范围窄,适应性差的缺点。本论文以电源控制器为主要研究对象,研究在可变负载情况下的频率跟踪效果,解决了电源启动慢,跟踪差的问题。同时简单的论述了电源控制器的应用,分析了基于感应加热和磁滞损耗两种加热形式的红外热成像缺陷检测效果。主要的研究内容有:(1)基于传统的模拟锁相环原理设计了改进型的数字锁相环结构,简要叙述了其工作原理和性能,并建立了其数学模型。对锁相功能实行了仿真验证,为后续电路设计建立了理论依据。(2)根据系统需求进行了电源控制器硬件电路的设计和制作,主要分为电源电路设计、主控电路设计、相位检测电路设计。由于A/D转化结果误差较大,设计了A/D校正算法提高精度到2%之内。针对电源启动快速、输出稳定的需求,设计了结合二分法与PI的频率跟踪算法,并且编写了整机程序。(3)搭建了整机实验平台,验证了设计的电源控制器在不同负载情况下的负载特性和频率跟踪性能,使电源启动时间控制在10ms左右,输出频率稳定度在200Hz以内。
[Abstract]:Non-destructive testing (NDT) is becoming more and more important due to the improvement of product quality. Nondestructive testing (NDT) based on infrared thermal imaging (IR) has become a hot research topic. In infrared thermal imaging testing, the heating time of excitation power supply is short, and the load inductance and resistance parameters may vary greatly, which results in the change of inherent resonance frequency of load. Frequency tracking is usually used to maximize the power output of the power supply. However, when the frequency changes greatly, especially when the power source starts up, the tracking speed may be slow or not, and the tracking range is narrow. The disadvantage of poor adaptability. In this paper, the power controller is taken as the main research object, the frequency tracking effect under variable load is studied, and the problems of slow starting and poor tracking of power supply are solved. At the same time, the application of power supply controller is briefly discussed, and the effect of infrared thermal imaging defect detection based on induction heating and hysteresis loss is analyzed. The main research contents are as follows: (1) based on the traditional analog phase-locked loop, an improved digital phase-locked loop structure is designed, its working principle and performance are briefly described, and its mathematical model is established. The function of phase lock is verified by simulation, and the theoretical basis for the subsequent circuit design is established. (2) the hardware circuit of the power supply controller is designed and manufactured according to the system requirements, which is mainly divided into the design of the power circuit, the design of the main control circuit, and the design of the main control circuit. Phase detection circuit design. Because the error of A- / D conversion is large, the accuracy of A- / D correction algorithm is improved to less than 2%. A frequency tracking algorithm combining dichotomy with PI is designed to meet the requirements of fast start and stable output of power supply. (3) A whole machine experiment platform is built. The load characteristics and frequency tracking performance of the designed power controller under different load conditions are verified. The starting time of the power supply is controlled around 10ms and the output frequency stability is within 200Hz.
【学位授予单位】：中国计量学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN86

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