微波冶金反应器嵌入式控制系统装置及控制策略研究

发布时间：2018-01-04 01:20

本文关键词：微波冶金反应器嵌入式控制系统装置及控制策略研究　出处：《昆明理工大学》2016年博士论文　论文类型：学位论文

【摘要】：随着微波应用技术的发展,微波已从传统的通信领域拓展到微波探测、微波加热、微波化学等多个领域。微波加热作为一种新型的加热方式已经在烘烤、冶金、材料烧结方面崭头露脚,它具有加热效率高、升温速度快、选择性加热以及易于控制等诸多优点,并且随着半导体和计算机软件技术的发展,它更容易实现控制的智能化、网络化。但是在微波加热中使用的磁控管都需要上千伏的驱动电压以及较大的驱动电流,使用传统的变压器升压和整流方式不仅设备笨重、体积庞大,并且效率低下。采用开关电源可以减轻设备重量、缩小体积,同时也能提高效率,但在高频、大功率条件下开关损耗不容忽视,它不仅导致开关管发热严重,设备效率无法进一步提高,严重时甚至会影响到电源的稳定性,同时还具有很强的电磁干扰,这对同一系统中使用低电压、弱电流的控制系统有很大的影响,特别是系统中的微弱信号检测电路,影响则尤为严重。电磁干扰对系统的可靠性和稳定性构成极大的隐患。微波反应器中既有高电压、大电流的磁控管电源驱动电路,又有低电压、弱电流的控制、通信电路,更有温度信号检测这样的电磁敏感电路。针对微波反应器的功能要求以及系统内部的复杂情况,首先要能精确控制微波反应器炉腔内温度及变化曲线,其次需使微波反应器的电源效率不低于96%,再次要让系统具有较高的稳定性和可靠性、以及较好的电磁兼容性。这对微波反应器的整体设计提出了更高的要求。本文意在利用电力电子技术及嵌入式技术搭建一个高效率、高功率密度、高稳定性、低成本,并且具有较好电磁兼容性的微波反应器控制系统。微波反应器中的磁控管由于其特殊的伏安特性,在工作区中,很小的电压变化量将会引起很大的电流幅度变化,从而引起较大的功率变化,若系统只通过检测电压的方式来控制磁控管,则系统很难得到稳定的功率输出,从而影响炉腔内温度的精确控制；若系统直接通过检测电流的方式来控制磁控管,则无法准确确定磁控管的当前工作区。本文采用了电压和电流相结合的控制方式,并配合以自适应模糊PID控制算法,这样能有效的控制磁控管的功率,在一些对温度曲线要求严格的材料烧结应用中,系统也能够很好的控制炉腔的温度曲线。工业用的高功率磁控管通常采用高压直流驱动,本文对驱动磁控管的AC-DC开关电源的原理及电磁干扰产生的机理进行了深入的分析,普通的开关电源相对于线性电源在效率上已经有了很大的提高,但是在进一步提高功率密度情况下,电源的效率则呈下降趋势,无法达到设计要求,本文采用了基于LCC谐振的软开关技术,即利用开关管在零电流或零电压条件下开通和关断的方法,大大降低了开关管的开关损耗,使得电源效率基本在96%以上。同时,由于开关管开通和关断的特殊条件,大大减少了系统的电磁干扰,也减少了电源模块对其它模块的干扰,提高系统的可靠性和稳定性。系统控制部分采用了嵌入式技术,以ARM CORTEX-M3内核的STM32微控制器作为主控芯片,利用微控制器自带的A/D转换器通过热电偶及辅助电路实现反应器内部温度数据的采集,利用双串口一方面和上位机进行通信,另一方面接收来自电参数测量模块的数据,对磁控管的功率进行实时监控,从而实现对温度和功率的有效控制。采用嵌入式技术大大降低了系统成本,同时微控制器强大的运算能力为算法的运算提供了条件。微波反应器控制系统硬件部分由主控制模块、电源驱动模块、电参数测量模块、温度检测模块、数据通信模块等组成,各模块之间通过RS-485总线进行连接。主控制模块通过电参数测量模块和温度检测模块实时监控磁控管功率和微波反应器腔内温度；通过数据融合和控制算法对电源驱动模块进行控制,实现特定要求的微波反应器加热控制；通过通信模块接收上位机的指令,同时反馈微波反应器的状态数据。模块化的设计方法使得系统较强的可测试性和可维护性,在最后的系统联机测试中也充分体现了这两点,测试结果表明本系统实际运行和理论分析基本一致,完全满足实际需求。
[Abstract]:With the development of microwave technology, microwave communication has been extended to the field from traditional microwave detection, microwave heating, a field of microwave chemistry. Microwave heating as a new heating mode in baking, metallurgy, sintering on brand head exposed foot, it has high heating efficiency, fast heating speed, selectivity heating and easy to control and many other advantages, and with the development of semiconductor technology and computer software, it is more easy to implement intelligent control network. But the use of magnetron in microwave heating are required driving voltage kV and the driving current is larger, the use of traditional transformer and rectifier not only heavy equipment, large volume, and low efficiency. The switching power supply can reduce the weight of the equipment, reduce the volume, but also can improve the efficiency, but in high frequency, high power under the condition of not switching loss Ignored, it not only causes the switch of severe fever, equipment efficiency, and even affect the stability of the power supply, but also has a very strong electromagnetic interference, the use of low voltage in the same system, has a great influence on the weak current control system, especially the weak signal detection circuit system the effect is particularly serious. The electromagnetic interference on the system reliability and stability pose a great risk. Both the high voltage microwave reactor, driving circuit of magnetron power supply of high current and low voltage, low current control, communication circuit, temperature detection circuit of electromagnetic signal is more sensitive to this. Considering the complicated situation inside the functional requirements of the microwave reactor and the system, we must first be able to accurately control curve of microwave reactor furnace chamber temperature and then need to make changes, the power efficiency of a microwave reactor rate of not less than 96%, Let the system has high stability and reliability to again, and good electromagnetic compatibility. The higher requirements of the overall design of microwave reactor is proposed. This paper aims to build a highly efficient use of power electronic technology and embedded technology, high power density, high stability, low cost, and has a microwave reactor control system good electromagnetic compatibility. The magnetron microwave reactor because of its special voltammetric characteristics in the work area, the variation of voltage will be small due to current amplitude changes greatly, which causes the great power changes, if the system only through the detection voltage to control the magnetron, the system is very difficult to obtain the power output stable, thus affecting the precise control of the temperature of the stove cavity; if the system directly through the current detection method to control the magnetron, currently can not accurately determine the magnetron The work area. This paper adopts the control mode of voltage and current are combined, and with adaptive fuzzy control algorithm to PID, which can effectively control the magnetron power, in some of the sintering temperature curve requires strict application, the system can control the furnace chamber temperature curve well. High power magnetron for industrial use the commonly used high voltage DC driving mechanism, the principle and the electromagnetic interference of AC-DC switch power supply for driving magnetron the in-depth analysis of the conventional switching power supply compared with the linear power supply efficiency has been greatly improved, but further improve the power density conditions, power supply efficiency decreased, not to meet the design requirements, this paper adopts LCC resonant soft switching technology based on the use of switch in zero current or zero voltage condition and shutdown method, large Reduces the switching loss of the switching tube, so that the power efficiency is above 96%. At the same time, due to the special condition of the switch turn-on and turn off, greatly reducing the electromagnetic interference of the system, but also reduce the interference of power supply module to the other modules, improve system reliability and stability control system. The embedded technology used ARM CORTEX-M3, with the STM32 microcontroller as the main control chip, the internal temperature data collected by the thermocouple reactor and auxiliary circuit using a micro controller with A/D converter, communication with a dual serial port and PC, on the other hand, receiving data from the electrical parameter measurement module, real-time monitoring of the magnetron power, in order to achieve effective control of temperature and power. Using the embedded technology greatly reduces the cost of the system at the same time, the micro controller of the computing ability is strong Provide the conditions for the arithmetic. The hardware part of the system controlled by the main control module of microwave reactor, power drive module, the electrical parameter measurement module, temperature detection module, data communication module, each module are connected by RS-485 bus. The main control module through the electrical parameter measurement module and temperature detection module and real-time monitoring of magnetron power microwave reactor cavity temperature; through data fusion and control algorithm of the power driving module to control the microwave reactor heating control to achieve the specific requirements of the host computer through the communication module; receiving instructions, state feedback data and microwave reactor. The method of modular design makes the system better testability and maintainability. At the end of the online test system is also fully embodies this point, the test results show that the actual operation of the system and a basic theoretical analysis To meet the actual needs.

【学位授予单位】：昆明理工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TF30;TP273

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