基于DSP和FPGA的中频感应加热电源的研究

发布时间：2018-08-23 09:11

【摘要】：感应加热技术就是利用电磁感应原理，在螺线管中通入交变的电流，从而产生交变磁场，通过工件切割磁场产生涡流，再利用工件自身的电阻发热，来达到加热效果的。感应加热电源具有对金属材料加热效率最高、速度最快，且低耗环保的优点。此外，感应加热电源还容易实现对温度的控制，作业环境好，能加热复杂形状的工件，因此，感应加热电源已经成为我国研究的热点问题。目前，可控硅中频感应加热电源存在一些问题，如电源功率因数低、启动困难、启动成功率低、功率调节有限、控制系统复杂等。对于功率调节和控制系统复杂的问题，制定了DSP和FPGA联合控制的解决方案，使得中频电源的控制更加智能化。对于电源功率因数低的缺点，设计了数字锁相环，采用定角控制，能够把电源的逆变角控制在一个很小的范围内，提高电源的功率因数。对于可控硅中频电源的启动问题，采用了辅助启动加扫频的启动方式，实现它激振荡转自激振荡，使得可控硅中频电源的启动成功率上升到99%。本课题针对原有传统模拟300KW并联谐振型中频感应加热电源，分析其负载特性，电源工作过程以及调功控制方式，然后，在此基础上运用DSP和FPGA芯片进行数字化的中频感应加热电源的改造。其中重点分析了传统模拟电源的控制策略和调功方式，实现了相序自适应的可控硅移相全桥控制模式。并深入分析了电源在加热过程中的负载特性，实现了逆变角定角控制和大范围的频率跟踪。同时针对其调功方式的不同，本课题设计了两种控制策略，，达到传统电源无法达到的效果。接着，分析了电源启动的问题，设计了辅助启动加扫频的启动方式。最后，进行了上机调试和带载实验，测量了电路工作时的相关波形。
[Abstract]:Induction heating technology is to use the electromagnetic induction principle, in the solenoid into the alternating current, so as to produce an alternating magnetic field, through the cutting magnetic field of the workpiece to generate eddy current, and then use the workpiece's own resistance to heat, to achieve the heating effect. Induction heating power supply has the advantages of the highest heating efficiency, the fastest speed and low consumption of environmental protection. In addition, the induction heating power supply is easy to control the temperature, the working environment is good, and it can heat the workpiece with complex shape. Therefore, the induction heating power supply has become a hot issue in our country. At present, there are some problems in thyristor medium frequency induction heating power supply, such as low power factor, difficult start-up, low success rate, limited power regulation, complex control system and so on. For the complex problem of power regulation and control system, the solution of DSP and FPGA joint control is developed, which makes the control of if power supply more intelligent. For the shortcoming of low power factor, a digital phase-locked loop is designed, which can control the inverter angle of the power source in a small range and improve the power factor of the power supply. For the start up of thyristor if power supply, the auxiliary start and sweep mode is adopted to realize its oscillation to self-excited oscillation, and the success rate of thyristor intermediate frequency power supply is increased to 99%. This topic aims at the traditional analog 300KW parallel resonant medium frequency induction heating power supply, analyzes its load characteristic, power supply working process and power regulation control mode, then, On this basis, DSP and FPGA chips are used to transform the digital if induction heating power supply. The control strategy and power regulation mode of the traditional analog power supply are analyzed, and the phase-sequence adaptive phase-shift full-bridge control mode is realized. The load characteristics of the power supply during heating are analyzed, and the inverter angle control and wide range frequency tracking are realized. At the same time, two control strategies are designed to achieve the effect that the traditional power supply can not achieve. Then, the problem of power supply startup is analyzed, and the starting mode of auxiliary start-up is designed. Finally, debugging and loading experiments are carried out, and the relevant waveforms of the circuit are measured.
【学位授予单位】：北京工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM924.01

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