中频感应加热电源的设计.doc

中频感应加热电源的设计

摘  要

中频感应加热以其加热效率高、速度快，可控性好及易于实现机械化、自动化等优点，已在熔炼、铸造、弯管、热锻、焊接和表面热处理等行业得到广泛的应用。
本设计根据设计任务进行了方案设计，设计了相应的硬件电路，研制了20KW中频感应加热电源。
本设计中感应加热电源采用IGBT作为开关器件，可工作在10 Hz～10 kHz频段。它由整流器、滤波器、和逆变器组成。整流器采用不可控三相全桥式整流电路。滤波器采用两个电解电容和一个电感组成Ⅱ型滤波器滤波和无源功率因数校正。逆变器主要由PWM控制器SG3525A控制四个IGBT的开通和关断，实现DC-AC的转换。
    设计中采用的芯片主要是PWM控制器SG3525A和光耦合驱动电路HCPL-316J。设计过程中程充分利用了SG3525A的控制性能，具有宽的可调工作频率，死区时间可调，具有输入欠电压锁定功能和双路输出电流。由于HCPL-316J具有快的开关速度（500ns），光隔离，故障状态反馈，可配置自动复位、自动关闭等功能，所以选择其作为IGBT的驱动。
对原理样机的调试结果表明，所完成的设计实现了设计任务规定的基本功能。此外，为了满足不同器件对功率需要的要求，设计了功率可调。这部分超出了设计任务书规定的任务。

关键词：感应加热电源；串联谐振；逆变电路；IGBT

Abstract

The Intermediate Frequency Induction Heating has been widely applied in melting, casting, bend, hot forging, welding, Surface Heat Treatment due to its advantages of high heating efficiency、high speed、easily controlled、easily being mechanized and automated.
The scheme has made a plan of designs based on the task of design, designed corresponding hardware circuit and developed 20kW intermediate frequency induction heating power system.
The thesis discusses the Choice of converter scheme in detail. Series Resonance Inverter has another name is Voltage Inverter. Its Output Voltage approaches square wave and load current approaches sine-wave. Inversion must follow the Principles of break before make and there is enough dead-time between turn-off and turn on in order to avoiding direct through in upper and lower bridges.     The thesis discussed the Choice of converter scheme in detail as well as introduced the control circuit of this power source and its design principle. Develop 20kW intermediate frequency induction heating power system with switch element IGBT. Make a research on Converter Circuit, control circuit, driver circuit etc.
The CMOS chip that is applied in the design is mainly PWM Controller SG3525A and optical coupler Drive Circuit HCPL-316J. The controlled feature of PWM Controller SG3525A is fully utilized in the process of design, which has wide adjustable operating frequency and dead time, input under voltage lock function and twin channel output current. The optical coupler Drive Circuit HCPL-316J is chosen as the driven of IGBT due to its functions, such as fast switch speed (500ns), optical isolation, the feedback of fault situation, wide operating voltage (15V～30V), automatic reset and automatic close down etc.

Key words：Induction heating power supply; series resonance；inverse circuit；IGBT

目    录

引言 1
1  绪论 2
1.1 感应加热的工作原理 2
1.2 感应加热电源技术发展现状与趋势 3
2  感应加热电源实现方案研究 5
2.1 串并联谐振电路的比较 5
2.2 串联谐振电源工作原理 7
2.3 电路的功率调节原理 8
2.4 本课题设计思路及主要设计内容 8
3  感应加热电源电路的主回路设计 9
3.1 主电路的主要设计元器件参数 9
3.2 感应加热电源电路的主回路结构 9
3.2.1主回路的等效模型 10
3.2.2整流部分电路分析 13
3.2.3逆变部分电路分析 15
3.3 系统主回路的元器件参数设定 16
3.3.1整流二极管和滤波电路元件选择 16
3.3.2IGBT和续流二极管的选择 17
3.3.3槽路电容和电感的参数设定 18
4  控制电路的设计 19
4.1控制芯片SG3525A 19
4.1.1内部逻辑电路结构分析 20
4.1.2芯片管脚及其功能介绍 21
4.2 电流互感器 23
5  驱动电路的设计 24
5.1 绝缘栅双极型晶体管（IGBT）对驱动电路的要求 24
5.1.1门极电压对开关特性的影响及选择 24
5.1.2门极串联电阻 对开关特性的影响及选择 25
5.2 IGBT过压的原因及抑制 25
5.3 IGBT的过流保护 26
5.3.1设计短路保护电路的几点要求 27
5.4 集成光电隔离驱动模块HCPL-316J 27
5.4.1器件特性 27
5.4.2芯片管脚及其功能介绍 28
5.4.3内部逻辑电路结构分析 28
5.4.4器件功能分析 29
5.4.5驱动电路的试验和注意问题 30
6  辅助直流稳压电源 31
6.1 三端固定稳压器 31
6.2 本次设计用的的电源 32
6.2.1 18伏，15伏稳压电压电源 32
6.2.2 ±12伏，±5伏双路稳压电源 32
6.2.3元器件选择及参数计算 33
7  硬件调试 34
8  结论 35
致谢 37
参考文献 38
附录一 整体电路原理图 39
附录二控制电路PCB 40