LLC谐振低频感应加热系统设计

Design of LLC Resonance Low-frequency Induction Heating System

对LLC谐振电路的电压增益、电流增益等特性进行了理论分析。通过Simulink搭建了基于LLC谐振电路的低频感应加热电源,对电路的预充滤波电路、整流电路、PID闭环控制电路、SPWM控制电路进行了仿真分析。搭建了基于LLC谐振的并联型低频感应加热电源,对电路的IGBT驱动信号、输出电流电压、工作频率和功率因素进行了测试。结果显示:加热电源的输出电压约200V,输出电流约310A,铝合金棒料加热温度超过450℃时,功率因素达到0.97。

Theoretical analysis was conducted on the voltage gain and current gain characteristics of the LLC resonant circuit.A low-frequency induction heating power supply based on the LLC resonant circuit was constructed by Simulink.The structures such as the pre-charging filter circuit,rectification circuit,PID closed-loop control circuit,and sinusoidal pulse width modulation control circuit were simulated and analyzed.A parallel-type low-frequency induction heating power supply based on LLC resonance was built,and tests were conducted on the insulated gate bipolar transistor driving signals,output current and voltage,operating frequency,and power factor.The test results show that the output voltage of the heating power supply reaches around 200 V,and the output current is around 310 A.When aluminum alloy bars are heated to above 450℃,the power factor reaches 0.97.