應用於感應加熱的負載串聯共振電壓型反流器設計與研製

Design and Implementation of Voltage-Fed Load Series Resonant Inverter for Induction Heating System

何金滿(Jin-Maun Ho) ； 許國展(Kuo-Chan Hsu)

《中原學報》 31卷3期 (2003/09) Pp. 263-270

https://doi.org/10.6358/JCYU.200309.0263

摘要

本論文的主要目標在建立一個以單晶片TMS320C240微處理器為基礎的數位化高頻感應加熱器。此數位化高頻感應加熱器已將切換頻率提高至70kHz，減短加熱過程所需的時間，並使用零電壓切換相移式脈波寬度調變技術，降低功率開關元件之切換損失、切換應力及電磁干擾。有鑑於加工物件在加熱過程中，其本身的電氣特性會隨之而改變，致使共振頻率亦隨著加熱時溫度之變化而變動。所以利用變頻控制技術來使驅動頻率追隨共振頻率，促使系統在運轉時的效率隨時保持於最佳狀態。同時，為了能夠調整輸出功率，乃藉由相移脈波寬度調變控制技術來改變輸出電壓的工作週期，來達成此一目標。
最後，将對加熱時產生的負載參數變化現象以及在負載變動下反流器的運轉性能等進行實際的量測及探討，並驗證此零電壓切換技術的確提高了系統的整體效率。

關鍵字

數位化高頻感應加熱器 ； 微處理器 ； 零電壓切換相移式脈波寬度調變技術 ； 加工物件

並列摘要

The main purpose of this study is to investigate the application of a single chip,TMS320C240,microprocessor to a fully digital high frequency induction heating system which has enhanced the switching to 70kHz can decrease time during heating process. By using the phase-shifted full-bridge zero-voltage-switched PWM technique, this system can reduce switching loss, component stress, and electromagnetic interference of power semiconductor devices. In induction heating applications, because the electrical characteristics of the workpieces will change in the processing, the circuit resonant frequency must be changed in accordance. Hence, the variable frequency control technique is used for tracking the resonant frequency to keep the system operating at the optimal condition. The phase-shift Pulse-Width-Modulated (PWM) is used for regulating the duty-cycle to control the output power. Finally, the efficiencies of this heater are measured and analyzed under load variations. Experimental results show that the ZVS PWM technique can improve the efficiency of this system.

並列關鍵字

fully digital high frequency induction heating system ； microprocessor ； phase-shifted full-bridge zero-voltage-switched PWM technique ； workpiece