基于EXB841的IGBT驅動與保護電路研究

摘要：本文敘述了絕緣柵雙極型晶體管IGBT對驅動和保護電路的要求。并簡要介紹了IGBT專用驅動芯片EXB841的驅動原理，進而針對EXB841典型IGBT驅動保護中存在的不足，提出了采用過流檢測電路精確調整過流閾值，延遲電路識別虛假過流和過流鎖定，采用外部成型電路提高負柵壓和系統應用中及時的故障顯示等改進方法。設計了相應的優化驅動電路，優化驅動電路在脈沖發生電源中得到應用。實際運行表明優化驅動電路克服了EXB841典型驅動的不足，改善了IGBT的驅動與保護性能，具有很好的實用性。 敘詞：IGBT EXB841 驅動電路 故障顯示 Abstract：This paper introduced the require of driving and protecting circuit for IGBT and gave a brief description of the Working principle of EXB841 that the special driving chip of IGBT. Based on the shortages of EXB841s typical driving circuit for IGBT, some effective countermeasures ,which included the over protection detecting circuit to modulate accurately over protection threshold , and the identifying and locking circuit of over-current malfunction to identify false over-current and to lock over-current , the external grid-voltage molding circuit to boost grid-voltage were put forward , and an optimum driving circuit was designed . The optimum dring circuit has been used in the pulse power of High-frequency and High-voltage . And the experiment result have proved that the optimum circuit not only overcomes the defects of EXB841 , but also improves greatly IGBTs driving and protection capability . As a result , the optimum circuit will have considerable value in practical application. Keyword：IGBT, EXB841, Driving circuit, Fault display