基于换流–短路双回路解耦的SiC MOSFET功率器件抗短路封装构型设计  

Anti-short-circuit Packaging Structure of SiC MOSFET Power Device With Commutation-short Circuit Path Decoupling

作　　者：罗皓泽[1] 高洪艺 朱安康 金昱廷 李武华[1] 何湘宁[1] LUO Haoze;GAO Hongyi;ZHU Ankang;JIN Yuting;LI Wuhua;HE Xiangning(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,Zhejiang Province,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《中国电机工程学报》2023年第7期2781-2789,共9页Proceedings of the CSEE

基　　金：国家自然科学基金青年科学基金项目(52107211);国家自然科学基金杰出青年科学基金项目(51925702);浙江省“尖兵”“领雁”研发攻关计划(2022C01094)。

摘　　要：由于栅极氧化层可靠性差、短路电流密度大以及短路结温上升速率高,SiC MOSFET功率器件的短路耐受能力较弱,制约着其在电能变换领域的广泛应用。在此背景下,为了提升SiC MOSFET功率器件的短路耐受能力,文中基于换流–短路双回路解耦的思想,设计出具有抗短路能力的SiC MOSFET功率器件封装构型。该构型将半桥中的两个换流回路在功率器件内部解耦,两换流回路的中点各自连接一个交流功率端子(AC+、AC-)。与现有半桥封装构型相比,抗短路构型功率器件的换流电流路径和换流电感Lσ不变,而当发生桥臂直通短路故障时,短路电流因需要额外流经AC+和AC-交流功率端子而延长了短路路径,同时DC功率端子与AC功率端子之间的互感进一步增大了短路回路电感Lsc。基于34mm封装构型设计制造具有抗短路极限工况能力的650V/162A SiC MOSFET功率器件,其短路故障回路电感达到了115nH,是正常换流回路电感的3.6倍;并且,通过短路实验验证所设计的构型相比于现有设计,短路电流峰值降低了20.07%,发热功率降低了21.41%,短路过程中的总发热量降低了30.04%,验证了所设计封装构型具有一定的抗短路性能。Due to poor gate oxide reliability,high short circuit current density and junction temperature rising rate,the short circuit withstand capability of SiC MOSFET power device is weak,which limits its wide application in the field of electric energy conversion.In this context,to improve the short circuit withstand capability of SiC MOSFET power device,this paper designs an anti-short-circuit packaging structure based on decoupling of commutation and short circuit path.The structure decouples the two commutation loops inside the power device,and the midpoints of the two commutation loops are respectively connected to an AC power terminal(AC+,AC-).Compared with the currently available structure,the commutation current path and inductance Lσof the anti-short-circuit power device structure remain unchanged.When a short circuit fault occurs,the short circuit current needs to flow through the AC+and AC-power terminals to extend the short circuit path.At the same time,the mutual inductance between the DC and AC power terminals further increases the short circuit loop inductance Lsc.In this paper,a 650V/162A SiC MOSFET power device with the ability to withstand short-circuit extreme conditions is designed and manufactured based on a 34mm package,and its Lsc reaches 115nH,which is 3.6 times of Lσ.Compared with the currently available design,the proposed structure reduces the peak value of short-circuit current by 20.07%,the heating power by 21.41%,and the total heat generation during the short-circuit process by 30.04%,which validates its certain anti-short-circuit capability.

关 键 词：换流–短路路径解耦 短路电感 短路抑制 

分 类 号：TM46[电气工程—电器]