【摘要】 新能源汽车动力电池发生短路故障时,可靠、快速地实现分断保护对于保护人身财产安全至关重要。传统的热熔型熔断器无法在低倍电流工况下实现稳定分断,而新型的烟火型熔断器则存在控制器判断失效的情况下无法执行保护动作的风险。为满足新能源汽车功率回路快速、可靠、被动分断的需求,在此采用固态分断电路的基本原理,基于SiC MOSFET设计了一种自锁型无极性过流保护单元,额定载流60 A,可以实现1.5倍分断保护(90 A)。该电路采用隔离电源直驱拓扑,结构简单,性能稳定。测试结果显示,在此所设计的过流保护单元保护动作时间8.4 ms,闭合动作时间22.8 ms,分断动作时间3.1 ms,满足新能源汽车应用要求。更多还原

【Abstract】 In the event of a short circuit fault in the battery of a new energy vehicle,reliable and fast breaking protection is essential to protect the safety of people and property.While the traditional hot-melt fuse can not achieve stable breaking under low current conditions,the new pyro-fuse risks not being able to perform protective actions if the judgment of the controller fails.In order to meet the needs of fast,reliable and passive breaking of power loop of new energy vehicle,a self-locking omni-polar overcurrent protection unit is designed based on SiC MOSFETs and solid state breaking circuit principle,with a rated current of 60 A and 1.5 times breaking protection(90 A).It has simple structure and stable performance with isolated power direct drive topology.The test results show that the designed overcurrent protection unit has a protection action time of 8.4 ms,a closing action time of 22.8 ms,and a breaking action time of 3.1 ms,which meets the requirements of new energy vehicle applications.更多还原