摘要
IGBT光耦驱动芯片的去饱和检测端阈值电压固定不可调,一般为6.5 V~10 V,此阈值保留的IGBT过流余量较大,难以将过载电流限制在过流发生的初期,给应用造成不便。提出一种通过改变PWM波占空比调整检测阈值的方法,设计了采用光耦、电压基准TL431和比较器LM2903的低成本方案,并详细分析了该电路的保护原理。该电路具有简单可靠、调试方便、利于生产等优点。实验表明,IGBT过流检测电路能迅速、准确地响应并动作,使IGBT在不同的过流情况下得到及时有效的保护。
The threshold voltage of the desaturation detection function of IGBT driver optocoupler is not adjustable,generally from 6.5 V to 10 V.The overcurrent margin retained by this threshold is too large,and it is difficult to limit the overload current to the initial stage,which causes inconvenient application.A method is proposed to adjust the detection threshold by changing the duty cycle of PWM wave,and a low-cost scheme is designed by using optocoupler,L431 and LM2903.,then the protection principle of the circuit is analyzed in detail.The circuit has the advantages of simple and reliable,convenient debugging and favorable production.Experiments show the IGBT overcurrent detection circuit can respond and operate quickly and accurately,so that the IGBT can be protected in time and effectively in different overcurrent conditions.
作者
李一文
LI Yiwen(Chongqing Research Institute Co.,Ltd.,of China Coal Technology and Engineering Group,Chongqing 400039,China;State Key Laboratory of Gas Disaster Monitoring and Emergency Technology,Chongqing 400039,China)
出处
《自动化与仪器仪表》
2021年第2期169-171,175,共4页
Automation & Instrumentation
基金
天地科技创新基金面上项目(No.2018-TD-MS074)
重庆市技术创新与应用示范专项产业类重点研发项目(No.cstc2018jszx-cyzdX0066)。
关键词
过流保护
检测电路
短路检测
IGBT驱动
overcurrent protection
detection circuit
short-circuit detection
IGBT drive
