一种基于反向串联稳压二极管钳位的IGBT导通压降在线监测电路

An Online Monitoring Circuit for IGBT Conduction Voltage Drop Based on Reverse Series Zener Diodes Clamping

绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)模块应用广泛。为保证IGBT可靠工作,其结温监测吸引了广泛的关注。而集电极–发射极导通压降Vce为IGBT结温监测中最常用的参数,故在线监测Vce具有重要意义。为解决传统Vce测量电路中钳位电路引入测量误差、共模干扰的问题,文中提出一种IGBT导通压降在线监测电路,采用二极管反向串联稳压二极管作为钳位电路,同时通过引入缓冲电容对此类测量电路拓扑中的负压过冲进行抑制,相比传统电路可提高精度,增强可靠性,减少成本。提出电路的性能通过实验验证,并通过温敏电参数Vce实现对IGBT结温的监测,并将其结果与红外测温仪所测结温进行对比,验证该方法的有效性。

Insulated gate bipolar transistor(IGBT)module is widely used.To guarantee the reliability of the IGBT,the junction temperature(Tj)monitoring attracts much popularity.Its collector-emitter conduction voltage(Vce)is the most commonly used parameter in Tj monitoring of the IGBT.Hence,on-line monitoring of Vce is of great significance.To solve the problem of measurement error and common mode interference introduced by the clamp circuit in the traditional Vce measurement circuit,this paper proposed an online monitoring circuit for Vce of the IGBT.This paper proposed to use diodes reverse series Zener diodes as the clamping circuit,and the buffer capacitor was introduced to suppress the negative pressure overshoot in the measurement circuit topology.Compared with the traditional circuit,the accuracy is improved,and accordingly the reliability enhancement and cost reduction are achieved.The performance of the proposed measuring circuit was verified by experiments.Moreover,Tj of the IGBT is monitored through the temperature-sensitive electrical parameter Vce.The results were compared with the Tj measured by the infrared thermometer,which verifies the effectiveness of the proposed measuring circuit.