On-line Junction Temperature Extraction For High Power IGBT Modules With Dynamical Temperture Sensitive Elecrical Paramaters(DTSEPs)

High power IGBT module is one of the core components of high-voltage and high-power converter. Online junction temperature measurment is not only the precondition of over temperature protection, but also the important procedure of condition monitoring. Therefore, the online junction temperature extraction methods with high accuracy and fast response have recently become an academic focus. In this paper, the relationship between the junction temperature and related dynamic electrical parameters is investigated. By further exploring the packaging characteristics of high power IGBT module, the intermedia function of parasitic inductor LeE in the high power IGBT module is discovered. In light of this discovery, the concept of Dynamic Temperature Sensitive Electrical Parameter (DTSEP) is proposed. The online junction temperature extraction methods have been implemented and extended to the high power P-i-N diodes. Furthermore, the classification rules of DTSEPs based on LeE and the corresponding comprehensive assessments are summarized in this paper.The high power IGBT switching characteristic testing platform is the fundamental conditions for studying on temperature sensitive electrical parameters. Firstly, this paper proposes a synthetical design for high power IGBT switching testing platform. And a 3600A of current level testing platform is built under the proposed design rules. By introducing two separate heating sources, the junction temperature difference of IGBTs and P-i-N diodes induced by working conditions can be simulated. Besides, the impacts of the junction temperature on the transient electrical parameters, switching power losses and switching trajectories are discussed. Then, the clear descriptions of temperature-dependent electrical parameters have now been revealed. Finally, based on a specific failure case of high power multi-chip IGBT module, a comprehensive failure mechanism is proposed, which provides a new idea for failure analysis of IGBT modules.The relationship between the junction temperature and dynamic electrical parameters is close. Based on the charge control principle, a charge extraction module is built and the relationship between turn-off switching parameters and charge carrier’s motion is revealed. The analysis results find that the relationship among the bus voltage, load current and junction temperature possesse presents regularity. Based on it, the turn-off delay time and the maxium turn-off dic/dt based TSEPs are proposed. Further, the two TSEPs can be extracted by the induced voltage veE across the parasitic inductor LeE. The experimental results have verified the correctness of the proposed two TSEPs and indicate the proposed method is of good adaptation and fast response.Secondly, on account of the problem of high current injection method for P-i-N diodes, this paper puts forward the maximum recovery current di/dt and the reverse recovery falling storage charge based TSEPs. Benefiting from the specific packaging of high-power and high-voltage module, the maximum recovery current di/dt can be extracted by measuring the negative peak voltage of veE. Similarly, the reverse recovery falling storage charge can be calculated by the timing and area information of the induced voltage veE.The theoretical analysis and experimental results indicate that the two TSEPs have high sensitivities at high temperature. The proposed methods provide a good solution for the junction temperature extraction of P-i-N diodes.Then, the one-to-one correspondence between the switching electrical parameters and the induced voltage veE has been revealed. According to the distribution characteristics of induced voltage veE on the plane coordinate, the dynamic electrical paramaters extracted by veE can be divided into three categories: Voltage-Oriented, Timing-Oriented and Charge-Oriented TSEPs. Furthermore, the last section discusses the comprehensive evaluation of DTSEPs in linearity, sensitivity, calibration and online implementation aspects.Finally, by taking advantage of the one-to-one correspondence between the switching electrical parameters and the induced voltage veE across on LeE, the junction temperature can be extracted by utilizing LeE.The proposed method does not require any additional auxilaury power level component and decapsulation of IGBT module. Furthermore, this approach avoids the measurement of the high voltage and high current directly. The proposed approach provided the junction temperature extraction with new ideas. This method applies not only to junction temperature rxtraction of IGBT and Diode chips in IGBT module, but also to the Silicon Carbide devices and IGCT modules.