%0 Journal Article
%T The Application of Approximate Entropy Theory in Defects Detecting of IGBT Module
%A Shengqi Zhou
%A Luowei Zhou
%A Suncheng Liu
%A Pengju Sun
%A Quanming Luo
%A Junke Wu
%J Active and Passive Electronic Components
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/309789
%X Defect is one of the key factors in reducing the reliability of the insulated gate bipolar transistor (IGBT) module, so developing the diagnostic method for defects inside the IGBT module is an important measure to avoid catastrophic failure and improves the reliability of power electronic converters. For this reason, a novel diagnostic method based on the approximate entropy (ApEn) theory is presented in this paper, which can provide statistical diagnosis and allow the operator to replace defective IGBT modules timely. The proposed method is achieved by analyzing the cross ApEn of the gate voltages before and after the occurring of defects. Due to the local damage caused by aging, the intrinsic parasitic parameters of packaging materials or silicon chips inside the IGBT module such as parasitic inductances and capacitances may change over time, which will make remarkable variation in the gate voltage. That is to say the gate voltage is close coupled with the defects. Therefore, the variation is quantified and used as a precursor parameter to evaluate the health status of the IGBT module. Experimental results validate the correctness of the proposed method. 1. Introduction The survey carried out in [1] shows that the reliability of power electronic converters deserves increasing interest from industry in recent years, but the satisfaction level with reliability monitoring is low at 50%. This suggests more research effort is needed. One of the major challenges is the health management of power electronic devices due to their significant impacts on the degradation of power electronic converters. At present, the IGBTs are the most used power electronic devices in many industrial applications as well as some safe-critical fields such as traction and renewable energy [2, 3], where stringent reliability is required. Though the reliability of IGBTs has been substantial developed recently, the failure rate of IGBTs dropped from 1,000 FITs in 1995 to 20 FITs in 2000, and to only a few FITs currently where 1 FIT is equal 1 ¡Á 10£¿9 failures per device-hour [4], the IGBTs used in those safe-critical fields mentioned above may undergo severe electrical and thermal stress. Such as wind power generation, the IGBTs are subject to large-junction temperature swings during normal operation due to the inherent intermittent nature of the wind speed and low-converter-modulation frequencies [5]. Therefore, monitoring reliability degradation of IGBTs becomes an important issue and still remains as an open topic for research [6]. Reliability is the ability of a product or system
%U http://www.hindawi.com/journals/apec/2012/309789/