Prethreshold Voltage as a Low-Component Count Temperature Sensitive Electrical Parameter Without Self-Heating

Abstract

Temperature Sensitive Electrical Parameters (TSEPs) are promising for measurement of the IGBT junction temperature. Many TSEPs have been proposed in the literature and most require current sensors, and convoluted hardware and data processing, which are associated with increased complexity and cost. In this letter, a new TSEP is proposed called pre-threshold TSEP, VGE(pre-th). VGE(pre-th) requires only a voltage sensor and a counter. Besides less hardware requirement, VGE(pre-th) does not suffer from self-heating -a problem that most TSEPs encounter. This letter presents the operation of VGE(pre-th) with the help of simulation. Experimental tests on a 3.3kV, 800A IGBT were conducted to characterize VGE(pre-th). It is shown that the new TSEP proposed has a sensitivity of -2.2mV/°C.

Ensuring a Reliable Operation of Two-Level IGBT-Based Power Converters: A Review of Monitoring and Fault-Tolerant Approaches

“…The other approach uses dynamic electrical parameters to estimate T j . Such dynamic parameters include the threshold voltage V th [31], [33], [80]- [83], Miller-plateau voltage V gp [84], turn-on delay time t don [85], maximum current slope of turn-on dI/dt max,on [85], turn-off time t off [85], [86], turn-off delay time t doff [87], the peak value of V EE max during turn-off [88], [89] and the flatband voltage V fb [90]. The following describes the above methods.…”

Gate–Emitter Pre-threshold Voltage as a Health-Sensitive Parameter for IGBT Chip Failure Monitoring in High-Voltage Multichip IGBT Power Modules

“…The main advantage of VGE(pre-th) over IG(peak) is that VGE(pre-th) employs a voltage sensor while IG(peak) utilises a current sensor. In general, voltage sensors are cheaper, simpler and lightweight compared to current sensors hence voltagebased HSPs are preferred from a practical perspective [57].…”

The Temperature Dependence of the Flatband Voltage in High-Power IGBTs

“…At this point, the gate capacitance reduces sharply and the gate begins to charge significantly faster before reaching the VTH approximately 400ns afterwards. Despite the effect of VFB illustrated above, previous literature discussing the switching of IGBTs has typically omitted mentioning the influence of VFB [2][3][4]. The variance of the gate capacitance during the turn-on delay is also not accounted for in device datasheets.…”

“…The past three years have seen a significant number of proposals relating to the use of TSEPs [2][3][4][5][9][10][11][12][13][14][15][16][17]. There are however several practical issues that hamper the use of TSEPs.…”

“…Another problem is that the majority of TSEPs have a dependency on load current. These TSEPs must undergo complex calibration procedures since the load current causes self-heating in the semiconductor which consequently must be compensated for [4,6,7].…”