The impact of gate-driver parameters variation and device degradation in the PV-inverter lifetime

Abstract

Abstract-This paper introduces a reliability-oriented design tool for a new generation of grid connected PV-inverters. The proposed design tool consists of a real field Mission Profile (MP) model (for one year operation in USA-Arizona), a PV-panel model, a grid connected PV-inverter model, an Electro-Thermal model and the lifetime model of the power semiconductor devices. A simulation model able to consider a one year real field operation conditions (solar irradiance and ambient temperature) is developed. Thus, one year estimation of the converter devices thermal loading distribution is achieved and is further used as an input to a lifetime model. The proposed reliability oriented design tool is used to study the impact of MP-variation, Gate-Driver (GD) parameters variation and device degradation in the PVinverter lifetime. The obtained results indicate that in order to improve the accuracy of the lifetime estimation it is crucial to consider also the device degradation feedback. Moreover the MP of the field where the PV-inverter is operating and the GDparameters selection has an important impact in the converter reliability and it should be considered from the design stage to better optimize the converter design margin.

Impact of the gate driver voltage on temperature sensitive electrical parameters for condition monitoring of SiC power MOSFETs

“…The higher temperature sensitivity of the on-state resistance and the current switching rate at low V GS voltages could be exploited using an intelligent gate driver [4,10] capable of applying customized occasional switching pulses for junction temperature estimation, as it has been already proposed [11]. The temperature sensitivity for multiple chip modules together with the stability of the proposed TSEPs during the ageing of the power module should be the next research steps.…”

“…In [10], a gate driver which can modify the output voltage and the output resistance was presented for achieving active thermal control, and in [11] the gate resistance was modified for identifying the junction temperature using the turn-off delay time as TSEP for SiC MOSFETs, thereby suggesting that the technology for implementing these techniques is already available.…”

“…As was already mentioned in Section 2.3, there are already intelligent gate drivers with the ability to change the output resistance and/ or the gate driver output voltage [10,11]. Together with gate drivers with di/dt control proposed for IGBTs [12], this suggests that it is possible to alter the gate drive resistance for occasional diagnostic pulses needed for on-line condition monitoring.…”

Review of Power Semiconductor Device Reliability for Power Converters

“…Gate voltage and the driving resistance have an effect on loss, the relationship among the gate voltage, resister and power devices lifetime has been estimated according to a real field mission profile [92]. Gate control does not affect the current ripple of the converter output, but gate control requires additional circuit.…”

Active thermal control of IGBT power electronic converters

“…Only few active thermal control approaches have been proposed so far. Chosen control parameters are the switching frequency [2], [14], the modulation method [15], the dc link voltage [16], the gate voltage [17] or circulating reactive power [18]. As an example, a shortterm temperature drop can be prevented or reduced when losses are increased temporary by increasing the switching frequency.…”