An Adaptive Current-Source Gate Driver for High-Voltage SiC mosfets

Abstract

This paper presents a novel current-source gate driver for Silicon Carbide (SiC) metal oxide semiconductor fieldeffect transistors (MOSFETs) with adaptive functionalities. The proposed driver aims to decouple and improve controllability of di/dt, dv/dt, as well as to decrease turn-on and turn-off delay times compared to conventional totem-pole voltage-source gate drivers and conventional current-source gate drivers. The circuit topology of the proposed gate driver and the working principle are analysed for the turn-on and turn-off processes. Furthermore, the driving requirements in terms of gate voltage and gate current for SiC MOSFETs that determine the design and tuning of gate drivers are presented. The performance of the proposed gate driver is validated experimentally on a 3.3 kV/750 A SiC MOSFET half-bridge power module. It is shown that, compared to conventional voltage-source gate drivers, the driver is capable of significantly reducing turn-on and turn-off delay times by approximately 57% and 33%, respectively. Moreover, the proposed gate driver enables 233% controllability of di/dt and 87% of dv/dt.

A Hybrid Current- and Voltage-Source Driver for Active Driving of Series-Connected SiC MOSFETs

“…4a. The inductor is pre-charged for a time ∆t pre , which depends on the magnetizing inductance of the inductor, leakage inductance, source voltage and amount of charge in the inductor required to discharge the gate capacitance of the SiC MOSFETs [37]. The required energy to discharge the input capacitance of the SiC MOSFET, C iss , is given by:…”

“…Besides, the possibility to control the switching losses, i.e. by for instance increasing the dv/dt and di/dt of the stack and reducing the switching loss, is enabled [37].…”

Multi-Pulse Si-MOSFET Gate Driving Utilizing Gate Loop Inductance

“…A common approach to improve performance and safety is the minimization of L P ar [1]- [3], which is effective but limited by thermal, mechanical, and cost constraints. Another promising approach to overcome the minimum damping requirement and improve performance of CGD are active gate drivers (AGD), which are able to generate non-linear driving signals by adjusting either their internal resistance [4]- [6], or gate voltage [7]- [9], or gate current [10]- [12]. However, a common problem with AGDs is the added complexity through either multiple stages [4]- [9], external components to form a resonant circuit [10]- [12], or both.…”

“…Another promising approach to overcome the minimum damping requirement and improve performance of CGD are active gate drivers (AGD), which are able to generate non-linear driving signals by adjusting either their internal resistance [4]- [6], or gate voltage [7]- [9], or gate current [10]- [12]. However, a common problem with AGDs is the added complexity through either multiple stages [4]- [9], external components to form a resonant circuit [10]- [12], or both. Other approaches focus on improving the efficiency and safety of the hard-switched application by actively suppressing false turn-ON failures via clamping circuits [13]- [15], with the drawback of added complex-ity.…”

“…What follows are the descriptions of the time intervals to determine t A and t B via the turn-ON Sequence, which is analog to the turn-OFF sequence as described in (12).…”