Abstract
This article discusses an active gate driver for a 1.7 kV/325 A SiC MOSFET module. The main purpose of the driver is to adjust the gate voltage in specified moments to speed up the turn-on cycle and reduce the amount of dissipated energy. Moreover, an adequate manipulation of the gate voltage is necessary as the gate current should be reduced during the rise of the drain current to avoid overshoots and oscillations. The gate voltage is switched at the right moments on the basis of the feedback signal provided from a measurement of the voltage across the parasitic source inductance of the module. This approach simplifies the circuit and provides no additional power losses in the measuring circuit. The paper contains the theoretical background and detailed description of the active gate driver design. The model of the parasitic-based active gate driver was verified using the double-pulse procedure both in Saber simulations and laboratory experiments. The active gate driver decreases the turn-on energy of a 1.7 kV/325 A SiC MOSFET by 7% comparing to a conventional gate driver (VDS = 900 V, ID = 270 A, RG = 20 Ω). Furthermore, the proposed active gate driver lowered the turn-on cycle time from 478 to 390 ns without any serious oscillations in the main circuit.
Highlights
Manufacturers of MV silicon carbide (SiC) MOSFETs provide new devices with short switching times counted in hundreds of nanoseconds which is related to low switching energies and power losses
The feedback signal of the active gate driver (AGD) was acquired with a switch voltage sensor based on an RC branch connected to the drain of the SiC MOSFET
There are studies with an AGD for a 1.7 kV SiC MOSFET where the feedback loop is based on the parasitic inductances of the source and drain [15], and the multi-level gate voltage method is used for turn-on and turn-off cycle improvement
Summary
Medium-voltage (MV) silicon carbide (SiC) MOSFET power modules are used in a significant amount of power applications, including electric vehicle power systems and small renewable power plants based on photovoltaics [1]. The switching trajectory improvement of an AGD for a 1.2 kV/40 A SiC MOSFET was discussed in [10], where the feedback loop of the driver was based on the resistive measurement derived from the drain-source voltage vDS and drain current iD. As the closed-loop test results showed, the authors accomplished balancing of the drain-source voltage values in series connection in comparison to natural voltage sharing In this case, the feedback signal of the AGD was acquired with a switch voltage sensor based on an RC branch connected to the drain of the SiC MOSFET. There are studies with an AGD for a 1.7 kV SiC MOSFET where the feedback loop is based on the parasitic inductances of the source and drain [15], and the multi-level gate voltage method is used for turn-on and turn-off cycle improvement.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.