Four Level Voltage Active Gate Driver for Loss and Slope Control in SiC MOSFETs

Abstract

Silicon Carbide power semiconductors exhibit fast dynamic behavior. This facilitates the design of high efficiency and high power density converters. However, the resulting current and voltage changing rates demand extensive filtering to avoid electromagnetic interference and ensure safe operation. In addition, temperature fluctuations due to varying load currents from renewable energy sources pose challenges for power semiconductor device lifetime and reliability. Active temperature control can reduce temperature fluctuations, but affects switching slopes simultaneously. This leads to variable electrical stress on both device and circuit level. In this paper, a four-level active voltage-source gate driver for SiC MOSFETs is proposed, enabling manipulation of switching and conduction losses. Switching losses are manipulated by controlling the duration as well as amplitude of intermediate gate voltage pulses during switching transients. Conduction losses can be influenced by adjusting the positive gate voltage. Simulations indicate that the proposed gate driver allows decoupling switching loss and slope control. To validate the gate driver concept, a prototype has been built and evaluated in double pulse test experiments.

Wireless Control of Active Gate Drivers for Silicon Carbide Power MOSFETs

“…A Four Level MLVSGD was used for demonstrating the application of BLE for wireless AGD control. This specific AGD was chosen for practical reasons, as it was studied in earlier work [8]. However, other AGDs like active current source, variable resistor, and other multilevel voltage gate drivers [2]- [6], [9], [10], [15]- [18], [20] could be used with the proposed wireless AGD control, if they implement control over a UART interface that can be connected to a BLE UART bridge, as will be explained below.…”

“…Vint,on 0 0 tint,on [8]: Idealized Gate Driver Output Voltage V GG and corresponding Control Signals for the half-bridge circuits HB1, HB2, and HB3 of the AGD The MLVSGD applies a configurable Intermediate Driving Voltage Level (IDVL) to the gate at turn-on (V int,on ) and another configurable IDVL at turn-off (V int,off ). The IDVLs 2) that is controlled by the TMS320F280049C MCU (AGD Control Unit in Figure 2) using the Serial Peripheral Interface (SPI).…”

“…As opposed to conventional gate drivers, AGDs are onlinereconfigurable circuits that can manipulate the gate charging process [2]- [6], [8]- [11]. AGDs have successfully activated the technological advantages of SiC MOSFETs by providing effective, yet fine-grain control of switching transitions [2]- [6], [8]- [11]. In addition, many AGDs incorporate sensors that enable monitoring key parameters of switching devices.…”

“…circuitry and operating principles, employed to achieve switching transient control. The majority of AGDs require timed multichannel digital signals [4], [9], [13], [15], [16], and in addition to that, some need another digital or analog configuration signal [8], [10], [17].…”

Real-Time Discrete Electrothermal Model of Dual Active Bridge Converter for Photovoltaic Systems

“…The proposed real-time model is suitable for implementation on digital signal processors (DSPs) deployed either locally in gate drivers or as central converter controllers. In particular, this model can be used in the intelligent gate drivers to perform active thermal control [9], [24]- [26] for enhancing either efficiency or reliability of the power electronic converters. The presented real-time model of the DAB converter lowers the simulation time significantly and can be used in digital control design [27], [28].…”