Analysis of cascaded silicon carbide MOSFETs using a single gate driver for medium voltage applications

Abstract

Medium voltage power supplies for applications such as electrostatic precipitators are used in industrial plants to remove particles from fumes. Current solutions based on silicon devices rely on high-voltage transformers to reach the required output voltage levels. New wide band gap materials such as silicon carbide have higher electric breakdown voltage, and thus fewer devices are required in series to withstand the output voltage. Owing to the faster switching speed of silicon carbide devices further demands are put on the serialisation method. In this study, a cascaded series-connection method using only a single external gate signal is analysed in detail, guidelines to size the resistor-capacitor-diode-snubber are proposed and its applicability is experimentally demonstrated. The circuit is tested with four series-connected devices in a double pulse test at 2400 V and current levels of 250-800 mA to show the load dependence. The serialisation technique is tested in a boost converter operating in discontinuous conduction mode but is limited to 1200 V due to an oscillating state occurring after zero current crossing. Finally, the technique is tested at 2400 V and 10 kHz in a synchronous boost converter, which demonstrates the proposed design guidelines.

Short-Circuit Characteristic of Single Gate Driven SiC MOSFET Stack and Its Improvement With Strong Antishort Circuit Fault Capabilities

“…2(a), their basic working principles are the same [22]. In addition, using an auxiliary isolated power supply to construct PDU is one option if it can provide enough driving power and isolation voltage [23]. However, as more devices are connected in series, more separated auxiliary power supplies are required, resulting in a higher cost.…”

Review on Driving Circuits for Wide-Bandgap Semiconductor Switching Devices for Mid- to High-Power Applications

“…A single gate driver was designed to drive four cascaded series-connected SiC MOSFETs for medium voltage applications [ 73 ]. This was realized using an auxiliary circuits consisting of diodes, zener diodes, resistors, and capacitors.…”

Performance evaluation of a grid‐connected three‐phase six‐switch boost‐type current source PV inverter under different switching strategies

“…Nonetheless, the parameters provided in datasheets are obtained from double pulse test (DPT) circuits where the switching cells emulate the operation of a voltage source power conversion topology M. H. Ahmed et al 22 and A. B. Jørgensen et al 23 The power topology of a buck chopper is commonly adopted to carry out the DPT as shown in Figure 4A. This implies that the commutation occurs under constant DC‐voltage.…”