Design of Si-IGBT Gate Driver for Inverter Applications

Gate driver plays an important role in control and protection of power semiconductor devices in converter structures. A careful design of the gate driver is essential for reliable converter operation. Gate resistor selection and isolation between the power and control circuit are of primary importance. Gate drivers are also expected to offer protection like Active Miller clamp (AMC), soft turn-off, short-circuit detection and under-voltage lockout. In this paper, a comprehensive design and selection of components for the various control and protection aspects of a 10kVA IGBT inverter gate driver is presented. The gate driver is built around ACPL-333J optocoupler IC. The protection schemes are discussed along with the inverter structure for better insight and design. A novel method of gate driver selection based on \frac{{di}}{{dt}} provided in the device datasheet is proposed to balance between switching speed and reduced EMI. The proposed method results in a simple analytical expression for gate resistor selection. With the selected gate resistor the device \frac{{di}}{{dt}} is obtained same as the datasheet value and is validated experimentally. Important aspects related to selection of an on-board integrated isolated power supply and printed circuit board (PCB) design considerations are also presented. Hardware results are provided for the discussed protection schemes.