Design of gate driver and current sensor for high power density converter with silicon carbide switches
Date of Issue2018-09-10
School of Electrical and Electronic Engineering
Power electronic converters have become the most fundamental element of electrical systems nowadays and their demand is increasing rapidly due to reasons such as, electrical systems are replacing conventional mechanical systems, utilisation of renewable energy sources is rising to meet the increasing energy demand and scarcity of fossil fuel. Power electronic converters offer numerous valuable advantages in terms of efficiency, reliability, life, form factor. There is a lot of emphasis being put on efficiency improvement of these power electronic converters which led to the development of SiC based semiconductor devices. The use of SiC based semiconductor in power converters facilitates betterment of efficiency, reduction in size, reduction in power loss. These benefits are exploited to design High Power Density Converters. In this dissertation work, firstly, investigation has been done on the benefits of deploying SiC semiconductor technology based MOSFET for power converters and how better are they when compared to the conventional Si semiconductor technology. Since the SiC semiconductor based MOSFETs are capable of operating at higher switching frequencies and higher voltages, the gate driver needs to be carefully designed. The various considerations to be taken into account while designing a gate driver like parasitic capacitance, power loss during switching, switching speed, galvanic isolation and protection schemes against faults like low supply voltage, transient overvoltage and short circuit are discussed in this thesis. After assessing and comparing the specifications of different options, a gate driver design has been proposed for driving the SiC semiconductor based MOSFET. After this, investigation on different methodologies to detect short circuit has been done and among them, Rogowski Coil based current sensor stands out to be the best suited. So, a modular PCB Rogowski Coil has been designed for power converters. The gate driver along with Rogowski coil together are offered as a complete solution to use with SiC semiconductor based MOSFET in order to build High Power Density Converters.
DRNTU::Engineering::Electrical and electronic engineering