Current-Transformer Based Gate-Drive Power Supply With Reinforced Isolation

In recent years, there is a clear trend toward increasing the demand for electric power in high-power applications. High-power converters are making major impacts on these high-power applications. Recent breakthroughs in Silicon Carbide (SiC) materials and fabrication techniques have led to the development of high-voltage, high-frequency power devices, which are at the heart of high-power converters. SiC metal-oxide semiconductor field-effect transistors (MOSFETs) have advantages over silicon (Si) devices due to their higher breakdown voltage, higher thermal capability, and lower on-state resistance. However, their fast switching frequency and high blocking voltage bring challenges to the gate-drive circuit design. The gate driver of SiC-MOSFETs requires a power supply that provides a high-voltage, high-density design, a low input-output capacitance (CI/O) transformer design, good voltage regulation, as well as good resilience to faults to enable safe and fast operation. In this thesis, a power supply that supplies multiple gate drivers for 10 kV SiC MOSFETs is presented. A transformer design approach with a single turn at the primary side is proposed. A 20 kV insulation is achieved by the primary HV cable insulation across a toroid transformer core. The CI/O is designed less than 2 pF to mitigate the Common-Mode (CM) noise. A circuit topology analysis is performed and the inductor/capacitor/capacitor/inductor (LCCL) – inductor/capacitor (LC) circuit is selected. This circuit allows Zero-Voltage Switching (ZVS) at full operation range. A Resonant-Current-Bus (RCB) is built at the transformer primary side to achieve load-independence.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Electrical Engineering

Department dc:contributor.department

Electrical and Computer Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2018

Author dc:creator

• Hu, Jiewen

Chair dc:contributor.committeechair

• Burgos, Rolando

Committee members dc:contributor.committeemember

• Boroyevich, Dushan
• Southward, Steve C.

• GaN
• Gate-Drive Power Supply
• Inter-winding capacitance
• 20 kV insulation
• Current Transformer

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10919/85050

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/85050