1. Fast high-voltage, high-current switching using stacked IGBTs
By: Zarir Ghasemi
Supervisor: Prof. S. J. Macgregor
Institute for Energy and Environment
University of Strathclyde
Glasgow

2. Pulsed Power System with Examples of System Components

3. Comparison of solid-state switching devices

4. An X2 Non-Inverting Blumlein Cable Generator

5. Problems associated with stacking IGBTs
Signal synchronisation
Signal isolation (Magnetic or Optical )
Voltage sharing (Passive or Active snubbers)
Current sharing
Stack configuration
Diagnostic
Protection

6. Photograph of 55 IGBT stack with voltage and current ratings of 2
Photograph of 55 IGBT stack with voltage and current ratings of 2.5 kV and 250 A, respectively.

7. Voltage across the device and output pulse for two 1.2 kV IGBTs

8. Photograph of 10 kV, 400 A stack of IGBT modules consisting of 105 1
Photograph of 10 kV, 400 A stack of IGBT modules consisting of 105 1.2 kV IGBTs.

9. Photograph of 10 kV, 400 A stack of IGBT modules, optically triggered

10. Photograph of 3 kV, 2 kA Marx generator

11. Conclusion
The IGBT was determined to be the preferred device for stacking
IGBT’s can handle a peak current of five times their normal rating during short-pulse conducting, if they are driven by fast gate pulses.
The dual degradation of the collector-emitter voltage exists in some of available IGBT devices.
A prototype stack at voltage and current ratings of 10 kV and 400 A, with a voltage fall-time of about 45 ns was successfully tested.
An optically-coupled stack of IGBTs with voltage and current ratings of 10 kV and 400 A was built and operated in a generator, used for Pulsed Electric Field (PEF) inactivation of microorganisms.
A modular Marx generator, having an output voltage rating of 3 kV and a peak current rating of 2 kA, was designed and evaluated.