Characterization of an n-type 4 kV silicon GTO for pulsed power applications


In order for pulsed power systems to improve as a whole, the individual components they are composed of must continue to improve. One of the key components of pulsed power systems are switching devices. Traditionally, switching devices utilized were of spark/gas-type. These types of devices boast high voltage and high current operation, making them quite desirable for pulsed power applications. Gas/spark-type switching devices do have several intrinsic deficiencies; specifically high conduction losses which must be dealt with via exhaustive cooling systems, large physical size and high maintenance. Solid state switching devices are an alluring solution to these issues with gas/spark-type devices. This thesis details experimental evaluation and simulation of a 4 kV n-type gate turn-off thyristor (GTO) designed for pulsed power applications. The primary criteria of evaluation are rate of current change (dI/dt), turn-on delay time (TD), and resistance of the device during turn-on events (Ron(t)). The device is an n-type, asymmetric-blocking GTO manufactured by Silicon Power (Part No. 14N40A10) with a DC blocking voltage of 4 kV. A test circuit was specifically designed to minimize stray inductance in order to capitalize on the dI/dt capabilities of the device under test (DUT). Experimental data collected from resistance measurements was used to develop a one-switch approximate model for use in simulation. Results of dI/dt experiments provide a profile of DUT operation at gate currents greater than initial test conditions (IG > ITG); specifically dI/dt > 70 kA/μs is achieved at IG ~3ITG. Turn-on delay time of the DUT is also characterized.



GTO, Pulsed Power, Power electronics, Thyristor