Modelling of switching transients in a GTO bridge inverter

A practical investigation, with some simplified supporting analysis, into the transient overvoltages induced across the stray circuit inductances by fast device switching in high power GTO thyristor circuits has previously been reported by Hall and Al Hakim (see IEE conf. publ. 291, p.103-6, 1988). The extension of that work into a full circuit model for the H-bridge inverter with inductive load is described. Not only is balanced device switching included, but also the practical effects of timing mismatch at GTO turnoff, and in the diode reverse recovery characteristics. Further practical results which relate to both quasi square and PWM control are presented, and compared with the computed results