Futoshi Tokunoh

A new high power low loss GTO

A new high power, low loss, and low snubber gate turn-off thyristor (GTO) which has a current capacity of 6 kA with a snubber capacitance of 6 /spl mu/F and blocking voltage of 6 kV has been developed. GTO has an advantage over conventional thyristors in its application to inverters. Recently GTOs have been applied to high power inverters for traction and industries, and static V.A.R. Generators (SVG). The ratings of these GTOs are such as 4.5 kV and 4 kA, or 6 kV and 3 to 4 kA by using a 4 inch silicon wafer. However, higher voltage, higher current GTOs are required for the application of motor control for iron mills, and SVGs for power supplies. On the other hand, reduction of power losses of GTO, and snubber capacitance were required for decreasing weight and volume and improving performance of equipment. For those reasons, a new high power, low loss, and low snubber GTO, FG6000AU-120D was developed. In order to develop this new GTO, we used some new technologies, and studied some parameters of device designs using some test samples. The development of this new GTO was based on the results of these studies and use of these new technologies. Design consideration of this GTO and electrical characteristics are described in this paper.

A new high power symmetrical GTO

A high-power symmetrical GTO (gate-turn-off) thyristor, rated 4.5 kV/3 kA with improved turn-off capability (3 kA with snubber capacitor=6 mu f and average current=1 kA) and frequency performance has been developed. It is based on a 76 mm-diameter silicon wafer and high-voltage, high-frequency GTO technology, including a smaller scale pattern rule and a novel emitter structure. Performance evaluations confirm that this GTO has many excellent features, such as high turn-off performance, high voltage stability, and low switching energy, and is suitable for application in a high-power current-fed inverter.<<ETX>>

12kV, 1kA thyristor

The u l t r a h i g h b l o c k i n g v o l t a g e t h y r i s t o r w i t h b l o c k i n g v o l t a g e s of 12kV and t h e a v e r a g e o n s t a t e c u r r e n L of 1kA w a s r e a l i z e d . I n o r d e r t o o b L a i n h i g h b l o c k i n g v o l l a g e s and t h e low on-sLaLe v o l t a g e , d i f f u s i o n p r o c e s s e s and t h e g a t e and c a t h o d e s L r u c L u r e were o p t i m i z e d and t h e f u l l p r e s s u r e c o n t a c l s t r u c l u r e w a s employed. T h i s p a p e r e x p l a i n s t h e s t r u c t u r e and t h e e l e c t r i c a l c h a r a c L e r i s t i c s o f t h i s d e v i c e .

4.5kV, 3000A reverse conducting GTO thyristor (R-C GTO)

A new reverse conducting GTO thyristor rated blocking voltage of 4.5kV and controllable on-state current of 3 0 0 0 A with a snubber capacitance of 4pF has been developed. This R-C GTO was adopted some new technologies. The first is a new grooving structure for isolation between GTO and Diode region. The second is a new shorted anode structure of isolation region. The third is a optimized pattern lay out of GTO, Diode, and gate contact area.