IJEDR1501035 International Journal of Engineering Development and Research (www.ijedr.org) 176 Emitter Turn-off Thyristor (ETO)- A High Power Semiconductor Switch (original) (raw)

Performance characterization of MOS turn off thyristors

Scripta Materialia, 2000

Recently, power semiconductor devices that combine the technology of MOS turn-o[f and bipolar conduction have been introduced for operation at high voltage and hi h current levels. The MOS Turn Off thyristor (MTO ) is a switching device based on the Gate Turn Off Thyristor. This paper is devoted to presenting the results from a study performed to examine the operating characteristics of the MTOTM. The study included experimental measurements of on-state properties and switching characteristics under snubberless hard switching. Turn off loss; device switching delay time, storage time, transition time and on-state losses are characterized. In addition to the experimental results, the paper also presents a brief review of operation of the device and the experimental procedure used in the study. Ti5

Chapter 3.4 MTO™ Thyristor 1 Power Switches Silicon Power Corporation (SPCO) a

The MTO™ thyristor, is being developed by SPCO 1, 2 because of the unique features that it offers for high voltage (>3kV), high power (1 to 20 MVA) applications requiring a fast gate-turn-off switch, such as static condenser/uninterruptible power supplies (STATCON/UPS) for power quality systems, motor drives for ship propulsion, and inverters for ac locomotives. Here, we will show that the advantages of the MTO thyristor span all the relevant points of view from fundamental power circuits, to power system cost and reliability, to device design and development, and to packaging techniques.

Emitter Turn-Off Thyristor ( ETO ) based converters for Energy Storage

2000

1 Email: mkevin@vpec.vt.edu For power electronic systems operating in the high power region, the conventional semiconductor switches available have been the Silicon Controlled Rectifier (SCR) and the Gate Turn-Off (GTO) thyristor. The SCR has the highest ratings of any semiconductor switch available but cannot be turned off by means of its control terminal. This prevents the use of SCRs in many applications where a switching frequency much higher than the fundamental AC line frequency is necessary in order to reduce filter size or improve performance. The SCR is therefore not suitable to many energy storage systems where high frequency are required such as STATic var COMpensators (STATCOMs) and SMES interfaces. The GTO is essentially an SCR with the ability to be turned off by means of its gate, hence the name. The GTO has traditionally been the only option for high power converters which require forced commutation capabilities. This gives the advantage of higher switching frequency...

High voltage dual-gate turn-off thyristors

2001

The quest of the last ten years for high power snubberless semiconductor switches has resulted in IGCTs (Integrated Gate-Commutated Thyristors) and IGBTs (Insulated-Gate Bipolar Transistors) currently available up to 6 kV. Both devices have inherently short switching times but are nevertheless frequency limited by their switching losses. 10 kV IGCTs have been shown to be useable up to about 5.5 kV DC and 400 Hz [1]. However market needs for PWM (pulse width modulation) at about 1 kHz cannot be satisfied above 3 kV DC, due to the inherent turn-off losses of the aforementioned bipolar components. The fundamental barrier presented by the charge stored in the n-base of IGBTs and IGCTs must be reduced at turn-off without increasing conduction losses. The use of a second, anode-side gate (n-gate) to reduce the high plasma density at turn-off has already been described for conventional snubbered GTOs [2,3] but the technique has not yet been applied to a snubberless device such as the IGCT. This paper will show the turn-off loss reductions which can be obtained by "grafting" a second gate to the conventional IGCT and will compare these results to those of a new type designed specifically for "gateassisted turn-off".

High Current, High DI/DT Switching With Optimised GTO Thyristors

1994

kicker systems [1] of the Large Hadron Collider, where a 35 kV, 30 kA, 3 us risetime switch successful, the switch is an interesting altemative to the gas switches for the beam dumping possible tum-on delay differences as well as the over-voltage protection circuit are discussed. If consisting of ten in series connected 4.5 kV FHCT devices is being prepared. The effect of losses and conduction losses are only a few Joules. At this moment the construction of a switch

Rajashekara, K., Bhat, A.K.S., Bose, B.K. “Power Electronics” The Electrical Engineering Handbook

The modern age of power electronics began with the introduction of thyristors in the late 1950s. Now there are several types of power devices available for high-power and high-frequency applications. The most notable power devices are gate turn-off thyristors, power Darlington transistors, power MOSFETs, and insulated-gate bipolar transistors (IGBTs). Power semiconductor devices are the most important functional elements in all power conversion applications. The power devices are mainly used as switches to convert power from one form to another. They are used in motor control systems, uninterrupted power supplies, high-voltage dc transmission, power supplies, induction heating, and in many other power conversion applications. A review of the basic characteristics of these power devices is presented in this section.

An experimental analysis of the dual gate emitter switched thyristor (DG-EST)

Solid-State Electronics, 1999

In recent years, various dual MOS gated thyristor structures have been proposed to improve the three pronged trade-o of forward voltage drop, turn-o time and forward biased safe operating area when compared to single gate devices. The dual gate emitter switched thyristor (DG-EST), with its unique thyristor current partitioning mechanism, has been reported to posses superior characteristics when compared to conventional single gate ESTs. In this paper, a detailed study of the device physics of operation of the DG-EST is presented, supported by two dimensional numerical simulations. Eects of variations in the¯oating emitter length, lifetime in the drift region and temperature on the forward voltage drop are experimentally observed. An analytical model predicting the maximum controllable current density (J MCC) of the DG-EST is reported and con®rmed through experimental measurements. The DG-EST is found to have a superior trade-o curve of on-state voltage drop versus turn-o time when compared to the conventional emitter switched thyristor (C-EST).

Turn-off operation of a MOS-gate 2.6 kV 4H–SiC gate turn-off thyristor

Solid-State Electronics, 2000

The turn-o operation of a 4H±SiC gate turn-o thyristor (GTO) with 2.6 kV breakover voltage has been investigated using an external Si-MOSFET as a gate-to-emitter shunt (MOS-gate mode), in the temperature interval 293±496 K. The maximum cathode current density j cmax that can be turned o in such a mode decreases from 1850 A/cm 2 at 400 K to 700 A/cm 2 at 496 K. The room temperature j cmax value is estimated to be about 3700 A/cm 2 . The above j cmax values are essentially higher than those observed when turning this thyristor o in the conventional GTO mode. Turn-o transients in the MOS-gate mode have been studied in both quasi-static and pulse regimes. Temperature dependencies of the turn-on and turn-o times, as well as those of the turn-on and turn-o energy losses have been measured. The upper switching frequency of the GTO is estimated to be about 700 kHz. Ó

A new gate drive circuit for safe switching of MOS Controlled Thyristor(MCT)

1997

The MOS Controlled Thyristor (MCT) is a relatively new class of MOS Gated Power Device having superior characteristics as compared to other similar type of devices. A new compact and reliable gate drive circuit for p-MCT has been developed having features of short-circuit/overcurremt and thermal protection along with bw delay times and high immunity against spurious disturbances. The drive circuit has been tested in a chopper circuit upto 12,0 KHz with test under both short-circuit and thermal stress. Test results from a MCT based PWM controlled AC/DC converter using this drive circuit has also been presented.

Series and parallel operation of the emitter turn-off (ETO) thyristor

IEEE Transactions on Industry Applications, 2002

By dramatically decreasing the storage time, the emitter turn-off thyristor (ETO) has a very good match in storage time. Storage time dispersion of less than 100 ns is normal for ETOs and can be further reduced through adjustment of the emitter switch gate resistance. Thus, the capacitance required for dynamic voltage balancing in the ETO series connection is significantly reduced. Uniform current sharing for parallel-connected ETOs is also guaranteed at the device level through the open-base p-n-p turn-off mechanism. The current-balancing inductance can be essentially removed. Theoretical analysis and experimental results of 53-mm ETOs are presented.