Comparison of Controllable Power Electronic Devices

Voltage, current and frequency ranges

The figure (in log-log scale) shows the power-frequency capability of the current devices and their future trends. The power is given by V-I ratings product, that is, the product of the maximum blocking voltage and maximum turn-off current. Note that the BJT is completely removed from the figure.

Thyristors and triacs are essentially low-frequency (50/60 Hz) devices, and currently the thyristor has the highest power rating.

The future trend, as indicated by the dashed curve, also indicates that has the highest power rating

High-power thyristors are used in high-voltage dc (HVDC) systems, phase-control type static VAR compensators (SVC), and large ac motor drives.

GTOs and IGCTs have a higher frequency range (typically a few hundred hertz to one kilohertz) but their power limits are lower than that of a thyristor. Normally, with a higher power rating, the switching frequency becomes lower, and this is indicated by tapering of the areas at higher frequency.

However, an IGCT’s switching frequency is somewhat higher than that of a GTO (not shown).

IGBT intelligent power modules (IPMs) come next with higher frequency but lower power range.

The lower power end of GTO/IGCTs overlaps with IGBTs.

The discrete IGBTs have higher frequency and lower power range, as shown.

Power MOSFETs have the highest frequency and lowest power range.

	Power MOSFET	IGBT	GTO	IGCT
1. Voltage and current ratings (selected device for comparison)	100 V, 20 A* (dc)	1.2 KV, 50 A* (dc)	6 KV, 6000 A* (pk)	4.5 KV, 4000 A* (pk)
2. Present power capability	1.2 KV, 50 A	3.5 KV, 1200 A or higher	6 KV, 6000 A	6.5 KV, 3000 A
3.Voltage blocking	Asymmetric	Asymmetric*	Asymmetric/symmetric	Asymmetric/symmetric
4. Gating	Voltage	Voltage	Current	Current
5. Junc. Temp. range	-55 to 175	-20 to 50	-40 to 125	-40 to 125
6. Safe operating area (ºC)	Square	Square	2nd breakdown	Square
7. Conduction drop (V) at rated current	2.24	2.65	3.5	2.7
8. Switching frequency	106 Hz	1 kHz – 20 kHz	400 Hz	1.0 kHz
9. Turn-off current gain	-	-	4 to 5	1
10. Turn-off di/dt	-	-	500 A/µs	3000 A/µs
11. Turn-on time	43 ns	0.9 µs	5 µs	2 µs
12. Turn-off time	52 ns	2.4 µs	20a µs	2.5 µs
13. Snubber	Yes or No	Yes or No	Yes (heavy)	Yes or No
14. Protection	Gate control	Gate control	Gate control or very fast fuse	Gate control or very fast fuse
15. Application	Switching power supply, Low power motor drive	Motor drive, UPS, induction heating, etc.	Motor drives, SVC, etc	Motor drives, HVDC, SVC etc.
16. Comments	Body diode can carry full current but sluggish (trr = 150 ns) Ipk = 56 A	Large power range, very important device currently *Reverse blocking available	Dv/dt = 1000 V/µs High uncontrollable surge current	Built-in diode, High uncontrollable surge current Dv/dt = 4000 V/µs
	*Harris IRF 140	*Powerex PM50RVA 120 7-pack IPM	*Mitsubishi -FG6000AU-120D	*ABB 5SHY35L4512

 

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