Controlling High Voltage: A Comparison of Electrical Switches

This report delves into the critical role of electrical switches in controlling high voltage during power generation and distribution. It meticulously compares three primary switch types: MOSFET, IGBT, and Thyristor, evaluating them based on several key parameters. These include efficiency, cost, turn-on and turn-off speed, voltage handling capacity, and safety measures. The analysis utilizes a quantitative approach, focusing on measurable data and experimental results to determine the suitability of each switch type for high-voltage applications. The report highlights the advantages and disadvantages of each switch, drawing on literature reviews and experimental data to support its conclusions. Ultimately, the report aims to provide a comprehensive understanding of the optimal electrical switch for high-voltage control, considering factors such as performance, reliability, and cost-effectiveness. The report concludes that both IGBT and Thyristor have higher efficiency than MOSFET and that the IGBT is superior to both MOSFET and Thyristor in terms of switching characteristics, voltage handling, and safety.

Electric Switches 1
ELECTRICAL SWITCHES TO CONTROL HIGH VOLTAGE DURING GENERATION AND
DISTRIBUTION OF ELECTRIC POWER
By Name
Course
Instructor
Institution
Location
Date

Electric Switches 2
PROBLEM DEFINITION
Which electrical switches like Thyristor, IGBT, or MOSFET would be appropriate for control of
high voltage during generation and distribution of electric power?
LITERATURE REVIEW
There are four different ways in which a researcher can determine the appropriate electrical
switch that can be used in controlling high voltage during generation and distribution of electric
power: using Cost, reliability, turn ON and OFF speed of the switch, voltage handling capacity,
efficiency of the equipment, and safety measures.
Efficiency
The IGBTs are designed specifically to turn OFF and ON rapidly since its frequency of pulse
repetition normally gets into the ultrasonic range. MOSFETs have the benefit of greater
efficiency and higher commutation speed during low operation voltage only hence they are not
suitable for controlling high voltage during generation and distribution of electric power
(Doohyung & Kim, 2012). The efficiency of Thyristor is definitely higher compared to the
efficiency of IGBT in case a comparison between a Voltage Source Inverter (with 6 IGBT and a
Current Source Inverter (with 6 SCR). The voltage drop between Thyristor and IGBT is not very
significant. Therefore, both IGBT and Thyristor have higher efficiency than MOSFET and the
two can both be used in controlling high voltage during generation and distribution of electric
power (Bauer, et al., 2012).
Cost

Electric Switches 3
An IGBT, Infineon IGW60T120 rated 60A and 1200V costs about $10 while 32A 2500V cost
$36 while a MOSFET of 60A 800V cost 20$. Thyristor 50A 1200V cost $75 making the IGBT
the cheapest for higher ratings than both MOSFET and Thyristor.
Turn ON and OFF Speed
The major disadvantage of IGBT is that holes are injected into the n-layer which is a high
resistive layer hence resulting in increased conductivity with the n-layer which minimize the
total on-state voltage of this switching device. The on-state voltage reduction of IGBT makes an
IGBT to experience slower switching during turn-on. In the case of MOSFETs, this problem is
solved by halting the electron flow by minimizing the gate-emitter voltage below the voltage of
gate threshold (Karas & Andy, 2019). Thyristor has been supplanted by the IGBTs because of
the faster switching capability. This is because Thyristor operates at a higher plasma density and
have approximately half the on-state voltage. Because of the superior switching characteristic of
IGBT despite slower turn-on, this device is far much superior to both MOSFET and Thyristor
(Shoji, et al., 2016).
Voltage Handling Capacity
The IGBT is a semiconductor device that combines the gate drive characteristics of a MOSFET
and the output characteristic of a bipolar transistor. Therefore, the IGBT is a device with
minority carrier with high current-carrying capacity and high input impedance compared to
MOSFET. The voltage drop between Thyristor and IGBT is not very significant. Thyristor, on
the other hand, can control a relatively large voltage and power compared to the IGBT which has
considerably weaker forward voltage drop compared to the other two switching devices.
Therefore in terms of voltage handling capability, Thyristor is superior to both MOSFET and

Electric Switches 4
IGBT but both Thyristor and IGBT have high voltage handling capability (Minamisawa, et al.,
2016).
Safety Measures
Since IGBTs are voltage-controlled bipolar component with the large current-handling capability
and high-input impedance, they can be controlled easily compared to the MOSFETs which are
current controlled devices in applications of high current. It is easier and safer to control a device
with large current-handling ability compared to a device with almost no input current to control
load current hence making MOSFET more resistive at the gate terminal due to the layer of
isolation between channel and gate (Anon., 2019). In case of power failure, the Thyristor can
damage other components, especially when used for power supplies for digital circuits.
Therefore, in terms of safety measures, the IGBT is safer to use in controlling high voltage
during generation and distribution of electric power than both MOSFET and Thyristor (Anon.,
2019).
Reliability
MOSFET is more vulnerable to electrostatic discharge since high impedance input would enable
the charge to dissipate in a more controlled manner. The IGBTs combines the low on-resistance
capability of a bipolar transistor and the voltage drive characteristic of MOSFETs, hence making
it very tolerant against voltage spikes and overloads (Kang, 2017). In case of power failure, the
Thyristor can damage other components, especially when used for power supplies for digital
circuits. Therefore, in terms of reliability, the IGBT is more reliable to use in controlling high
voltage during generation and distribution of electric power than both MOSFET and Thyristor
(Ostrenko, 2012).

Electric Switches 5
SELECTING QUALITATIVE AND/OR QUANTITATIVE APPROACH
2.1 Quantitative Approach Method
1. Illustrate parameters that needs to be determined in the research (Quantitative data source)
The quantitative parameters in the experiment suggested would be:
 Turn ON and OFF speed of MOSFET, Thyristor, and IGBT
 Voltage handling capability of MOSFET, Thyristor, and IGBT
 The efficiency of MOSFET, Thyristor, and IGBT
 Cost of MOSFET, Thyristor, and IGBT
This data could be gathered in a controlled laboratory using Voltage Source Inverter and Current
Source Inverter.
2. Illustrate factors that show the need to work directly with people in gathering qualitative data
All the required data is from physical phenomenon happening on any switching component.
There is no interaction with the switching components directly although some indirect assistance
may be needed during the experiment (Anon., 2019).
3. Describe factors that may dictate a low structure level in this research
Numerous experiments would be conducted for this research with the data gathered, analyzed,
and evaluated, compared against each of the switching devices, namely MOSFETS, IGBT, and
Thyristor. The results submission would be structured in terms of various differences between
the switching devices.
2.2 Qualitative Approach Method
1. Describe the qualitative data sources required for research

Electric Switches 6
I will only be analyzing and gathering quantitative data in this research to determine various
features of all the switching devices and their comparison
2. Describe factors that show the need to work directly with people in gathering qualitative
data
There will be no need for qualitative data in this research question. However, there will be a
substantial level of communication with other subjects when performing the experiments (Anon.,
2019).
3. Illustrate factors that may dictate a low structure level in this research
As outlined in 2.1, the research will involve a high structure level.
Considering the responses provided in 2.1 and 2.2, which research methodology will be
applied in the research?
For this question topic, the selected methodology is the quantitative research method

Electric Switches 7
REFERENCE
Anon., 2019. Choosing Between Qualitative and Quantitative Research Methods. s.l.:The Balance Small
Business. https://www.thebalancesmb.com/choosing-between-qualitative-and-quantitative-methods-
2297137
Anon., 2019. Difference Between IGBT and MOSFET | Difference Between. s.l.:Differencebetween.net.
http://www.differencebetween.net/technology/difference-between-igbt-and-mosfet/
Anon., 2019. MOSFET vs. IGBT. s.l.:Electronic Products.
https://www.electronicproducts.com/Analog_Mixed_Signal_ICs/Discrete_Power_Transistors/
MOSFET_vs_IGBT.aspx
Bauer, F., Nistor, I., Mihaila, A. & Antoniou, M., 2012. Superjunction IGBT Filling the Gap Between SJ
MOSFET and Ultrafast IGBT. s.l.:IEEE Electron Device Letters. Vol 33. pp. 1288-1290.
Doohyung, c. & Kim, K., 2012. Trench Power MOSFET using Separate Gate Technique for Reducing Gate
Charge. s.l.:Journal of IKEEE. Vol 16. pp. 283-289.
Kang, G., 2017. The Optimal Design of High Voltage Non Punch Through IGBT and Field Stop IGBT.
s.l.:Journal of the Korean Institute of Electrical and Electronic Material Engineers. Vol 30. pp. 214-217.
Karas, M. & Andy, A., 2019. How to reduce MOSFET turn-off delay. s.l.:Electrical Engineering Stack
Exchange. https://electronics.stackexchange.com/questions/74465/how-to-reduce-mosfet-turn-off-
delay
Minamisawa, R., Vemulapati, U., Mihaila, A. & Papadopoulos, C., 2016. Current Sharing Behavior in Si
IGBT and SiC MOSFET Cross-Switch Hybrid. s.l.:IEEE Electron Device Letters. Vol 37. pp. 1178-1180.
Ostrenko, V., 2012. Determination of the maximum value of the switching frequency IGBT module.
s.l.:Electrical Engineering and Power Engineering. Vol 0.
Shoji, H., Uruno, J. & Masayuki, M., 2016. Full-bridge/Half-bridge Switching Inverter with IGBT Leg and
MOSFET Leg for All-metals Induction Heating Systems. s.l.:IEEJ Transactions on Industry Applications. Vol
136. pp. 443-449.

Electric Switches 8
Anon., 2019. Choosing Between Qualitative and Quantitative Research Methods. s.l.:The Balance Small
Business. https://www.thebalancesmb.com/choosing-between-qualitative-and-quantitative-methods-
2297137
Anon., 2019. Difference Between IGBT and MOSFET | Difference Between. s.l.:Differencebetween.net.
Anon., 2019. MOSFET vs. IGBT. s.l.:Electronic Products.
Bauer, F., Nistor, I., Mihaila, A. & Antoniou, M., 2012. Superjunction IGBT Filling the Gap Between SJ
MOSFET and Ultrafast IGBT. s.l.:IEEE Electron Device Letters.
Doohyung, c. & Kim, K., 2012. Trench Power MOSFET using Separate Gate Technique for Reducing Gate
Charge. s.l.:Journal of IKEEE.
Kang, G., 2017. The Optimal Design of High Voltage Non Punch Through IGBT and Field Stop IGBT.
s.l.:Journal of the Korean Institute of Electrical and Electronic Material Engineers.
Karas, M. & Andy, A., 2019. How to reduce MOSFET turn-off delay. s.l.:Electrical Engineering Stack
Exchange. https://electronics.stackexchange.com/questions/74465/how-to-reduce-mosfet-turn-off-
delay
Minamisawa, R., Vemulapati, U., Mihaila, A. & Papadopoulos, C., 2016. Current Sharing Behavior in Si
IGBT and SiC MOSFET Cross-Switch Hybrid. s.l.:IEEE Electron Device Letters.
Ostrenko, V., 2012. Determination of the maximum value of the switching frequency IGBT module.
s.l.:Electrical Engineering and Power Engineering.
Shoji, H., Uruno, J. & Masayuki, M., 2016. Full-bridge/Half-bridge Switching Inverter with IGBT Leg and
MOSFET Leg for All-metals Induction Heating Systems. s.l.:IEEJ Transactions on Industry Applications.