EJEEE
https://doi.org/10.62909/ejeee.2024.003 Edison Journal for Electrical and Electronics Engineering
Article
Single-switch PWM converters for DC-to-DC power with relia-
bility tolerance for battery power purposes
Ahmed Mahmood Khudhur 1, *, , Faisal Ghazi Saber 2, and Mokhalad Abdulameer Kadhim Alsaeedi 3,
1 Information Technology Department, College of Computer Science and Information Technology, University
of Kirkuk, Kirkuk 36001, Iraq; Dr.ahmedm@uokirkuk.edu.iq
2 Department of Electronics, Kirkuk Technique Institute, Northern University, Mosul 41003, Iraq; faisel.g.sa-
ber@ntu.edu.iq
3 Department of Computer Eng. Tech., Bilad Alrafidain University Collage, Baqubah 32001, Iraq; khal-
doon@bauc14.edu.iq
* Correspondence: Tel.: +964-7719539367
Abstract: The functioning of fault-tolerant boosted conversions in both good and bad circumstances
is covered in this work. The majority of our power plants and automotive applications make exten-
sive use of surge conversions. Every component in a converter is accountable for causing one of the
many problem kinds that affect the converter. In order to construct a tolerant of faults DC-DC con-
verter, the reaction of the single switch DC-DC converter under various potential failures was ex-
amined. Utilizing a MATLAB Simulink approach, the response of each device across both typical
and various potential fault scenarios was derived. The booster converter can also undergo addi-
tional heat research to determine how the converters react at various temps.
Keywords: tolerance for faults; fault evaluation; DC supply; charging batteries; DC to DC converters
1. Introduction
Scaling either up or down the input voltage as well as controlling the DC voltage are
the two functions of the DC-DC converters. DC-DC converters that operate with a single
switch are typically used in recharging purposes. A power supply plus a DC-DC con-
verter makes up a typical charging system. The dc-dc converter's input needs to be loss-
less in order for the system to charge effectively [1, 2]. To enhance the charging system's
efficiency, a wideband dc-dc converter has to be properly designed.
Faults that are caused by external as well as internal variables can account for a por-
tion of the charging system's issues. Short circuit and open circuit defects in the electrical
system are the primary causes of internal faults [3, 4]. The primary causes of external
faults include spikes in temperature across the system, rapid increases in earth fault cur-
rent, or issues with anchoring.
When designing dc-dc power converters using pulse width modulation (PWM), fault
analysis is crucial [5]. It provides us with comprehensive information about the potential
harm and aids in our understanding of the severity of different fault types. It provides us
with precise details regarding the highest resist durability of each part of a converter. It is
quite helpful to us while constructing the converters to operate within their maximum
capabilities. In this section we measure the converter's performance after introducing var-
ious flaws [6]. Anything in the circuit could have a fault; in this case, we'll be looking at
the switch between [7-10], diode, inductor, capacitor, and load. Therefore, we have exam-
ined several defects in each of the converter's components in this research and have of-
fered a comparison of the single switch dc-dc converter's efficiency. An effective fault
Citation: Khudhur, A.M., F.G. Sa-
ber, and M.A.K. Alsaeedi, Single-
switch PWM converters for DC-to-
DC power with reliability tolerance
for battery power purposes. Edison
Journal for electrical and electronics
engineering, 2024. 2: p. 12-19.
Academic Editor: Prof Dr. Moham-
med Azmi Al‑Betar
Received: 2/2/2024
Revised: 3/4/2024
Accepted: 12/4/2024
Published: 16/4/2024
Copyright: © 2024 by the authors.
Submitted for possible open access
publication under the terms and
conditions of the Creative Commons
Attribution (CC BY) license
(https://creativecommons.org/license
s/by/4.0/).
EJEEE 2024, Vol.2 13 of 19
tolerant single switch dc-dc converter might be constructed for a variety of purposes by
taking into account the reaction of the converter during diverse failure scenarios.
2. Materials and Methods
2.1 Overview of the System
Depending on the purpose, the single switch dc-dc converter can be utilized to in-
crease or decrease the input voltage. These are a few examples of popular single switching
dc-dc converters that are employed in a variety of real-world scenarios. In this study, we
analyze the efficiency of a boost converter. The boost converter schematic is displayed in
Figure 1. A voltage at the output that is higher than the input voltage in a switch mode
DC to DC converter is called a boost converter. The charging and discharge process of an
inductor is the foundation of the boost converter's primary operation. It is resistant to
abrupt input modifications [10, 11]. The resultant value is equivalent to the input voltage
while the toggle switch is off, and the inductor charges (i.e., stores energy as a magnetic
field) and releases it if the switching is active.
2.2 Variables for Modelling
The load's variables are displayed in Figure 1. We tested the converter in this study
by using a battery as the load. DC-DC converters are typically employed in battery charg-
ing scenarios. Therefore, for the battery to be charged effectively, an efficient charging
mechanism is always essential. Based on the simulation findings of the converter linked
to the battery, a comparison has been done to determine which single switch dc-dc con-
verter is most effective in recharging a battery under both typical and abnormal condi-
tions.
Figure 1: Boost converter circuit diagram
The converters are examined for various open and short circuit problems, and the
efficiency of the converters is used to determine the outcomes. A short circuit fault at the
switch itself results in extremely high current flowing via it and a rise in the temperature
throughout the device, both of which lower the converter's effectiveness. While the move
in the converter is open circuited, the inductor charges continuously and loses its mag-
netic property over time. Prior research has addressed these issues and provided strate-
gies to identify and lessen switch faults [12-14]. Other components of the converter, such
as the diode, inductor, and capacitor, may experience the same open or short circuit issue.
These errors undoubtedly lessen the charging system's efficacy, and some of them have
the potential to harm the circuit's components by abruptly increasing voltage or current.
These errors are displayed below after being examined with the MATLAB Simulink pro-
grammed [15].
2.3 Dc-Dc Converter with Single Switch Tolerance for Faults
The purpose of a fault-tolerant booster converter is to completely eliminate all poten-
tial flaws in a circuit. The error is detected and mitigated by a device called a controller.
The circuit's magnet element is mostly utilized to detect errors. Here, the type of problem
is identified by taking into account the voltage generated by the inductor.
EJEEE 2024, Vol.2 14 of 19
Figure 2(a) Boost conversion with fault tolerance
Figure 2(b) Circuit diagram for identifying faults
The fault tolerant boost converter is depicted in Figure 2(a). To safeguard the circuit's
electronics from excessive current flow, a fuse wire is attached in close proximity to the
load and supply. Normally, depending on the duty ratio, the voltage between the inductor
will rise and discharged. However, the inductor typically loses its magnetic characteristic
following the malfunction. As a result, the inductor voltage waveform acquired following
the fault will undoubtedly differ from the waveform obtained during normal operation.
The inductor's waveform is displayed in Figure 3(b) when it is operating normally, when
there is an open circuit issue with the diode. We can see a distinct variation in the wave-
form during ordinary and fault scenarios when we examine Figures 3(b). The voltage
across the inductor either rises to an extremely high level or falls to an extremely low level
in open and short circuit problems. An error signal is formed through the comparison of
both of these messages, and the controller processes it from there.
Figure 3(a) Battery production of boost converter in stand-
ard process
Figure 2(b) Displays the fault detecting circuit's block schematic. The voltage across
the inductor under typical operating conditions is known as the standard inductor volt-
age. The voltage over the inductor under present conditions of operation is the real induc-
tor value. If both signals have identical magnitude, the comparator's output is one; when
the signals have different magnitudes, the output is zero. The comparator signal that is
provided to the circuit breaker powers the controller. The controller triggers the circuit
breaker to allow current to flow via the main switch or the extra switch, depending on
whether the operational situation is normal or unusual. Figure 4(a) Displays the battery
output when the controller is operating. The expanded waveform displays the controller's
position in operation. Figure 4(a) clearly shows the brief shift in battery output that occurs
for a few milliseconds at 0.5s when the fault occurs. The battery's performance will not be
impacted by the slight decrease in output. In this case, the controller starts working right
away after the error.
EJEEE 2024, Vol.2 15 of 19
The output waveforms of the single switch DC-DC converter are displayed in Figure
4(b) under both failure and typical circumstances. In this case, the fault happens at time
0.5s, and the shape of the waveform shows that the output waveform stays constant even
after the fault. The controller detects the malfunction right away and modifies the con-
verter to maintain a steady output even following the malfunction.
Figure 4: The resilient boost converter's battery power (a) in
fault situation
3. Results
The outcomes of simulations will provide a good understanding of the regular and
fault situations of the converters' operation. Buck and boost conversions are the most often
utilized single switching converters in charging situations. A fault-tolerant boost con-
verter that can withstand frequently occurring converter defects is created by projecting
the boost converter's outcomes under both normal and defective situations.
The efficiency of the booster converter under typical circumstances is displayed in
the waveforms that follow. Figure 2(a) Displays the battery's voltage, current, and charge
level in a typical situation. The battery voltage and current measured are in close proxim-
ity to the values mentioned in Figure 1. Figure 2(b) Displays the voltage waveform
through the inductor. calculating the duty cycle worth, we are able to see that the inductor
charges and discharges properly.
The switch's voltage and current wave is displayed in Figure 5(a). It is easy to see
why the waveform depicts the voltage across the toggle switch in the neutral state and the
current that passes across the device in the on state. The diode's typical operating voltage
and current waveforms are displayed in Figure 5(b). The diode's current and voltage at-
tain a value that is closer to the specified values once the toggle switch is turned on as
well.
The waveform of the voltage across the capacitor under typical conditions is depicted
in Figure 6. The output voltage and the voltage over the capacitor are identical.
EJEEE 2024, Vol.2 16 of 19
Figure 5(a) Current and Voltage at the switch
(b) The waves of current and voltage at a diode.
Table 1. Summit rates for various factors in Diode
open circuit error in Boost converter
Inductor
Switch
Capacitor
Voltage(V)
Current(A)
Voltage(V)
Current(A)
Voltage(V)
-149
0.099
149
0.099
-0.255
Diode
Battery
Voltage(V)
Current(A)
Voltage(V)
Current(A)
SOC
0.79
0
-0.255
0
NC
Figure 6: Capacitance Voltage
Open circuit diode
The highest values across a range of variables after an open circuit fault across a di-
ode are displayed in Table 1. Following the fault, the voltage across the switch and induc-
tor rises to an extremely high amount. The voltage's amplitude indicates how serious the
fault is. As a result, an open circuit diode can quickly harm its switch and inductor. Figure
7(a) Displays the boost converter's battery settings in the event of a diode open circuit
problem. It is evident from the pattern that the output voltage drops to an extremely tiny
amount and the output current hits zero. As a result, battery charging becomes less effec-
tive. Similar to this, when a diode is open circuited, other converters' ability to charge a
battery is diminished. Figure 7(b) Demonstrates that the voltage across the inductor only
reaches aberrant peak levels when there is an enhanced converter diode open circuit mal-
function. When the problem occurs, the voltage reaches its maximum value (in this case,
it occurs at 0.5 seconds). These extremely high peak voltages have the potential to seri-
ously harm the inductor.
EJEEE 2024, Vol.2 17 of 19
Figure 7(a) Open circuit diode
Figure 7(b) Inductor voltage in boost converter
Flip Open The circuit
The peak values of multiple parameters after an open circuit failure for the boost
converter are displayed in Table 2. The table shows that there isn't an interruption in the
battery charging process and that the output voltage reduces by just a couple of volts. The
inductor loses its magnetizing ability when there isn't a pathway for it to departure, which
is the sole issue in the event of a switch open circuit defect. The voltage over the inductor
drops to zero when the current through the inductor stabilizes. After a malfunction, the
converter will not do any boosting action; instead, only the input will be supplied to the
outputs no changing activity.
Short Circuit Failure in Switches
The switch itself experiences constant, extremely high current flow whenever it is
shorted. This will raise temperatures throughout the gadget and have an impact on how
well it works. The inductor lacks its magnetizing ability as an outcome of the same charg-
ing and discharge issues that affect the capacitor. Table 3 shows that the current via the
switch and inductor reach an extremely significant level, which will undoubtedly cause
the circuit to fail.
As the amount of time rises, we may see that the voltage flowing through the induc-
tor climbs linearly to an extremely high level. Comparably, in the event of a switch short
circuit malfunction, the gadget sustains significant harm as the current flowing through
the switch's contacts rises linearly with time. The boost converter's ability to increase the
voltage at the output is likewise stopped by a short circuit defect; instead, the input volt-
age is sent to the output without any switching occurring. The power source is still being
charged, but at a lower voltage, which is not what is desired for efficient battery charging.
Table. 2. summit quantities of various parameters in Switch
Open Circuit fault for Boost Converter
Table. 3. summit quantities of various parameters in Switch Short
Circuit error for Boost Converter
Defect in Resistor Open Circuits
Capacitor open circuitry is a different sort of malfunction. Since it doesn't raise the
circuit's voltage or current, this defect doesn't harm any devices. However, it cuts off the
load's availability.
The distribution of voltage and current in the circuit. The output voltage remains
unchanged long following a malfunction. Therefore, the efficiency of charging the power
source is unaffected by the open circuit defect in the capacitor. The open circuit fault at
Inductor
Switch
Capacitor
Voltage(V)
Current(A)
Voltage(V)
Current(A)
Voltage(V)
0
>399
8.9
>399
8.19
Diode
Battery
Voltage(V)
Current(A)
Voltage(V)
Current(A)
SOC
0.79
3.49
8.19
3.49
Charging
Inductor
Switch
Capacitor
Voltage(V)
Current(A)
Voltage(V)
Current(A)
Voltage(V)
0
3.21
8.9
0
8.19
Diode
Battery
Voltage(V)
Current(A)
Voltage(V)
Current(A)
SOC
0.79
3.21
8.19
3.16
Charging
EJEEE 2024, Vol.2 18 of 19
the power source is the final potential defect. The device's whole supply is shut off from
the other components if this scenario occurs. Thus, the output is going to be close to nil.
As a result, the various faults that could arise in a boost converter circuit are examined,
and their respective responses are recorded and contrasted. As we observe, there are times
when defects cause the voltage and current to spike to extremely high levels, which puts
stress on the circuitry and degrades production efficiency. Therefore, the purpose of a
tolerant of faults boost converter is to prevent unneeded stress from being produced by
various defects while maintaining the device's efficiency.
5. Conclusions
It is evident from the findings provided that short circuit and diode open circuit prob-
lems are among the most frequent and dangerous types of defects. The optimum solution
for these issues is a fault tolerant DC to DC converter. Although there are several fault-
tolerant converters on the market, they don't always work right away. When a controller
is present in the circuit, it detects the defect and acts on the converter to lessen its impact.
Although the additional switch, diode, and controller are more expensive, they provide
the converter with greater safety and extend its lifespan while improving performance.
Therefore, fault analysis assists in developing a fault-tolerant DC-DC converter by indi-
cating the severity of different errors. To gain more insight into the converter's operation
during various failure scenarios, additional temperature measurement may be conducted.
Acknowledgments: The authors would like to express their sincere gratitude to three Iraqi univer-
sities: Kirkuk, Northern Technique, and Bilad al-Rafidain, for providing technical input.
Conflicts of Interest: Declare conflicts of interest or state “The authors declare no conflict of inter‑
est.”
EJEEE 2024, Vol.2 19 of 19
References
1. Nie, S., et al., Fault diagnosis of PWM DC–DC converters based on magnetic component voltages equation. IEEE transactions on
power electronics, 2013. 29(9): p. 4978-4988
2. Kadhim, A.A., A.M. AL-Jumaili, and K. Hussain, Converter for Voltage Source HVDC Links: Current Status and Future
Challenges. Edison Journal for electrical and electronics engineering, 2023. 1: p. 17-23
3. Lu, B. and S.K. Sharma, A literature review of IGBT fault diagnostic and protection methods for power inverters. IEEE Transactions
on industry applications, 2009. 45(5): p. 1770-1777
4. Khalid, O.W. and N.A. Hasan, Contrasting Energy Storage Systems for Small-Scale Isolated Grids. Edison Journal for electrical
and electronics engineering, 2024. 2: p. 6-11
5. Pei, X., S. Nie, and Y. Kang, Switch short-circuit fault diagnosis and remedial strategy for full-bridge DC–DC converters. IEEE
transactions on power electronics, 2014. 30(2): p. 996-1004
6. Pei, X., et al., Open-circuit fault diagnosis and fault-tolerant strategies for full-bridge DC–DC converters. IEEE transactions on
power electronics, 2011. 27(5): p. 2550-2565
7. Jamshidpour, E., et al., Single-switch DC–DC converter with fault-tolerant capability under open-and short-circuit switch failures.
IEEE transactions on power electronics, 2014. 30(5): p. 2703-2712
8. Ribeiro, E., A.J.M. Cardoso, and C. Boccaletti, Open-circuit fault diagnosis in interleaved DC–DC converters. IEEE transactions
on power electronics, 2013. 29(6): p. 3091-3102
9. Shahbazi, M., et al., Open-and short-circuit switch fault diagnosis for nonisolated DC–DC converters using field programmable gate
array. IEEE transactions on industrial electronics, 2012. 60(9): p. 4136-4146
10. Wu, R., et al. Catastrophic failure and fault-tolerant design of IGBT power electronic converters-an overview. in IECON 2013-39th
Annual Conference of the IEEE Industrial Electronics Society. 2013. IEEE
11. Al-Zuhairy, Y.A.L. and F.Q. Mohammed, Tilos Island's ideal microgrid size for wind, solar, and batteries. Edison Journal for
electrical and electronics engineering, 2023. 1: p. 11-16
12. Ribeiro, E., A.J.M. Cardoso, and C. Boccaletti, Fault-tolerant strategy for a photovoltaic DC--DC converter. IEEE transactions on
power electronics, 2012. 28(6): p. 3008-3018
13. Sheng, H., F. Wang, and C.W. Tipton IV, A fault detection and protection scheme for three-level DC–DC converters based on
monitoring flying capacitor voltage. IEEE Transactions on Power electronics, 2011. 27(2): p. 685-697
14. Park, T. and T. Kim. Novel fault tolerant power conversion system for hybrid electric vehicles. in 2011 IEEE Vehicle Power and
Propulsion Conference. 2011. IEEE
15. Eitelman, S., Matlab Version 6.5 Release 13. The MathWorks, Inc., 3 Apple Hill Dr., Natick, MA 01760-2098; 508/647-7000, Fax
508/647-7001, www. mathworks. com. Ergonomics in Design, 2003. 11(3): p. 27-29