Effect of DC voltage source on the voltage and current of transmitter and receiver coil of 2.5 kHz wireless power transfer

Bulletin of Electrical Engineering and Informatics
Vol. 9, No. 2, April 2020, pp. 484~491
ISSN: 2302-9285, DOI: 10.11591/eei.v9i2.2060  484
Journal homepage: http://beei.org
Effect of DC voltage source on the voltage and current
of transmitter and receiver coil of 2.5 kHz wireless
power transfer
A. H. Butar-Butar1
, J. H. Leong2
, M. Irwanto3
1,2,3
Fellow of center of Excellence for Renewable Energy, School of Electrical System Engineering,
Universiti Malaysia Perlis (UniMAP), Malaysia
1
Department of Electrical Engineering, Medan State University, Indonesia
3
Department of Electrical Engineering, Institut Teknologi Medan (ITM), Indonesia
Article Info ABSTRACT
Article history:
Received Sep 30, 2019
Revised Nov 15, 2019
Accepted Dec 28, 2019
A solenoid supplied by alternating current (AC) voltage generates
electromagnetic which has a field area depends on the level of supplied
voltage and current flows through the solenoid. The electromagnetic filed can
be captured by the other solenoid in the field area. This concept can be
applied in a wireless power transfer (WPT) as presented in this paper.
The WPT has transmitter coil and receiver coil which each has form
of solenoid. The transmitter coil is connected a half bridge circuit to generate
AC voltage on the transmitter coil which transferred to the receiver coil.
In the experimental set up, the receiver coil is supplied by DC voltage source
and it is changed to observe its effect on the voltage and current
on the transmitter and receiver coil of the WPT system.
Keywords:
DC voltage source
Receiver coil
Transmitter coil
Wireless power transfer
This is an open access article under the CC BY-SA license.
Corresponding Author:
M. Irwanto,
Department of Electrical Engineering,
Institut Teknologi Medan (ITM), Indonesia.
Email: mhd-irwanto@itm.ac.id
1. INTRODUCTION
The function of cable as a transmission medium already can be seen in the use of telegrams
as a telecommunications medium. In the telegram, the message was encoded into the password morse
and then translated into electrical signals that are then sent through a piece of wire by Morse in the year
of 1844 [1, 2]. The working principle of telegram later became the basis of the development of shipping
technology information using media cable. Along with the development of technology, the transmission
of information in the end can also be conducted through the medium of non-cable, called wireless.
Wireless communication is done with how to utilize electromagnetic waves as a media delivery information.
Through an antenna, the electromagnetic waves emitted and captured to processed into useful information.
Recent developments in electronic devices have seen increasing demand for embedding electronics
into fabrics for wearable applications. One of the difficulties with such applications is how to provide
a sufficient and reliable power source. Traditional batteries are not an ideal solution for this application
because its bulky size makes it difficult to be integrated into fabrics. Furthermore, they have limited capacity
and, therefore, require constant maintenance such as replacement or recharging [3, 4]. Research on flexible
energy storage devices, such as batteries and supercapacitors, has been reported by [5, 6], but their capacity

Bulletin of Electr Eng & Inf ISSN: 2302-9285 
Effect of DC voltage source on the voltage and current of transmitter and receiver (A. H. Butar-Butar)
485
and performance to date are relatively poor. Thus, an alternative power source is important to be looked for
as DC voltage source in the electronic device, especially in the wireless power transfer (WPT) system.
A solenoid is coil wound into tightly packed helix. A long straight coil of wire can be used
to generate a nearly uniform magnetic field. The magnetic field is concentrated into nearly uniform field
in the centre of a long solenoid. The field of side is week and divergent. The magnetic field density
in a solenoid can be generated if there are current flows through it. The mechanical connection between
the current and magnetic field is explained by [7]. It is considered that the current was somehow gripping
the molecular vortices of the magnetic fields and causing them rotate. The magnetic field in solenoid has
been applied in some areas. The energy of magnetic field generated in the solenoid is transferred using
a concept of magnetic resonant and it is called a WPT [8, 9].
There are some concpets of transmitter and receiver coil applied in WPT system. A circular spiral
coil is designed by [10] for transmitter and receiver coil. It studied the effect of distance between transmitter
and receiver coil on the performance of the WPT system. A single squarel plane inductor is designed by [11]
for the transmitter and receiver coil of WPT system using Matlab software. A single layer dual band printed
spiral inductor is designed by [12]. It studied the effect of frequency given on the peak transfer efficiency
(PTE). A metal wall power transfer is applied by [13] trough 3.1 mm aluminium barrier. The design is based
on Class E amplifier and the result shows that it can achieve a power gain of 25.2 dB and efficiency of 57.3%
at the frequency of 200 Hz. Generally, the electrical power transferred from transmitter to receiver coil is AC
that has a frequency. The required frequency is very important in the design of WPT as has been explained
by some reserchers. The study of WPT system by [14] that apply the frequnacy of 2 GHz and the frequency
of 2.45 GHz is studied by [15-18]. The WPT system can be applied in the electrical area, especially
in the biomedical device as explained by [19-24]. It can also be applied as battery charging [25] for DC
source of electrical vehicle [26].This paper present the effect of DC voltage source on the voltage
and current of 2.5 kHz WPT system. A propose 2.5 kHz WPT system is explained in a block diagram
and implemented in hardware. An experimental setup is conducted to observe the effect of DC voltage
change on the voltage and current of the 2.5 kHz WPT system.
2. RESEARCH METHOD
A research method that consists of a block diagram and experimental setup of effect of DC voltage
change on the WPT system are presented in this section. The block diagram contains the DC voltage source,
driver circuit which drive the circuit of transmitter, receiver circuit and rectifier circuit. The experimental
setup conducts the WPT system implemented in a hardware and it is tested for the condition of differenct
and same turn number of transmitter and receiver coil. The DC vottage source is changed for the constant
distance between the transmitter and receiver coil.
2.1. Block diagram of 2.5 kHz wireless power transfer
The first concept of 2.5 kHz WPT is an induction process of AC voltage waveform on the side of
transmitter coil that produces an electromagnetic field as function of time and induces AC voltage waveform
on the side of the receiver coil. The second concept is following electromagnetic resonance, whereas if the
transmitter and receiver coil are in the same frequency, thus the received power by the receiver coil to be
effective.
The transmitter and receiver coil transmits and receives the 2.5 kHz AC voltage waveform.
The AC voltage is a conversion result from DC voltage to be AC voltage that it is converted by half bridge
circuit that connected to the negative terminal of photovoltaic module as shown by block diagram
of proposed 2.5 kHz WPT in Figure 1. The positive terminal of photovoltaic module is connected
to the centre tap of transmitter coil. The half bridge circuit is constructed by MOSFET with its gate terminal
is driven by the pre amplifier circuit. It is constructed by transistor that its base terminal is driven by the pulse
driver circuit which is microcontroller PIC16F628A as a main component.
The 2.5 kHz AC voltage waveform induced by the transmitter coil is received by the receiver coil.
The type of AC voltage waveform is not suitable for the normal AC loads. It is due its frequency
is categorized as high frequency voltage level. The normal frequency AC loads are always 50 Hz or 60 Hz.
Therefore, the AC voltage waveform on the side of receiver coil should be rectified by the rectifier circuit
to be applied into the DC loads. The detail explanation of each part of transmitter and receiver side of
2.5 kHz WPT are explained in sub chapter below.

 ISSN: 2302-9285
Bulletin of Electr Eng & Inf, Vol. 9, No. 2, April 2020 : 484 –491
486
Battery
Half bridge
circuit
Pulse
driver
circuit
Transmitter
coil
2.5 kHz
induced
AC voltage
waveform
Pre
amplifier
circuit
Receiver
coil
Rectifier
circuit
DC
loads
DC voltage
source
- +
Figure 1. Block diagram of proposed 2.5 kHz wireless photovoltaic power transfer
2.2. Experimental setup of 2.5 kHz wireless power transfer
The experimental setup of 2.5 kHz WPT for the number of turn of receiver coil is lower than
and equals the number of turn of transmitter coil is conducted into four circuit conditions. The first condition
is for the pulse driver circuit. The second condition is for the transmitter and receiver circuit without
the connection of rectifier circuit. The third condition is for the transmitter and receiver circuit
with the connection of rectifier circuit but no connecting the DC loads. The fourth condition is
for the transmitter and receiver circuit with the connection of rectifier circuit and the DC loads.
The first objective of experimental setup for the condition observation of pulse driver circuit is to
make sure that the pulse wave generated by the microcontroller PIC16F628A has the frequency of 2.5 kHz
or period of 400 µs. It is due that the pulse waves are a main driver to drive the transistors MJE13001
and MOSFETS IRFP 460 to generate a 2.5 kHz sinusoidal waveform at transmitter coil. The pulse wave
outputs at pin 11 and pin 12 of the microcontroller PIC16F628A are measured using textronix oscilloscope
as shown in Figure 2. The second objective of experimental set up for the transmitter and receiver circuit
without the connection of rectifier circuit is to observe the 2.5 kHz AC voltage waveform on the transmitter
and receiver side. The magnitude AC voltage, current and power on the both side are also observed and
analysed, especially for the efficiency of the WPT.
Figure 2. Experimental setup of pulse waves generated by the microcontroller PIC16F628A
The third objective of experimental set up for the transmitter and receiver circuit
with the connection of rectifier circuit but no connecting the DC loads is to observe the DC voltage
on the output of the rectifier circuit which is as the DC voltage source of DC loads. The DC voltage is a
result of rectified voltage of the AC voltage waveform on the terminal of capacitor on the receiver coil.
The DC voltage is compared to the input DC voltage of the transmitter side and analysed in term of the losses
on the transmitter side and the receiver side. Figure 3 shows the experimental set up for the transmitter and
receiver circuit with and without the connection of rectifier circuit.The input of transmitter coil of 2.5 kHz
WPT is connected to the DC power supply and the receiver coil is connected to the LED lamp.
Figure 4 shows the experimental set up for 2.5 kHz WPT connected to DC loads.

487
Figure 3. Experimental set up on
the constant distance
Figure 4. Experimental setup for the 2.5 kHz WPT
connected to DC loads
3. RESULTS AND DISCUSSION
2.5 kHz WPT system is designed to have a capability to transfer DC voltage source using
the concept of electromagnetic principle generated by transmitter coil which it is solenoid concept. 2.5 kHz
WPT system has a good performance and stable in the process of transferring power. It means that
the 2.5 kHz WPT system can respond well the change of DC voltage source on the input terminal
of transmitter side. The pulse wave driver circuit can generate well 2.5 kHz pulse wave by pin 11 and 12
of microcontroller PIC16F628A. These two pulse waves drive the two MOSFET IRFP 460 to generate
the 2.5 kHz sinusoidal voltage waveform on the transmitter coil and transmits to the receiver coil based
on the concept of electromagnetic principle. An experimental setup has been conducted to prove this concept
and their results as stated and explained in this sub section.
3.1. 1 pulse and sinusoidal voltage waveform on transmitter and receiver side
A measurement of pulse wave on the pin 11 and 12 of microcontroller PIC16F628A has been
conducted following Figure 2. The measurement use tektronik oscilloscope. Its objective is to prove that
the pulse wave generated by microcontroller PIC16F628A has frequency of 2.5 kHz as shown in Figure 5.
The sinusoidal AC voltage waveform of transmitter and receiver coil for the receiver solenoid diameter
of 16.6 cm is shown in Figure 6.
Figure 5. Pulse wave of pulse driver circuit on the
pin pin 11 and 12 of microcontroller PIC16F628A
Figure 6. AC voltage waveform on transmitter and
receiver coil for receiver solenoid diameter
of 16.6 cm

 ISSN: 2302-9285
488
The transmitter coil of WPT system has a centre tap because the type of bridge circuit is half bridge
circuit and measurement of AC voltage on the transmitter coil is on the position of line to line. Normally,
the line to line voltage of transmitter coil is equal to twice of the line to neutral voltage. The measurement is
done on the distance of 5 cm between transmitter and receiver coil for DC voltage source of 18 V at the input
terminal of transmitter side and the receiver coil is not connected to the rectifier circuit.
The line to line AC voltage and line to neutral AC voltage of transmitter coil are 26.30 V and
13.06 V, respectively. The AC voltage of receiver coil is 4.2 V. By observing the AC voltage waveform of
transmitter coil that it has period, T=8 small scales=3600
, thus 1 small scale is 450
. The AC voltage waveform
of receiver coil appears 5 small scales=2250
after appearing the AC voltage waveform of transmitter coil.
It indicates that the AC voltage waveform of receiver coil leads the AC voltage wave form of the receiver
coil by 2250
and it means that the transmitter side is more inductive compared to the receiver side of
WPT system
3.2. Effect of DC voltage change on the WPT system
The effect of DC voltage source change on the AC voltage and current of transmitter coil and also
on the AC voltage and current of receiver coil for the constant distance of transmitter and receiver coil
of 5 cm as shown in Figure 7 and Figure 8. It is applied on the condition that the rectifier circuit
is not connected to the receiver coil.
Figure 7 and Figure 8 show that for the constant distance between the transmitter and receiver coil,
if the DC voltage source on the input terminal of transmitter side is increased, thus the AC voltage
and current of transmitter and receiver coil will increase also. It is due to the DC voltage source is main DC
voltage source and its positive polarity is directly fed to the centre tap of transmitter coil and its negative
polarity is connected to the negative of transmitter circuit. The magnitude of DC voltage source is directly
converted to be AC voltage by switching the MOSFETs in the half bridge circuit. When the magnitude of AC
voltage generated by transmitter coil is increased, thus the magnitude of AC voltage of receiver coil will
increase also. It is due to the magnetic field generated and arrive the receiver coil is proportional
to the AC voltage.
(a) (b)
Figure 7. Effect of DC voltage source change on the AC voltage and current of transmitter coil
(a) AC voltage, (b) AC current
Based on the Figure 7 and Figure 8, it can be seen that the AC voltage of transmitter, Vt is higher
than the AC voltage of receiver coil, Vr, but the AC current of receiver coil, Iris higher than the AC current of
transmitter coil, It. It is due to the turn number of transmitter coil, Nt=78 turns is higher than the turn number
of receiver coil, Nr=42 turns. It is following a characteristic of magnetic circuit with a transmitter material
media. In this case, air is as transmitter material media and the comparison of the AC current
of transmitter coil, It and the AC current of receiver coil, Ir is explained below.

489
t
r
t
r
t
r
r
t
I
N
N
I
N
N
I
I
x
=
=
When the turn number of transmitter coil, Ntis higher than the turn number of receiver coil, Nr.It means that
the comparison of Nt: Nr> 1, thus the AC current of receiver coil, Ir is higher than the AC current
of transmitter coil, It.
(a) (b)
Figure 8. Effect of DC voltage source change on the AC voltage and current of receiver coil (a) AC voltage,
(b) AC current
The function of rectifier circuit on the receiver side of WPT system is to rectify the AC voltage
of receiver coil. Figure 9shows the AC voltage waveform of receiver coil that it is rectified by rectifier
circuit. It is tested on the DC voltage source of 18 V that produce the rms AC voltage of receiver coil
of 4.2 V and the DC voltage output of rectifier of 6.18 V for the distance between transmitter and receiver
coil is 5 cm. The DC voltage source changes the open circuit voltage of rectifier circuit. The increasing DC
voltage source causes the increasing of rms AC voltage of receiver and the open circuit voltage of rectifier
circuit as shown in Figure 10.
Figure 9. AC voltage waveform of receiver coil and
DC voltage output of rectifier circuit
Figure 10. rms AC voltage of receiver coil and open
circuit voltage of rectifier circuit

 ISSN: 2302-9285
490
4. CONCLUSION
The magnetic field density and power on the receiver side of WPT system are affected
by the magnitude of DC voltage source converted to be AC voltage and AC current that flows through
the transmitter coil for the turn number of transmitter coil. The magnitude of AC current that flows through
the transmitter coil depends on the level of DC voltage source. The increasing of DC voltage source causes
the increasing of AC current and magnetic field density on the transmitter coil and increasing the capability
of arriving magnetic field on the receiver coil, lastly the DC power rectified by the rectifier circuit
will also increase.
REFERENCES
[1] S. A. S. John, “Investigating Wireless Power Transfer,” Physics Education, vol. 52, no. 5, pp. 1-7, 2017.
[2] D, Johnson,et al.,“Electric Circuit Analysis”. Prentice-Hall, 1989.
[3] Z. G. Wan, et al., "Review on Energy Harvesting and Energy Management for Sustainable Wireless Sensor
Networks,” Proc. IEEE Intern. Conf. Communication Technology, pp. 362-367, 2011.
[4] A. P. Sample, D. T. Meyer and J. R. Smith, "Analysis, Experimental Results, and Range Adaptation of
Magnetically Coupled Resonators for Wireless Power Transfer," in IEEE Transactions on Industrial Electronics,
vol. 58, no. 2, pp. 544-554, Feb. 2011.
[5] A. M. Gaikwad, et al., "A Flexible High Potential Printed Battery for Powering Printed Electronics,” Appl. Phys.
Lett. 102 233302, 2013.
[6] S. Yong, et al., "Fabric Based Supercapacitor,” Journal of Physics: Conference Series, vol. 476, no. 1, 2013.
[7] F. D. Tombe, “The Link Between Electric Current and Magnetic Field, “The General Science Journal,vol. 29.
pp. 1-11, 2006.
[8] B. Somashekar & D. D. Livingston, “Matlab Simulation and Programming for Wireless Power Transfer Through
Concrete,” Inter. J. Recent Innovation Trends in Compuing Communication, vol. 3, no. 7, pp. 4869-4872, 2015.
[9] L. Aravind & P. Usha, “Wireless Power Transmission Using Class E Power Amplifier From Solar Input,” Inter. J.
Engin. Res. Tech. (IJERT), vol. 4, no.6, pp. 390-395, 2015
[10] A. Ali, et al., "Design and Analysis of 2-Coil Wireless Power Transfer (WPT) Using Magnetic Coupling
Technique,” International Journal of Power Electronics and Drive System (IJPEDS), vol. 10, no. 2,
pp. 611-616. 2019.
[11] S. I. Kamarudin, et al., "Magnetic resonance coupling for 5G WPT applications,”Bulletin of Electrical Engineering
and Informatics (BEEI), vol. 8, no. 3, pp. 1036-1046, 2019.
[12] L. L. Pon, “Non-radiative wireless energy transfer with single layer dual-band printed spiral resonator,” Bulletin of
Electrical Engineering and Informatics (BEEI), vol. 8, no. 3, pp. 744-752, 2019.
[13] T. A. Vu, et al., “Wireless power transfer through metal using inductive link,” International Journal of Power
Electronics and Drive System (IJPEDS), vol. 10, no. 4, pp. 1906-1913, 2019.
[14] Nai-Chung Kuo, Bo Zhao and A. M. Niknejad, "Near-field power transfer and backscattering communication to
miniature RFID tag in 65 nm CMOS technology," 2016 IEEE MTT-S International Microwave Symposium (IMS),
pp. 1-4, San Francisco, CA, 2016.
[15] X. Chen, W. G. Yeoh, Y. B. Choi, H. Li and R. Singh, "A 2.45-GHz Near-Field RFID System With Passive
On-Chip Antenna Tags," in IEEE Transactions on Microwave Theory and Techniques, vol. 56, no. 6,
pp. 1397-1404, June 2008.
[16] L. H. Guo et al., "A small OCA on a 1/spl times/0.5-mm/sup 2/ 2.45-GHz RFID Tag-design and integration based
on a CMOS-compatible manufacturing technology," in IEEE Electron Device Letters, vol. 27, No. 2,
pp. 96-98, 2006.
[17] Wooi Gan Yeoh et al., "A 2.45-GHz RFID tag with on-chip antenna," IEEE Radio Frequency Integrated Circuits
(RFIC) Symposium, 2006, San Francisco, CA, 2006, pp. 4.
[18] L. H. Guo et al., "Design and Manufacturing of Small Area On-Chip-Antenna (OCA) for RFID Tags," 2006
European Solid-State Device Research Conference, Montreux, pp. 198-201, 2006.
[19] K. Agarwal, R. Jegadeesan, Y. Guo and N. V. Thakor, "Wireless Power Transfer Strategies for Implantable
Bioelectronics," in IEEE Reviews in Biomedical Engineering, vol. 10, pp. 136-161, 2017.
[20] A. M. Sodagar and P. Amiri, "Capacitive coupling for power and data telemetry to implantable biomedical
microsystems," 2009 4th International IEEE/EMBS Conference on Neural Engineering, pp. 411-414,
Antalya, 2009
[21] D. Rozario, N. A. Azeez and S. S. Williamson, "Analysis and design of coupling capacitors for contactless
capacitive power transfer systems," 2016 IEEE Transportation Electrification Conference and Expo (ITEC),
pp. 1-7, Dearborn, MI, 2016.
[22] A. I. Al-Kalbani, M. R. Yuce and J. Redouté, "A Biosafety Comparison Between Capacitive and Inductive
Coupling in Biomedical Implants," in IEEE Antennas and Wireless Propagation Letters, vol. 13,
pp. 1168-1171, 2014.
[23] A. M. Sodagar and K. Najafi, "Wireless Interfaces for Implantable Biomedical Microsystems," 2006 49th IEEE
International Midwest Symposium on Circuits and Systems, pp. 265-269, San Juan, 2006.
[24] M. Takhti, F. Asgarian, and A. M. Sodagar, “Modeling of a capacitive link for data telemetry to biomedical
implants.” in 2011 IEEE Biomedical Circuits and Systems Conference, pp. 181–184, BioCAS 2011.

491
[25] F. Musavi, M. Edington and W. Eberle, "Wireless power transfer: A survey of EV battery charging
technologies," 2012 IEEE Energy Conversion Congress and Exposition (ECCE), Raleigh, NC,
pp. 1804-1810, 2012.
[26] A. F. A. Aziz, et al., "CLL/S detuned compensation network for electric vehicles wireless charging application.”
International Journal of Power Electronics and Drive System (IJPEDS), vol. 10, no. 4, pp. 2173-2181, 2019.
BIOGRAPHIES OF AUTHORS
A. H. Butar-Butar received his Master degree in Electrical Engineering from Universiti Gadjah
Mada (UGM), Indonesia in 2002. He is currently as lecturer in Medan State University, Medan,
Indonesia and as PhD student in Electrical System Engineering, Universiti Malaysia Perlis
(UniMAP). His research interest includes electrical mechine, solar energy and photovoltaic
application system.
J. H. Leong received his Master and PhD degree in Electrical and Electronic Engineering from
Universiti Sains Malaysia (USM) and University of Sheffield, respectively. His research interest
includes power electronic, DC/AC motor drives and solar power generation system.
M. Irwanto received his PhD degree in Electrical System Engineering from Universiti Malaysia
Perlis (UniMAP), Malaysia in 2012. His research interest includes power electronic, electrical
power system stability, solar energy and photovoltaic application system.

Effect of DC voltage source on the voltage and current of transmitter and receiver coil of 2.5 kHz wireless power transfer

More Related Content

What's hot (20)

Similar to Effect of DC voltage source on the voltage and current of transmitter and receiver coil of 2.5 kHz wireless power transfer (20)

More from journalBEEI (20)

Recently uploaded (20)

Effect of DC voltage source on the voltage and current of transmitter and receiver coil of 2.5 kHz wireless power transfer