This document discusses a project that investigates energy harvesting from magnetic induction around power lines. It examines harvesting energy from a 10A power line using different magnetic core materials and dimensions in a coil setup. The highest power harvested was 343mW using a nanocrystalline core with dimensions of 48*24*19mm and permeability of 50,000 for 100 coil turns. Thicker, higher permeability cores and optimizing coil turns were found to increase power output. Nanocrystalline cores had the best performance and are suitable for further improving magnetic induction-based energy harvesting from power lines.

1. Background
Methodology
Energy harvesting is an emerging area with a wide range
of applications. This project mainly focus on energy
harvesting based on magnetic induction. By using the
principle of electrical transformer the energy can be
captured around the power line and supplied at certain
locations where both main power and battery power are
not possible.
 Basic principle
The change of magnetic field can induce the electric
field, thus the induced EMF. Following the Faraday’s
Law, ideally a certain design of the coil around the
flowing current would harvest enough energy to supply
small low power devices like sensor.
• Biot-Savart law
• Faraday’s Law of induction
 Applications
• Remote overhead transmission line
• Mobile phone base station
• wireless sensor node
• wireless charging
etc
 Experiment set up
• 50Hz, AC signal generator
• AC Ammeter
• Oscilloscope
• Multimeter
Results & analysis
 Power density (D= Power/volume)
 Current vs. winding number vs. power
Conclusion
 Best result
 Winding number N vs. Power
 Dimension vs. power
 Circuit diagram
• Tuned circuit
• Impedance matching
 Magnetic core
• Ferrite core (Iron oxides combined with Nickel, Zinc
etc)
42*26*18, μ=10,000
• Nanocrystalline core (Iron, Silicon, Boron, Nickel,
Carbon, Copper etc)
In this project the highest power harvested from 10A power
line is 343mW when using nanocrystalline core with dimension
of 48*24*19 and permeability of 50,000 for 100 turns.
According to the comparative test, there are several conclusion
can be drawn.
 nanocrystalline core has better performance than ferrite
core in terms of permeability and saturation magnetic flux
density
 smaller inner diameter and thicker core tend to increase
the power density
 maximizing the number of winding leads to the power
increase nonlinearly only before saturation
For future research, Nanocrystalline is the suitable material to
be focused on. To improve the results, more research and
experiments should be conducted in terms of dimension and
permeability of the core.
Fig. 1 Basic principle of
magnetic-induction based
energy harvesting [1]
Ref:https://retasite.wordpress.com/tag
/joe-anglin/
Ref:http://www.mcf.amta.org.au/newsl
etters/Mobile.InSite.February.2013?Arti
cle=41853
ENERGY HARVESTING FROM TRANSMISSION LINE
SI LIU (201063072)
PROJECT SUPERVISOR: DR. JIAFENG ZHOU PROJECT ASSESSOR: DR. HARM VAN ZALINGE
DEPARTMENT OF ELECTRICAL ENGINEERING AND ELECTRONICS, UNIVERSITY OF LIVERPOOL, UNITED KINGDOM
Reference
[1] H.J. Visser and R.J.M. Vullers, “RF Energy Harvesting and Transport for
Wireless Sensor Network Applications: Principles and Requirements,”
PROCEEDINGS OF THE IEEE, vol. 101, no. 6, 2013, pp. 1410-1423.
[2] S. Yuan, et al., “Magnetic Field Energy Harvesting Under Overhead Power
Lines”, IEEE Transactions on Power Electronics, vol. 30, no. 11, 2015, pp. 6191-
6202; DOI 10.1109/TPEL.2015.2436702.
[3] H.Chuang, “Energy harvesting from domestic power lines”, Master of
science dissertation, Dept. Electronic & Elec. Eng., Univ. of Liverpool, Liverpool,
UK, 2015.
Core material Nanocrystalline
Dimension 48*24*19
Permeability 50,000
Turns 100
Open circuit voltage V 8.54
Load voltage V 3.36
Resistance Ω 32.87
Capacitance µF 187
Power W 0.343
Fig. 4 the voltage waveform for open
circuit
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 50 100 150 200 250
Power, W
turns
43*23*19, μ=70000, 10A
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0 50 100 150
Power, W
turns
48*24*19, μ= 50000
5A
10A
15A
20A
https://wmich.edu/sites/default/files/i
mages/u681/2015/smartsensors.jpg
Fig. 2 Circuit diagram
for the experiment
Table. 1 Highest power and corresponding parameters
Fig. 3 The voltage waveform of load
resistor
Using nanocrystalline core with dimension of
48*24*19 and permeability of 50,000 for 100 turns
yields the highest power 343mW in condition of 10A.
Fig. 5 the relation between winding number N and power,
43*23*19, μ=70000
As shown in figure 5 The winding number increases
from 20 turns to 200 turns. The power reaches
0.235W when there’s only 20 turns. It keeps
increasing slightly as the winding number adding until
around 60 turns. The maximum power 0.308 appears
at around 60 turns. It can be observed that power
slightly reduces and then remains around 0.291W
after 60 turns. This is because when the magnetic flux
density B is saturated, the change of B become zero,
thus zero voltage.
Fig. 7 Power density of 4 different type of cores
The thickness of the magnetic core have significant
impact on the increment of output power. In addition,
smaller inner diameter tend to yield higher power.
0.343
0.291
0.255
0.152
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
48*24*19 μ=
50000
43*23*19
μ=70000
54*36*23
μ=50000
43*29*19
μ=70000
Power, W
Dimension vs. Power
100 turns
Fig. 6 the relation between dimension and power
Core type Pictures
Volume
(cm3)
Thickness (cm)
43*23*19,
μ=70000
19.7 1
43*29*19,
μ=70000
15.04 0.7
48*24*19,
μ=50000
25.79 1.2
54*36*23,
μ=50000
29.26 0.9
Increasing the current yields almost linear increment for
output power. However, For 5A, the core is efficient
enough for 15 turns while the core needs about 50 turns
to be efficient enough for 20A.
Fig. 8 Current vs. winding number vs. power
As discussed with figure 6, under this condition, the
thicker the core is, the higher the power density is. Also,
the permeability contribute to higher power density.
Fig. 9 Power density vs. current
14.77
10.1
13.3
8.71
14.92
9.51
12.48
8.71
0
2
4
6
8
10
12
14
16
43*23*19,μ=70000 43*29*19,μ=70000 48*24*19,μ=50000 54*36*23,μ=50000
mW/cm3
Power density
100 turns
50 turns
5A 10A 15A 20A
Power density 6.09 13.3 19.34 26.02
0
5
10
15
20
25
30
mW/cm3
48*24*19,μ=50000, 100 turns