Transcript How to measure high Frequency Voltage

Voltage Transients
and
Health
Mikko Ahonen
PhD, Researcher
University of Tampere, Finland
Table of Contents
What are voltage transients – discussion about power quality
How to measure and record voltage transients
What are symptoms and mechanisms of effect
Impact on wellbeing technology and its development
A little Finnish-Russian pilot
My background
• Earlier worked in the Telecom and IT industry (TeliaSonera etc.)
• PhD in computer science
• Researcher at the University of Tampere
• Co-operating with FinnMedi Ltd (Tampere, Finland) &
with Kazan State University (Russia) &
with measurement manufacturers (Germany & USA)
• Founder and Partner
Measuring Services
Sustainable Mobile Ltd 
(http://www.sustainablemobile.com, http://twitter.com/SustainableM )
From sine wave to transients
- definitions
50 Hz sine wave & magnetic field
Generally, electricity in its
purest form does not seem to
cause health problems
(Mandeville et al., 1997 &
McCann et al., 1993)
Only magnetic fields starting from
0.3 uT (mikroTesla) have
been linked to childhood leukemia
(Greenland et al. 2000; Ahlbom et
al., 2000). BUT results are
inconclusive.
Are there other factors? High electric fields
(in connection to low-level magnetic fields)
• Miller et al. (1996): 4 x leukemia risk in
Canadian power company workers.
"This study suggests
that electric fields are potentially critical to cancer risk” 1
• Guénel et al. (1996): 7 x brain cancer risk, when
electric utility workers were exposed more than
25 years
• Villeneuve et al. (2000) : 10 x leukemia risk ,
23
elevated Non-Hodgin’s lymphoma 1
Please, note: Very limited amount of evidence
Voltage transients (or simply “transients” or “micro surges”)
“Transients are voltages
and currents of short
duration, typically less than
one-half a cycle and
possibly of larger
amplitude than that of the
normal steady state. These
will either add or subtract
from the nominal
waveform.”
Source: Dranetz BMI (1997)
Harmonic overwaves (harmonics)
“We define harmonics as
voltages or currents at
frequencies that are a
multiple of the fundamental
frequency. For European
systems, the harmonic order
is 100 Hz, 150 Hz, 200 Hz
etc.”
Source: Dranetz BMI (1997)
Intermediate Frequencies (IF): 300 Hz – 100 kHz
• Another name for the range of voltage transients
• “As an overarching need, further research on
intermediate frequencies (IF), usually taken as
frequencies between 300 Hz and 100 kHz, is
required, given the present lack of data in this
area.” (WHO, 2007)
From a review article – Voltage transients:
“Environmental exposure to High-Frequency Voltage
Transients is an interesting EMF exposure metric, which
might explain the spurious results from epidemiological
studies using 'standard' ELF and RF exposure metrics.
However, at present, methodological problems in published
studies prohibit the valid assessment of its biological
activity.”
Source: De Vocht (2010)
What causes voltage transients?
Main sources of voltage transients
- Switching power on/off continuously
- Static power converters
with GR-diodes
- Faulty electrical installations
- Loose connections
- Overloaded phases
- Dimmers
- Energy-saving lamps
- etc
Picture: PhD, engineer Berthold Fuld (http://www.fuld.de/html/vortrag_pfc.pdf )
Laptops – occasionally extremely high voltage transients
Typical frequency values for highest micro surges caused by laptops:
D laptop computer = 25 kHz
D tower computer = 16.6 kHz
Source: D. Stetzer
A computers = 12.5 kHz
Reason for high transient reading? Poor quality switching power supplies
Low-frequency transient electric and magnetic
fields coupling to child body / in the frequency
range from 50 Hz up to 100 kHz - Ozen (2008)
“The results show that the transient electric and
magnetic fields would induce higher current density in
the child body than power frequency fields with similar
field strength”.
118004
-times
higher!
Which frequency ranges match with highest
amplitude of electrical fields?
Source: Lundmark et al. 2005
A related finding, shown on the video. Demonstrated with a frequency generator.
Which devices cause the biggest amplitude
changes?
(VDU = Video Display Unit, HF-fitting=fluorescent tubes equipped with high-frequency electronic ballasts)
Source: Lundmark et al. 2005
See also: Oliveira et al. (2006)
There are differences in lamps and light bulbs
Video 1
Video 2
Source: Havas (2008)
Accurate measurements of compact fluorescent lights: Maes (2009)
General observations
• Power quality has an effect on machines and
their proper functioning.
• Ground current problem noticed first in farms in
USA and Canada. Related to voltage transients.
• Various filters have been developed that reduce
transients and harmonic overwaves.
• The term ”Reactive Power Compensation”
means improving power quality.
How to measure voltage transients?
(1/2)
Unit: dV/dt  the average magnitude of the rate of change of voltage
as a function of time. Measured often between 2 kHz – 150 kHz.
Advanced
Graham-Stetzer
MicroSurge Meter
Fluke
VR1170
Gigahertz Solutions
NFA-1000
Fluke Scopemeter
199C
How to measure transients?
(2/2)
Output:
L / PE / N
+
Oscilloscope
or
Spectrum
analyser
Adapter for Harmonic Analysers /
Auskoppeladapter
For measurement of conducted electromagnetic
interference in the frequency range from 10kHz to
30MHz based on CISPR 16 for measurements in
accordance to EN 55011…22
Transients in red – Minimal
Measured with a Fluke Scopemeter
Transients in red - Increased
Measured with a Fluke Scopemeter
Back to research results of transients
Armstrong, Thériault et al. (1994): Workers exposed to
transients had 6 x risk of developing lung cancer (even
non-smokers).
Consequence: The Canadian power company confiscated data
and further research was not possible1
Milham & Morgan (2008) The teachers' chances of
developing melanoma, thyroid cancer, and uterine cancer
were particularly high, as great as 13 times the average.
 Consequence: Researchers were not able to access the school any more 1 , 2 , 3
Please, note: Very limited amount of evidence +
Extremely difficult to conduct studies in this area!
Regularly clusters where low level magnetic field or power density
readings can not explain the whole “picture” - examples
http://www.nbcsandiego.com/news/health/Cancer-Cluster-at-UCSD-Building.html
http://www.news.com.au/national/another-abc-staffer-has-breast-cancer/story-e6frfkvr-1225833135423
http://blink.ucsd.edu/safety/resources/public-health/lit-building/
Lots of discussion about melatonin and electro-magnetic fields:
ELF-EMF may act at the cellular level to enhance breast cancer
proliferation by blocking melatonin’s natural oncostatic action in MCF-7 cells
(Liburdy, 1993; Luben et al., 1996; Morris et al., 1998; Blackman et al., 2001; Ishido
et al., 2001, Girgert et al., 2010) .
Is low level magnetic field value here more important than transient intensity?
Please, note: Other environmental factors like heavy chemical exposure should be understood.
Symptoms and improvements with transient filters
(examples)
1. Allergy and asthma:
- No inhalators needed any more
- Less skin problems
Havas & Olstad (2008)
NFAM (2008)
2. Diabetes
- Type 1 diabetics require less
insulin and Type 2 diabetics have
lower levels of plasma glucose
Havas (2008), video
3. Multiple Sclerosis and other
neurodegenerative illnesses:
- Less tremors
- Better movability
Havas (2006)
3. Concentration and sleep:
- Less anxiety and restlessness
- Better sleep quality
Genuis (2007)
Please, note: The evidence is still limited.
About mechanisms of effect
High tissue gradients by high voltage transients
•
Bawin and Adey (1976) showed that a 56 V/m ELF field (in 50 Hz) induces a tissue
gradient of 10-7 V/cm, whereas a 56 V/m 147 MHz signal induces a tissue gradient of
10-1 V/cm, a million times higher. (See also: Cherry, 2002; Blank & Goodman, 2004)
Professor
Martin Blank
About mechanism: Stress response in DNA
• ”Induction of the stress response involves activation of
DNA, and despite the large difference in energy between
ELF and RF, the same cellular pathways respond in both
frequency ranges. Specific DNA sequences on the
promoter of the HSP70 stress gene are responsive to
EMF, and studies with model biochemical systems
suggest that EMF could interact directly with electrons in
DNA. While low energy EMF interacts with DNA to induce
the stress response, increasing EMF energy in the RF
range can lead to breaks in DNA strands”.
Blank & Goodman (2009)
About mechanisms: Gap junctions = protein bridges
between cells  Transients may interfere gap opening
Gap junction flow is significantly altered as a function of 50 Hz
magnetic field strength, Li et al. (1999).
Gap junction opening is regulated by calcium ions and pH, Alberts et al. (1994).
(Experiments in Canada: pH-levels acid when high transients, alcaline when minimal transients).
About mechanism: Alternative explanations
• Atmosferics, weather-related electrical activity in kHzrange have historically caused health problems
(Schienle, Stark, Walter & Vaitl, 1996; Reiter, 1995;
Dubrov, 1978) and now this frequency range is artificially
created in the electrical network.
• Certain frequencies inhibit DNA-repair and cause
weakening of the immune system (Belyaev et al. (2009),
RNCNIRP (2008). Frequency-windows exist and some
frequence/power density combinations are harmful.
(Blackman, 2009).
About mechanism – One expert opinion
Transients are created when current is repeatedly interrupted. A CFL, for
instance, saves energy by turning itself on and off repeatedly, as many as
100,000 times per second.
So how does the human body respond to this pulsing radiation? "Think of a
magnet," explains Dave Stetzer, an electrical engineer and power supply expert
in Blair, WI. "Opposite charges attract, and like charges repel. When a transient
is going positive, the negatively charged electrons in your body move toward
that positive charge. When the transient flips to negative, the body's electrons
are pushed back. Remember, these positive-negative shifts are occurring many
thousands of times per second, so the electrons in your body are oscillating to
that tune. Your body becomes charged up because you're basically
coupled to the transient's electric field."
Keep in mind that all the cells in your body, whether islets in the pancreas
awaiting a signal to manufacture insulin or white blood cells speeding to the site
of an injury, use electricity — or "electron change" — to communicate with each
other. By overlapping the body's signaling mechanisms, could transients
interfere with the secretion of insulin, drown out the call-and-response of
the immune system, and cause other physical havoc? 1 , 2 , 3
About mechanism:
There is much we don’t know, no single
mechanism is fully established!
Impact on wellbeing technology
and its development
Mobile phone components – producing transients
continuosly in stand-by mode
Question: How risky is it to keep to a mobile phone attached to the body
continuously? Is it really a personal health monitoring device?
Smart meters and other utility equipment –
transmitting RF-signals in the electrical circuit
and power lines
• Vignati & Giuliani (1997) investigated
powerlines: “Electric current at 100 kHz
can penetrate much more deeply through
the plasmatic membrane than current at
50/60 Hz.”
• Italy: Frequencies used by utilities for
data transmission range from 104 to 288
kHz.
• Israel: Powerlines lines are used to
transfer information. The frequency range
is 30 to 450 kHz.
• What is the current and future situation?
• Which frequencies are the most critical
from health perspective?
What happens when RF-frequencies are “run”
in a powerline that is originally optimised
for 50 Hz sine wave?
The gain of the powerline as a radiator increases rapidly with frequency
(Hare, 2003 ).  Powerline starts to act as an antenna and extends wider.
Filters reduce voltage transients
• A simple condenser/capacitor as a filter
• Or… a special line filter (from Graham-Stetzer, Bajog etc.).
 Suitable for interference suppression for switching power supplies
and phase controlled modulators
Observation: Voltage transients are similar to pulsed microwaves.
Making epidemiological studies is very complicated.
Radio and TV-transmitters:
Effect: Dolk et al. (1997a), Hocking & Gordon (2003),
Ha et al. (2007), Mascarinec et al. (1994, Michelozzi et al.
(2002), Morton & Phillips (1983), Park et al. (2004)
[Mostly increased leukemias and lymphomas]
No effect: Dolk et al. (1997b), Mersenich et al. (2008)
Mobile Phone Base Stations:
Effect: Abdel-Rassoul et al. (2007),
Eger et al. (2004), Hutter et al. (2006),
Navarro et al. (2003), Santini et al. (2003),
Wolf & Wolf (2004), Blettner et al. (2008)
[great variety: from headaches to breast cancer]
No effect: Meyer et al. (2006), Berg-Beckhoff et al. (2009)
http://www.chronicexposure.org
Our little pilot in a Finnish (and a Russian) school
• Starting point: Teachers and students had many health problems
and complaints in a high school. Minimal amount of mold was found
and removed. Ventilation was improved in the school. Still, problems
remained.
• We measured transients in every class room. Protocol: Similar to
Trushina et al. (2010), co-operating with prof. Maksim Trushin
• Thereafter we checked if symptoms and transient readings match.
Interestingly: There was a match, the 2 teachers who had the biggest
health problems (asthma that required inhalators, skin problems,
watery eyes, continuous coughing) worked in those 2 class rooms
with highest transient readings.
• Outcome: Filters that drop the HF-transients were installed for testing
purposes. Symptoms of teachers were reduced. We need(ed) more
information about exposure conditions at home + earlier chemical
exposure. Reseach continues both in Tampere-area and Kazan …
Additionally, we have a pilot starting in a hospital.
Are we saving energy on the cost of health?
Already we know that many appliances and machines could be designed in a better way.
Our research hopefully helps to make those “Smart Meters”, “Smart Grids” and “Smart Houses”
more sustainable and healthier. Additionally, electronics, wires and power supplies in schools,
homes and work places could be improved with small costs and simple means. Within Green IT
and Green Computing we should perhaps start discussing about health issues and transients.
What about standards and guidance levels?
DIN EN 61000-3-2; VDE 0838-2:2010-03 Electromagnetic compatibility (EMC)
ICNIRP-guidance level – no consideration of:
- wavelength/frequency
- overall duration of exposure (continuous, interrupted), acute and
chronic exposures
- polarization (linear, circular)
- continues wave (CW) and pulsed fields
(pulse repetition rate, pulse width or duty cycle, pulse shape, pulse to
average power, etc.)
- modulation (amplitude, frequency, phase, complex)
- static magnetic field at the place of exposure
- electromagnetic stray field (Belyaev, 2008; Blackman, 2007)
SanPin is perhaps the only health standard that considers these?
Thank you!
Questions and comments welcome!
Mikko Ahonen
PhD, Researcher
University of Tampere
Finland
Telephone
Skype
+358-3-3551 8069
ahosmikko
E-mail
mikko . ahonen [at] uta . fi
Info
http://www.uta.fi/~mikko.ahonen/
Blog
http://beyondradiation.blogs.com