System-Wide Power Quality Monitoring using Machine-to-Machine Wireless Broadband Technology A
F. Salim, Member, IEEE, K. M. Nor, Senior Member, IEEE, D. M. Said, Member, IEEE, M. S. Serwan
quality for the US distribution system. Abstract-the concern towards power quality has increased
In New Zealand, a Power Quality in Future Electricity
rapidly due to the amount of losses it created. Throughout the
Networks Project has been initiated with the main objective is
world, many researchers have proposed a study on various
to develop the power quality guidelines and to identify the
aspects of power quality, which may be used to overcome or reduce the effects. In this paper, a project initiated by the Energy Commission of Malaysia has been carried out to find the level of
mitigation techniques [2]. As one of the project objectives is to influence the power quality standards,
the New Zealand
power quality in Malaysia as well as to estimate the cost
government has made a major chance in the structure and
associated with power quality. The Malaysian data on power
regulatory framework of the Electricity Industry. On the 1
quality will be recorded and collected by using the standards
April 2010, the Electricity Regulations 1997 has been replaced
compliance
equipments,
Fluke
1750.
The
advanced
in
the
sl
with the Electricity (Safety) Regulations 2010. This is the
communication network has made this project successful as a large amount of data can be downloaded online. The analysis of the recorded data can be made systematically as much software is
most substantial change in power quality regulations in New Zealand for 29 years. NZCEP36 has been mandatory and
available in the market which helps the consultant to develop a
AS/NZS61000 standards voluntary; however, the changes give
more user friendly database. The findings from this project will
more weight to AS/NZS61000 standards as they are a possible
be used to determine the best possible solution for the national
means of compliance.
interest.
In Malaysia, power quality problems have been identified
Index
Terms-Harmonics,
Power
Quality,
and recognized in early 1990 but the progress in managing the
Reference
problems nationally has been rather slow. In 2009, Energy
Impedance, Voltage Sag,
Commission of Malaysia has taken the initiative to conduct a study on power quality environment, current industry baseline
I. INTRODUCTION
as well as the impacts of standard compliance and mandatory
Power quality problem has existed a long time ago since
enforcement on stakeholders. By using the outcomes from this
the electricity was generated. However, during that time, it is
study, it is hope that the quality of the supply electricity is
not a major concern as most electric and electronics equipment is
not
as
sophisticated
as
today.
With
the
emerged
of
microprocessor technologies, electrical equipments have been generate
more
revenue.
Unfortunately,
cost as well as comfortable quality of life. Among
designed to meet customer's satisfaction; high productivity and
essential for the national economic competitiveness, optimum the
challenges
in
system-wide
power
quality
monitoring is the location of recorders, their optimum number
the
and data collection. In the past, recorders are independently
microprocessor-based equipment has become less tolerant to
located and the analysis of the data from the many recorders
the irregularity in the power supply.
includes single events recognized as multiple events due to
With most country around the world is now relying to the
differences in recorder's clock, recording blind spots as well as
automation and digital technology, managing power quality
the data collection cost. There have been studies where the
problems is a challenge. In 1990, Electric Power Research Institute (EPRl) has initiated a monitoring project for duration of 24 months. About 300 sites have been monitored to gather the power quality data at the distribution system level [1]. The recorded data have been used to perform the baseline of power
recorders are connected via wired communication such as through
leased
significant
telecommunication
communication
cost.
lines This
and paper
this
incur
reports
a
successful power quality monitoring project where multiple recorders are placed in optimum location to avoid blind spots and networked using machine-to-machine technology (M2M)
F. Salim is with Centre of Electrical Energy Systems (CEES), Universiti Teknologi Malaysia,(UTM),Malaysia (e-mail:
[email protected]). K. M. Nor is with Centre of Electrical Energy Systems (CEES),Universiti Teknologi Malaysia,(UTM),Malaysia (e-mail:khalidmn@tke. utm.my). D. M. Said is with Centre of Electrical Energy Systems (CEES),Universiti Teknologi Malaysia, (UTM),Malaysia (e-mail: dalila@tke. utm.my) M. S. Serwan is with Advanced Power Solutions Sdn Bhd (APS), Shah Alam,Malaysia (e-mail:
[email protected])
978-1-4673-1943-0/12/$31.00 ©2012 IEEE
in a Virtual Private Network through a public
wireless
broadband system. II. PROJECT BACKGROUND Power quality management is a very important activity in the electricity industry. Regulator of the Energy Commission
124
2
The flow chart to accomplish the data measurement and
has commendably taken a very pro-active role in initiating and carrying
out
the
Baseline
Study
Consultancy Project
on
Power
Quality
acquisition is shown in Figure 1. It will begin with the
30-month
literature study of the power quality event with the emphasis
consultancy project has been awarded to Global Technology
will be given to voltage sag. To get the Malaysian power
and Innovation Management Sdn Bhd (GTIM), the consulting
quality data, three methods have been identified; PQ logging,
for
Peninsular
Malaysia.
This
PQ monitoring and PQ survey. In this paper, only power
arm of Universiti Teknologi Malaysia (UTM).
quality data collected through the PQ monitoring will be
The objectives of this project are as follows: i)
To validate the international power quality standards
discussed in detail.
applicability to Malaysian environment.
A. Power Quality Monitoring
ii) To obtain baseline data on power quality events and sources of events through the power quality monitoring
Power quality monitoring is used to record the voltage sag events. The monitoring devices used in this project are Fluke
programs. iii) To estimate the industry economic loss due to power
1750, which will be installed at the point of common coupling (PCC) of the selected sites for duration of one year.
quality events.
In this project, Fluke 1750 power quality recorder has been
iv) To determine the standard utility and consumer reference
selected to record power quality events. The recorder has a
impedance of the Malaysia electricity supply network. v) To determine the suitable period for implementation and enforcement of the regulations and standards.
local area network (LAN) network interface using the TCP/IP. Thus, a part from transferring the recorded data via SD card, the data can also be downloaded via the LAN interface. The voltage sag data recording will be event triggered, i.e.
III. DATA MEASUREMENT AND ACQUISITION
record will be done whenever a voltage sag event is occurred.
The power quality data will be measured at the industrial,
Data that will be recorded during the event are RMS voltage
commercial and residential sites in the Peninsular of Malaysia.
for all phases, including neutral at pre-event, minimum and
Since only harmonics and voltage sag, is the main concern, the
maximum during event and post event with duration of an
data measurement and acquisition will be based on the general
event. Full waveform comprised of voltage and current for all
principles which are:
phases, including neutral at prior, during and post event will
i)
Site's selection is based on proper sampling to ensure the
also be captured during the occurrence of the event. The
results represent all stakeholders' loads and equipment.
power quality monitor will also record trending data like RMS
ii) All measurements will use IEC standards equipment with
voltage, RMS current, true power factor, percentage of total th distortion and harmonic spectrum up to 50
priority on safety and accuracy.
harmonic
iii) Data collection is through the efficient computer network
harmonics.
with sufficient backup to ensure no corruption or missing
B.
data. Raw data are achieved for independent verification.
Selection ofPower Quality Monitor Locations
use internationally accepted
Fluke 1750 must be placed at a suitable location to reduce
standards and from publication of high international
the number of non-monitored bus as it can eliminate the blind
iv) Data
and
cost
analysis
standings. The analysis technique will be transparent
spot area of the monitor. The blind spot area is the area where
such that independent party can repeat the analysis for
the monitor cannot detect the occurrence of certain voltage sag
verification if necessary.
events. In this project, a minimum of three different monitor locations
v) Data and results of analysis are benchmarked against international
findings
to
help
be
based
in
verification
and
will
be
used
to
ensure
the
reliability
of
the
monitoring system and the correctness of the monitor reading through recording's redundancy.
validation. data
In order to identify the suitable monitor locations, the first
analysis, simulation of practical scenarios and feedback
step is to run a fault analysis simulation by using the
from all stakeholders.
PowerWorld Simulator. By using the method of fault position,
vi) Recommendation
will
on
real
data,
the symmetrical and unsymmetrical faults are located at every Literature study
bus in the system. The objective is to have the during-fault voltage magnitude for every bus in the system. The during fault voltage magnitude is then will be analyzed by using a
Select representative industries for PQ Monitoring
searching
procedure
that
has
been
developed
using
the
MATLAB software. The detailed of the search procedure and its application can be referred in [3]-[5]. By using the proposed search procedure, about 20 monitor
Monitor PQ events for the selected sites for over a year
locations has been identified to monitor the Peninsular of Malaysia. As the Energy Commission of Malaysia needs to increase the level of redundancy, 50 monitors will be installed at customer sites. During the first year, the monitors will be located at 25 selected sites in the northern and eastern region
Develop power quality database Figure 1: Flow Chart of Data Measurement and Acquisition
and another 25 sites at the central and southern region during the second year of the project. The identified locations of monitor are shown in Figure 2. The length of the Peninsular
125
3
Malaysia is about lOOOkm and its widest it is about 350km
network SIM card will provide a dynamic or private internet
wide.
protocol (IP) address for every recorder used in this project. Some of the low-voltage substation or switch room, where the monitor is to be located, has very weak public wireless
egen : • Monitor Locations
communication coverage. This is due to the service provider signals being weak, or it is located in an enclosed area such that the signals cannot penetrate with sufficient strength. In these circumstances, the Viola Artic Modem may need to be located outside the building,
where the service provider
strength is stronger. We have also asked the service provider to optimize the signal strength from their nearby base station to optimize our VPN connection. As the modem may be subject to weather-related disturbances, such as lightning induction, a weatherproof box has been designed to protect the modem. The box is as shown in Figure 4, where the box contains surge protection device and the box itself complies with IP 55standards (Ingress Protection standard).
200km I
Figure 2: 50 Monitor Locations for Peninsular Malaysia
C. Communication Devices Since
the
power
quality
monitors
are
installed at
the
customer site which is far away from the operation office, live
Figure4: 3G High Speed Wireless Router in the Weatherproof Box.
communication between the monitor and the office has to make available. This can be achieved through the usage of Viola Artic Modem with the mobile network SIM (Subscriber
D. Online Remote Data Access
Identity Module) card is attached to it and a Viola M2M gateway installed at the operation office.
The server located in the operation office will be connected to Viola machine-to-machine Virtual Private Network (M2M VPN) gateway, which allows it to communicate with the monitors. The connection is via a public wireless broadband connection using 3G/GPRS technology. The 3G connection has a surfmg speed of 384kbps, while the GPRS connection is about five times slower. The Viola M2M gateway has been used for this project to enable a secure VPN connection between the server network and the remote routers. The VPN connection allowed a user to configure and view the status of every remote monitor. The event recorded can be downloaded and will be stored in the power quality database through the communication
system
provided.
configuration is shown in Figure 5.
Figure 3: Artie 3G High Speed Wireless Router.
By
using
the
network
port
available
at
the
monitor,
connection to the Viola Artic Modem can be made through the local area network (LAN) as shown in Figure 3. The mobile
126
The
communication
4
severity occurred, the recorded data can be retrieved quickly for immediate analysis and action, without the need to travel long distances to get them.
Communication Network
TABLE I TYPICAL DAILy DArA DOWNLOADING TIMES Fluke
1750
Data Transfer
PQ Monitor
PQ Recorder
IP Address
Communicates using TCPliP
Microsoft:® SQL and Web Server
attheOfflce
Size
Time
Rate
(Bytes)
(s)
(byte/s)
172.16.15.2
38718224
960
4033l.483
172.16.2.2
38371732
1140
33659.414
172.16.10.2
52021484
1440
36126.031
-...
Table I shows typical downloading times, the slowest, medium and the fastest, from the recorder to the server. Time
Figure 5: Communication Network Configuration.
taken per site is about 20 minutes. The effective download speed is about 35kbps and thus, the maximum communication
As it has been mentioned before, Fluke 1750 has its own software, which allows users to download via command from
speed of the wireless broadband network of 384kbps is more than sufficient.
The turnaround time for downloading is
a computer. The Fluke also allows connection via Bluetooth's
affected
interface. Since the command has to be initiated manually, the
transmission of data packet. The 384kbps is not the maximum
by
network
latency
and
resending
of
failed
recorded data can only be downloaded by a user at sites. In the
speed service, but the service fee is the lowest and thus the
implementation of this project, two weeks are needed to travel
most cost-effective for the project.
and collect the recorded data from the 25 sites as every
In
this
project,
the
monitor
locations
are
purposely
monitor site is quite far from each other. This is very time
designed to ensure every voltage sag event can be recorded by
consuming and not an effective way in collecting the recorded
more than one monitor. The usage of the gateway and wireless
data.
router help in stay away from counting the same event more
Thus, an application to have an online communication and remote data capturing with every monitor is developed. The application OHCO,
an
is
developed Odin
by
using
Proprietary
constant
provided
Communication
than
ones
[6],
and
it
allowed
the
usage
of
sufficient
redundancy level in recorded the power quality event [7].
by
Protocol
E.
Limitation a/Online Remote Data Capturing
supplied by Fluke. The constant provided by OHCO is used in
The usage of communication devices (Viola M2M gateway
developing the application in Microsoft® C++ for request and
and Viola Artic Modem) through the 3G communication
response with the monitor in order to determine the status of
network has made the online data access and downloading less
connection, status of monitor, data request and end of data. In
costly as it made use of public networking infrastructure based
this manner, data from every monitor can be downloaded
on competitive fees instead of dedicated leased line.
automatically from the operation office and stored in the
However, there is some limitation on the online remote data
database without having someone has to go to every monitor
capturing: one computer can only be connected to one monitor at one time and one monitor can only be connected by one
location.
computer at one time, i.e only one monitor can download the
As online remote data reading is used in this project, another issue that has to be resolved is time synchronization.
data at one time. Due to this limitation, process of data
Time synchronization is important to avoid miscounting the
downloading from all monitors is achieved by queuing the
same event more than ones due to time differences because of
monitors. Once the downloading from one monitor is finished,
an unsynchronized power quality monitor clock. The power
another
quality monitors time is synchronized daily using command
downloading process is finished, a response such as all data is
issued by the server which updated its clock via internet time.
completely downloaded
An alternative method for time synchronization can be
monitor
will
continue or
to
download.
communication
is
When no
the
longer
available will be indicated by OHCO.
achieved by using the recorder that has a GPS receiver. The
There is also a different between downloading data by
receiver hardware and software will add additional cost to the
using the Fluke 1750 software and by using the developed
monitor. In the configuration that has been adopted, time
online application. Data that is downloaded by using the Fluke
synchronization has been achieved without additional cost.
1750 software is saved in the proprietary FLUKE odn format.
Another advantage of VPN connection to the PQ records is
The downloaded file can only be opened when the download
that their status can be continuously monitored. Whenever the
process is completed properly. If the downloaded process did
PQ recorder fails to function, such as when the software
not complete properly (such as when the communication fails
freezes
halfway), the file is not properly closed and cannot be re
(hang)
or
the
local
power
supply
goes
off,
inadvertently switched off or localized power failure, the
opened. The downloading process has to be repeated all the
server will give an alert so that appropriate action can be
way from the beginning.
taken. Furthermore, whenever an event with a high degree of
127
5
This has been modified in our own developed application,
recorded time accuracy is almost similar if we used the GPS.
where the downloaded data is inserted into the database by a
After the database has been developed, further analysis will
small packet continuously during the data-acquisition process.
be carried out by using software such as three-phase load flow,
If the downloading process did not complete successfully, then
symmetrical
we only need to continue at the point where the download
computation. Automation in analyses will be achieved by
process has stopped. This has made the downloading process
extraction of data from
faster and easier to handle the bulky data.
application. The results from the application will also be put in
and asymmetrical fault database
calculation and cost
and for any particular
the database for consistency and trending behavior. IV. POWER QUALITY DATABASE The
power
quality
database
will
be
built
from
V. VOLTAGE SAGS ANALYSIS
the
consultant's experience of developing a similar database for
Since this project focused on national interest under the
Tenaga Nasional Berhad (TNB) Malaysia. The difference will
Energy Commission of Malaysia, it will provide independent
be based on customization required for the objectives to be
analysis, which will be beneficial to all stakeholders.
achieved. The monitored data, survey data and network data
Voltage sag analysis in this study will use method of fault
will be integrated and managed by using the Microsoft SQL
position where a number of faults are spread throughout the
Server software. The entity relationship in the database is
system to investigate the effect of fault location in the system under study. From the sag depth information and the position
shown in Figure 6.
of the monitor,
the analysis can be narrowed down to
geographical location in identifying the sag source location and the probable cause.
DATA BASE
nd Figure 7 shows voltage sag events occurred on the 22 th th January 2011, 24 January 2011 and 25 January 2011. These
Network Data
D &J Inventory
t2
�
monitor locations. The voltage sag magnitude shows is in per unit. The voltage waveform on the 22
Specification, F utu re I n put, Data Identification
SERVER
if
external events have been captured and recorded by different
Logged Data
Reference Impedance
t:J
nd
January 2011 event is
shown in Figure 8. The fault has been identified occurred at the eastern region of Peninsular Malaysia (the deepest voltage
Monitored Data
waveform is recorded by the nearby monitor). This event is a major event occurred and has been recorded
Inventory
by the monitor that has been installed at the northern region of Peninsular Malaysia. Statistics that consist of voltage sag magnitude and its duration will be developed by the database reporting system.
Harmonic Analysis
To date, over a year of recording has been successfully
Voltage Sag Analysis
obtained. All events originating from the grid have been Statistical Analysis
Simulation
identified and the extent of the impacts per network event has been successfully determined. The data from the statistics will
Figure 6: Power Quality Database Arrangement.
then be compared with the equipment voltage tolerance curve such as SEMI F-47 and MS IEC 61000-4-34 to determine the
The monitored data (data recorded by Fluke 1750) will be
event severities. Final analysis will include the estimation of
pulled and downloaded automatically by the server regularly
economic impacts of those events.
except under some contingencies such as if the monitor is not VI. CONCLUSION
responding or the monitor needs to switch off when the selected sites have to shut down. The
server
will
regularly
synchronize
the
data.
Important information and data have been gathered through
The
database will store raw data with time sampling. The server
the
system-wide
power
quality
monitoring
programs.
will use the internet time as the reference and the event
Date and Time 11 Jail 2011 3 :50 Pi\1 24 Jail 2011 11:19 .-\,,"11 15 Jail 1011 11:11.-\J.\1
�Ionitoring L oe.ations 1
1
3
4
:.
0.8 8
6
7
0.883 0.893
0.810
0.825
8
9
10
11
0.892
0.895
0.87 9
0.8�7
11
0.8-12
Figure 7: Voltage Sags Event Recorded By Multiple Monitors
128
13
14
15
16
17
18
19
10 OJ 9
11
11
13
14
15
6 [6]
[7] 0.86+_---1I-_+_-+_ 1 ---1--+-+-----,�"_+-+_-+___+-_+_-+____1
f o M t o a t a t i i o l t a g L o 2 0 1 � � ' � " " � O O V e r o n r c o n � � � ' ' � � ' o l t a g f o M i t o a t L o a t i � � v l �����������������· VVoltageef� orr Moonnitorr at Loccatioonn 1J2 f ����B3 t::::::t:
[8]
O.82
0.78
E3=t=E3=1=!�E:i=:E:;=t==t=±=±==:3
0.7 4 0.70+_--+ --I--+_ ---1--+-·��I___+-� Legend:
0.66
0.62
0.58
0.540
0.01
0.02
0.03
0.04
0.05
0.06 0.07 Time, (5)
0.08
0.09
• • • • o
G. Olguin and M. H. J. Bollen, "Optimal Dips Monitoring Program for Characterization of Transmission System," IEEE Power Engineering Society General Meeting,vol. 4,pp. 2484-2490,2003. Mohamed Amin Eldery, Ehab F. EI-Saadany, Magdy M. A. Salama and Anthony Vannelli, "A Novel Power Quality Monitoring Allocation Algorithm," iEEE Trans. On Power Delivery, vol. 21,no. 2,2006. MS IEC 61000-3-2:2002, Electromagnetic Compatibility (EMC)-Part32: Limits-Limits for Hannonic Current Emissions (Equipment Input Current < 16 A per Phase).
--,
6 9 7
0.10
0.11
0.12
0.13
IX. BIOGR.APHIES Fatimah Salim was born in Kuala Lumpur, Malaysia. She received B. Eng. degree and MEE from the Universiti Teknologi Malaysia, Malaysia. She is currently working toward the Ph.D degree in the Faculty of Electrical Engineering, Universiti Teknologi Malaysia, Malaysia. Her current research interest is in power quality and power system analysis.
0.14
Figure 8: Voltage Wavefonn for Voltage Sag Event.
The
site
selection's
criterion
which
used
a
sufficient
redundancy level is not an issue as recent technology can synchronise the monitors via efficient communication network and PQ monitor cost has decreased from the past. Knowledge in the economic analysis is very important in order to estimate the losses due to harmonic and voltage sag
Khalid Mohamed Nor (M'I98I, SM'I992) was born in Sungai Pelong, Selangor, Malaysia. He received B. Eng. degree with a first class honors from the University of Liverpool, UK. He later received a M. Sc. Degree in 1978 and Ph.D in 1981, both from the University of Manchester Institute of Science and Technology, UK. He is currently a professor in the Faculty of Electrical Engineering, Universiti Teknologi Malaysia. His research interests are in the field of electrical power system simulation
and the mitigation cost. The consultant needs to consider the best and reasonable mitigation technologies in order to arrive at fair mitigation cost estimation. This information and the many standards that have been established will be utilized in this project to detennine the status and statistics of power quality in Peninsular Malaysia. and power quality.
VII. ACKNOWLEDGMENT The authors wish to express their sincere thanks to Centre of
Dalila Mat Said was born in Pulau Pinang Malaysia. She received B.Eng degree and M.Sc degree from Universiti Teknologi Malaysia. She is currently working towards PhD degrees at the Faculty of Electrical Engineering Universiti Teknologi Malaysia. Her research interest includes power quality and energy supply reliability
Electrical Energy Systems (CEES) as well as to Universiti Teknologi Malaysia (UTM) for providing all the facilities to support
this
research
and
Malaysian
Electricity
Supply
Industries Trust Account (MESITA), under the Ministry of Energy, Green Technology and Water (KeTTHA) Malaysia and the Energy Commission of Malaysia for the fmancial support to this research. VIII. REFERENCES [I ]
[2] [3]
[4] [5]
E. W. Gunther, H. Mebta, "A Survey of Distribution System Power Quality-Preliminary Results,"iEEE Transactions on POlVer Delivery, Vol. 10,No I,pp. 322-329,Jan 1995. Neville R. Watson,"Power Quality, a New Zealand Perspective," Power Quality Symposium (PQS 2010), Kuala Lumpur,July 13-14,2010. F. Salim and K. M. Nor, "Optimal Voltage Sag Monitor Locations," Australasian Universities Power Engineering Conference (AUPEC) 2008. F. Salim and K. M. Nor, "Voltage Sag Observation through Optimal Monitor Locations," ICHQP 2010. F. Salim and K. M. Nor, "Voltage Sag Detection via Optimal Monitor Locations," International Conference: Electrical Energy and Industrial Electronic System,EEIES 2009.
Mohd Salleh Serwan obtained his first degree in Bachelor of Science in Mechanical Engineering (majoring in Computer Aided Design and Computer Aided Manufacturing) from the University of Southwestern Louisiana. He is the software development and software support manager in Advanced Power Solutions (APS) Sdn Bhd. He has developed many customized software solutions for power industry such as TNB Fault and Computer Software Program (TPPLAN, PSS Engine) and database development with data automation and utilization using web as interfacing and interacts with simulation software.
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