Measurement 56 (2014) 1–7
Contents lists available at ScienceDirect
Measurement
journal homepage: www.elsevier.com/locate/measurement
Development of adapted ammeter for fraud detection
in low-voltage installations
H.O. Henriques a, A.P.L. Barbero a, R.M. Ribeiro a, M.Z. Fortes a,⇑, W. Zanco a, O.S. Xavier a,
R.M. Amorim b
a
b
Department of Electrical Engineering (TEE), Fluminense Federal University (UFF), Niterói, RJ, Brazil
Light S.E.S.A, Rio de Janeiro, RJ, Brazil
a r t i c l e
i n f o
Article history:
Received 13 October 2013
Received in revised form 10 June 2014
Accepted 19 June 2014
Available online 27 June 2014
Keywords:
Electric energy measurement
Fraud detection
Plastic fiber optic
Radio frequency
a b s t r a c t
This article describes the development and implementation of a modified ammeter to facilitate fraud detection in low-voltage consumer units. The device has three modules: the first
is a meter affixed to the top of a stick, which is the local unit and it measures the consumer
current; the second is another instrument that transmits the measured current after the
customer’s meter via radio frequency, and it is the remote unit; and the third is a receiver
unit that displays the measurements made by the local and remote units. On the receiver
unit display, the operator can check and compare the two (local and remote) measures
detecting fraud by determining if there is a difference between the measures. The paper
illustrates field measurements performed in a test for a Brazilian electric utility.
Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction
A common problem in electric power distribution utilities in Brazil is fraud committed by some consumers who
use illegal connections. For these consumers, the energy
quantity consumed is not the same registered in their individual electrical meter. These deviations cause economic
loss to the electricity concessionaire that financially penalizes honest consumers, since the loss by fraud has been
inserted in the recent years’ electricity prices. Research aiming to avoid or mitigate fraud is common at different sectors
as telecommunications networks [1] or systems [2].
In electrical systems, there are some important investigations, such as three different techniques for non-technical loss in power utility analyses [3] and expert system to
support non-technical losses [4,5]. Another important
⇑ Corresponding author. Address: Passo da Pátria Str., 156, Room E-431,
21240-210, Niterói, RJ, Brazil. Tel.: +55 2126295358; fax: +55
2126295700.
E-mail address: mzf@vm.uff.br (M.Z. Fortes).
http://dx.doi.org/10.1016/j.measurement.2014.06.015
0263-2241/Ó 2014 Elsevier Ltd. All rights reserved.
study is on the Iran electric power distribution system as
presented by [6]. In Brazil, analyzing consumer behavior
is one focus [7]. Some recent work considering low cost
equipment that analyzes electrical measurement is
disseminated in [8,9]. When new technologies are discussed, optical technology is referred to as important
[10], but there are others, such as digital smart meters
[11] and current measurement with a non-contact thermometer [12]. The use of electric measuring instruments,
particularly the current type, has various applications, such
as for medical systems monitoring [13], as well as for current density dispersion evaluation in electronic scans [14].
For identification of energy fraud, some techniques can
be utilized, such as meters connected in parallel as demonstrated in [15] or a direct analysis as shown by [16] in
1990. The use of specialist systems has attracted great
attention from researchers: using data history to identify
frauds [17,18], the technique known as optimum-path forest (OPF) [19], the intelligent system named Support Vector Machine (SVM) [20] and Differential Evolution in
[21]. In this paper, we present a measurement system
2
H.O. Henriques et al. / Measurement 56 (2014) 1–7
modified/upgraded to detect fraud. This system was developed in the LETD (Transmission and Distribution Research
Laboratory) at Fluminense Federal University (UFF) and
was supported by the regional electric utility company,
where some regular testing equipment was changed to
avoid current meters in low-voltage commercial consumer
installations. This system does not consider special energy
quality analyses, but an interesting system considering this
specific measurement is presented in [22].
The methodology adopted for identifying fraud is to
measure and compares the electrical current in the client
connection (before and after the individual meter is taken).
The measurement difference, if any, is evidence of fraud via
illegal, electric power connections. To support the fraud
identification, the instrument that is developed and
described in this text has three modules: the first module,
or local unit, is a type of ammeter-clamp, affixed to the tip
of a stick, which measures the current in the client connection. The clamp or current ‘‘grab’’ is opened through a
mechanism developed especially for this purpose, and it
is manipulated by the operator from the base of the stick.
The current measured by the local unit is transmitted to
a receiver unit located at the base of the stick, which can
give the current reading measured by the local unit, using
an optical interface via a plastic optical fiber [14]; the base
of the stick also contains the opening mechanism of the
clamp. The second module or remote unit is responsible
for the client circuit current measurement (after the
meter). The current measured by the remote unit is transmitted through a communication interface for radio
frequency (RF) to a receiver unit. The frequency used was
433 MHz because it is an open air frequency and does
not need licensing. The receiver unit is the third module.
The receiver unit measurements taken at the local unit
and remote unit are read and compared. The local unit current measurement is transmitted to the receiver unit via an
optical interface using a plastic optical fiber. Already the
current measured by the remote unit is transmitted to
the receiver unit via radio frequency. The absolute and percentage difference is shown on the receiving unit in a
liquid crystal display. If there is a difference, this denotes
fraud. Information about some basic features of the instruments used in this project adaptation can be found in the
Refs. [23,24].
A preliminary prototype was built and tested in the
field with electric utility company workers that supported
the equipment development herein. The tests were considered satisfactory, and the equipment proved to be practical, with only minor changes necessary in the final product.
tested for accuracy and given calibration certificates. The
measurement equipment used in the development project
was prepared physically in a laboratory before insertion in
the prototype; all necessary tests were performed in this
manner. The prototype is built based a clamp ammeter
cat. III – 600 V in according with the NBR-5410 (Low Voltage Electrical Installation Standard – Brazil) and IEC
61010-1 (Safety Requirements for Electrical Equipment
for Measurement, Control, and Laboratory – Part 1: General
requirements).
The prototype part is the magnetic transducer, i.e., a
current measurement instrument in the form of an ammeter clamp to be installed around the cord, allowing the
researcher to measure the current with sufficient accuracy,
without stopping or diverting the current flow. In this way,
the magnetic field generated by the electrical current to be
measured is transformed into an electrical current (secondary) of lesser intensity. This lower current intensity is
then measured and coded through analog-to-digital electronic circuit conversion. The digital data, still in the electric domain, is transformed to the optical domain through
the electric/optical interface.
The first practical development step, after some acquisitions took place, was assembling a test set as illustrated by
Fig. 1.
The purpose of this suit is to test and calibrate the
ammeter using a power analyzer as electrical current secondary standard equipment. More specifically, the test
suite is intended to check and calibrate local and remote
units. The idea is to supply an electrical current up to
100 A in order to test the operation of the ammeter. The
combination of resistive decade and a variac, shown in
Fig. 1, supplies the necessary calibration current. It should
be noted that the energy analyzer will measure the same
current that passes through the cane clamp and flows
through the resistive bank, as shown in Fig. 2.
In this way, it is possible to calibrate the equipment in
development up to a resolution of 0.1 A. Some peripheral
equipment for measuring different parameters is also part
of the test suite as follows: arbitrary signal generator, oscilloscope, current source and optical power meter, although
its use in testing and calibration steps is restricted to fault
2. Methodology
2.1. Test equipment mounting
The main challenge of this project is to develop prototype equipment for use in the field that is simple, robust,
and operational, and that it is still accurate and reliable.
The purpose of this research is to obtain an instrument to
support fraud detection in residential and/or commercial
facilities. For this, all prototype development steps were
Fig. 1. Test suite panoramic photography.
ID
730176
Title
Developmentofadaptedammeterforfrauddetectioninlow-voltageinstallations
http://fulltext.study/article/730176
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