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This paper presents the importance of the network voltage monitoring which means amplitude, rms value and frequency measuring and following the deviation of the voltage shape too. To ensure and maintain the energy quality, the parameters of the network voltage must be kept within optimal values. This is important for users and loads, because they may work wrongly or may fail in case of an irregularity of the supply voltage. Will be discussed about the most important phenomenons in voltage variations and how they can be observed with an energy quality measurement instrument. The bloc scheme of the monitoring system will be presented, which was realised for a plant grower, and the used components from different companies, and the posibility of using and connecting to a second supply in case of cutoff of the primary network. The monitoring system is realised around a programmable compact PLC which can be used for all requirements in industrial and building automation as well as machine control. The main functions and the programming possibilities of the programmable compact PLC are presented.
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Available online at www.sciencedirect.com
Available online at www.sciencedirect.com
ScienceDirect
Procedia Manufacturing 00 (2017) 000–000
www.elsevier.com/locate/procedia
* Paulo Afonso. Tel.: +351 253 510 761; fax: +351 253 604 741
E-mail address: psafonso@dps.uminho.pt
2351-9789 © 2017 The Authors. Published by Elsevier B.V.
Peer-review under responsibility of the scientific committee of the Manufacturing Engineering Society International Conference 2017.
Manufacturing Engineering Society International Conference 2017, MESIC 2017, 28-30 June
2017, Vigo (Pontevedra), Spain
Costing models for capacity optimization in Industry 4.0: Trade-off
between used capacity and operational efficiency
A. Santanaa, P. Afonsoa,*, A. Zaninb, R. Wernkeb
a University of Minho, 4800-058 Guimarães, Portugal
bUnochapecó, 89809-000 Chapecó, SC, Brazil
Abstract
Under the concept of "Industry 4.0", production processes will be pushed to be increasingly interconnected,
information based on a real time basis and, necessarily, much more efficient. In this context, capacity optimization
goes beyond the traditional aim of capacity maximization, contributing also for organization’s profitability and value.
Indeed, lean management and continuous improvement approaches suggest capacity optimization instead of
maximization. The study of capacity optimization and costing models is an important research topic that deserves
contributions from both the practical and theoretical perspectives. This paper presents and discusses a mathematical
model for capacity management based on different costing models (ABC and TDABC). A generic model has been
developed and it was used to analyze idle capacity and to design strategies towards the maximization of organization’s
value. The trade-off capacity maximization vs operational efficiency is highlighted and it is shown that capacity
optimization might hide operational inefficiency.
© 2017 The Authors. Published by Elsevier B.V.
Peer-review under responsibility of the scientific committee of the Manufacturing Engineering Society International Conference
2017.
Keywords: Cost Models; ABC; TDABC; Capacity Management; Idle Capacity; Operational Efficiency
1. Introduction
The cost of idle capacity is a fundamental information for companies and their management of extreme importance
in modern production systems. In general, it is defined as unused capacity or production potential and can be measured
in several ways: tons of production, available hours of manufacturing, etc. The management of the idle capacity
Procedia Manufacturing 32 (2019) 380–384
2351-9789 © 2019 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
10.1016/j.promfg.2019.02.229
10.1016/j.promfg.2019.02.229 2351-9789
© 2019 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
Available online at www.sciencedirect.com
ScienceDirect
Procedia Manufacturing 00 (2018) 000000
www.elsevier.com/locate/procedia
2351-9789© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license(https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
The 12th International Conference Interdisciplinarity in Engineering
Voltage Monitoring and Supply Controlling System
Ágoston Katalina,
0F*
Department of Electrical Engineering and Computers, University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Nicolae
Iorga st., No.1, 540088 Targu Mures, Romania
Abstract
This paper presents the importance of the network voltage monitoring which means amplitude, rms value and frequency
measuring and following the deviation of the voltage shape too. To ensure and maintain the energy quality, the parameters of the
network voltage must be kept within optimal values. This is important for users and loads, because they may work wrongly or
may fail in case of an irregularity of the supply voltage. Will be discussed about the most important phenomenons in voltage
variations and how they can be observed with an energy quality measurement instrument. The bloc scheme of the monitoring
system will be presented, which was realised for a plant grower, and the used components from different companies, and the
posibility of using and connecting to a second supply in case of cutoff of the primary network. The monitoring system is realised
around a programmable compact PLC which can be used for all requirements in industrial and building automation as well as
machine control. The main functions and the programming possibilities of the programmable compact PLC are presented.
© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
Keywords: power quality; supply monitoring; voltage controlling system; EasySoft.
1. Introduction
The power quality problems are increasingly complex and important for consumer and provider too. It is an
important requirement of customers to sustain and ensure the quality of the energy, who use and work with modern
equipments sensible to energy changes and disturbances. The energy is determinated through voltage and current, so
these define the power quality too. The assessment of the voltage and the current are made through indicators whose
* Corresponding author. Tel.: +4-0743-794-319.
E-mail address: katalin.agoston@ing.upm.ro
Available online at www.sciencedirect.com
ScienceDirect
Procedia Manufacturing 00 (2018) 000000
www.elsevier.com/locate/procedia
2351-9789© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license(https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
The 12th International Conference Interdisciplinarity in Engineering
Voltage Monitoring and Supply Controlling System
Ágoston Katalina,
0F*
Department of Electrical Engineering and Computers, University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Nicolae
Iorga st., No.1, 540088 Targu Mures, Romania
Abstract
This paper presents the importance of the network voltage monitoring which means amplitude, rms value and frequency
measuring and following the deviation of the voltage shape too. To ensure and maintain the energy quality, the parameters of the
network voltage must be kept within optimal values. This is important for users and loads, because they may work wrongly or
may fail in case of an irregularity of the supply voltage. Will be discussed about the most important phenomenons in voltage
variations and how they can be observed with an energy quality measurement instrument. The bloc scheme of the monitoring
system will be presented, which was realised for a plant grower, and the used components from different companies, and the
posibility of using and connecting to a second supply in case of cutoff of the primary network. The monitoring system is realised
around a programmable compact PLC which can be used for all requirements in industrial and building automation as well as
machine control. The main functions and the programming possibilities of the programmable compact PLC are presented.
© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
Keywords: power quality; supply monitoring; voltage controlling system; EasySoft.
1. Introduction
The power quality problems are increasingly complex and important for consumer and provider too. It is an
important requirement of customers to sustain and ensure the quality of the energy, who use and work with modern
equipments sensible to energy changes and disturbances. The energy is determinated through voltage and current, so
these define the power quality too. The assessment of the voltage and the current are made through indicators whose
* Corresponding author. Tel.: +4-0743-794-319.
E-mail address: katalin.agoston@ing.upm.ro
2 Ágoston Katalin / Procedia Manufacturing 00 (2018) 000000
values are established based on specific requirements and standards. The quality and efficiency of industrial and
non-industrial activities depend largely on supply voltage whose variations must be within acceptable limits. The
power quality can be defined by users as characteristics of the power supply which enables a proper work of the
equipment. Any problem, deviation in voltage, current or frequency may result failure or misoperation of the
equipments. Today the electricity is considered a basic right, and should be present always with optimal
characteristics. [1],[6]
In many cases the customers’ equipment are the causes of the voltage or current variations. The power electronic
equipments have become more sensitive to voltage disturbances, and cause disturbances for other users, too. The
different power electronic equipments, frequency converters, nonlinear loads, switching power supply, changes in
functioning parameters and other devices cause nonlinear current which propagate in electric network. The
produced electromagnetic disturbances affect the power quality at other customers. The power supply interruption
leads to damages, loss of production times, reduces the profit. The users must make steps to diminish their own
disturbance. So the power quality problem can be solved through collaboration between energy suppliers and
customers.
In many fields of applications the quality of the services is influenced by the power quality. To avoid the
misunderstandings and confusions referring to the power quality, concepts and indicators of the power quality have
been determinated, and performance criteria have been standardized. The standardization is important because there
are a lot of energy producers and energy suppliers. At the same time there are used modern data acquisition and
processing measurement systems for continuous voltage and current monitoring to determine the disturbances and
the unwanted events. The adopted standads related to the power quality handle and define these disturbances and
fluctuations both in time domain and frequency domain [2],[7].
Power quality monitoring is important in energy fault detection, it allows to identify any problem and can ensure
energy continuity with optimal characteristics. The energy suppliers ensure only the quality of the voltage, they have
no control over the current which depends on loads. Within this context the power quality can be equal with voltage
quality. The standard requirements consern the voltage parameters. The most important phenomena in voltage
variations defined by standards are: [4]
Sag is a decrease in rms value of the voltage for a duration less than one minute.
Swell is an increase in rms value of the voltage for a duration less then one minute.
Overvoltage or undervoltage is an increase or decrease of the rms value of the voltage for a duration more then
one minute and these rms values are outside of the optimum operational values. The undervoltages lead to
malfunction and data losses.
Harmonics are used for current description and show that there are components with other frequencies then the
basic frequency. The harmonics are produced by non-linear loads.
Transient is a sharp disturbance, brief discotinuity of the voltage or current waveform for a very short time (less
then a cycle). Transients can have values to over 20kV. There are few devices which can tolerate more than twice
their normal operational voltage. This means that transients can cause faults in electronic equipments.
Noise are unwanted electrical signals which are added to the basic signal and vary it, but it isn’t swell, sag,
overvoltage or undervoltage. A noisy signal can cause also problems, wrong functioning in electronic equipments.
2. Causes of voltage deviations
The network voltage deviations cause malfunctioning, incorrect measurements, sudden disconnections, damages
in equipments, states changes in automation systems, data losses, etc. According to the level and time of the voltage
variations appear production losses, irrecoverable material damages which cause financial problems. There are
important places where correct and uninterrupted functioning is vital [4],[6].
There are a lot of causes of voltage deviations. Some of these can happens in energy transport and distribuition
systems, but users can also cause voltage variations. Some of the most important causes of voltage deviations are:
Flickers are voltage fluctuations due to the equipments that consume current with variable amplitude and these
fluctuations propagate through the net.
Voltage gaps appear at fast shortcircuit or fast increase of the current in energy supplier systems at the connection
of protection systems.
Ágoston Katalin / Procedia Manufacturing 32 (2019) 380–384 381
Available online at www.sciencedirect.com
ScienceDirect
Procedia Manufacturing 00 (2018) 000000
2351-9789© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license(https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
The 12th International Conference Interdisciplinarity in Engineering
Voltage Monitoring and Supply Controlling System
Ágoston Katalina,
0F*
Department of Electrical Engineering and Computers, University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Nicolae
Iorga st., No.1, 540088 Targu Mures, Romania
Abstract
This paper presents the importance of the network voltage monitoring which means amplitude, rms value and frequency
measuring and following the deviation of the voltage shape too. To ensure and maintain the energy quality, the parameters of the
network voltage must be kept within optimal values. This is important for users and loads, because they may work wrongly or
may fail in case of an irregularity of the supply voltage. Will be discussed about the most important phenomenons in voltage
variations and how they can be observed with an energy quality measurement instrument. The bloc scheme of the monitoring
system will be presented, which was realised for a plant grower, and the used components from different companies, and the
posibility of using and connecting to a second supply in case of cutoff of the primary network. The monitoring system is realised
around a programmable compact PLC which can be used for all requirements in industrial and building automation as well as
machine control. The main functions and the programming possibilities of the programmable compact PLC are presented.
© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
Keywords: power quality; supply monitoring; voltage controlling system; EasySoft.
1. Introduction
The power quality problems are increasingly complex and important for consumer and provider too. It is an
important requirement of customers to sustain and ensure the quality of the energy, who use and work with modern
equipments sensible to energy changes and disturbances. The energy is determinated through voltage and current, so
these define the power quality too. The assessment of the voltage and the current are made through indicators whose
* Corresponding author. Tel.: +4-0743-794-319.
E-mail address: katalin.agoston@ing.upm.ro
Available online at www.sciencedirect.com
ScienceDirect
Procedia Manufacturing 00 (2018) 000000
2351-9789© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license(https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
The 12th International Conference Interdisciplinarity in Engineering
Voltage Monitoring and Supply Controlling System
Ágoston Katalina,
0F*
Department of Electrical Engineering and Computers, University of Medicine, Pharmacy, Sciences and Technology of Targu Mures, Nicolae
Iorga st., No.1, 540088 Targu Mures, Romania
Abstract
This paper presents the importance of the network voltage monitoring which means amplitude, rms value and frequency
measuring and following the deviation of the voltage shape too. To ensure and maintain the energy quality, the parameters of the
network voltage must be kept within optimal values. This is important for users and loads, because they may work wrongly or
may fail in case of an irregularity of the supply voltage. Will be discussed about the most important phenomenons in voltage
variations and how they can be observed with an energy quality measurement instrument. The bloc scheme of the monitoring
system will be presented, which was realised for a plant grower, and the used components from different companies, and the
posibility of using and connecting to a second supply in case of cutoff of the primary network. The monitoring system is realised
around a programmable compact PLC which can be used for all requirements in industrial and building automation as well as
machine control. The main functions and the programming possibilities of the programmable compact PLC are presented.
© 2018The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)
Selection and peer-review under responsibility of the 12th International Conference Interdisciplinarity in Engineering.
Keywords: power quality; supply monitoring; voltage controlling system; EasySoft.
1. Introduction
The power quality problems are increasingly complex and important for consumer and provider too. It is an
important requirement of customers to sustain and ensure the quality of the energy, who use and work with modern
equipments sensible to energy changes and disturbances. The energy is determinated through voltage and current, so
these define the power quality too. The assessment of the voltage and the current are made through indicators whose
* Corresponding author. Tel.: +4-0743-794-319.
E-mail address: katalin.agoston@ing.upm.ro
2 Ágoston Katalin / Procedia Manufacturing 00 (2018) 000000
values are established based on specific requirements and standards. The quality and efficiency of industrial and
non-industrial activities depend largely on supply voltage whose variations must be within acceptable limits. The
power quality can be defined by users as characteristics of the power supply which enables a proper work of the
equipment. Any problem, deviation in voltage, current or frequency may result failure or misoperation of the
equipments. Today the electricity is considered a basic right, and should be present always with optimal
characteristics. [1],[6]
In many cases the customers’ equipment are the causes of the voltage or current variations. The power electronic
equipments have become more sensitive to voltage disturbances, and cause disturbances for other users, too. The
different power electronic equipments, frequency converters, nonlinear loads, switching power supply, changes in
functioning parameters and other devices cause nonlinear current which propagate in electric network. The
produced electromagnetic disturbances affect the power quality at other customers. The power supply interruption
leads to damages, loss of production times, reduces the profit. The users must make steps to diminish their own
disturbance. So the power quality problem can be solved through collaboration between energy suppliers and
customers.
In many fields of applications the quality of the services is influenced by the power quality. To avoid the
misunderstandings and confusions referring to the power quality, concepts and indicators of the power quality have
been determinated, and performance criteria have been standardized. The standardization is important because there
are a lot of energy producers and energy suppliers. At the same time there are used modern data acquisition and
processing measurement systems for continuous voltage and current monitoring to determine the disturbances and
the unwanted events. The adopted standads related to the power quality handle and define these disturbances and
fluctuations both in time domain and frequency domain [2],[7].
Power quality monitoring is important in energy fault detection, it allows to identify any problem and can ensure
energy continuity with optimal characteristics. The energy suppliers ensure only the quality of the voltage, they have
no control over the current which depends on loads. Within this context the power quality can be equal with voltage
quality. The standard requirements consern the voltage parameters. The most important phenomena in voltage
variations defined by standards are: [4]
Sag is a decrease in rms value of the voltage for a duration less than one minute.
Swell is an increase in rms value of the voltage for a duration less then one minute.
Overvoltage or undervoltage is an increase or decrease of the rms value of the voltage for a duration more then
one minute and these rms values are outside of the optimum operational values. The undervoltages lead to
malfunction and data losses.
Harmonics are used for current description and show that there are components with other frequencies then the
basic frequency. The harmonics are produced by non-linear loads.
Transient is a sharp disturbance, brief discotinuity of the voltage or current waveform for a very short time (less
then a cycle). Transients can have values to over 20kV. There are few devices which can tolerate more than twice
their normal operational voltage. This means that transients can cause faults in electronic equipments.
Noise are unwanted electrical signals which are added to the basic signal and vary it, but it isn’t swell, sag,
overvoltage or undervoltage. A noisy signal can cause also problems, wrong functioning in electronic equipments.
2. Causes of voltage deviations
The network voltage deviations cause malfunctioning, incorrect measurements, sudden disconnections, damages
in equipments, states changes in automation systems, data losses, etc. According to the level and time of the voltage
variations appear production losses, irrecoverable material damages which cause financial problems. There are
important places where correct and uninterrupted functioning is vital [4],[6].
There are a lot of causes of voltage deviations. Some of these can happens in energy transport and distribuition
systems, but users can also cause voltage variations. Some of the most important causes of voltage deviations are:
Flickers are voltage fluctuations due to the equipments that consume current with variable amplitude and these
fluctuations propagate through the net.
Voltage gaps appear at fast shortcircuit or fast increase of the current in energy supplier systems at the connection
of protection systems.
382 Ágoston Katalin / Procedia Manufacturing 32 (2019) 380–384
Ágoston Katalin / Procedia Manufacturing00 (2018) 000000 3
Voltage variations are due to the on-off coupling of the equipment to the network or to the transient state which
appears at electric circuits’ parameters changes.
Overvoltages in distribution networks appear at switches and safety devices operations which cause downloads in
the neighborhood of these networks.
Temporary overvoltages are due to the interruption of the null conductor at the users’ installation or at the power
supply.
Harmonics are voltages with higher frequency than the base frequency and are caused by frequency converters,
switching power supply or nonlinear loads at the user side. These harmonics can propagate through the net hundreds
of kilometers and disturb the functioning of other equipments.
The unbalances of the triphase voltages systems are caused by unequal load on the phases. The different loads
consume different current and lead to the null mouvement. If the null mouvement or the current on the null phase is
greater than the admissible value, the safety system activates, and disconnects the triphase voltages system
[3],[4],[5].
In supply voltage variation analysis for a consumer, the reference value is the declared supply voltage UC, which
is the same with the nominal voltage Un of the network. The nominal voltage is a characteristic, through a system
can be identified. The declared supply voltage is related to the rated voltage Ur of the equipments, which is defined
by the producer together with other characteristics of the equipment, to ensure the good functioning. The supply
voltage variation in low voltage system is defined for a week. The measured average voltage in 10min must be
between Un±10% for 95% from this time.
To determinate the energy quality due to the supply voltage variation at a consumer, the average voltage U for
10min is measured, and with the declared supply voltage UC indicators are calculated, which define the energy
quality in normal state functioning:
relative deviation of the voltage
εU=U−UC
UC100 [%] (1)
average value of the relative deviation of the voltage
 =1

0 (2)
irregularity degree
2=1
2
0 (3)
The irregularity degree is used to estimate the supply voltage quality, for
210% the voltage quality is very
good, for 10% ≤ 
220% the voltage quality is good.
In normal state functioning, the voltage deviations in network nodes are due to uncontrolled reactive power flow.
The reactive power sources (capacitor batteries) should be controlled in adaptive way, to bring the power factor to
admissible value. Usually these remain coupled even if the load is disconnected, so excess of reactive power
appears. For this reason it is hard to keep the voltage level and addition active power losses appear, to. The on-off
coupling of the capacitor batteries are followed by transient states, which produce other types of disturbances.
3. Control system for auxiliary supply
There are installations, equipments which should be working continuously, and for this reason the power supply
failure, voltage gap or lack affect the production and yield. Such an example is a hothouse where seedlings are
grown. Here is very important that the temperature, humidity, degree of illumination and fertilizer providing is held
4 Ágoston Katalin / Procedia Manufacturing 00 (2018) 000000
uninterrupted. All these are controlled by a surveillance system whose right functioning depends on energy and
supply voltage quality.
To ensure a continuous and right functioning for the hothouse, a control system was designed and realized. This
control system is monitoring the supply voltage variations and in case of a failure or breakdown, switches the
additional source. The block diagram of the control system is presented below.
Fig.1. The block diagram of the control system.
The voltage monitoring is made with a multifunctional measuring and monitoring relay EMR5 type from
EATON Electric. This equipment is powered from the measuring circuit and has the following functions: three-
phase monitoring, phase sequence, phase failure, overvoltage, undervoltage, and asymmetry monitoring. The
threshold values for overvoltage, undervoltage and imbalance are adjustable. The circuit commands two switches
whose on-off delay is also adjustable. One of these is used as input to the control system. [8]
The main part of the control system is an extensive easyRelay. This device belongs to a PLC family which allows
the use of these in industrial and building automation also. The easyRelays are universal systems with common
programming software and simple operations. Also the simplest device has many functions: counters, analogue
comparators, impulse relay, multifunction timing relay, analog and digital inputs, display, connection possibility to
the Ethernet. The advantage of easyRelays is the programmability through buttons from the front panel and the
programme steps can be followed on the display, or the programme is built with Easy Soft and then loaded in the
easyRelay. This allows modifying or developing the programme and the functionality during the use according to
the needs of the easyRelay. For this control system the EASY 719-DA-RC type was used.
The Easy Soft graphic editor displays the desired circuit diagram representation. The contacts, coils and different
functions can be selected and connected simply. The integrated off-line simulation tool enables users to check the
correct functioning of the circuit diagram before loading and without a connected device. [9],[10]
Figure 2 presents a programme part developed with Easy Soft for the desired control system.
The control system has three main inputs, two of these detect the network voltage variation and one detects the
additional source state.
The start of the additional source is not simple because a mechanical switch must be replaced with an electrical
impulse having a right length and intensity and must be repeated 4-5 times. For this counters and timers are used.
When the network voltage is established again the control system commands the controlled switch after a delay,
interrupts the fuel feeding of the additional source and returns to the initial state.
It is very important to respect the delays at the controlled switch command, the user must be separated totally
and safe from one supply when it is coupled to the other. It is also important that the voltages must be at the nominal
values.
The role of the easyRelay can take over a microcontroller. These are cheaper, but they are not implemented in
industrial way. The signals connected at the inputs of a microcontroller must have certain values, so conditioning
circuits are needed. Likewise the outputs provide only a few mA and to obtain a corresponding power control signal,
adaptation circuits are required.
The controlled switch must meet the user’s requirements, both voltage and current.
Ágoston Katalin / Procedia Manufacturing 32 (2019) 380–384 383
Ágoston Katalin / Procedia Manufacturing00 (2018) 000000 3
Voltage variations are due to the on-off coupling of the equipment to the network or to the transient state which
appears at electric circuits’ parameters changes.
Overvoltages in distribution networks appear at switches and safety devices operations which cause downloads in
the neighborhood of these networks.
Temporary overvoltages are due to the interruption of the null conductor at the users’ installation or at the power
supply.
Harmonics are voltages with higher frequency than the base frequency and are caused by frequency converters,
switching power supply or nonlinear loads at the user side. These harmonics can propagate through the net hundreds
of kilometers and disturb the functioning of other equipments.
The unbalances of the triphase voltages systems are caused by unequal load on the phases. The different loads
consume different current and lead to the null mouvement. If the null mouvement or the current on the null phase is
greater than the admissible value, the safety system activates, and disconnects the triphase voltages system
[3],[4],[5].
In supply voltage variation analysis for a consumer, the reference value is the declared supply voltage UC, which
is the same with the nominal voltage Un of the network. The nominal voltage is a characteristic, through a system
can be identified. The declared supply voltage is related to the rated voltage Ur of the equipments, which is defined
by the producer together with other characteristics of the equipment, to ensure the good functioning. The supply
voltage variation in low voltage system is defined for a week. The measured average voltage in 10min must be
between Un±10% for 95% from this time.
To determinate the energy quality due to the supply voltage variation at a consumer, the average voltage U for
10min is measured, and with the declared supply voltage UC indicators are calculated, which define the energy
quality in normal state functioning:
relative deviation of the voltage
εU=U−UC
UC100 [%] (1)
average value of the relative deviation of the voltage
 =1

0 (2)
irregularity degree
2=1
2
0 (3)
The irregularity degree is used to estimate the supply voltage quality, for
210% the voltage quality is very
good, for 10% ≤ 
220% the voltage quality is good.
In normal state functioning, the voltage deviations in network nodes are due to uncontrolled reactive power flow.
The reactive power sources (capacitor batteries) should be controlled in adaptive way, to bring the power factor to
admissible value. Usually these remain coupled even if the load is disconnected, so excess of reactive power
appears. For this reason it is hard to keep the voltage level and addition active power losses appear, to. The on-off
coupling of the capacitor batteries are followed by transient states, which produce other types of disturbances.
3. Control system for auxiliary supply
There are installations, equipments which should be working continuously, and for this reason the power supply
failure, voltage gap or lack affect the production and yield. Such an example is a hothouse where seedlings are
grown. Here is very important that the temperature, humidity, degree of illumination and fertilizer providing is held
4 Ágoston Katalin / Procedia Manufacturing 00 (2018) 000000
uninterrupted. All these are controlled by a surveillance system whose right functioning depends on energy and
supply voltage quality.
To ensure a continuous and right functioning for the hothouse, a control system was designed and realized. This
control system is monitoring the supply voltage variations and in case of a failure or breakdown, switches the
additional source. The block diagram of the control system is presented below.
Fig.1. The block diagram of the control system.
The voltage monitoring is made with a multifunctional measuring and monitoring relay EMR5 type from
EATON Electric. This equipment is powered from the measuring circuit and has the following functions: three-
phase monitoring, phase sequence, phase failure, overvoltage, undervoltage, and asymmetry monitoring. The
threshold values for overvoltage, undervoltage and imbalance are adjustable. The circuit commands two switches
whose on-off delay is also adjustable. One of these is used as input to the control system. [8]
The main part of the control system is an extensive easyRelay. This device belongs to a PLC family which allows
the use of these in industrial and building automation also. The easyRelays are universal systems with common
programming software and simple operations. Also the simplest device has many functions: counters, analogue
comparators, impulse relay, multifunction timing relay, analog and digital inputs, display, connection possibility to
the Ethernet. The advantage of easyRelays is the programmability through buttons from the front panel and the
programme steps can be followed on the display, or the programme is built with Easy Soft and then loaded in the
easyRelay. This allows modifying or developing the programme and the functionality during the use according to
the needs of the easyRelay. For this control system the EASY 719-DA-RC type was used.
The Easy Soft graphic editor displays the desired circuit diagram representation. The contacts, coils and different
functions can be selected and connected simply. The integrated off-line simulation tool enables users to check the
correct functioning of the circuit diagram before loading and without a connected device. [9],[10]
Figure 2 presents a programme part developed with Easy Soft for the desired control system.
The control system has three main inputs, two of these detect the network voltage variation and one detects the
additional source state.
The start of the additional source is not simple because a mechanical switch must be replaced with an electrical
impulse having a right length and intensity and must be repeated 4-5 times. For this counters and timers are used.
When the network voltage is established again the control system commands the controlled switch after a delay,
interrupts the fuel feeding of the additional source and returns to the initial state.
It is very important to respect the delays at the controlled switch command, the user must be separated totally
and safe from one supply when it is coupled to the other. It is also important that the voltages must be at the nominal
values.
The role of the easyRelay can take over a microcontroller. These are cheaper, but they are not implemented in
industrial way. The signals connected at the inputs of a microcontroller must have certain values, so conditioning
circuits are needed. Likewise the outputs provide only a few mA and to obtain a corresponding power control signal,
adaptation circuits are required.
The controlled switch must meet the user’s requirements, both voltage and current.
384 Ágoston Katalin / Procedia Manufacturing 32 (2019) 380–384
Ágoston Katalin / Procedia Manufacturing00 (2018) 000000 5
Fig.2. A programme part in Easy Soft.
4. Conclusions
A control system was developed and realized to monitor the supply voltage variations and in case of breakdown
or failure to swich to an other auxiliary source. So a continuous and right functioning of the user’s equipments is
ensured which in this case is a hothouse. The control system can be used for any equipment or plant, with the
condition that the components of the system must have the required power, voltage and current.
The main part of the system is an easy Relay with many functions. For the chosen device a programme was
developed in Easy Soft to obtain the required functions. The advantages of these types of devices are: easy use and
programming, it has a wide range of functions, digital and analog inputs and outputs.
However the commutation time has a certain length, a few minutes, it is much shorter than the failure or
breakdown duration.
References
[1] Dan Maxcy, What is Power Quality, Power Protection Products, Inc., 2013, www.p3-inc.com
[2] Bălan G., Pencioiu P., Golovanov N., Probleme actuale privind calitatea energiei electrice în sistemele electroenergetice, International
Conference “Energy of Moldova-2012 Regional Aspects of Development”, Chisinau, republic of Moldova, 2012, pag.236-242.
[3] Ciprian O. M. Dughir, Contribuţii la monitorizarea calităţii energiei, Teză de doctorat, Editura Politehnica, Timisoara, 2010.
[4] Coca Eugen, Perturbaţiile din reţelele de alimentare şi calitatea energiei electrice, partea1, SEM110kV-PRAM.
[5] T.Laughner, PE, Intro to Power Quality, TVA, 2017, http://sites.ieee.org/chattanooga/event/introduction-to-power-quality/
[6] Surya Santoso, Power Quality Requirements for Reliability: Towards ‘Perfect’ Power Quality, GCEP-Advanced Electricity Infrastructure
Workshop, 2007, Global Climate &Energy Project, Stanford University, http://www.academia.edu/
[7] *** Analiza calităţii energiei, ARC Brasov, http://www.arc.ro/fascicole/fascicol%206/Analiza-calitatii-energiei.pdf
[8] *** EMR measuring and monitoring relays, Catalogue EATON, 2012, EATON Corporation, www.eaton.com
[9] *** Manual de programare easySoft, http://www.moeller.net/
[10] *** Wiring Manual 2011, Eaton, https://ecat.eaton.com/flip-cat/?edition=WMERS&startpage=83#page_1
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Розроблено апаратне та програмне забезпечення стабілізатора змінної напруги з мікроконтролерним управлінням на платформі Arduino. Розроблено принципову електричну схему і модель стабілізатора змінної напруги з мікроконтролерним управлінням. Складено алгоритм його роботи і програмне забезпечення на мові C у середовищі Arduino IDE для вбудованих систем на платформі Arduino. Стабілізатор змінної напруги побудовано за модульним принципом, що дає змогу швидко його модернізувати. Пристрій має можливість налаштування максимальної та мінімальної напруги мережі для спрацювання захисту. Стабілізатор змінної напруги дає змогу підтримувати напругу живлення на навантаженні у допустимих межах за значних її відхилень, має можливість налаштування діапазону напруги мережі для роботи стабілізатора, потенціометрами ручного налаштування. У стабілізаторі використано електронні силові ключі на MOSFET транзисторах, перемикання яких синхронізовано з роботою мережі живлення, що зменшує електромагнітні завади. Силовий модуль та мікроконтролерний модуль управління гальванічно розв'язані. Перемикання силових ключів відбувається в моменти переходу синусоїдальної напруги мережі через нуль. Швидкість спрацювання захисту навантаження від перенапруги та регулювання (стабілізації) напруги на навантаженні становить менше 20 мс. Інформаційні повідомлення про стан мережі живлення та напруги на навантаженні виводяться на рідкокристалічний дисплей (РКД) та в послідовний порт для віддаленого моніторингу. Стан мережі можна контролювати за світлодіодними індикаторами. У разі відхилення мережі за допустимі межі, спрацьовує звукова та візуальна сигналізація, інформація передається також у послідовний порт. У разі перевантаження стабілізатора по струму спрацьовує автоматичний вимикач. Автономне живлення плати управління дає змогу передавати аварійні повідомлення зв відсутності напруги в мережі. Пристрій має ширші можливості, дешевший порівняно з наявними стабілізаторами з такими ж характеристиками.
What is Power Quality
  • Dan Maxcy
Dan Maxcy, What is Power Quality, Power Protection Products, Inc., 2013, www.p3-inc.com
Probleme actuale privind calitatea energiei electrice în sistemele electroenergetice
  • G Bălan
  • P Pencioiu
  • N Golovanov
Bălan G., Pencioiu P., Golovanov N., Probleme actuale privind calitatea energiei electrice în sistemele electroenergetice, International Conference "Energy of Moldova-2012 Regional Aspects of Development", Chisinau, republic of Moldova, 2012, pag.236-242.
Contribuţii la monitorizarea calităţii energiei
  • O M Ciprian
  • Dughir
Ciprian O. M. Dughir, Contribuţii la monitorizarea calităţii energiei, Teză de doctorat, Editura Politehnica, Timisoara, 2010.
Perturbaţiile din reţelele de alimentare şi calitatea energiei electrice
  • Coca Eugen
Coca Eugen, Perturbaţiile din reţelele de alimentare şi calitatea energiei electrice, partea1, SEM110kV-PRAM.