Design and Implementation of Real Time Electrical Substation Monitoring and Data Acquisition System

This project report deals with the complete design and implementation of a data acquisition system for an Electrical Substation. The data acquisition system gathers real time information of various electrical components that are connected within an electrical substation.

SEN719 PROJECT SCOPING AND PLANNING
ASSIGNMENT 3 (FINAL PROJECT REPORT)
PROJECT TITLE: DESIGN AND IMPLEMENTATION OF
REAL TIME ELECTRICAL SUBSTATION MONITORING
AND DATA AQUISITION SYSTEM
PROJECT SUPERVISOR: MR. MAHBUB RABBANI
STUDENT NAME: SAYYED MUSHAYYED ABRAR MAJID
STUDENT ID: 217014858

Abstract:
This project report deals with the complete design and implementation of a data acquisition
system for an Electrical Substation. The data acquisition system gathers real time information
of various electrical components that are connected within an electrical substation. In modern
time scenario electric power is an important and essential part of human life. Every works
depend on it. Therefore, it is very important to continuously monitor the electrical parameters
of a substation to provide power supply to the consumers without any interruption. A
substation includes power generation, transmission and distribution of electrical power. The
distribution of power involves the transformation of electric voltages at different levels: from
high transmission voltage to low distribution voltage. The interconnection of voltages from
different plants may lead to abnormal events and transformer failures in the substation.
Therefore it is becoming very important to automate supervision and control the operation of
an entire substation, and to notify the central relay system in case of any abnormal power
reading or emergencies. The proposed system continuously monitors the status of the
distribution transformer by measuring some electrical parameters: current, voltage and
physical parameters: temperature, vibration. The real time information are uploaded
continuously in a webserver for remote monitoring purpose.
Introduction:
Power system automation is becoming an important ingredient in any electrical power
network in terms of safety and protection. The data acquisition system plays a great role
while talking about automation. It acts as a basic and central component of the system.
Earlier days monitoring of electrical components was limited to manual measurement and
control. With present trends it is now essential to transform the manual measurement and
testing into digitalized and remote monitoring. The digitization is done with the help of
computerized system. With the increasing demand of uninterrupted power supply,
computerized network for data acquisition system aids the system as well as the controller to
obtain and monitor the electrical and physical parameters with higher accuracy and precision
for continuous time period. The power system automation includes supervision, control and
protection of different parts connected to the system network of the substation (Swarup,
Shanti & Uma Mahesh, P. 2006).
It collects the real time information about different physical and electrical parameters of the
network, locally and remotely controlled functions with more advanced electrical system
protection. The heart of automation process lies on locally decision making, data
communications with active control and monitoring. Maintenance is one of the vital schemes
at power system in terms of providing faultless and uninterrupted operation of the system. It
entails a greater amount of resources; both in human and economical for effectiveness. Now-
a-days, decontrol and denationalization of markets responsible for electric goods have
resulted in huge increase of competition in environment. With addition the existing
infrastructure is getting old and exhaustive. Keeping the price down, by increasing the gross
incomes and by improving the reliability causes to rethink and invest in new management
strategies. For the improvement of the cost-effectiveness of the system, a variety of measures

have been taken into consideration. A transformation from preventive maintenance based on
time (TBM) towards a maintenance based on condition (CBM) is taking place. By using
predictive maintenance one can cut down in the effective cost as it requires less maintenance
cost for the components. These permit either to anticipate to abnormal metering or
breakdowns at the distribution network. The importance of remote monitoring and controlling
are well understood by the various electricity boards in the country today. Not only does
remote controlling lead to much power efficiency and better decision systems, it also brings
intangibles like safety to the system. Though there are different automation systems available
in the market that leads to remote monitoring, none of them has become an industry standard.
The main reason behind this is basically due to the limitation of computing power and lack of
customizability to high price and deficiency of local technical support. The substation may
face various emergent faults due to transmission and distribution of power from different
substations. Therefore prevention of the substation from any unwanted phenomenon or faults
is very important. The faults are causes due to over voltage/current, under voltage/current,
overload to the transformer, single phasing, speed variation, vibration and temperature.
Among them the most important parameters are voltage, current, vibration and temperature.
The computerized data acquisition system consists of mainly: sensors and transducers, signal
conditioning unit and recording or display units. Different analog sensors are used for the
collection of real time data. The potential transformer, current transformer and temperature
sensors are used to estimate errors present in the physical parameters. Potential transformer is
for the protection of over voltage. Similarly, current transformer is in uses for over current
and over load protection and the temperature sensors for sensing temperature of transformer
winding. Supervision of the subsystem can be done for various purposes. The most evident is
to obtain the status of the electrical equipment.
Importance of conditional monitoring of electrical substation:
The importance of condition monitoring of an electrical substation arises to step down the
electrical voltage from a high valued network to a low valued network. The condition
monitoring can be used to distribute a regulated power supply among all the power networks.
Electrical substation is operated and managed for an electrical utility. Electrical substations
are owned by commercial industries. The electrical substations convert high voltage to low
and vice versa as per the requirements. Substations for transmission of the voltage values of
35kV, 110kV and 220kV use low voltage controls and distribution gears. Indoor substations
with high voltage of 110-220 kV are usually built in densely populated areas in the large
cities. Electrical substations for distribution and transmission of voltage values of 800kV and
1500kV uses high voltage controls and have much complex conversion equipment. The need
is arising for electrical substation is to maintain the power quality and it affects the operating
conditions of the whole transmission and distribution networks. The substations are important
part of electrical power transmission system, as it is responsible for the generation of
electricity, transmission and distribution of electric power. There are different types of
electrical substations, such as Distribution substations, Transmission substations, Collector
substations, Converter substation, Switching substations, and Mobile substations. and the
voltage level and their applications reflect the importance of an electrical substation. The

circuit breaker, transformer, insulator, bus-bar, wave trapper, isolator, batteries, and current
carrying materials are the main components of an electrical substation. Whenever a fault
occurs in the system, the circuit breaker comes into operation to remove the fault. Wave
trapper trips the high frequency wave and diverts these waves to telecom panel. Carrier
current equipment is installed in the substations for communication, relaying or for
supervisory control.
Importance of conditional monitoring of transformers in electrical substation:
The importance of conditional monitoring of transformers in substations is to monitor the
change in two different voltage levels i.e. high and low. So that number of defects and faults
can be reduced. In other words, transformers are important at the interconnection of two
different transmission lines of voltages and a transformer is used to either step up or step-
down the desired voltage level for efficient transmission of electricity. The conditional
monitoring of transformer plays a great role for controlling the unwanted high voltage and
power which can damage the electrical equipment of power station. In Power system, user
turn on and turn off power according to the requirement. With the advancement in technology
with the integration of conditional monitoring, provides number of good features that help to
continuous monitoring the power supply of substation. The main work of transformer is to
step up the voltage at transmission end to achieve high economical voltage, 400kVor even
higher, to be transmitted over the line with minimal losses and at distribution points, step
down to desired voltages like 400 V or 200 V for used in domestic as well as commercial
purposes. Intermediate Transformers are used to intermediate the networks. Step up
substations transform the voltage produced by the generators into higher voltage that is
important for transmission of electric power over the transmission lines. Step down
transformers transform the primary voltage of electric power system to lower secondary
voltage. The site of a transformer substation depends on the station’s purpose and the nature
of the loads. The 3-Phase transformers are those which connected to the three phase
networks: star or delta connection where one of the terminal is connected to a common
terminal, called the neutral. The 3-phase voltages are 120 degrees out of phase from the other.
3-Phase transformer can be constructed by connecting three single phase transformers
together. Three phase transformers are the backbone of electric power distribution. The need
of transformer is to improve efficiency by reducing the overall heat loss in the power lines
and reduce the voltage.
The functional blocks of substation automation:
The functional blocks of substation automation are as follows:
a) Electrical Protection
b) Control
c) Measurement
d) Monitoring
e) Data Communications
a) Electrical Protection:

Protection of electrical equipment and personals are an important part of substation
automation system. Though it is a local block and can perform independently from the
automation. Automation system provides a convenient and efficient protection to limit
the damage at faults as discussed in the above section.
b) Control:
Power system Automation consists of both local and remote control. Local control
includes the activity of the devices which can be taken logically by their own such as
bay-interlocking, switching-sequences, and synchronization check). Remote control
operates to control the substation from a remote place with the help of SCADA.
Instructions are sent directly to the remote control devices such as opening and
closing of circuit breakers, setting of relays etc. This removes the personnel
performance switching operations. And moreover the actions can be taken in faster
way. The operator and engineer have a total overview of the entire power system
network.
c) Measurement:
Measurement is another important function in power system automation. The real
time information of the equipment is collected and recorded in the control room. The
information are displayed and stored in a data base for further analysis. It completely
eliminates the fact of going the personnel to the substation or switching area to collect
the information. It also cut down workloads. The data received can be used further to
quantify network studies, like: load-flow analysis, planning for future and preventing
interruptions in the substation. Earlier the word Measurement refers to different
electrical parameters such as voltage, current and frequency. And the word Metering
refers to the terms like power, reactive power and energy (KWh). The different
phrases are used due to the usage of different instruments for obtaining the values. At
present the two functions are combined by computerized devices.
d) Monitoring:
Monitoring of the substation is related to the maintenance of the power system
automation technique. It keeps a track of sequence of operations, status and condition
of the system along with the maintenance data and relay-settings etc. The record can
help in determining the causes of faults, what where when why it happened. It is used
to improve the performance of the network (Wen-ge, D. 2015).
e) Data Communications:
Data Communication falls under the signal conditioner part of the data acquisition
system. It is the core functional block of the system. It connects the local devices with
the remote control centre. Without proper communication the local device and
protection tasks cannot be performed automatically. The data communication can be
wired or wireless.
Result and Discussion

The internet of things (IOT) has been used to collect the real time data from the local device:
transformer and sent to the web portal, http://www.embeddedspot.top to make and record a data
base and to view the graphical pattern of the physical quantities. From the substation the
following physical parameters are measured: voltage, current, temperature and vibration.
Reference value has been taken for all the mentioned quantities. Here another parameter has
been also considered as STATUS which basically provides the information about the
threshold value of the measured quantities. If the measured value exceeds the reference value,
it notified as a HIGH in status. Otherwise it shows NORMAL state of the parameter. Here
some of the collected values are shown in the following table:
Table 1: Real time data collected displayed on web portal
In the above table it can be seen that voltage, current, temperature and vibration of the real
time has been recorded and displayed along with the exact date and time. The column,
STATUS provides a clear picture about the threshold values of the parameters. Whenever the
current value goes higher than the reference value it notifies a change in state as
HIGH_CURRENT.
The Standard values for physical quantities are as below:
Voltage Limit is 230 volt, Current Limit is considered as 300. If the measured value is less
than 300 mA, the STATUS will show a Normal state, and if the value exceeds 300 mA the
STATUS will reply with a High in state. Temperature threshold value is taken as 40 degree
Celsius and on server it is than 40 degree Celsius. Vibration 0 represents the state of No
vibration in the measured device and 1 for vibration present in the local device.
The graphical representation has also been made in order to monitor the function of
substation devices. The following figures depict about the same.

Fig. 1 Plot of voltage with respect to time
Fig. 1 and Fig. 2 reply the continuous time information about the voltage and current values
respectively with respect to time. Whereas Fig. 3 and Fig. 4 depict the real time information about
temperature and vibration respectively with respect to time.
Fig. 2 Plot of current with respect to time

Fig. 3 Plot of temperature with respect to time
Fig. 4 Plot of vibration with respect to time
Conclusion:
This report explains about the Design Implementation of real time electrical substation
condition monitoring system. The status of substation transformer is being monitored from a
remote location. The methodology includes the design and implementation of a Data
Acquisition system (DAC) using Raspberry pi. The internet cloud server has been used for
data storage on the web portal. The dashboard of the portal has also been designed to show
the measured values. And alarm monitoring of the system has also been developed whenever
the physical quantities exceed their respective threshold values. Based on the alarm
monitoring system an alert based logic has also been implemented on the server. The web
server describes to do all the quantitative and qualitative analysis of the parameter, to view
and use of the parameters, information of the system in different forms (tabular and
graphical) and to perform conditional monitoring tasks under normal and abnormal
conditions. The designed substation conditional monitoring is developed and implemented
with the help of Internet of Things. Both the offline and online monitoring system has been

used in this project. Here only four parameters of the transformer have been taken in
consideration for the condition monitoring of the substation. In future other than these
physical parameter some additional important parameters can also been taken for monitoring
purpose. And along with the condition monitoring the automatic control and monitoring of
the electrical substation can also be implemented.
References:
Swarup, Shanti & Uma Mahesh, P. (2006). Computerized data acquisition for power system
automation. 2006 IEEE Power India Conference. [online]. May. Available from:
https://www.researchgate.net/publication/4242857_Computerized_data_acquisition_for_pow
er_system_automation [Accessed 03 June 2019]
Wen-ge, D. (2015) A Monitoring Data Acquisition System for Substation Using ARM And
3G. International Industrial Informatics and Computer Engineering Conference. [online].
Available from: file:///C:/Users/Admin/Downloads/17060.pdf. [Accessed 03 June 2019]