Electrical Engineering Project: Voltage Stabilizer CDR Report

This document is a Competency Demonstration Report (CDR) detailing a student's project on developing an AC voltage stabilizer. The project involved designing and implementing a voltage stabilizer using parallel cascaded relays to address voltage fluctuations. The report covers the project's background, objectives, the student's role as team leader, and the engineering knowledge applied, including the use of Faraday's Law for transformer design. The student describes the design process, including the transformer core, circuit design, and testing of various modules. Challenges encountered, such as determining current requirements, are also addressed, along with the solutions implemented. The report concludes with a review of the project's outcomes, highlighting the successful achievement of the objectives and the constant output voltage despite input voltage variations. The student's contributions encompass hardware identification, team guidance, and problem-solving. The report is a comprehensive overview of the project, from conceptualization to final testing and evaluation.

Competency
Demonstration Report
(CDR)
Career Episode 3

CE 3.1: Project Introduction
Name of the Project : Application of Parallel Cascaded Relay for Stabilizing
and Improving the Performance of AC Voltage Stabilizer
Geographical Location : [Please Fill]
Project Duration : [Please Fill]
Organization : [Please Fill]
Position in the Project : Team Leader
CE 3.2. Project Background
CE 3.2.1: Characteristics of the Project
Considering the electrical power system, voltage has been identified as a vital parameter
required for pushing the current through the conductor. Ensuring the stability of the of the
voltage helps in ensuring the optimum performance and safety of the electrical appliances.
Therefore it is required to provide acceptable amount for voltage to the circuit for ensuring the
electrical appliances’ performance. In addition to that, I have found that deviation of voltage
from the optimum amount would negatively impact the appliances connected to the circuit.
Therefore, I undertook this project for the development of the automatic prototype model of the
voltage stabilization while including the design, packaging, evaluation and construction. In this
project, I have used parallel cascaded relay for the implementing the prototype stabilizer. I have
used parallel cascading relay for developing the oscillation of the damp power system.
Page 1 of 9

CE 3.2.2: Objectives developed for project
While working in this project, I have observed that due to unplanned and uneven
distribution of electricity throughout the area the voltage varies significantly. In this project, I
have aimed at assembling the voltage stabilizer in a metal box. Through this I have aimed to
achieve compact and portable voltage stabilizer that could be utilized with any devices. The
application of the voltage stabilizer would assist in providing constant value of voltage to the
appliances. In order to ensure the proper stable supply of voltage to the electrical appliances with
the development of portable voltage stabilizer, I have formulated the following objectives:
 To identify the working principle of the proposed relay stabilizer;
 To identify the hardware element and develop the block diagram for the stabilizer;
 To construct the transformer core required for the stabilizer;
 To provide proper specification of the transformer;
 To developing the appropriate design of the transformer;
 To develop the circuit design of thee controller;
 To evaluate the performance of the developed prototype model of the stabilizer;
CE 3.2.3: My area of work
Before initiating any practical work in this project, I have identified the issue and
problem existing due to the fluctuation of the voltage in the electrical devices. I have reviewed
past literature while identifying appropriate technologies and processes that can be utilized in the
improving the performance of the voltage stabilizer.
CE 3.2.4: Project Group
Page 2 of 9

Figure 1: Team Member Associated with the Project
CE 3.2.5: My responsibilities throughout the project
I undertook the entire responsibility of allocating the work among the team members and
guiding them with the development and implementation of the voltage stabilizer. I have selected
the application of switching devices, comparator, regulator, filter, and regulator and transformer
circuit for developing the transformer. I have developed the appropriate design for the
transformer, core magnetic circuit, winding electric circuit and control circuit.
CE 3.3: Distinctive Activity
Page 3 of 9

CE 3.3.1: Comprehending the Theory of the project
I have employed the technique of cascading parallel relay for developing the appropriate
design of the voltage stabilizer. I have used filter unit, rectifier, transformer unit and regulator
unit for developing the comparator. Further, with the application of comparator, I have evaluated
the reference voltage and available voltage along with the observed difference between them. I
have further utilized the difference in the voltage for triggering up the cascaded parallel relay
associated with the comparator. The connection of the cascading relay allows in producing
voltage through the transformer. In addition to that, I have used laminated plate for providing
appropriate dimension and shape of the machine. I have further ensured that the transformer was
wounded in the clockwise direction for completing core circumference.
Figure: Schematic Diagram for the system
CE 3.3.2: Engineering Knowledge and Skills applied in the project
I have employed the filter and rectifier circuit for smoothing and rectifying the alternative
voltage obtained from the transformer. Through this I was able to obtain DC voltage free from
ripple for energizing the comparator circuit. While developing the design of the transformer, I
have applied my knowledge of the Faraday’s Law of electromagnetic induction for determining
the flux and emf of the transformer. I have further determined the variation of flux within the
Page 4 of 9

quarter cycle of the transformer. I have observed that for the developed transformer, the flux
significantly increased from the lowest value to Φm (maximum value) within one quarter cycle.
Therefore, for obtaining the average flux change, I have used the following formula:
Change in flux = ΦM / (1/4 f)
= ΦM x 4 f
= 4 f ΦM wb / s
Therefore, I have identified that the per turn average emf as 4 f ΦM volts. I have further
considered variation of the sinusoidal flux and determined the emf value for the rms as
E = 1.1. x average value
Further replacing the average value obtained from the above equation, I have evaluated
the 4.44 f ΦM of emf of rms per turn. Therefore, in the primary winding, for obtaining the value
of induced emf I have multiplied the total number of primary turns with the induced emf
observed per turn. Therefore, for the primary windings, I have found the value of primary
windings to be 4.44N1Bm A.
CE 3.3.3: Accomplishment and Task Performed
After determining various specification of the transformer, I have kept the frequency to
be 50 cycle/ sec with single phase core. I have further ensured that the density of the transformer
rangers from minimum of 2 A/mm2 to maximum of 3 A/mm2 for continuously operating
electronic devices. While developing the prototype model of the voltage stabilizer, I have kept
the distance between the width and core twice the distance between the limb and core.
Page 5 of 9

Further, I have followed and developed the design of the system using modular basis. I
have carried out the individual testing of the different unit including comparator, regulator,
smoothing unit and rectifier. I have further fed AC power supply from the variac. Through this I
was able to obtain the voltage output between 0 to 300V ac. Apart from that, I have used a digital
voltmeter for monitoring the readings of the output voltage.
CE 3.3.4: Identified Issues and Their Solutions
Issue: I have determined that for the primary circuit, total numbers of 240 turns were
required. On the other hand, for the secondary circuit, total number of 247 turns was required. I
have developed the design of the auto transformer using single phase. I have ensured the voltage
capacity was steady at 280 volt. The problem I have encountered was during the determination of
the current requirements based on the number of turns. The practical value obtained from the
prototype was more than the obtained value gained from the theory.
Solution: With the aim to rectify the issue, I have worked on determining the current
density based on the conductor size. For this, I have used the following formula
 (Density) = 1 /a (area) = 2.5A/mm2
From the applicant of the formula, I was able to obtain the cross sectional value of the
primary circuit as 2.12 mm. This has provided me with the appropriate value of current required
for the transformer.
CE 3.3.5: Plan for producing creative and innovative work
I have supplied 17 v of rms for powering the control circuit while using the diode for
rectification and capacitor for smoothening. I have further used zener diode and potentiometer
Page 6 of 9

and connected them with the transistor in the first and second stage of the relay. Through this I
have achieved auto- transformer taping while cascading the five relays in parallel. After
completion of the design of the prototype model, I have involved myself in the project for
evaluating the performance and operation of the prototype module. I have carried out the testing
procedure individually with each module of switching devices, comparator, regulator, smoothing
unit and rectifier. After that, I have integrated all the units together and conducted major test on
the system.
CE 3.3.6: Collaborative work
I was provided with the job of assisting and managing the project team associated with
the project. I have identified the activities and divided the working module among the team
members for timely completion of the Voltage Stabilizer implementation. Apart from that, I have
developed and followed a communication matrix for highlighting the communication channel
between the members and ensure proper flow of information.
CE 3.4: Project Review
CE 3.4.1: Project Overview
After the completion of the modular and entire system testing, I have observed that
output voltage from the system were constant even when the input voltage of the system was
varying. The application of the parallel cascading relay had made the system operate with even
low input of 90 voltages. Therefore, through the project, I was able to obtain all the objectives
and aim developed before started working the project.
CE 3.4.2: My contribution to work
Page 7 of 9

In this project, I have identified the hardware element required for the design
development of the project. Through the application of my technical knowledge and managerial
skills, I was to provide the effective guidance to the project team. In addition to that, I have
identify the underlying technical problem faced during the project and provided justifies solution
for mitigation.
Page 8 of 9