University: University Of Nairobi
Write career episode 3 for a CDR of Electrical Engineer.
Location: Amman, Jordan
Name of the organization: Architecture and Engineering
Project Title: DESIGN OF A MICROCONTROLLER BASED POWER TRANSFORMER PROTECTION
Position Title: Electrical Engineer
Background of Work performed
The main aim of this project is to design a microcontroller system that can aid power transformer safety. I have used the systems to evaluate the operating parameters of a transformer and it helped in isolating in quantifying the current flow in the transformer. I have mainly aimed to design a transformer that can detect current above normal operating levels in advance and can aid in isolating the power transformer from the distribution line. I have designed an isolation process to ensure the safety of the transformer and enhancing its longevity by preventing its damage from overheating. I have used a current sensor ACS712x series to project the interface between power transformer and PIC16F690. I have used a series of relay and switching gears to isolate the transform from the power source in case of any fault. In case of overloading, an operator will be automatically warned by the monochrome LCD that can detect any unusual delay in power transmission. Piezoelectric buzzers are also used to warn an operator in case of current lag. All these tools are monitored and operated by the help of microcontroller. It has been evident to me that in the design process there are various factors that needs to be controlled which calls for the urgent need of cost control and maintenance. I have to be very specific in including the safety measures to avoid any casualties that may occur from any major misfit in the project work.
Conceptual Framework related to the work:
The Transformer Protection system used in this context covers major concepts and terminologies related to distribution channels of electrical power. The transformer uses the relative process of induction to transfer electrical power from one source to another source quite conveniently. The transfer of power makes uses of electromagnetic field of induction in which the current is created by placing a conductor in a magnetic field. The voltage is induced through the adherence of electrical power equipments to create electromagnetic induction. The equipments include wire brush, solenoid and other magnetic permeable objects.
Microcontroller is basically a semiconductor chip which is designed to control various electronic systems used in various destinations for appropriate use of electrical appliances. Microcontroller has mainly no memory and is proposed to monitor a number of operation at a single point of time. The components of Microcontroller are oscillator, RAM, Program memory, A/D converter and semiconductor chip. It is noted that PIC16F690 microcontroller used in this project is a 20 pin, 8-bit microcontroller used for controlling different units at different substations. I have used the pin for optimizing the input and output parameters of operational activities in the programmable memory of the transmission system.
Fig: A typical microcontroller
(Source- Self Obtained)
Another component used in this project is Liquid Crystal Display, which uses a predominant two layers of polarizing material to reflect the image that is coded through the system. The crystal allows the passage of electric current in such a manner that the light does not pass through it. The principle of the image transfer lies upon the use of Monochrome LCDs that produces either dark or blue images upon transmission. The color LCD uses numerical figures and characters to display a variety of images at 8-bit interfaces. The data can be hatched from a variety of sources that makes use of the enable pin because of its higher frequency relative to the other components.
Discourse on own role performed:
I have monitored various safety measures and environment friendly techniques to install the transformer at the destined location. I have installed a microcontroller in meantime to generate smooth and error free currents for the large proportion of population. It monitors the rate of power consumption by increasing system components to a nominal value and does the demand for optimal power use goes to a greater extent. The consequences of power transmission can be aligned with cases of overload to prevent the transformer from being damaged. My main aim is to protect the electrical components from major electric faults and therefore i have used microcontroller in the eruptive design to eradicate any possible causes of power loss. I have understood the mechanism of instrument transformers, switchgears and protective gears for maintaining the safety of power line to an optimum level. I have coordinated the subordinates about the use of protective gears and switchgears in the transmission system to facilitate appropriate protection system for the transformer. The circuit breaker has an intensive use in stepping down the transfer of stopping the flow of currents at their destined location and breaking the contacts of the system at the destined source where the fault occurs. I have convinced my seniors to use protective gears for the insulation process, which comprises of protective relays as impedance, frequency and voltage regulators. My major aim was to convince my colleagues about the use of several cost effective protective components like circuit breakers, instrument transformers, switchgears and station batteries to ensure the smooth operation of transmission system.
Application of Engineering Knowledge and Skills:
The engineering knowledge’s and skills that I have used in this memorandum are as follows:
Electromagnetic Induction: When a current carrying conductor is placed in a magnetic field an electromagnetic flux equal to the rate of change of flux and proportional to the number of turns in the conductor is induced which is given in the following expression-
Where ⱷ denotes the magnitude of electrical flux in the expression
Fig: A typical representation of electromagnetic induction
(Source- Self obtained)
Restricted Earth Fault:
I have used the following scenario to determine the internal causes of fault analysis for any transformer windings that are connected in an inappropriate way. It can detect any fault below the bottom line and segregate the differential relay in accordance to the fault.
My knowledge about current sensor enabled me to detect any AC or DC current flowing in the conductor and as such it gave me appropriate proportion to analyze the corresponding digital signal arising from the fault. It helped me in measuring the amount of current in the conductor and controlling other allied devices conducting these currents.
The relay is procured to isolate the transformer from main power supply if there is any fault in the power system as such. The relay coil circuit is sensible to any foreign current or overloading and as such it trips the power supply from the main source to ensure the safety of the appliances.
Important Task delegated:
My main area of performances revolved in this context is to design and manufacture an electrical system that uses microcontroller and other allied devices to protect the power transformer. I am responsible to conduct the following tasks:
I have investigated the scope of the work by building transformer protection modules to enable a proper extension of work in case of any current spikes and overloads. I have analyzed the nature of the electrical power system that is aligned with the generation and distribution of electricity to the consumers worldwide. There are various power transmission devices that is used for smoother power transfer as evident to me which comprises of step up and step down transformer protective devices and many more. The power generation techniques involve the model of circuit breaker that automatically exerts a warning signal whenever there is any discrepancy in the power transmission method. I have designed a creative circuit breaker for making heavy networks in case of any faulty power generation. The circuit breaker mainly works on the principle of tripping signals whenever there is a fault detected from any major source and subsequently the circuit breaker closes itself. I have creatively invented the idea of fault prevention by stopping the spreading of the system despite of preventing the flowing of the current. My duty is to protect the equipment from overcurrent, overvoltage and frequency drift that has the potential to destroy the equipment.
Technical problems faced during the execution of work:
The application of engineering knowledge’s and skills mainly revolves around the insulation techniques to develop protection measures in case of overloading problems. I have catered other problems during my journey through this project, which are given as follows:
Creative Strategies devised by me:
I have convinced my team members about the reliability of the power protection components in order to integrate these tools in the manufacturing of transmission lines by making the following strategy-
I have adopted the first use first disposal policy to maintain the projectivity of the electrical appliances in a deemed manner. I have briefly categorized different electrical lines based on their thickness and volume to surface area ratio and analysed the impact of sagging on them in order to estimate their appropriate time of disposal. The transformers system is either step up or step down based on the voltage needs and thus i have categorized different switchgears as per their capacity to withstand higher voltage in a proportionate manner.
Working experience with other team members:
Team working capabilities is an important aspect in featuring the different components of project in a predominant way. It portraits different technical aspects of the project and it also maintains the coordination of team members to bring out their potential energy in a cumulative way. I have understood that the effective support of team members is very important to carry out the delegators of the project in an evident manner and to carry a flawless project wiping out any possible occurrence of discrepancies. The team coordination activity executes all the bidding aspects of the project amongst with making the scheduling and forecasting prospects intact in their place. I have efficiently delivered my ideas about project deliverables to cater the increasing demands of power for executing a flawless project. I have adopted possible means of audiovisuals in order to make my seniors approachable to my reason of adopting microcontroller in the electrical transmission lines. I have also learnt to keep my subordinates as well as my seniors update about my progress and to plan efficiently before carrying out the execution activity in general.
It is quite evident to me from the above context that the tangible network of current sensor can be used to detect any electrical faults or discrepancies at an earlier stage to devise strategic plans to prevent any possible power loss. It is the most evident solution to optimize the resource parameters present in the project and to effectively maintain the cost. I have also understood the proximity of relay and switchgears in transformer insulation system to prevent any casualty in the electrical transmission system. The counterproductive design in the microcontroller system devices any programmable system in the given schedules as such. I have also summarized the facts about using electrical insulation system in a transmission line which are as follows: