Fault Detection and Control in Power System Equipments using Atmega 16 Shivangi Gupta#1, Srishti Khare#2, Utkarsh Mishra#3, Pranjal Pathak#4 Electrical and Electronics Department, Uttar Pradesh Technical University Lucknow, Uttar Pradesh. 1gptshivangi.28@gmail.com 2srishtikhare14@gmail.com 3zutkarsh2011@gmail.com 4pathak.pranjal@gmail.com Abstract— This paper proposes methods for fault detection in power system equipments which include overvoltage and over current in transmission line. It also deals with fault detection in transmission line using a camera and image acquisition technique in matlab. There are partial arc discharges on faulty insulators, transmission lines and transformers. By detecting the spark images using a camera, the location of the faulty insulator or any other equipment can be estimated. I. INTRODUCTION Power transmission and distribution lines are the most essential links in power system. Load centres are connected to generating station via transmission lines. Since transmission lines are essential for the continuity of supply, hence quick fault detection and removal becomes prominent. The present day digital methods for fault detection in transmission line include Artificial Neural Network, Fuzzy logic, Fuzzy Neuro and Fuzzy logic wavelet based. Microcontrollers being electronic devices are highly reliable and accurate. Hence, if proper research is done, these devices can be extensively used in power system and will increase stability substantially. During arc initiation in various equipments such as insulators, transformers, transmission lines, etc., a spark is produced which can be detected using a camera. This helps to anticipate the fault and hence protects the system against any severe damage. II. Overvoltage originated by lightning is a major cause of flashovers on overhead powerlines. In an electric power system, over current or excess current is a situation where a larger than intended electric current exists through a conductor, leading to excessive generation of heat, and the risk of fire or damage to equipment. Possible causes for over current include short circuits, excessive load, and incorrect design. OVERVOLTAGE AND OVERCURRENT PROTECTION The problem of lightning protection has been seriously reconsidered in recent years due to the proliferation of sensitive loads and the increasing demand by customers for good quality in the power supply. Fig 1. Measurement of overvoltage and over current in transmission line A. Overvoltage Protection of Transmission Lines The supply voltage which is 220 V is scaled down using a Potential divider. The new voltage Vₒ= (R2/R1+R2) Vcc, where R1=R2=47 K. This AC voltage is converted into DC using a diode IN4007. The DC hence obtained is smoothened using a capacitor of 10μF. This regenerated DC voltage which is in a range of 0-5 V is fed to microcontroller which further activates the relay and hence the faulty line is removed. B. Overcurrent Protection of Transmission Lines A current transformer is used to measure the over current. The current is reduced to a lower value using a current divider. The reduced AC current is converted into a smooth DC value by using an IN4007 diode and a 10μF capacitor. This DC current is fed to microcontroller which activates the relay. III. HARDWARE AND SOFTWARE SELECTION A. Hardware / Components Used ATMEGA 16 is a low power CMOS 8 bit high performance microcontroller of Atmel’s Mega AVR family. A 5V DC Power supply is used to provide electrical energy to all electronic components. Transformer. Bridge rectifiers which employ diodes IN4007 are used for output smoothing. A voltage regulator is used to produce a constant linear output voltage. The regulators used are 7805 and 7812. A capacitor filter. LCD for display. Relay B. Softwares Used IV. OPERATIONAL DIAGRAM The three parameters which the microcontroller controls are voltage, current and sparking. Since the voltage input to the microcontroller should be DC, so AC is converted using a transformer, full bridge rectifier which uses IN4007 and voltage regulators 78XX. The microcontroller activates the relay after fault or spark is detected. On detection of spark the location of fault can be detected. Fig 3. Operational Block Diagram of the overall Fault Detection Scheme V. CONCLUSIONS AVR Studio: 1. It is an integrated development environment for writing and debugging AVR applications. In order to improve the power system industry and the 2. It provides a project management tool, stability of transmission lines, new tools and algorithms are source file editor and chip simulator. needed to maintain system reliability and security within acceptable levels. This paper is an attempt to propose the most MATLAB: In the proposed project MATLAB is used comprehensive set of references on the subject of recent for spark detection.The name MATLAB stands for techniques in protection of power system equipments. matrix laboratory. In this paper, a new inspection system for high-voltage 1. It is a technical computing environment for insulators and transmission lines is proposed and highly efficient numeric computation and demonstrated. visualization. Hence, the integration of the above mentioned hardware 2. It integrates numerical analysis, matrix and software makes the system more flexible and reliable. computation, signal processing (via the Signal Processing Toolbox), and graphics into a user friendly environment where VI. ACKNOWLEDGMENT problems and solutions are expressed in their mathematical form, without much conventional programming. It gives us a great sense of pleasure to present the report of the B. Tech Project undertaken during B.tech. final year. We owe special debt of gratitude to our supervisor Mrs. Akanksha Image Acquisition Using MATLAB: A sample image similar to that during the arc is generated Shukla, Department of Electrical and Electronics Engineering, using MATLAB image processing tool box. Thereafter a Galgotias College of Engineering & Technology for her program is created using MATLAB which compares any constant support and guidance throughout the course of our random image (i.e. spark produced by faulty equipment work. Her sincerity, thoroughness and perseverance have been detected by camera) to the sample image. If the random image a constant source of inspiration for us. It is only her consistent efforts and guidance that our endeavours have seen the light of matches the sample sound then the fault is detected. the day. Isolation of Faulty Equipment We express our deep sense of gratitude to Professor & Head A program is created using MATLAB which detects any Dr. Prabhakar Tiwari, Department of EEE for his constant disturbance and checks whether it is same as that during spark. official support, encouragement and motivation for our project If yes then the microcontroller operates and clears the fault. work. We also do not like to miss the opportunity to acknowledge the contribution of all faculty members and lab-Instructors of the department for their kind assistance and cooperation during the development of our project. Last but not the least, we acknowledge our friends for their contribution in the completion of the project. VII. REFERENCES [1] B. Lian and M. M. A. Salama, “An overview of digital Fault Location Algorithms for power transmission lines using transient waveforms,” Electric Power Systems Research, vol. 29, pp. 17–25, 1994. 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