FUZZY CONTROLLER BASED DIFFERENTIAL PROTECTION SCHEME FOR POWER TRANSFORMER
* ACKNOWLEDGEMENT (i) * CERTIFICATE (ii)
* CONTENTS (iii) * ABSTRACT (iv)
1.2 MOTIVATION FOR UNDERTAKING THE PROJECT. 1.3 AIMS AND OBJECTIVES OF THE PROJECT.
REVIEW OF LITERATURE.
IMPLEMENTATION OF THE PROJECT.
DATA COLLECTION AND ANALYSIS OF THE RESULT.
5.1 DISCUSSION OF THE RESULT AND CONCLUSION. 5.2 DISCUSSION OF THE RESULT AND CONCLUSION.
iv ABSTRACT The power transformer is an essential component of electrical power system that needs continuous monitoring and effective protection scheme. As, it is very expensive and supplies a large portion of the load in the power system. When protection scheme operates, a large portion of the power system and the load is disconnected and thus reliability of the protection scheme is very much necessary. The most common protection scheme used is the percentage differential logic, that provides discrimination between an internal fault and different operating conditions. Today, the need of the power system is digital and in the presence of the spurious data and noise in the system the protection scheme used may mal operate. Thus, it requires some intelligent technique i.e. fuzzy logic, to deal with the uncertainty and ambiguity in the power system data. This work proposes the development of a new algorithm to improve the differential protection performance by using fuzzy logic. The simulation results are compared with the conventional results.
REVIEW OF LITERATURE:
PROTECTION OF POWER TRANSFORMERS:
Large power transformers belong to a class of very expensive and vital components in electric power systems. If a power transformer experiences a fault, it is necessary to take the transformer out of service as soon as possible so that the damage is minimized. The costs associated with repairing a damaged transformer may be very high. The unplanned outage of a power transformer can also cost electric utilities millions of dollars. Consequently, it is of a great importance to minimize the frequency and duration of unwanted outages. Accordingly, high demands are imposed on power transformer protective relays. The requirements include dependability (no missing operations), security (no false trippings), and speed of operation(short fault clearing time).The operating conditions of power transformers do not make, however, the relaying task easy. Protection of large power transformers is perhaps the most challenging problem in the power system relaying area.
5 Problems in differential relaying for power transformer :
Fig-1 Hardware structure of a digital relay for power transformers. The...