Fault Detection And Fault Location In Transmission Line

Transmission lines,between other power system components,suffer from unexpected faults due to various random reasons.These faults interrupt the reliability of power system operation.When unpredictable faults occur,the system needs to be protected to prevent the spread of these faults and to protect the system from the abnormal operation caused by them.The functions of these protection systems are to detect and classify faults,and to determine the location of faulty lines when faults are detected in the magnitude of voltage and/or current lines.Once a fault is detected and classified,the protection relay sends a trip signal to the circuit breaker to disconnect(isolate)the fault line.With the changing demand and increasing complexity of power system,new requirements are put forward for improving reliability protection and fault location of power system.With the occurrence of power system faults,the traditional transmission line protection method based on distance relay has attracted more and more attention.There are different types of switch transient generation.For example,at 50 Hertz(the power frequency),higher frequencies caused by the resonance of LC components in the system,and very high frequency transient caused by lightning surge.The magnitude and delay rate of these transients depend on many factors,such as fault location,fault type,system parameters,etc.These transients make it difficult to define the relationship between bus voltage and line current.And many time the traditional protection method fail to operate accurately.Artificial neural networks(ANNs)may provide a novel solution for detecting power system failures.ANN can be used as a powerful tool as an alternative to solving problems accurately and efficiently.The characteristics of neural networks,such as their learning,generalization,and parallel processing capabilities,make their applications ideal for many systems.Using neural networks as a pattern classifier is one of its most common and powerful applications.