Executive Summary : | Local protective devices operate mainly based on local measurements. However, they may fail to visualize the effect of their decision making process for the entire system particularly during severe disturbance conditions. Application of synchrophasor can provide a unique opportunity to monitor the power system at a wide area level. These measurements could be further used to develop monitoring applications to improve security and dependency of the power system protection.
Due to dissimilar weather conditions, animal or human contacts and vegetation contacts, power system network is subjected to various types of faults. Once circuit breakers clear the fault following relays trip command, the fault point must be determined and proper action must be taken to expedite troubleshooting and minimize repair time. Various fault detection and location methods based on single-end impedance and using unsynchronized two-end measurements have been proposed in literature. Though the former method is simple and easy to implement, its accuracy might be affected by remote infeed and fault parameters. The later method has higher accuracy than the former one. However, availability of measurements through the entire network might not be feasible due to the cost and installation concerns. Development of Phasor Measurement Units (PMUs) has introduced various synchrophasor based fault detection and location methods. These are based on Clarke transformation, synchronized fundamental phasor measurements, bus impedance matrix, travelling wave and measurement of time of arrival of electromagnetic traveling waves along with utilization of artificial neural network. Though the aforementioned methods give high accuracy, they require special measurement device with high sampling rate to capture electromagnetic transients, which increases cost of implementation. Therefore, this research is leading to develop a new fault detection and location technique based on sparse PMU measurements.
This project primarily involves development of a synchrophasor test bed to obtain synchrophasor output data streams according to the IEEE C37.118 standard. The project envisages developing a fault detection technique also capable of finding precise location of fault using sparse PMU measurements. At the same time, discrimination between permanent single line to ground fault and transient fault will be useful to auto-reclosing activity. The important final aim of this project is to develop a second zone acceleration technique for distance relay that helps in improving overall reliability of the system. This research will open new avenues of collaboration between the power utilities, industry and the academic institutes working in the area of application of synchrophasor in power system. The utilities will get the benefit of this work in the area of importance of PMU measurements in power system protection, monitoring and control. |