Search

Nowadays, the increase in electrical energy consumption and power system restructuring have posed new challenges to the operation, control, and monitoring of power systems. In this situation, the supervisory control and data acquisition (SCADA) system is not enough to ensure power system security and stability. The SCADA is often unable to measure data of all buses simultaneously. In addition, the sampling rate in this system is not enough for some power system applications. Therefore, the information obtained from SCADA does not show power system dynamics properly. In order to improve the power system monitoring, wide area measurement system (WAMS) has been developed to overcome the problems of SCADA system. Phasor measurements units (PMUs) are the main part of WAMS system and it basically consists of three essential processes including collecting, transmitting, and analyzing data. WAMS receives obtained data via a high speed communication links. After data processing and extracting appropriate information, decisions are made to improve the power system performance. Efficient use of power system data to achieve a secure operation strategy is targeted using the WAMS system. Due to the effective role of WAMS and PMUs in the reliable operation of power system, it is necessary to study their concept and applications in this chapter. The history of PMU and its structure is presented in this chapter. In addition, the necessity of WAMS for future power system and its difference from SCADA system have been investigated in this chapter. Different algorithms and application of the WAMS are also introduced in this chapter which can be implemented to improve the performance of the future power system.

Partial discharge (PD) test is one of the most commonly used methods for monitoring the status of generator insulation system. Despite the major use of this method, the interpretation of its results faces many challenges. Therefore, it is necessary to study and recognize the PD pulse propagation process in the stator winding. In this study, the characteristic impedance of a generator bar is calculated to increase the accuracy of modeling the stator winding. Depending on how the bar positioned in the stator core, the characteristic impedances of the slot part and the end winding are obtained using finite element method. Finally, based on the results obtained, a suitable model for PD pulse propagation is implemented in EMTP software to compare the simulation results with the previous experimental studies.