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The traditional backup protection system of transmission lines are self-contained and only use from local measurements and generally, don’t use from wide area measurements. Hence, it can misoperate when the power system is extremely under stress conditions. So, the zone 3 of distance relays have been recognized as one of important participating causes of cascading phenomena that lead to major power system blackouts. In modern societies, power systems have become one of most important critical infrastructures, accordingly, blackouts can have catastrophic effects. Therefore, the novel backup protection schemes are required to improve security and dependability of protection system.
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The introduction of Wide Area Measurement Systems (WAMS) made it possible to monitor the stability online. This thesis presents a method for the optimal restoration planning based on Wide Area Measurement System (WAMS). In fact, the practical use of WAMS at the early stages of restoration provides precise determination of generators loading steps. Moreover, unification of phase angle references at different islands and presentation of tie line energizing priority list are significant benefits of WAMS at the last stages of restoration. The presented method uses observability analysis and Power Transfer Distribution Factor (PTDF) concept. The PTDF concept is applied to decrease the... 

Power system restoration is the procedure of restoring generators, transmission lines and loads in a minimum time without damaging power system elements. There are different strategies to restore a power system after a blackout. The one that we will introduce here is the build-upward or parallel restoration strategy. In this method power system will be divided into some independent islands firstly and then the restoration process will begin in each island separately and at the same time. The islands then will be connected together to have a complete restored network. The significant advantage of this strategy is minimizing duration of restoration. On the other hand, the use of Wide Area... 

In the early days of implementing state estimation in power systems, only the steady-state and quasi-steady-state models of the system were considered for formulating the state estimation problem, accordingly called, Static State Estimation (SSE). However, after a few decades, with the growing diversity of power system components and complexity of its dynamic phenomena, uncertainty in the power system has dramatically increased. Consequently, the need for situational awareness of the dynamic states of the system (such as rotor angle and speed of the generators) is felt more than ever. In addition, occurrence of the catastrophic blackouts in the world owing to deficiency in dynamic monitoring... 

Although voltage control and stability issues are not new to the electricity industry, but nowadays, in most modern power systems, special attention has been paid to this issue. Once, only weak systems with long lines were involved in voltage instability, while today due to heavy loading, voltage stability is a serious concern even in developed networks. Over tim, with increasing demand for electricity and emergence of electricity market and economic constraints, power systems are more exposed to voltage instability and even voltage collapse. Therefore, reliable operation of the system in such circumstances requires evaluating voltage stability of the network at both stages of planning and... 

A power transmission system includes transmission lines that are interconnected for economic and security reasons. Power systems are often prone to faults at the transmission level, since transmission lines are spread over vast geographical areas. Being the most serious events in power systems, blackouts are often initiated by a fault and a sequence of events afterward leads to partial or complete power outage. In this condition, fault diagnosis is the first step for power system restoration. In this research work, a new approach utilizing impedance-based fault location is introduced for fault diagnosis. By developing wide-area measurements in the context of smart grids, accurate... 

Nowadays, by proliferation the basis of the phasor-based synchronous wide area measurement system (WAMS), its application for improving electromechanical oscillations damping has been considered by researchers. In interconnected power systems, inter-area modes are usually critical modes. There are two approaches for damping these modes by utilizing WAMS: 1) the traditional approach of using power system stabilizers with wide area signals; and 2) discrete corrective actions by changing the operating conditions. The first approach requires a thorough study at the design stage, installation and testing. Besides, the controller is designed for a specific operating point. Nevertheless, in the... 

Fast and accurate fault diagnosis has a significant role in the power system operation. For a power system to come back to the normal state, the precise fault diagnosis is necessary. The current practice in power system fault diagnosis needs operators in the control center to use data of PR and CB in order to infer the faulted section based on their experiences. Expert systems and artificial intelligence have been suggested as alternatives to the human expert experience and inference. Other model- and optimization-based methods have also been reported for fault diagnosis, provided that similar data is available from the SCADA system.Nevertheless, in large disturbances resulting in partial or... 

In this thesis, the problem of placing a minimum number of phasor measurement units (PMUs) in a transmission system is considered so that faults on all lines of the network can be diagnosed and located irrespective of their locations. For this purpose, a PMU placement algorithm is proposed to calculate the required data for impedance-based fault-location of any fault line in the network, achieving the full potential of the circuit laws throughout the system. Another algorithm is then proposed to compute the voltage and current values of the fault line for fault-location purposes. Moreover, as many networks are already equipped with PMUs, the proposed algorithm makes it possible to locate... 

Wide-area measurement system (WAMS), which is enabled by broad installation of phasor measurement units (PMUs), is a novel solution for the secure and reliable operation of modern power systems. The adequate number and appropriate location of PMUs has been introduced as a challenging research area in recent years. This dissertation is the first effort to assess the cost/worth analysis of WAMS design and PMU locationing in a probabilistic manner. In the studies conducted here, power network monitoring and control associated with the energy management system (EMS), among miscellaneous applications of WAMS, have been taken into consideration. First, the conventional deterministic definition of...