Research Article April 2017 © 2017, IJERMT All Rights Reserved Page | 161 International Journal of Emerging Research in Management &Technology ISSN: 2278-9359 (Volume-6, Issue-4) Recent Development in Power System Dynamic State Estimation Arpit Khandelwal * PG Student, EE Dept., SKIT, Rajasthan, India Akash Saxena EE Dept., SKIT, Rajasthan, India Ankush Tandon EE Dept., SKIT, Rajasthan, India Abstract— ue to the expansion of power systems there is a challenge of real time monitoring and control by placing important parameters at various points for efficient functioning of the power system. There can be drastic changes during hourly load fluctuations, component outages, or network switching. In such conditions, the inclusion of predicted values could degrade the power system state estimation hence the need of state estimation is must. Synchronized Phasor Measurement Units (PMU) are being placed along with the GPS (global positioning system) to enhance the monitoring of the power system. It depends on the measurement numbers, types and locations. This paper aims to present the main categories for PMUs placement strategies which considers main factors that required for enhancing the performance of a state estimation process such as reliability, accuracy and the special requirements of the modern distribution grid. Keywords— Phasor Measurement Unit, Global Positioning Systems, State Estimations, Weighted Least Square Method, Observability I. INTRODUCTION The enlargement of power system has made more and more intricacy so real time checking and control became very significant for the consistent operation of power system and which the Energy Management System (EMS) cures. In this system, the State estimation forms the spine of the energy management system by providing a database of the real time state of the system for using in other EMS functions [1]. Therefore, efficient and accurate state estimation is a prerequisite for an efficient and consistent operation of the power system. State estimation is a technique where the voltage, magnitude and angles at all the buses of a power system are recorded from the existing measurements. These measurements are obtained through a suitable communication standard and are processed through state estimation procedures, to obtain the voltage magnitude and angle at all the buses of the network under consideration. As we know that the power system is a quasi-static system, hence changes slowly but progressively which are driven by dynamic load so the generations also have to be adjusted accordingly, which in turn changes the flows and injections across the system, which makes the entire system dynamic in nature. Therefore, in order to have a continuous monitoring of the power system, we must perform the state estimation at regular interval of time. However, by the expansion of power system, along with addition of generations and loads, this system becomes more complex for such monitoring, which requires heavy computing resources. Hence, static state estimators may not capably capture this dynamic behavior of the power system. This lead to the necessity of another set of procedures called the "Dynamic State Estimation" (DSE) techniques, where we use the actual physical modeling of the time varying nature of the power system. These procedures have dual advantages of being more accurate and possessing the ability to predict the state of the system at next step. That is, from the knowledge of the state vector at an instant of time "t", and the mathematical model of the system, the DSE techniques forecast the state vector of the power system at the next instant of time i.e. "t+1". This predicting ability has remarkable advantages, as security analysis can now be performed one-time stamp ahead and hence allows more time for the operator to take control actions, especially in cases of any emergency [2]. Hence, DSE algorithms for power systems form an important branch of power system state estimation techniques, with a potential to impact the very nature of operation of the real time monitoring and control of power systems. Currently, there is a need for secure operation of power system because of the advanced dependency on electricity over different aspects of our life activities including the activities which are related to national security and human safety which is employed by computer–aided programs like the state estimation operation that achieve the requirements of steady state monitoring inside the control hubs [3]. These hubs receive their data from different power system elements by different meters that connected with Remote Terminal Units (RTU). The RTUs transfer the measured quantities and other required data via the Supervisory Control and Data Acquisition (SCADA) system. This system delivers the orthodox measurements, which contain voltage magnitudes in each bus bar, real and reactive power in the buses, real, and reactive power flows in lines to the control centers for using them by the Energy Management System (EMS) programs. In practice, SCADA system cannot capture the measurements of transient periods and other emergency conditions, which are necessary for robust monitoring and dynamic state estimation operation [4]. However, a drastic change occurred in this field by the development of synchronized Phasor Measurement Units (PMU) in 1980s. This event provides the state estimator with a device that can deliver efficient and fast measurement data with high sampling rates via D