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This paper presents an approach for dynamic state estimation of aggregated generators by introducing a new correction factor for equivalent inter-area power flows. The spread of generators from the center of inertia of each area is summarized by the correction term α on the equivalent power flow between the areas and is applied to the identification and estimation process. A nonlinear time varying...
This paper proposes a method for identifying event sequences leading to blackouts in power systems. To identify the cascades, grid is modeled like an event tree where each branch represents a contingency and each node represents state of the system. Due to huge number of possible paths in the event tree, computational burden is the key issue in searching the cascades. In this paper, computational...
This paper proposes operational and control strategies for islanded microgrids with wind energy conversion system (WECS) and diesel generator system. The considered wind-diesel microgrid presents high penetration level of wind generation. The proposed control enables two operation modes for the microgrid: wind-only (WO) and wind-diesel (WD) modes. A control loop, added to a DC dump load (DL), is proposed...
The interconnections and mutual impacts between the real-time market update process and the physical response of the power system will bring about new stability issue. This paper presents a more realistic discrete-time pricing model including congestion management, then models the coupling dynamics of the power systems and markets as a nonlinear hybrid system. And based on the locally sampling theorem,...
In this paper we propose a modified primal-dual gradient dynamical system to solve non-convex optimal power flow problems. The modified gradient dynamics maintains the naturally distributed structure and it has isolated equilibrium points as the primal and dual optima. Under mild conditions we show the locally asymptotic stability of the modified gradient dynamics. Simulations on the IEEE 14-bus benchmark...
We investigate an optimal bidding and an optimal and worst case pricing under a dynamic integration mechanism for linear quadratic Gaussian (LQG) power networks. The participant of the dynamic integration mechanism is divided into two kind of players, that are generators and/or consumers, called agents, and one public commission, called utility. In the mechanism, each agent decides private control...
This paper presents the possibility of use of Dynamic Thermal Line Rating for the electrical system protection and stability improvement. One analyzing the recent decade blackout occurrences finds their common features and development causes and presents the applicable solution for avoiding them in the future as the anti-blackout protection.
In this paper we have described a hybrid automaton based approach towards the development of a simplified Medium Voltage Direct-Current (MVDC) Shipboard Power System (SPS) model. SPS is considered a good subject of hybrid modeling and hybrid control system design as it combines a variety of continuous component dynamics, discrete control actions as well as a variety of switching components. Therefore,...
This paper first puts the challenges from design constraints imposed by mission load requirements on future naval surface combatants into context. Moreover, it provides results from experiments at the three partner universities designed to de-risk emerging medium voltage DC (MVDC) technology based systems and to provide validated models for future systems studies. These experiments are carries out...
A Medium Voltage DC (MVDC), modular multilevel converter (MMC)-type, MW-scale, power hardware-in-the-loop (PHIL) advanced test facility is being utilized to better understand the impact of fast power transfer between dynamic loads in a notional MVDC shipboard system. In these experiments PHIL simulations demonstrate the transfer of power between two MW-scale, MMC-based loads in a time frame of milliseconds...
In this paper we present a hierarchical control structure for dynamic management of electrical power networks with distributed generation and storage. The proposed control structure consists of three layers. At the upper level a (dynamic) Optimal Power Flow (OPF) solver computes the optimal power references for distributed generators and storages at slow rate. These references are then transmitted...
A predictive decision support algorithm for power systems with a high share of renewable generation is presented. We consider a scenario where, e.g. within 1 hour, the renewable share is first gradually increased and compensated by secondary reserve. Then, a sudden disconnection of one or several wind farms occurs, e.g., because of violated fault ride through requirements. This disconnection has to...
Among the power system corrective controls, defensive islanding is considered as the last resort to secure the system from severe cascading contingencies. The objective is to maintain the stability of the resulting subsystems and to reduce the total loss of load in the system. The slow coherency based islanding can successfully be applied for the defensive islanding. In this paper, two new partitioning...
In recent years the penetration of renewable energy based resources has increased significantly. This development has a high impact on the network control behavior. The renewable energy sources can be used to contribute to the ancillary services for enhancing the quality of service and the resilience of the power system. In the current study, an approach of applying a reactive power management using...
This paper presents a phasor type model of variable speed wind turbine with Permanent Magnet Synchronous Generator (PMSG) for dynamic simulation study on Matlab/Simulink. Aim of the phasor model is to diminish the complexity and simulation time of the analysis of grid connected wind farm. The proposed phasor type model can be used as aggregated and individual model representations for the wind generators...
This paper presents a controlled islanding algorithm based on k-means clustering. It considers Voltage Source Converter-based HVDC (VSC-HVDC) links within a synchronous system and places one VSC-HVDC terminal in each island so that power can be exchanged between the islands. This limits load shedding and/or generator tripping and reduces the overall restoration costs. The controlled islanding algorithm...
This paper examines the use of the symmetrical components theory for the representation of unbalanced conditions, when using the concept of analog emulation for highspeed power system analysis. This concept has been proven and validated through the realization of a mixed-signal hardware platform dedicated to power system studies. Computations related to the grid are handled by analog electronics,...
Due to the integration of Distributed Energy Resources (DERs), both non-synchronous generators and energy storage technologies, the dynamic behavior of power systems is changing. The extent of the impact is yet to be fully investigated and quantified. Proper models, suitable for large scale studies but also representing all the DER control and protection mechanisms that affect the dynamic behavior...
This paper describes the development process of the Dynamic Study Model (DSM) for the synchronously interconnected power system of Continental Europe in different simulation tools1. The model was developed by the European Network of Transmission System Operators for Electricity (ENTSO-E) working group System Protection and Dynamics2 and the University of Erlangen-Nuremberg within a collaboration....
When performing transient stability simulations or studies to examine the dynamic frequency behavior of large electric transmission systems, a detailed dynamic model of the system is used to evaluate the time domain behavior after specific events (e.g. short circuits or fast load changes). When dealing with large power systems with a large number of synchronous generators, the simulation durations...
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