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This paper presents comparative study of reduced order models (ROMs) of a doubly fed induction generators (DFIG) for normal operation. A DFIG with detailed mechanical, electrical and control components is the basis for model development. Two control strategies, the maximum power point tracking and set point tracking, are considered for normal operation. In these cases, the dynamic model of DFIG can...
Disturbances as generation trips, load shedding or other switching events propagate measurably throughout power systems as electromechanical interactions and may cause undesirable phenomena as power oscillations. Therefore, it is essential to have a deeper understanding of the electromechanical phenomenon to improve current countermeasures. For this reason, the present study analyzes the impacts on...
The recent advent of the phasor measurement unit (PMU) and their associated networks has revealed that forced oscillations are a common occurrence in synchronized power systems. Forced oscillations are not be confused with electromechanical oscillations. Forced oscillations are typically caused by some rouge input driving the system into a sustained oscillation. An example is an ill-operating power-plant...
This paper investigates the applicability of numeric Wazwaz El Sayed modified Adomian Decomposition Method (WES-ADM) for time domain simulation of power systems. WES-ADM is a numerical method based on a modified Adomian decomposition (ADM) technique. WES-ADM is a numerical approximation method for the solution of nonlinear ordinary differential equations. The non-linear terms in the differential equations...
Distributed control algorithms are becoming promising approaches in the context of smart microgrids since they can be more robust and resilient to network variations. We propose a distributed microgrid management system based on distributed dynamic population games to respond dynamically to the requirements of the microgrid. This paper extends the distributed replicator dynamics algorithm to include...
The Power System Toolbox (PST) is a MATLAB-based package for simulating power system electromechanical dynamics. In this paper, we report on code that we developed to augment the capabilities of the PST, which enables the possibility of including the automatic generation control (AGC) system in simulations. In the process, we have also modified the linearization capability of the PST so as to include...
Wind power plants installation in the electrical power networks has been growing through the last years and a larger penetration is expected in the near future. Because of this, wind farm technologies will influence the power system behavior modifying its dynamics by reducing power systems global inertia. Hence, there is an increased interest and need to study the wind turbine farms behavior and their...
Methods to modify power system dynamics through the addition of synthetic inertia have gained increasing research attention over the past several years. Many researchers justify this focus by implicitly assuming that adding inertia increases a system's stability, and only focusing on the frequency nadir as a measure of performance. In this paper, we draw attention to the fact that adding synthetic...
Power plants are subject to introduce disturbances in the power grid, resulting from interactions with the dynamical behavior of the energy source subsystem. In the case of hydropower plants when used to compensate for variations of power generation and consumption, instabilities or undesirable disturbances may arise. They may be caused by phenomena such as part load vortex rope pulsations in the...
The goal of this paper is to propose and validate standstill DC-Decay measuring methods for a rotor in arbitrary position. The first new method (DC-Decay I) delivers the equivalent circuit with a few measurements. The second new method (DC-Decay III) permits to catch the full equivalent circuit of both axes in only one measurement which is unique and a breakthrough in parameter identification. A new...
In this paper, a new approach based on dynamic relative gain is proposed for partitioning voltage control areas in bulk power systems. The critical nodes of voltage stability are determined using voltage stability index, “L index”. The cross relative gain between the critical nodes and other nodes are calculated based on the concept of dynamic transfer function (DTF) and dynamic cross relative gain...
This paper develops a robust extended Kalman filter to estimate the rotor angles and the rotor speeds of synchronous generators of a multimachine power system. Using a batch-mode regression form, the filter processes together predicted state vector and PMU measurements to track the system dynamics faster than the standard extended Kalman filter. Our proposed filter is based on a robust GM-estimator...
The dynamics governing power systems are being modified by the continued increase in the installation of wind turbine-generators (WTGs). This paper presents a small-signal analysis on the impact of the power electronic interface of large quantities of wind generation have on the inter-area oscillation of a two-area system. In particular the sensitivity of this inter-area mode with respect to: (i)...
This paper shows how generic protection relay models available in planning tools can be augmented with settings that are based on NERC standards or best engineering practice. Selected generic relay models in Siemens PSS®E have been used in dynamic simulations in the proposed approach. Undervoltage, overvoltage, underfrequency, and overfrequency relays have been modeled for each generating unit. Distance-relay...
This paper presents three alternatives to database adequacy aiming at on-line dynamic security assessment. Usually, on-line data available at the control centers are not prepared to be directly used in dynamic simulations due to discrepancies between power system data models used in EMS' databases and power system analysis software (off-line). Challenges and requirements of such adequacy are initially...
Protective relays used in power system today measure external signals to diagnose the internal state of the equipment they protect. Based on measurements of voltage, current, frequency at the bus, the decision is made whether the equipment is healthy or faulty. Due to advances in sensing and computing, it has become possible to use the external measurements to dynamically estimate the internal state...
This paper describes an analysis of a variable speed heat pump (VSHP), which responds to direct load control (DLC) signals to provide grid frequency regulation (GFR) ancillary service, while ensuring the comfort of building occupants. A data-driven dynamic model of the VSHP is developed through real-time experimental studies with a time horizon ranging from seconds to hours. The model is simple, yet...
This paper presents a novel particle filter based dynamic state estimation scheme for power systems where the states of all the generators are estimated. The proposed estimation scheme is decentralized in that each estimation module is independent from others and only uses local measurements. The particle filter implementation makes the proposed scheme numerically simple to implement. What makes this...
This paper solves an optimal power flow problem to minimize the emission due to carbon oxides, nitrogen oxides and sulfur oxides with cost as a constraint for a wind-thermal power system. Wind energy can reach significant penetration in modern power system and the wind power will introduce additional uncertainties. Market price is mainly influenced by the generating fuel cost, as the wind power being...
The steady-state analysis of power system voltage stability usually overlooks the dynamic characteristic of internal impedance of synchronous generators, which may cause errors when evaluating the margin of voltage stability. In this paper, the dynamic generator internal impedance (dGII) is calculated based on phasor measurements. Then the dGIIs are incorporated into the modal analysis of the power...
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