Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 36 for “"small-signal stability"”.
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Dynamic phasor modelling of VSC FACTS devices for small signal stability studies
… phasor models;A development of harmonic stability criteria for the proposed modelling is presented. The proposed modelling is employed to present the harmonics effect on the STATCOM and SSSC response and to identify their unbalanced operation in frequency domain. The main features of the …
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Comparison of three power system software packages for small-signal stability analysis
Many power system simulation tools exist for small-signal stability analysis. This is due to the rapid development of computer systems, higher industrial growth and the need for reliable power system simulation tools for efficient planning and control of electric power systems. Three power system …
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D-Q Frame Impedance Based Small-signal Stability Analysis of PV Inverters in Distribution Grids
… which brings in the possibility of system instability. Recent evidence suggests that large-scale penetration of PV inverters increases the probability of instability. While IEEE standard 1547 newest version requires PV inverters to have reactive power control, there have been few …
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SMALL SIGNAL STABILITY ANALYSIS OF THREE-PHASE MICROGRID SYSTEM IN THE PRESENCE OF CONSTANT POWER LOADS
Small-signal stability is of great concern for three-phase microgrid systems with regulated power converters which are used for connecting multiple distributed energy resources (DERs) and in various motor drive applications. The converters behave as constant-power loads (CPLs) and cause instability …
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DQ-Frame Small-Signal Stability Analysis of AC Systems with Single-Phase and Three-Phase Converters
… and data centers has introduced significant stability challenges. This dissertation presents a novel approach to modeling and comprehensive stability analysis for both single-phase and three-phase converters, addressing vital gaps in the existing literature. The first part of the dissertation …
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Development of differential evolution based Power System Stabilizer (PSS) with HVDC in small signal stability analysis using MATLAB
… Voltage Direct Current (HVDC) to improve the small signal stability (SSS). The Power System Toolbox version 3 MATLAB based software is used as a tool to simulate the results. The results shown that the location of HVDC supplementary in the network contribute to the effectiveness in improving …
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Variations in modeling and algorithmic factors impacting on small-signal stability results : assessment of five industrial-grade power system simulation tools
… industrial-grade simulation tools, used for small-signal stability studies, that are commercially available on the market. However, these tools differ in their components modeling and solution methodology. Therefore, different simulation tools can give different results for the same power …
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Investigation into voltage and angle stability of a hybrid HVAC-HVDC power network
This study investigates the power stability problems of HVDC and VSC-HVDC interactions on their hybrid networks with HV AC link, with the intention of bringing out their weaknesses and strengths. The knowledge of this will assist network planners to be informed on ways of improving the efficiency …
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A Unified Technique for Dynamic Modeling and Stability Analysis of Microgrid Systems
… a unified method for dynamic modeling and stability analysis of microgrid power systems. Using the automated state-model generation algorithm, a state-space model of the microgrid power system is derived. The model may be used to conduct time-domain simulations and analyze system response …
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Stability effects of frequency controllers and transmission line configurations on power systems with integration of wind power
This thesis investigates the stability effects of the integration of wind power on multi-machine power systems. First, the small-signal stability effects of turbine governors connected to synchronous generators in the presence of large-scale penetration of wind and load power disturbances are …
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Analysis and design of microprocessor-controlled peak-power-tracking system
… microprocessor control are performed. Large-signal stability of the system for various modes of operation is analyzed to predict system dynamics. The stability analysis is supported mainly by qualitative graphical representations of different component blocks of the system. Small-signal …
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High-Fidelity Power Injection From A Fuel Cell Onto A Variable-Frequency AC Power Bus
… fed DC to AC inverter in simulation and a small-signal stability study using Lyapunov's indirect method is performed. The results demonstrate that the fuel cell, or any other DC-source, impedance and the inverter controller has a direct effect on the system small-signal stability.</p>
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Stability Analysis of Three-Phase AC Power Systems Based on Measured D-Q Frame Impedances
Small-signal stability is of great concern for distributed power systems with a large number of regulated power converters. These converters are constant-power loads (CPLs) exhibit a negative incremental input resistance within the output voltage regulation bandwidth. In the case of dc systems, …
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A Practical Method for Power Systems Transient Stability and Security
<p>Stability analysis methods may be categorized by two major stability analysis methods: small-signal stability and transient stability analyses. Transient stability methods are further categorized into two major categories: numerical methods based on numerical integration, and direct methods. The …
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Avaliação da estabilidade a pequenos sinais em sistemas CA/CC em paralelo
… parallel with AC systems from the perspective of small-signal stability of electric power systems. We present aspects related to linear and nonlinear representation of the DC link controls. The studies are performed using modal analysis techniques for power systems, as well as linear and nonlinear …
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D-q impedance identification in three phase systems using multi-tone perturbation
… as output-regulated power converters may bring instability problem to AC or DC distributed systems. Impedance based stability criteria has been proven a good tool for small-signal stability analysis. This works focuses on the developing of a comprehensive software tool which can extract DC or …
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Shipboard MVDC Voltage Stabilization by Negative Load Energy Storage Compensated Virtual Capacitance
… This recharging constant power itself introduces small signal instability to the MVDC bus voltage. This thesis investigates the advantages of adding a dynamically tuneable virtual capacitor and resistor in parallel to the pulsed load for maintaining small signal stability. The stabi-lizer is …
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Robust stability analysis for large-scale power systems
… to increase variability and uncertainty, making stability verification more challenging. This thesis extends the technique of robust stability analysis to large-scale electric power systems under uncertainty. In the first part of this thesis, we examine the use of the technique to solve real …
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Computer Modeling and Simulation of Power Electronics Systems for Stability Analysis
… and to set conditions for safe operation. The stability analysis of this type of power systems has been approached using time domain simulations. There are three types of stability analysis that are studied: steady-state, small-signal analysis and large signal analysis. The steady-state …
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Robust stability assessment for future power systems
Loss of stability in electrical power systems may eventually lead to blackouts which, despite being rare, are extremely costly. However, ensuring system stability is a non-trivial task for several reasons. First, power grids, by nature, are complex nonlinear dynamical systems, so assessing and …
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