scholarly journals Novel Simplified Model for Asynchronous Machine with Consideration of Frequency Characteristic

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Changchun Cai ◽  
Ping Ju ◽  
Yuqing Jin
Keyword(s):  
Power Systems ◽  
Frequency Characteristic ◽  
Digital Simulation ◽  
Large Error ◽  
The Novel ◽  
Third Order ◽  
Machine Model ◽  
Transient Model ◽  
Asynchronous Machine ◽  
Electric Equipment

The frequency characteristic of electric equipment should be considered in the digital simulation of power systems. The traditional asynchronous machine third-order transient model excludes not only the stator transient but also the frequency characteristics, thus decreasing the application sphere of the model and resulting in a large error under some special conditions. Based on the physical equivalent circuit and Park model for asynchronous machines, this study proposes a novel asynchronous third-order transient machine model with consideration of the frequency characteristic. In the new definitions of variables, the voltages behind the reactance are redefined as the linear equation of flux linkage. In this way, the rotor voltage equation is not associated with the derivative terms of frequency. However, the derivative terms of frequency should not always be ignored in the application of the traditional third-order transient model. Compared with the traditional third-order transient model, the novel simplified third-order transient model with consideration of the frequency characteristic is more accurate without increasing the order and complexity. Simulation results show that the novel third-order transient model for the asynchronous machine is suitable and effective and is more accurate than the widely used traditional simplified third-order transient model under some special conditions with drastic frequency fluctuations.

Decentralized H ∞ control for damping power system oscillations

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Guo-Jie Li ◽  
Tek Lie
Keyword(s):  
Power Systems ◽  
Power System ◽  
Large Scale ◽  
Digital Simulation ◽  
Design Procedure ◽  
Disturbance Attenuation ◽  
System Stability ◽  
Frequency Noise ◽  
Stability Robustness ◽  
Norm Bound

AbstractInter-area oscillations are serious problems to large-scale power systems. A decentralized H ∞ generator excitation controller of a power system is proposed to damp the inter-area oscillations and to enhance power system stability. The design procedure for a linear composite system is presented in terms of positive semi-definite solutions to modified algebraic inequalities. The resulting controller guarantees closed-loop stability, robustness and an H ∞-norm bound on disturbance attenuation even under uncertainties such as high frequency noise. The control is decentralized in the sense that the control of each generator depends on local information only. The effectiveness of the H ∞ controller is demonstrated through digital simulation studies on a two-machine power system.

scholarly journals A numerical implementation of the unified Fokas transform for evolution problems on a finite interval

2017 ◽  
Vol 29 (3) ◽  
pp. 543-567 ◽  
Author(s):  
EMINE KESICI ◽  
BEATRICE PELLONI ◽  
TRISTAN PRYER ◽  
DAVID SMITH
Keyword(s):  
Numerical Evaluation ◽  
Space Dimension ◽  
Finite Interval ◽  
Representation Formula ◽  
The Novel ◽  
Numerical Implementation ◽  
Third Order ◽  
Linear Evolution ◽  
Time Stepping ◽  
Solution Representation

We present the numerical solution of two-point boundary value problems for a third-order linear PDE, representing a linear evolution in one space dimension. To our knowledge, the numerical evaluation of the solution so far could only be obtained by a time-stepping scheme, that must also take into account the issue, generically non-trivial, of the imposition of the boundary conditions. Instead of computing the evolution numerically, we evaluate the novel solution representation formula obtained by the unified transform, also known as Fokas transform. This representation involves complex line integrals, but in order to evaluate these integrals numerically, it is necessary to deform the integration contours using appropriate deformation mappings. We formulate a strategy to implement effectively this deformation, which allows us to obtain accurate numerical results.

A modern digital simulation laboratory for power systems

1990 ◽  
Vol 3 (2) ◽  
pp. 16-19 ◽  
Author(s):  
M. Foley ◽  
Y. Chen ◽  
A. Bose
Keyword(s):  
Power Systems ◽  
Digital Simulation ◽  
Simulation Laboratory

Design and Evaluation of the AIMS Combustor

2004 ◽  
Author(s):  
Andrei Colibaba-Evulet ◽  
Michael J. Bowman ◽  
Anthony R. Brand
Keyword(s):  
Power Systems ◽  
Steam Injection ◽  
Premixed Flame ◽  
Inlet Temperature ◽  
The Novel ◽  
Assembly Design ◽  
Full Speed ◽  
Partially Premixed Flame ◽  
Micro Turbine ◽  
Research Facilities

This paper describes a reduced NOx and CO, partially premixed flame combustor that has been developed for the 175 kW Advanced Integrated Microturbine System (AIMS) recuperated cycle gas micro-turbine. The AIMS turbine is equipped with a recuperated silo combustor. The new, reduced emissions combustor retains key features of the conventional Dry Low NOx (DLN) combustors; the differences are the arrangement of the premixers, the novel head-end assembly design, and the liner cooling and dilution features. The combustion system was designed and tested at the GE Global Research facilities in Niskayuna, NY and leverages technology developed by GE Power Systems (GEPS) and GE Aircraft Engines (GEAE). Laboratory tests show that when firing with natural gas, without water or steam injection, NOx and CO emissions from the new combustor are in single digits at full-speed, full-load conditions. CO emissions show a strong pressure effect, increasing at base load (when compared to similar conditions in commercial combustors running at higher pressures). The standard combustor on the AIMS gas turbine is a reversed flow cylindrical can. An array of 4 fuel nozzles is located at the head end of the can and produces a swirl stabilized premixed flame. The liner contains an array of cooling and dilution holes that provide the air needed to dilute the burned gas to the desired turbine inlet temperature.

A Method of Automatic Voltage Optimization Control Based on Real Time Digital Simulation

2013 ◽  
Vol 336-338 ◽  
pp. 653-658
Author(s):  
Yu De Yang ◽  
Yu Sheng Qiu
Keyword(s):  
Power Systems ◽  
Real Time ◽  
Reactive Power ◽  
Digital Simulation ◽  
Voltage Control ◽  
Test Method ◽  
Control Effectiveness ◽  
Advantages And Disadvantages ◽  
The Status ◽  
Optimal Control Scheme

With the development of smart grid, regional grid automatic voltage control (AVC) system has been widely used in power systems, but the effect is uneven, and there are not relating tools to evaluate its performance. The paper proposes a Closed-loop test method combining Real Time Digital Simulation system (RTDS) with reactive optimization procedures to simulate and optimization the status of actual grid. An optimal control scheme of the actual grid from the new method can be used to judge the advantages and disadvantages of actual AVC system. Simulation tests show online RTDS-based power system reactive power and voltage control simulation is good. It can be regard as reference to evaluate the control effectiveness of the actual AVC system.

Sign in / Sign up

Export Citation Format

Share Document