scholarly journals Rotor loss and temperature variation under single and combined faults composed of static air‐gap eccentricity and rotor inter‐turn short circuit in synchronous generators

2021 ◽  
Author(s):  
Yu‐Ling He ◽  
Wen Zhang ◽  
Ming‐Xing Xu ◽  
Wen‐Qiang Tao ◽  
Hui‐Lan Liu ◽  
...  
Keyword(s):  
Temperature Variation ◽  
Short Circuit ◽  
Air Gap ◽  
Synchronous Generators ◽  
Rotor Loss

scholarly journals Optimal Control of the Positional Electric Drive and Its Implementation

Machines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 70
Author(s):  
Vladimir Dotsenko ◽  
Roman Prokudin ◽  
Alexander Litvinenko
Keyword(s):  
Optimal Control ◽  
Wind Turbine ◽  
Electric Drive ◽  
Minimum Energy ◽  
Air Gap ◽  
Synchronous Generators ◽  
Capacitor Discharge ◽  
Wind Speeds ◽  
Minimum Energy Consumption ◽  
Low Wind Speeds

The article deals with the optimal control of the positional electric drive of the stator element of a segment-type wind turbine. The calculation options charts current in the assumption of the minimum energy consumption and the implementation of line chart current using the phenomenon of capacitor discharge. The analysis of the implementation is expressed in a jump-like change in current and a triangular graph of the speed change. This article deals with small capacity synchronous wind turbine generators with a segment type stator. These units have the possibility of intentionally changing the air gap between the rotor and stator. This allows: (1) Reduce the starting torque on the rotor shaft, which will allow the rotor to pick up at low wind speeds. (2) Equivalent to change of air gap in this case is change of excitation of synchronous generators. Thus, the purpose of the article is to consider a method of excitation of generators in a segmented design, by controlling the gap with the electric drive, while providing control should be carried out with minimal losses.

Short-Circuit Model and Simulation Characteristics of Synchronous Generators

2012 ◽  
Vol 241-244 ◽  
pp. 709-716
Author(s):  
Wan Qing Song ◽  
Qi Zhong Liu ◽  
Xu Dong Teng ◽  
Chao Gang Yu
Keyword(s):  
Theoretical Analysis ◽  
Simulation Model ◽  
Short Circuit ◽  
Influence Factors ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Model And Simulation ◽  
Simulation Results ◽  
Physical Quantities ◽  
Tremendous Impact

In this paper, the electrical transient mode of synchronous generators is studied, four different simulation model of synchronous generator on sudden short circuit was built, various physical quantities were studied by simulation during the short circuit. By comparing theoretics with simulation, various physical quantities of synchronous generator produced tremendous impact and surge during the sudden circuit and they stabilized in the proceeding state of short circuit. Thoroughly simulation analyzed, the results of simulation are identical with theoretical analysis. The simulation results show that these influence factors should be considered when we design the relay protections.

scholarly journals Adaptive Armature Resistance Control of Virtual Synchronous Generators to Improve Power System Transient Stability

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2365
Author(s):  
Daniel Carletti ◽  
Arthur Eduardo Alves Amorim ◽  
Thiago Silva Amorim ◽  
Domingos Sávio Lyrio Simonetti ◽  
Jussara Farias Fardin ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Power System ◽  
Transient Stability ◽  
Short Circuit ◽  
Stability Margin ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Resistance Change ◽  
Clearing Time ◽  
Fault Current Limiters

The growing number of renewable energy plants connected to the power system through static converters have been pushing the development of new strategies to ensure transient stability of these systems. The virtual synchronous generator (VSG) emerged as a way to contribute to the system stabilization by emulating the behavior of traditional synchronous machines in the power converters operation. This paper proposes a modification in the VSG implementation to improve its contribution to the power system transient stability. The proposal is based on the virtualization of the resistive superconducting fault current limiters’ (SFCL) behavior through an adaptive control that performs the VSG armature resistance change in short-circuit situations. A theoretical analysis of the problem is done based on the equal-area criterion, simulation results are obtained using PSCAD, and experimental results are obtained in a Hardware-In-the-Loop (HIL) test bench to corroborate the proposal. Results show an increase in the system transient stability margin, with an increase in the fault critical clearing time (CCT) for all virtual resistance values added by the adaptive control to the VSG operation during the short-circuit.

scholarly journals Direct-Drive Synchronous Generators with Excitation from Strontium-Ferrite Magnets: Efficiency Improvement

2012 ◽  
Vol 49 (4) ◽  
pp. 3-13
Author(s):  
A. Serebryakov ◽  
N. Levin ◽  
A. Sokolov
Keyword(s):  
Permanent Magnets ◽  
Strontium Ferrite ◽  
Air Gap ◽  
Electric Machine ◽  
Specific Power ◽  
Hard Material ◽  
Efficiency Improvement ◽  
Direct Drive ◽  
Synchronous Generators ◽  
Starting Torque

Direct-Drive Synchronous Generators with Excitation from Strontium-Ferrite Magnets: Efficiency Improvement The authors consider the possibility to raise the specific power of synchronous generators with excitation from inexpensive permanent magnets. For this purpose, it is proposed to use tooth-wise windings and permanent magnets based on inexpensive magneto-hard material, e.g. strontium-ferrite. The magnets are to be placed between the rotor teeth, the alternate polarity of which is facing the air-gap. This provides a simpler and cheaper technology of making such a generator and improves its reliability. The proposed rational bevelling of the stator teeth not only raises the specific power of the generator but also reduces the level of noise and vibrations, extends the longevity of the magnets and bearings as well as facilitates the starting torque of the electric machine, e.g. if it is employed as wind generator.

scholarly journals Comparative Simulation Study on Synchronous Generators Sudden Short Circuits

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Lucian Lupşa-Tătaru
Keyword(s):  
Mathematical Model ◽  
Time Domain ◽  
Short Circuit ◽  
Structural Equations ◽  
Process Models ◽  
State Variables ◽  
Synchronous Generators ◽  
State Equations ◽  
Starting Point ◽  
Short Circuits

Although of a great extent in time, the research works directed at studying transients in synchronous generators have not yet provided fully sufficient comparative studies in respect to sudden short circuits of the machine. The present paper puts forward novel and comprehensive process models for dynamic simulation of short circuit faults of initially unloaded synchronous generators, using the generalizedd-q-0 mathematical model as starting point in derivation. Distinct from the time-domain analysis, the technique proposed here allows an effective comparative overview by employing a specialized procedure to perform repeated time-domain simulations accompanied by peak values recording for the various circumstances. The time consuming matrix numerical inversion at each step of integration, usually performed when selecting currents as state variables, is eliminated by advancing the process models in a convenient split matrix form that allows the symbolic processing. Also, the computational efficiency is being increased by introducing a set of auxiliary variables common to different state equations. The models derivation is carried out without altering the structural equations of the generalizedd-q-0 mathematical model of synchronous generators whilst the simulation results are both compared and discussed in detail.

scholarly journals Stator Winding Fault Diagnosis in Permanent Magnet Synchronous Generators Based on Short-Circuited Turns Identification Using Extended Kalman Filter

ACTA IMEKO ◽  
2014 ◽  
Vol 3 (4) ◽  
pp. 4 ◽  
Author(s):  
Brice Aubert ◽  
Jérémi Régnier ◽  
Stéphane Caux ◽  
Dominique Alejo
Keyword(s):  
Kalman Filter ◽  
Permanent Magnet ◽  
Extended Kalman Filter ◽  
Permanent Magnets ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Network ◽  
Synchronous Generators ◽  
Permanent Magnet Synchronous Generators ◽  
Fault Indicator

<p class="Abstract">This paper deals with an Extended Kalman Filter based fault detection for inter-turn short-circuit in Permanent Magnet Synchronous Generators. Inter-turn short-circuits are among the most critical faults in the PMSG. Indeed, due to permanent magnets, the short-circuit current is maintained as long as the machine is rotating. Thus, a specific faulty model in d-q frame is developed to estimate the number of short-circuited turns which are used to build a fault indicator. Simulation results demonstrate the sensitivity and the robustness of the proposed fault indicator against various operation points on an electrical network even for a few number of short-circuited turns.</p>

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