scholarly journals STUDY OF ELECTROMECHANICAL COMPLEXES WITH SYNCHRONOUS GENERATORS WITH DIFFERENT SYNCHRONIZATION MODES

2018 ◽  
Vol 1 (12) ◽  
pp. 54-57
Author(s):  
Yuriy Konovalov ◽  
Stepan Sadovskiy ◽  
Maksim Krivosheev ◽  
Angelina Tihonova
Keyword(s):  
Short Circuit ◽  
Experimental Studies ◽  
Synchronous Generator ◽  
Parallel Operation ◽  
Synchronous Generators

The results of experimental studies of various methods of synchronization of electromechanical complexes with synchronous generators arising when the synchronous generator is turned on for parallel operation with the network and during self-synchronization during emergency modes of a short circuit are presented.

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 The Short-Circuit Protections in Hybrid Systems with Low-Power Synchronous Generators

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 160
Author(s):  
Bartosz Rozegnał ◽  
Paweł Albrechtowicz ◽  
Dominik Mamcarz ◽  
Natalia Radwan-Pragłowska ◽  
Artur Cebula
Keyword(s):  
Single Phase ◽  
Low Voltage ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Electrical Systems ◽  
Protection Devices ◽  
Short Circuits ◽  
Damage Type

Single-phase short-circuits are most often faults in electrical systems. The analysis of this damage type is taken for backup power supply systems, from small power synchronous generators. For these hybrid installations, there is a need for standard protection devices, such as fuses or miniature circuit breaker (MCB) analysis. Experimental research mentioned that a typical protective apparatus in low-voltage installations, working correctly during supplying from the grid, does not guarantee fast off-switching, while short-circuits occur during supplication from the backup generator set. The analysis of single-phase short-circuits is executed both for current waveform character (including sub-transient and transient states) and the carried energy, to show the problems with the fuses and MCB usage, to protect circuits in installations fed in a hybrid way (from the grid and synchronous generator set).

scholarly journals ANALYSIS OF OVERVOLTAGE POSSIBILITY ON THE EXCITATION WINDING OF A SYNCHRONOUS GENERATOR OF AUTONOMOUS POWER SUPPLY SYSTEM IN CASE OF EXTERNAL SYMMETRICAL SHORT CIRCUIT

2021 ◽  
pp. 112-115
Author(s):  
V.B. Beliy ◽  
Keyword(s):  
Power Systems ◽  
Power Supply ◽  
Short Circuit ◽  
Electric Energy ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Excitation System ◽  
Three Phase ◽  
Short Circuits ◽  
Analytical Expressions

Reliable supply of consumers with electric energy largely depends on the reliability of power source function-ing. In the context of this paper it depends on synchronous generators operating in autonomous power supply sys-tems. In contrast to the power plant generators which are part of power systems and are protected from the loads by sufficiently large resistances, power supply systems withautonomous generators are characterized by rather low resistances. Abrupt changes in the supply load parameters, their own transient and emergency modes, for example, short circuits at the generator terminals, forcing excitation, etc. may lead to various failures in the synchronous gener-ator operation. This paper discusses the possibility of over-voltage in the valve excitation system of a synchronous generator with external three-phase short circuits. On the basis of analytical expressions describing the physical pro-cesses occurring in the excitation system of synchronous generators, the conditions for the occurrence of overvolt-ages are identified

scholarly journals System Independent Fault Diagnosis for Synchronous Generator

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Jeet Gandhi ◽  
R. Gopinath ◽  
C. Santhosh Kumar
Keyword(s):  
Fault Diagnosis ◽  
Performance Improvement ◽  
Classification Accuracy ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Single Step ◽  
Fault Models ◽  
Synchronous Generators ◽  
Performance Accuracy ◽  
Three Phase

Creating a unified fault diagnosis model that can detect faults across systems with different ratings (system independent fault diagnosis) would be of great interest in making condition-based maintenance (CBM) more popular. In this work, three phase synchronous generators with 3 and 5 kVA ratings are used for detecting stator inter-turn short circuit faults.Our baseline is a 3 kVA generator working at 1 A load during training and testing, to emulate the system/load dependent fault diagnosis. We obtained a classification accuracy of 99.75%, 100% and 100% for R phase, Y phase and B phase faults respectively. Subsequently, we evaluated the system for its load independent performance. Performance accuracy deteriorated due to the load specific variations (LSV) in the input feature vector (IFV). LSV is undesired, and we used nuisance attribute projection (NAP) to remove them. Using NAP, we obtained a performance improvement of 23.13%, 17.75% and 20.72% for three fault models on the 3 kVA generator and similar performance improvement was obtained for 5 kVA generator also.Further, we experimented for load and system independent fault diagnosis. In this case, we consider LSV and system specific variations (SSV) on IFV as undesired. We experimented with two types of NAP, (1) single step NAP, (2) stacked NAP. Experimental results show that the two staged stacked NAP outperforms. We obtained an improvement of 23.99%, 16.06% and 28.39%, in classification accuracy for three fault models, resulting in overall classification accuracy of 89.22%, 94.67% and 94.59% for R phase, Y phase and B phase fault models respectively.

scholarly journals Adaptive Protection Coordination Method Design of Remote Microgrid for Three-Phase Short Circuit Fault

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7754
Author(s):  
Wookyu Chae ◽  
Jung-Hun Lee ◽  
Woo-Hyun Kim ◽  
Sungwook Hwang ◽  
Jun-Oh Kim ◽  
...  
Keyword(s):  
Short Circuit ◽  
Renewable Energy Sources ◽  
Current Source ◽  
Synchronous Generator ◽  
Voltage Source ◽  
Small Island ◽  
Fault Current ◽  
Synchronous Generators ◽  
Adaptive Protection ◽  
Protection Method

Generally, the fault current supplied by inverter-based renewable energy sources (IBRES) and electrical storage systems (ESS) is about 1.2 to 2 times their rated current and much lower than synchronous generators because the former acts as a current source and the latter acts as a voltage source. A conventional power system in a small island is composed of only synchronous generators and protected from short circuit faults using an overcurrent relay (OCR). However, in the remote microgrid with IBRES, ESS, and synchronous generators, the fault current varies depending on the configuration of generation sources. Namely, the fixed OCR protection method cannot protect microgrids from short circuit faults. This paper proposes an adaptive protection method to protect the microgrid from faults by actively changing the OCR setting according to the state of the generator source combination. A microgrid with ESS and a synchronous generator is modeled and simulated through PSCAD/EMTDC software to validate the proposed adaptive protection method.

scholarly journals Determination of the Leakage Reactance of End Windings of a High-Power Synchronous Generator Stator Winding Using the Finite Element Method

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7091
Author(s):  
Sebastian Berhausen ◽  
Stefan Paszek
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Power ◽  
Short Circuit ◽  
Three Dimensional ◽  
Synchronous Generator ◽  
The Finite Element Method ◽  
Synchronous Generators ◽  
Calculation Results ◽  
Element Method

The paper presents a description of the method and the results of calculating the leakage reactance of high-power synchronous generator end windings using the finite element method. This reactance is one of the components of the stator leakage reactance of synchronous generators. The calculations were carried out under the assumption of a three-dimensional field distribution in a synchronous generator. The thus calculated value of the leakage reactance of the end windings was compared with the calculation results obtained using traditional, analytical formulas known from the literature. The analysis of the influence of the reactance value of the end windings on the transient waveforms at a three-phase short-circuit of the stator windings was performed based on a two-dimensional field-circuit model.

scholarly journals Stability Assessment of Renewable Energy Integrated Power System

2019 ◽  
Vol 8 (2S11) ◽  
pp. 3301-3307
Keyword(s):  
Power Generation ◽  
New England ◽  
Reactive Power ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Small Signal Stability ◽  
Synchronous Generators ◽  
Pv System ◽  
Negative Damping ◽  
Pv Generator

This paper investigates the small-signal stability of grid integrated Doubly Fed Induction Generator (DFIG) based Wind Turbine Generator (WTG) and Photovoltaic (PV) system. The short-circuit study is conducted for the New England 39-bus system using DIgSILENT PowerFactory software. The short-circuit study and dynamic simulation are performed for the study system with distributed generators. Furthermore, the eigenvalues are computed for the various damping level of synchronous generators. The influence of negative damping of synchronous machine with PV generator, DFIG based WTG in the study system is investigated. The eigenvalue analysis results shows that due to negative damping of synchronous generator the system become unstable even with PV generator and DFIG based WTG in the system. The time domain simulation results show that real power generation of the synchronous generator is decreased due to negative damping and its reactive power generation is increased.

scholarly journals Electromagnetic Forces and Mechanical Responses of Stator Windings before and after Rotor Interturn Short Circuit in Synchronous Generators

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Gui-Ji Tang ◽  
Hong-Chun Jiang ◽  
Yu-Ling He ◽  
Qing-Fa Meng
Keyword(s):  
Electromagnetic Force ◽  
Mechanical Response ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Element Model ◽  
Stator Winding ◽  
Synchronous Generators ◽  
Mechanical Responses ◽  
Before And After ◽  
Frequency Components

This paper studies the stator winding electromagnetic force behaviors before and after rotor inter-turn short circuit (RISC) in synchronous generator. Different from other studies, this paper not only studies the electromagnetic force characteristics, but also investigates the mechanical responses, the damage regularity, and the countermeasure of the stator winding. Firstly, formulas of electromagnetic force online and end part are obtained. Then, a 3D finite element model of a 3-pair-pole simulation generator is applied to get the electromagnetic force, and the dangerous stator slot is found. Finally, the mechanical response of each end winding is acquired, and especially the directional deformations of nose part are calculated. It shows that the occurrence of RISC will bring in times of rotor rotating frequency components to electromagnetic force, but the DC component and 2p times of rotor rotating frequency components are still the main that will be decreased. Additionally, the winding insulation wear in the same layer is more serious than that in a different layer, nose fatigue fracture begins with the center, and nose insulation wear starts from the top.

scholarly journals The Analysis of the Symmetrical Short-Circuit Currents in Backup Power Supply Systems with Low-Power Synchronous Generators

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4474 ◽  
Author(s):  
Dominik Mamcarz ◽  
Paweł Albrechtowicz ◽  
Natalia Radwan-Pragłowska ◽  
Bartosz Rozegnał
Keyword(s):  
Low Power ◽  
Power Supply ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Short Circuit Current ◽  
Synchronous Generators ◽  
The Difference ◽  
The Individual ◽  
Short Circuit Currents ◽  
Selection Of

This paper presents an analysis of the short-circuit currents of a synchronous generator with a rated power of 16 kVA. For this purpose, the authors carried out measurements of real short-circuit currents during laboratory tests. Additionally, a simulation model of the generator was developed according to the individual machines data from the catalog and field calculations in ANSYS Maxwell software. Based on the mentioned research, the authors compared waveforms of the symmetrical short-circuit currents. In this paper, the last compared family of short-circuit current waveforms was obtained using analytic calculations. As the presented comparison shows, the assumed method of selecting short-circuit waveforms impacted their values. However, the difference in energy related to short-circuit currents did not influence on the selection of the short-circuit protections, especially at low values of steady-state short-circuit currents and short time constants characteristic for the generators, performing the functions of an alternative power supply. Regardless of the research method, the results presented in the article show that the selection of the short-circuit protections is complicated in case of hybrid electrical systems equipped with low power generators.

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