scholarly journals ANALISA PROTEKSI HILANG EKSITASI PADA GENERATOR SINKRON DI PLTGU MUARA TAWAR GT UNIT 1.3

Sutet ◽  
1970 ◽  
Vol 7 (2) ◽  
pp. 124-132
Author(s):  
Redaksi Tim Jurnal
Keyword(s):  
Delay Time ◽  
Reactive Power ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Protection System ◽  
Power Generator ◽  
The Future ◽  
The Impact

One of the operating disruptions that occur in the synchronous generator is the loss of excitation. Where this interference will cause the generated reactive power generator is reduced even lost so that the synchronous generator must absorb the reactive power of the system. If this condition occurs continuously can cause damage to the stator coil, will occur worsening insulation and the stator end iron so as to cause short circuit, or interruption of soil relations in the future. So to anticipate the impact of such disturbances required a protection system. The protection system used in PLTGU Muara Tawar GT unit 1.3 is a minimum reactance relay. This jurnal discusses how to determine the value of loss excitation protection setting using minimum reactance relay and offset relay mho so that synchronous generator can work optimally. From the research calculation the minimum reactance relay usage will work on XA-setting value zone (-2.55 p.u) with 0.5 seconds delay time, XB-setting (offset) of -0.1156 p.u with 0.5 seconds delay time. As for offset relay mho will work on zone 1 and zone 2 for offset value of -0.109 p.u with delay time 0.1 second. As for zone 1 for the base impedance ( ) of -1.0 p.u with a delay time of 0.1 seconds and zone 2 synchronous reactance value ( of 2.423 p.u with a delay time of 0.5 seconds. From those results it is considered sufficient to detect the loss of excitation in the synchronous generator.

scholarly journals Improved Control Strategy of MMC–HVDC to Improve Frequency Support of AC System

2020 ◽  
Vol 10 (20) ◽  
pp. 7282
Author(s):  
Zicong Zhang ◽  
Junghun Lee ◽  
Gilsoo Jang
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Control Method ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Frequency Stability ◽  
Offshore Wind ◽  
Inertial Response ◽  
Control Evaluation ◽  
The Impact

With the continuous development of power electronics technology, variable-speed offshore wind turbines that penetrated the grid system caused the problem of inertia reduction. This study investigates the frequency stability of synchronous, offshore wind-farm integration through a modular-multilevel-converter high-voltage direct-current (MMC–HVDC) transmission system. When full-scale converter wind turbines (type 4) penetrate the AC grid, the AC system debilitates, and it becomes difficult to maintain the AC system frequency stability. In this paper, we present an improved inertial-response-control method to solve this problem. The mathematical model of the synchronous generator is based on the swing equation and is theoretically derived by establishing a MMC–HVDC. Based on the above model, the inertia constant is analyzed using a model that integrates the MMC–HVDC and offshore synchronous generator. With the new improved control method, a more sensitive and accurate inertia index can be obtained using the formula related to the effective short-circuit ratio of the AC system. Moreover, it is advantageous to provide a more accurate inertial control evaluation for AC systems under various conditions. Furthermore, the impact of the MMC–HVDC on system safety is assessed based on the capacitor time constant. This simulation was implemented using the PSCAD/EMTDC platform.

scholarly journals Grid-connected Response Verification of AC Microgrid under Single Line-to-ground Short Circuit

2019 ◽  
pp. 1-10
Author(s):  
Maruf A. Aminu
Keyword(s):  
Power Systems ◽  
Reactive Power ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Dynamic Responses ◽  
Single Line ◽  
Physical Systems ◽  
Short Circuits ◽  
Power System Performance ◽  
Grid Interconnection

In design of power systems, assumptions are made to model the physical systems. The assumptions may not sufficiently reflect the behavior of the system under normal and faulted conditions. Under short circuit conditions, system parameters vary significantly, particularly in microgrids with grid interconnection capabilities. This paper presents the result of validating the response of a microgrid which is capable of grid interconnection and islanding under voltage and reactive power control regimes. The microgrid is modeled to incorporate two wind turbines, each rated 5.5 kW, 400 V. The utility has synchronous generator rated 100 MW, 13.8 kV. Both the utility and microgrid are capable of exchanging active power and reactive power. Single line-to-ground short circuits are introduced and withdrawn at 30.00 s and 32.00 s, respectively. The dynamic responses of the testbed are captured pre-, during- and post-short circuit in grid-connected mode under both control regimes. The response of the testbed is verified to be consistent with established short circuit theory, verifying the validity of the system for short circuit detection and analysis. The testbed can therefore be used for short circuit and related studies, design optimization and power system performance prediction.

scholarly journals Impact of Single and Combined Faults Composed of Rotor Eccentricity and Stator Interturn Short Circuit on Electromagnetic Torque Ripples in Synchronous Generator

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Yu-Ling He ◽  
Zhi-Jie Zhang ◽  
Xiao-Long Wang ◽  
Peng Gao ◽  
David Gerada ◽  
...  
Keyword(s):  
Experimental Study ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Magnetic Flux Density ◽  
Electromagnetic Torque ◽  
Element Calculation ◽  
Single Fault ◽  
Torque Ripples ◽  
The Impact ◽  
Short Circuit Fault

In order to comprehensively study and identify the electromagnetic torque (EMT) difference among the single static air-gap eccentricity (SAGE) fault, the single stator interturn short circuit fault (SISC), and the combined fault composed of these two, this article investigates the EMT ripple properties due to the mentioned three faults. Different from other studies, this paper considers not only the effect of the single fault types but also the impact of the single fault combinations on the EMT ripple characteristics. Detailed EMT expressions for each fault are firstly derived on the basis of the magnetic flux density (MFD) analysis. Then, finite element calculation and experimental study on a CS-5 prototype generator with two poles at 3000 rpm, which is specifically designed and manufactured ourselves, are carried out to validate the analysis result. It is found that the three faults will induce different ripple components in EMT. The combined faults have the most intensive impact sensitivity on the EMT ripples, while the single SAGE fault ranks the last in the impact effect.

Loss Of Excitation (LOE) Protection of Synchronous Generator

2017 ◽  
Vol 8 (1) ◽  
pp. 230 ◽  
Author(s):  
Hui Hwang Goh ◽  
Sy yi Sim ◽  
Mohd. Nasri Abd Samat ◽  
Ahmad Mahmoud Mohamed ◽  
Chin Wan Ling ◽  
...  
Keyword(s):  
Reactive Power ◽  
Harmful Effect ◽  
Synchronous Generator ◽  
Synchronous Generators ◽  
Financial Cost ◽  
New Techniques ◽  
Power Generator ◽  
Grid Systems ◽  
Protection Scheme ◽  
Power Swing

<p>Synchronous generators require certain protection against loss of excitation because it can lead to harmful effect to a generator and main grid. Systems of powers are evolving with applications of new techniques to increase reliability and security, at the meantime techniques upgradation is being existed to save financial cost of a different component of power system, which affect protection ways this report discuss the way of loss of excitation protection scheme for an increase in a synchronous generator. It is obvious that when direct axis synchronous reactance has a high value, the coordination among loss of excitation protection and excitation control is not effective. This lead to restricting absorption capability of the reactive power generator. This report also reviews the suitable philosophy for setting the limiters of excitation and discusses its effect on loss of excitation protection and system performance. A protection scheme is developed to allow for utilization of machine capability and power swing blocking is developed to increase the reliability when power swing is stable.</p><p><em> </em></p>

scholarly journals Analysis of power system operation at asymmetrical load

2018 ◽  
Vol 19 ◽  
pp. 01029
Author(s):  
Stefan Paszek ◽  
Adrian Nocoń ◽  
Piotr Pruski
Keyword(s):  
Power System ◽  
Short Circuit ◽  
Synchronous Generator ◽  
Angular Speed ◽  
Power Line ◽  
Model Parameters ◽  
System Operation ◽  
Two Phase ◽  
The Impact ◽  
Generator Stator

The paper presents a mathematical model of a power system (PS) consisting of a generating unit (with a synchronous generator) connected by a high voltage (transmission) power line to a bus. The state and output equations of the generator are expressed in the coordinate system d, q, 0 and with the use of phase quantities of the generator stator, the bus and the power line, which is especially useful in the analysis of asymmetrical states. A disturbance of the steady state in the form of a two-phase short-circuit in the transmission line was taken into account in the made calculations. The influence of the excitation system and angular speed control system of the generator as well as the impact of selected generator model parameters on the waveforms were investigated.

Eccentric operation of STATCOM using Predictive Controller

2018 ◽  
Vol 9 (1) ◽  
pp. 150
Author(s):  
K. Varalakshmi ◽  
Narasimham R.L. ◽  
G. Tulasi Ramdas
Keyword(s):  
Distribution System ◽  
Reactive Power ◽  
Short Circuit ◽  
Open Circuit ◽  
Complete Analysis ◽  
Control Structures ◽  
Predictive Controller ◽  
On Line ◽  
The Impact ◽  
Transmission And Distribution

<p>The impact of multilevel converter STATCOM in transmission and distribution system is given high importance. Increment of number of switches in multi-level cascaded H-bridge converter, made it more vulnerable to open circuit and short circuit faults. To reduce the effect of faults on line voltage magnitude, in this paper an advanced improved predictive controller is used to generate PWM pulses for the power electronic devices. A Cascaded H-bridge STATCOM, interconnected to a distribution system with linear and non-linear loads. The feedback control structure of STATCOM has an advantage of reducing THD and controllable reactive power. A switch fault detection and elimination method is proposed with a bypass switch connected to each H-bridge to surpass the faulty  H-bridge. The complete analysis with all control structures is designed in MATLAB/Simulink representing dynamic graphs and feasibility of proposed method is verified.</p>

scholarly journals Electric Vehicle Ultra-Fast Battery Chargers: A Boost for Power System Stability?

2021 ◽  
Vol 12 (1) ◽  
pp. 16
Author(s):  
Fabio Mandrile ◽  
Davide Cittanti ◽  
Vincenzo Mallemaci ◽  
Radu Bojoi
Keyword(s):  
Power System ◽  
Electric Vehicle ◽  
Reactive Power ◽  
Short Circuit ◽  
Electric Power System ◽  
System Stability ◽  
High Peak Power ◽  
Charging Station ◽  
Fast Charging ◽  
The Impact

As a consequence of the exponential growth of the electric vehicle (EV) market, DC fast-charging infrastructure is being rapidly deployed all around the world. Ultra-fast charging (UFC) stations are starting to pose serious challenges to the electric power system operation, mostly due to their high peak power demand and unregulated discontinuous operation. To address these issues, local energy storage can be installed, ensuring a smoother grid power absorption profile and allowing to provide grid-supporting features. In this work, a control solution for the grid-side AC/DC converter of next-generation EV UFC stations is proposed. A virtual synchronous compensator (VSC) control algorithm is implemented, in order to lessen the impact of the charging station on the utility and to provide the full spectrum of grid ancillary services (i.e., frequency regulation, reactive power compensation, harmonic reduction, short circuit current generation, etc.). The proposed control strategy is verified experimentally on a downscaled 15 kVA three-phase inverter, emulating the grid front-end of the charging station.

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 Modelling and Load Test Analysis of a Wind farm for 14 Bus System

2021 ◽  
pp. 279-284
Author(s):  
Abirami K ◽  
Dr. P. Maruthupandi
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Short Circuit ◽  
Load Condition ◽  
Synchronous Generator ◽  
Test System ◽  
Load Test ◽  
Test Analysis ◽  
Wind Generator ◽  
Bus System

This paper describes about the reliable and secure operation of a power system network is an indispensable concern for the system operator. The modelling of wind farm and load test analysis is used to identify the real and reactive power by using DIgSILENT power factory simulation software.By developing the 5MW Wind farm modelling by using Permanent Magnet Synchronous Generator (PMSG).The main aim is to analyze the performance of wind farm modelling with load Test System and also to detect the fault occurrence by using the condition of short circuit studies in the system. In IEEE 14 bus system it is used to identify the wind generator is in overload condition and the wind generator is in lower load condition.

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