scholarly journals Transient Stability Analysis of a System of Two Machines Connected to an Infinite Bus

2018 ◽  
Vol 3 (10) ◽  
pp. 81-89
Author(s):  
Aniagboso John Onah
Keyword(s):  
Power System ◽  
Transient Stability ◽  
Synchronous Generator ◽  
Frequency Instability ◽  
First Case ◽  
System Collapse ◽  
Clearing Time ◽  
Steady State Stability ◽  
Two Machines ◽  
Large Disturbance

Abstract The term large disturbance is often used in place of system collapse. It is the process by which the series of events accompanying voltage instability, frequency instability, and transient instability leads to a blackout or abnormally low voltages in a significant part of the power system. Large disturbance may be due to tripping of the lines on an account of fault or increase in load than the available supply. Transient stability deals with the effect of large and sudden disturbances in the system, while steady-state Stability deals with the effect of small disturbances in the system. Small disturbance can be a change in the gain of the automatic voltage regulator in the excitation system of a large generating unit. This paper studies the effect of a large disturbance in a power system. The system is represented by a two-machine system connected to an infinite bus. This study involves the effects of the fault on the speed of the rotor of the synchronous generator. Two cases were investigated: firstly, when fault occurred on a bus, and secondly, when fault occurred on the middle of a line. The conditions of the network before, during and after the fault are established in this paper. The equal area criterion was applied to the swing curves obtained to predict the critical clearing time of the system. The critical clearing time was found to lie between 0.20s and 0.225s if the fault occurred on the bus, and lies between 0.245s and 0.355s if the fault occurred at the middle of a line. Thus the system is more transiently stable in the second case than in the first. Machine 1 was less stable in the first case, while machine 2 was less stable in the second case. The critical clearing time is essential to the design of proper relaying schemes for fault clearing.

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.

Distributed Virtual Synchronous Generator approach versus Singular Virtual Synchronous Generator approach: A dynamic stability evaluation

2020 ◽  
pp. 0309524X2097546
Author(s):  
Abdul Waheed Kumar ◽  
Mairaj ud din Mufti ◽  
Mubashar Yaqoob Zargar
Keyword(s):  
Power System ◽  
Transient Stability ◽  
Reactive Power ◽  
Magnetic Energy ◽  
Dynamic Performance ◽  
Synchronous Generator ◽  
Rate Of Change ◽  
Clearing Time ◽  
Magnetic Energy Storage ◽  
Virtual Synchronous Generator

This paper reports the modeling and dynamic performance of a wind penetrated multi-area power system incorporating a Singular Virtual Synchronous Generator (SVSG)/Distributed Virtual Synchronous Generator (DVSG). The active and reactive power controls are achieved by using Superconducting Magnetic Energy Storage (SMES) as Virtual Synchronous Generator (VSG). SMES based VSG control parameters are tuned offline using genetic algorithm (GA). Two topologies of VSGs are considered in this paper: SVSG at lowest inertia generator bus (SVSGGENBUS), SVSG at load bus (SVSGLOADBUS) and DVSG of comparatively smaller rating at three lowest inertia generator buses. A modified 18 machine, 70-bus power system is simulated in MATLAB/Simulink environment. System performance is assessed for two different types of disturbances: step wind disturbance and three-phase fault. The simulation results show that rate of change of frequency (ROCOF), deviations in frequency and voltage are minimized with DVSG. Transient stability measured in terms of critical clearing time (CCT) verifies that CCT is increased by DVSG topology.

scholarly journals Design of Optimal Power System Stabilizer Using ETAP

2012 ◽  
pp. 221-224
Author(s):  
Raja Nivedha. R ◽  
Sreevidya. L ◽  
V. Geetha ◽  
R. Deepa
Keyword(s):  
Power System ◽  
Optimal Power Flow ◽  
Transient Stability ◽  
Transient Behavior ◽  
Steel Plant ◽  
Power System Stabilizer ◽  
Optimal Power ◽  
Clearing Time ◽  
System Stabilizer ◽  
System Power

The main objective of this paper is to improve the critical clearing time of the Steel Plant 35 MW Turbo generator. In order to enhance the transient behavior of the system, Power System Stabilizer is added so that proper damping is done. Damping intra area and inter area oscillations are critical to optimal power flow and stability on a system. Power system stabilizer is an effective damping device, as they provide auxiliary control signals to the excitation system of the generator. Transient stability analysis was carried out for the Steel plant. The three phase to ground and line to ground fault was simulated. The critical clearing time was found to be more when Power System Stabilizer was added and when Power System Stabilizer was not added the critical clearing time has considerably reduced.

Critical Clearing Time Associate with Relation of Power Load Factor and Frequency in Transient Stability

2015 ◽  
Vol 743 ◽  
pp. 257-262
Author(s):  
Ming Jong Lin
Keyword(s):  
Power System ◽  
Power Factor ◽  
Transient Stability ◽  
Automatic Monitoring ◽  
Load Factor ◽  
Protection Relay ◽  
Power Load ◽  
Clearing Time ◽  
The One ◽  
Time Point

Critical clearing time is to determine the time point of the collapse of the power system when the power system occur transient stability by a huge of failure. So that the one is an important data on protection system in power system. Therefore as an electrical engineer must to look on mostly the point of one to analyze and design in the power. In this paper, through the protection relay and breaker analysis of operation to know the team of protection relay how to complete the automatic monitoring and isolated the fault-equipment in power system. To study and analyze the swing equation and equal area criterion, we found out the relation of critical clearing time is changed with power factor and frequency. The critical clearing time was verified a non-constant value which is changed with the power factor and; if the load power factor is high, the critical clearing time is high but the frequency is high, the critical clearing time is low with system swing in the transient stability. This paper will be verify below each paragraph.

scholarly journals Steady-State Stability of Sending-End System with Mixed Synchronous Generator and Power-Electronic-Interfaced Renewable Energy

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Kaiyuan Hou ◽  
Zeyu Li ◽  
Lei Chen ◽  
Deming Xia ◽  
Qun Li ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Steady State ◽  
Stability Analysis ◽  
Power System ◽  
Classical Model ◽  
Stability Limit ◽  
Synchronous Generator ◽  
Transformation Model ◽  
Power Electronic ◽  
Steady State Stability

Coupled with the power system through power-electronic interfaces, renewable energies including wind power and photovoltaic can control the power quickly and flexibly. In the steady-state stability analysis, by neglecting the fast dynamics of power-electronic interfaces, the renewable energy power is simplified to a static power injection model and can be described as an algebraic equation in the dynamic process. Based on this simplified model, the steady-state stability of sending-end system with mixed synchronous generator and power-electronic-interfaced renewable energy is studied. By proposing a triangular transformation model based on the classical model of power system, the steady-state stability analysis becomes feasible. The mechanism of steady-state stability is revealed, and the influence of renewable energy on the steady-state stability limit is quantitatively investigated. When the renewable energy power increases, the steady-state stability limit of the sending-end system first increases and then decreases. Reducing the power output of synchronous generator can change for a higher integration limit of renewable energy. Simulation results validate the conclusion.

scholarly journals Enhancement Stability of the Power System Using Static Synchronous compensators Connected in Different Formats

2021 ◽  
Vol 28 (1) ◽  
pp. 1-12
Author(s):  
Maha Al-Flaiyeh ◽  
Nagham Aziz
Keyword(s):  
Power System ◽  
Transient Stability ◽  
Reactive Power ◽  
Research Strategy ◽  
Static Synchronous Compensator ◽  
Clearing Time ◽  
Better Than

The research strategy focuses on the effect of connecting a STATCOM to mend critical-clearing-time (CCT) for the studied system and its transient stability. This paper targets to connect STATCOM in two situations, grouped and distributed. The first situation connects STATCOM at one placement with 100 MVAR reactive power while the second situation connects two STATCOMs at two different placements with the value 50 MVAR for each one and 60 MVAR,40 MVAR in another case. It has been found through this research that when distributing the necessary compensation capacity to more than one static synchronous compensator better than from combined them in one compensator in improving the CCT. It used MATLAB / ver.2017 for simulation of our studied system (IEEE-9 nodes).

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