Research on Stability of Power System with Distributed Generation Synthesis Load Model

2013 ◽  
Vol 341-342 ◽  
pp. 1374-1379
Author(s):  
Yang Liu ◽  
Zhen An Zhang ◽  
Wei Liu ◽  
Ya Nan Wang
Keyword(s):  
Power System ◽  
Distributed Generation ◽  
Transient Stability ◽  
Power Grid ◽  
Stable Operation ◽  
Power Network ◽  
Small Hydropower ◽  
Large Power ◽  
Load Model ◽  
The Stability

With different element models and parameters in power system, the transient stability analysis results are also different, especially the model of generator and load. Based on the actual parameters of Hunan power grid, this paper builds the synthesis load model of the distribution network with small hydropower considered, and then the Hunan simulation network can also be got. Using PSASP, analyses the transient stability of Hunan power system with distributed small hydropower under different operation modes systematically and comprehensively. Through an overall check of the stability level in each Hunan area, and then compared with the analysis results of Hunan power grid based on the currently used load model , the influences of the distributed small hydropower on the safe and stable operation of the large power network are summarized.

Reliable Analysis on Fast Valving of Ultra-Supercritical Unit Under Transient Fault Conditions

2017 ◽  
Author(s):  
Yu Cai ◽  
Wei Li ◽  
Bao Zhang ◽  
Wenjian Wu ◽  
Deren Sheng ◽  
...  
Keyword(s):  
Power System ◽  
Steam Turbine ◽  
Dynamic Model ◽  
Transient Stability ◽  
Power Grid ◽  
Load Shedding ◽  
Control Mode ◽  
Normal Operation ◽  
Transient Fault ◽  
The Stability

Fast valving of ultra-supercritical unit has great effects on over-speed prevention, load-shedding control, transient stability analysis of electrical system and other security problems. The purpose of fast valving is to maintain the stability of power system once fault or load shedding of unit occurs in the electric power system. Therefore, it is of great significance to study the reliability of fast valving for ultra-supercritical unit. In this paper, the KU ( short shedding) logic condition of SIEMENS T3000 system is analyzed as the research object of fast valving. The unit can be avoided over speed by monitoring the unit load and fast valving under faulty grid conditions based on the KU control. A series of measures will be taken after KU is triggered, for instance the governing valving will be closed quickly and the DEH (digital electro-hydraulic) control of the steam turbine will be switched to speeding control mode. On the other hand, the unit will return to normal operation if the transient fault of power grid disappears. The key contributions of this thesis include three parts: Firstly, based on the analysis of control characteristics of ultra-supercritical unit and protective logic and triggered conditions of KU function, a novel dynamic model by coupling the fast valving of steam turbine and the transient stability of generator is established by applying the PSCAD software. Then, the dynamic response process of ultra-supercritical unit is simulated and calculated by adopting the coupling dynamic model when KU function is triggered. Also the influence factors and reliability of fast valving are analyzed under transient fault conditions. Finally, two optimized measures by increasing the time delay and the speed of quantitative judgment are put forward to reduce risks and avoid the misoperation of signal distortion which may be caused by the power transmitter under transient fault conditions. The results of this study can not only help to evaluate the reliability of fast valving function scientifically in power grid transient fault, but also guide the technicians to analyze the stability of the power grid.

Mid-Term Stability Assessment of Jiangxi Power Grid

2013 ◽  
Vol 732-733 ◽  
pp. 882-887
Author(s):  
Yong Chun Su ◽  
Hao Wei Jia
Keyword(s):  
Power System ◽  
Power Grid ◽  
Assessment Method ◽  
Control Measures ◽  
Assessment Process ◽  
Jiangxi Province ◽  
Stable Operation ◽  
Stability Assessment ◽  
Term Stability ◽  
The Stability

Mid-term stability assessment is an important work to support power system operation in a province power grid of China every year. The stability assessment method and process was introduced in this paper. As an example, the stability of Jiangxi province power system was evaluated in the following two years. Weak area and weak transmission line were found out in each power supply area. Prevention and control measures were proposed. According to problems among the assessment process and using the state monitoring data, an approach was discussed to increase the assessment result accuracy. The analysis conclusion provides the reference to the safe and stable operation of Jiangxi power system.

Transient Stability Enhancement of a Wind Energy Distributed Generation System by Using Fuzzy Logic Stabilizers

2012 ◽  
Vol 36 (6) ◽  
pp. 687-700 ◽  
Author(s):  
M. A. Ebrahim ◽  
K. A. El-Metwally ◽  
F. M. Bendary ◽  
W. M. Mansour
Keyword(s):  
Power System ◽  
Wind Energy ◽  
Wind Turbine ◽  
Distributed Generation ◽  
Transient Stability ◽  
Synchronous Generator ◽  
Large Power ◽  
System Stabilizer ◽  
Stability Enhancement ◽  
Operating Points

This paper proposes a new power system stabilizer based on fuzzy systems. The new controller is applied to a wind turbine generating system comprising of a wind turbine driving a 3 - phase synchronous generator connected to a large power system. The new controller significantly improves system performance. The enhancement in the dynamic response of the system is verified through simulation results of a system under different operating points and exposed to both small and large disturbances. Extension to the wind energy distributed generation based multi-machine case is also included to illustrate the effectiveness of the proposed stabilizer in damping power system swing mode oscillations that follow disturbances.

scholarly journals Transient Stability Improvement of the Power Systems

2018 ◽  
Vol 12 (3) ◽  
pp. 916
Author(s):  
Zaid H. Al-Tameemi ◽  
Hayder H. Enawi ◽  
Karrar M. Al-Anbary ◽  
Hussam M. Almukhtar
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Lines ◽  
Transient Stability ◽  
Electrical Power ◽  
Limiting Factor ◽  
Stable Operation ◽  
Electric Power Networks ◽  
Matlab Package ◽  
The Stability

<p>During the last few decades, electrical power demand enlarged significantly whereas power production and transmission expansions has been brutally restricted as a result of restricted resources as well as ecological constrains. Consequently, many transmission lines have been profoundly loading so the stability of power system became as Limiting factor for transferring electrical power. So, maintaining a secure and stable operation of the electric power networks is deemed an imporatant and challenge issue.transient stability of a power system has been gained a considerable attention from researchers dute to it importance . Therefore,this paper sheds light on A substantial number of the adopted techniques, including an inclease in  inertia constant of generator, shunt capacitor, reduction reactance of the transmission line to acheive this purpose. A 7-Machine CIGRE system has been considered a case study. Matlab package has been employed to implement this study. The simulation results show that the transient stability of the repective system enhanced considerably with these techniques.</p>

Research on Load Models Effect on Stability of Voltage of DC End Power System

2013 ◽  
Vol 347-350 ◽  
pp. 1404-1410 ◽  
Author(s):  
Xiao Ming Liu ◽  
Xin Sheng Niu ◽  
Jie Zhang ◽  
Yi Zhu
Keyword(s):  
Power System ◽  
Induction Motor ◽  
Power Grid ◽  
Load Ratio ◽  
Transient State ◽  
Ratio Distribution ◽  
Load Model ◽  
Load Models ◽  
The Stability ◽  
Simulated Analysis

Load characteristic is one of the vital factors that effect the stability of voltage of power system. As the most important dynamic load in power system, induction motor is one of the most direct reasons which resulting in instability of voltage. In simulated analysis, the establishment of load model, choice of parameter as well as ratio distribution of different kinds of load will lay considerable influence on the stability of system. This thesis establishes the load model of induction motor in stable and transient state and simulates on the basis of Shandong power grid. As the simulating result shows, load ratio of induction motor has fundamental effect on the voltage stability of Shandong power grid. As the load ratio of induction motor increases, the stability of voltage of Shandong power grid decrease and the voltage may even break down.

scholarly journals ANN Controller for Damping of Oscillations using Interline Power Flow Controller of AC Transmission System

2019 ◽  
Vol 8 (6) ◽  
pp. 54-58
Keyword(s):  
Power System ◽  
Power Flow ◽  
Reactive Power ◽  
Stable Operation ◽  
Power Network ◽  
Rotor Speed ◽  
Flow Controller ◽  
The Stability ◽  
Power Flow Controller ◽  
Load Angle

Interline Power Flow Controller is series compensating device for series compensation of Active and reactive power with distinctive ability of power flow management between many transmission lines in power network. During disturbances in power system, the stability of system causes deviation from stable operation and causes variation in different parameters of power system like load angle and Rotor speed. To suppress oscillations in load angle and rotor speed, the Artificial Neural Network (ANN) controller with IPFC is proposed to increase the stability of power network. IPFC with ANN is considered for analysis of IEEE 14 Bus system. For different fault conditions analysis is carried out using MATLAB/Simulink.

scholarly journals Analysis of Various ESDD of Contaminant Insulator Flashover Acoustic Signal by Wavelet Packet

2016 ◽  
Vol 16 (6) ◽  
pp. 220-231
Author(s):  
Hong Kun Wang ◽  
Shou Xiang Wang ◽  
Jing Nie
Keyword(s):  
High Voltage ◽  
Acoustic Signal ◽  
Wavelet Packet ◽  
Power Grid ◽  
Acoustic Signals ◽  
Salt Deposit ◽  
Power Network ◽  
Large Power ◽  
Insulator Flashover

Abstract With the formation of China’s large power grid, the security of the network is particularly important. The contaminant flashover of insulators has a serious impact on the operation safety of a high voltage power network. In this paper, the acoustic signals’ characteristics of the contaminant insulators flashover are analyzed, and, as a result, the correlation between the acoustic signal and the contaminant insulator flashover is established. To experiment with contaminant insulator for three different Equivalent Salt Deposit Densities (ESDD), acoustic signals were collected separately. Then, the contaminant insulators’ acoustic signals of flashover were analyzed by wavelet packet. The characteristics of the signals were obtained, and they can be judged for contaminant flashover warning.

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