scholarly journals Reliability and Dynamic Performance Simulation Based on Relay Protection Summary

2021 ◽  
Vol 2074 (1) ◽  
pp. 012020
Author(s):  
Fei Li ◽  
Luochen Zhuyuan

Abstract With the development of science and technology, national security and social life can not be separated from electricity every moment, and the safety of power grid is becoming more and more important. At present, the research on relay protection model in dynamic simulation of power system in China is still in the primary stage. Because the research is not deep enough, the control law of relay protection elements can not be well grasped. The failure can not be handled well. Therefore, in order to ensure the safe operation of the power system, we must first strengthen the grid structure of the power system, improve the elasticity coefficient, distribute the reserve capacity reasonably, strengthen the adjustment ability of the tie line between the major power grids, and improve the stable reserve of the power grid. In order to improve the authenticity and reliability of dynamic simulation, it is necessary to establish a set of relay protection models, which should be consistent with the actual relay protection. In this way, the stability problem in power system can be analyzed accurately to improve the reliability of power system. The relay protection model established in this paper reduces the complexity of modeling and can reflect the dynamic characteristics of power system after interference. It is of great significance to the analysis and research of power system.

Author(s):  
Yu Cai ◽  
Wei Li ◽  
Bao Zhang ◽  
Wenjian Wu ◽  
Deren Sheng ◽  
...  

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.


2013 ◽  
Vol 732-733 ◽  
pp. 882-887
Author(s):  
Yong Chun Su ◽  
Hao Wei Jia

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.


2014 ◽  
Vol 960-961 ◽  
pp. 1588-1591
Author(s):  
Xiang Dong Zhao ◽  
Xin Zhao ◽  
Ming Jun Lv ◽  
Jian Guo Liu ◽  
Feng Zhen Liu ◽  
...  

The Internet and the gradual implementation of the continuous power grid market in recent years make the power system more complex under different operating environment. Safe and stable operation of power grids have become increasingly important . With the rapidf development of the grid and constant innovation, safe and stable operation also has a new requirement , because the rapid development of the power system brings more This paper analyzes the causes of blackouts and reviews security of the power system stability problems related to measures on the security and stability of the power system operation .


2014 ◽  
Vol 950 ◽  
pp. 314-320 ◽  
Author(s):  
Jun Jia ◽  
Xin Xin Hu ◽  
Ping Ping Han ◽  
Yan Ping Hu

With the scale of wind farm continuously increasing, when grid fault, the influences of the wind turbines connected to the grid on the stability of the power grid can never be ignored. Therefore, there are higher standards of the wind turbines’ abilities of fault ride-through (FRT) and producing reactive power. This paper studies the direct-drive wind power system, and the main point is the fault ride-through (FRT) of the permanent magnetic synchronous generator (PMSG) with Chopper. By establishing the dynamic model of PMSG under the environment of DigSILENT, this paper simulates the fault ride-through (FRT) of the direct-drive wind power system connecting into power grid. During the research, we focus on the stability of voltage about the Chopper to the DC bus under faults. What’s more, in this paper, we analysis the data about how the Chopper help the DC bus to improve its stability. The simulation results show that: when there is a fault on the point of common coupling, the permanent magnetic synchronous generator has the capability of fault ride-through (FRT). Especially when there is a voltage dip on the grid side, the permanent magnetic synchronous generator could produce reactive power for power grid, effectively preventing the system voltage from declining seriously, so as to improve the system stability under faults.


2013 ◽  
Vol 446-447 ◽  
pp. 853-857
Author(s):  
Qian Jin Wu ◽  
Xue Zhi Wang

Commutation Failure is the common fault of HVDC, continuous commutation failure may lead to HVDC block and affect the stability of the power system. Especially in southern power grid, china, its special that the end of four HVDC system are all in Guangzhou. If the AC system occurs serious fault, all of the HVDC system may occur commutation Failure, HVDC block, even occurs large area blackout. So how to avoid continuous commutation failure and restore the stability of HVDC is important for AC and DC parallel power system. This paper based on the mechanism of commutation failure, analyze the reason of commutation failure and identification method, preventive measures. At last, this paper uses actual recorded wave to analyze the diversification of system after commutation failure.


2019 ◽  
pp. 29-33 ◽  
Author(s):  
Vladislav Khramenkov ◽  
Aleksei Dmitrichev ◽  
Vladimir Nekorkin

We report the results of study of two models of power grids with hub cluster topology based on the second-order Kuramoto system. The first model considered is the small grid consisting of a consumer and two generators. The second model is the Nizhny Novgorod power grid. The areas in the parameter spaces of the grids that corresponds to different modes, including working synchronous one, of their operation are obtained. The dynamic stability of synchronous mode in the Nizhny Novgorod power grid model to transient disturbances of the power at its elements is tested. We show that the stability of peripheral elements of the grid to disturbances depends significantly on the lengths of their connections to the rest of the grid


2016 ◽  
Vol 839 ◽  
pp. 49-53 ◽  
Author(s):  
K. Shafeeque Ahmed ◽  
Shanmugam Prabhakar Karthikeyan ◽  
Sarat Kumar Sahoo

Any power system network is subjected to disturbances at any time and place. It is considered as one of the most stochastic system ever seen by the human beings. To enhance the power system reliability, System Protection Scheme (SPS) is an effective tool for utilizing the power grid during rare contingencies. This method is often employed as secondary protection schemes. SPS is also termed as Special Protection Scheme. SPS is referred with different names by different users such as IEEE as System Integrity Protection Scheme (SIPS), Bonneville Power Administration (BPA) as Remedial Action Scheme (RAS) and WECC and others as SPS. In India, only in late 90s, the concept of SPS was introduced to solve the above problem. In Indian power grid different SPS has been designed and implemented successfully. This paper presents a complete knowledge, need , general structure, characteristics and a brief description of the major SPS employed in various Indian Power grids. Post - commissioning performance of these SPS has also been analyzed briefly. Finally, highlights of major issues involved with the employment of SPS in the Indian scenario.


2011 ◽  
Vol 421 ◽  
pp. 240-245
Author(s):  
Xiang Han

Performance simulation for driver-tricycle-road hasn’t been reported currently. According to rigid-flexible coupling dynamic theory, this article took the frame and the spring as the spatial flexible body, used the UA tire model, considered the engine and the road surface drove, established tricycle rigid-flexible coupling dynamic model based on driver-tricycle-road environment and simulated its system modality, acceleration and brake dynamic characteristic. The simulation result indicated this tricycle has the good dynamic performance and the conclusion has the important project practical value.


2014 ◽  
Vol 521 ◽  
pp. 167-172
Author(s):  
Yan Xu ◽  
Guo Lin Huang

With the development of power system, the main unit is gradually becoming larger and larger, thus length of time that large generators after experiencing disturbances in power grid needed to adjust and maintain the stability is more important than ever. Generator out-of-step prediction which is a part of security and automaticity equipment of power system, sends out the corresponding operation instructions in order to keep the whole system stay stability, according to the initial system state and fault severity. The paper analyzes and classifies several schemes and principles on generator out-of-step prediction. The actual advantages and disadvantages are pointed out. At last, the development of out-of-step prediction is also presented.


2016 ◽  
Vol 17 (5) ◽  
pp. 541-546 ◽  
Author(s):  
Helmy M. El-Zoghby ◽  
Ahmed F. Bendary

Abstract In this paper Static Synchronous Compensator (STATCOM) is used for improving the performance of the power grid with wind turbine that drives synchronous generator. The main feature of the STATCOM is that it has the ability to absorb or inject rapidly reactive power to grid. Therefore the voltage regulation of the power grid with STATCOM device is achieved. STATCOM also improves the stability of the power system after occurring severe disturbance such as faults, or suddenly step change in wind speed. The proposed STATCOM controller is a Proportional-Integral (PI) controller tuned by Genetic Algorithm (GA). An experimental model was built in Helwan University to the proposed system. The system is tested at different operating conditions. The experimental results prove the effectiveness of the proposed STATCOM controller in damping the power system oscillations and restoring the power system voltage and stability.


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