Resilience for coupled oscillatory power network via phase difference

Author(s):  
Li-Xin Yang ◽  
Jun Jiang ◽  
Xiao-Jun Liu

This paper investigates the resilience of oscillatory power networks with Kuramoto-type nodal dynamics via phase difference. Here, we propose a general framework to measure the resilience of power network in response to perturbations affecting nodes and transmission lines during operation. Moreover, the assessing resilience approaches provide an estimation of the phase difference and power difference. To identify the resilience of power network that makes stable operation possible, several small-size oscillatory networks are selected to validate the effectiveness and feasibility of the proposed schemes. Simulation results show that the resilience plays a crucial role in the synchronous performance.

2013 ◽  
Vol 325-326 ◽  
pp. 673-676
Author(s):  
Lian Yang ◽  
Bin Wang ◽  
Xiao Feng Li ◽  
Chuan Hu

500kV EHV transmission networks have become the main one of the national grid, carring out live working for 500kV EHV transmission lines is the objective requirements to ensure the stable operation of the grid system. This paper uses a new system to simulate and analyse the way of entering the high electric area on 500kV transmission line. The system has built the ZM1 transmission tower and line model, accurately accounted the complex gap and satety distance. The simulation results show that the system can effectively get the best secure route and determine the way to enter into the equipotential with the safety margin.


2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiun-Wei Horng

This paper describes a current-mode third-order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current-mode sinusoids with90°phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.


2013 ◽  
Vol 291-294 ◽  
pp. 2381-2386 ◽  
Author(s):  
Wen Xia Liu ◽  
Ji Kai Xu ◽  
Hong Yuan Jiang ◽  
Yong Tao Shen

It is the foundation for evaluating the reliability of transmission lines to obtain and analyze the original reliability parameters. However, these parameters depend on long- term statistic and calculation. In the case of lacking such parameters in a new project , this paper proposes a method of Principal Component Analysis to obtain the principal component of the impacting factors ,in which various factors affecting reliability parameters are taken into account. Through this method, we can use PCR to obtain the failure rate of the unknown transmission lines on the base of the known credible lines’ rates. The simulation results show that the proposed approach possesses higher forecasting accuracy and provides references for the power system dispatching departments and transmission lines maintenance departments.


Clean Energy ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 196-207
Author(s):  
Shoichi Sato ◽  
Yasuhiro Noro

Abstract The introduction of large-scale renewable energy requires a control system that can operate multiple distributed inverters in a stable way. This study proposes an inverter control method that uses information corresponding to the inertia of the synchronous generator to coordinate the operation of battery energy storage systems. Simulation results for a system with multiple inverters applying the control method are presented. Various faults such as line-to-line short circuits and three-phase line-to-ground faults were simulated. Two fault points with different characteristics were compared. The voltage, frequency and active power quickly returned to their steady-state values after the fault was eliminated. From the obtained simulation results, it was verified that our control method can be operated stably against various faults.


2013 ◽  
Vol 448-453 ◽  
pp. 2636-2641
Author(s):  
Hai Long Bao ◽  
Chen Fang ◽  
Jian Lin Yang ◽  
Qiang Yin

As the urbanization of cities is rapidly developing in China, metropolitan regions establish the clustered power network planning scheme on the background of the clustered city planning of the adjacent areas. Base on the functional orientation and difference of clusters, as well as the theory of hierarchical clustered city planning, the article puts forward the power network planning thoughts and methods. As cluster becomes a planning unit, the load density method is applied in the differential load forecast and the location of substations as well as the path of transmission lines is selected with the thoughts of separation according to different layers and areas. And then, the results will be compared and verified with the planning scheme of the other clustered cities which have the similar function orientation and planning strategy. Finally, the planning methods will be standardized. The application in the power network of Cluster of Livable Education City in Zhengzhou has proved that the methods and steps of the power planning method proposed is able to meet the demand of the network development under the situation of the rapid growth of load.


2014 ◽  
Vol 1044-1045 ◽  
pp. 482-485
Author(s):  
Jin Hu Zhang ◽  
Zhen Yu Xu ◽  
Zhi Peng Su

The distance relays of transmission lines find limitations in the presence of series compensated capacitor. One of them is the distance relay setting issue, in which either over-reach problem or under-reach problem may occur. To deal with this issue, a differential equation based adaptive distance relaying setting method for series compensated line is proposed. As for it do not need to identify whether SC/MOV is in fault loop, not need to know the parameters and the operating states of SC/MOV/GAP, and furthermore, it can be realized without the iterative calculation, it is very suitable to be used for the distance relaying adaptive setting of series compensated line. Simple simulation results certificate the proposed adaptive setting method.


Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1994
Author(s):  
Yanchen Liu ◽  
Minfang Peng ◽  
Xingle Gao ◽  
Haiyan Zhang

The prevention of cascading failures and large-scale power outages of power grids by identifying weak links has become one of the key topics in power systems research. In this paper, a vulnerability radius index is proposed to identify the initial fault, and a fault chain model of cascading failure is developed with probabilistic attributes to identify the set of fault chains that have a significant impact on the safe and stable operation of power grids. On this basis, a method for evaluating the vulnerability of transmission lines based on a multi-criteria decision analysis is proposed, which can quickly identify critical transmission lines in the process of cascading failure. Finally, the proposed model and method for identifying vulnerable lines during the cascading failure process is demonstrated on the IEEE-118 bus system.


2017 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Guohua Zhang ◽  
Zhen Li ◽  
Qiaoli Zhang

With the progress of time, the power network has been the basis of economic development. However, people have little knowledge of the controllability of the power network. This article will study eight power networks and compare the controllability of the power network in many aspects.


Author(s):  
Yadi XIE ◽  
Baina HE ◽  
Lemiao WANG ◽  
Renzhuo JIANG ◽  
Yuyang ZHOU ◽  
...  

Abstract With the continuous expansion of the scale of power system, corridor resources of overhead transmission lines tend to be saturated in China, making AC/DC erection on the same tower a trend in future development. The AC/DC coupling effect will cause DC line to generate secondary arc current at the point of failure when transmission line fails, which affects the DC restart. On account of the mechanism of generating secondary arc current by AC/DC lines erected on the same tower, this paper uses PSCAD to establish simulation model for AC/DC erected on the same tower. And the effects of different fault locations, lengths of coupling sections, and different transposition modes of AC lines on the secondary arc current and recovery voltage of AC and DC lines are studied. The results show that secondary arc current on DC line is greatly affected by fault location and length of coupling line, and using different transposition modes of AC lines can reduce secondary arc current on the DC lines effectively. According to Yunguang UHV DC restart time sequence, setting the restart time sequence can increase the first restart deionization time to ensure the stable operation of the system.


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