Risk Assessment Model of Cascading Failures in Power System Based on Danger Lines

2013 ◽  
Vol 373-375 ◽  
pp. 1349-1352
Author(s):  
Fu Chun Zhang ◽  
Jia Dong Huang

Based on the theory of risk, a new model is proposed for cascading failure in power system. According to fault factor of power line itself and the impact of real-time power flow, the branch outage probability model is established, and then the probability of cascading failure can be calculated. The severity function of cascading failure is defined by the analysis of fault consequences including the decrease of load margin, bus voltage offset and power line overload. The use of the set of danger lines which is judged by the amount of active power increase and load margin of power line can speed the search of fault mode. The simulation and analysis of IEEE 39-node proves the effectiveness of the method.

2013 ◽  
Vol 373-375 ◽  
pp. 1312-1317
Author(s):  
Fu Chun Zhang ◽  
Jia Dong Huang ◽  
Xin Sun ◽  
Qing Jie Zhou

In order to prevent large scope blackouts, the paper has established a model of power system cascading failures from the perspective of risk .Taking both the load of branch and the power flow changes into account, the model defines the probability of branch outage which can reflect the real-time operating condition. The consequences severity of cascading failure is measured by bus low voltage, power line overload level and the amount of isolated loads. In the process of searching fault link, the paper uses the structure transmission importance of branch to determine the next breaking branch, which can speed the search of the cascading failure mode. The simulation of the IEEE 39-node system shows the effectiveness of the method.


2014 ◽  
Vol 631-632 ◽  
pp. 718-722
Author(s):  
Peng Jia Shi ◽  
Neng Xu ◽  
Jian Ying Chen ◽  
Chuang Xin Guo

This paper investigates the effect of Unified Power Flow Controller (UPFC) on the risk of cascading failure which resulted from adverse weather based on the risk-based security assessment (RBSA) method. An improved piecewise probability model is described to reflect the impact of adverse weather condition and overloads. Based on power-injection model of UPFC, an optimal power flow control strategy is integrated into the RBSA procedure to relieve the risk of cascading failure caused by initiating event. Furthermore, a sensitivity based approach is adopted to determine the optimal location of UPFC. The effectiveness of the proposed method has been tested on IEEE RTS-79 system.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3843
Author(s):  
Sultan Sh. Alanzi ◽  
Rashad M. Kamel

This paper investigates the maximum photovoltaic (PV) penetration limits on both overhead lines and underground cables medium voltage radial distribution system. The maximum PV penetration limit is estimated considering both bus voltage limit (1.05 p.u.) and feeder current ampacity (1 p.u.). All factors affect the max PV penetration limit are investigated in detail. Substation voltage, load percentage, load power factor, and power system frequency (50 Hz or 60 Hz) are analyzed. The maximum PV penetration limit associated with overhead lines is usually higher than the value associated with the underground cables for high substation voltage (substation voltage = 1.05 and 1.04 p.u.). The maximum PV penetration limit decreases dramatically with low load percentage for both feeder types but still the overhead lines accept PV plant higher than the underground cables. Conversely, the maximum PV penetration increases with load power factor decreasing and the overhead lines capability for hosting PV plant remains higher than the capability of the underground cables. This paper proved that the capability of the 60-Hz power system for hosting the PV plant is higher than the capability of 50 Hz power system. MATLAB software has been employed to obtain all results in this paper. The Newton-Raphson iterative method was the used method to solve the power flow of the investigated systems.


2013 ◽  
Vol 385-386 ◽  
pp. 1078-1081 ◽  
Author(s):  
Fang Zhang ◽  
Jian Ping Chen ◽  
Chuan Dong Li ◽  
Yan Juan Wu

The main objective of power flow control for unified power flow controller (UPFC) is to increase the transmission capacity over the existing transmission corridor or line. This paper presents a practical engineering methodology of embedding the power flow control model of UPFC into the commercial software -- power system analysis software package (PSASP) based on its user program interface (UPI) function. In the proposed methodology, the interface currents of UPFC series side and UPFC shunt side between the UPFC device and the network are used to control the transmission line power flow and UPFC bus voltage, respectively. In UPFC series side, the current of UPFC series branch is calculated from the power target equation of the controlled line. In UPFC shunt side, the shunt reactive current of UPFC is used to control the bus voltage. Simulation results on a practical power system show that the proposed methodology can be efficiently applied to the engineering research and analysis of the real power grid with UPFC with good convergence and only one control parameter needed to be prescribed.


Author(s):  
Anuj Singh ◽  
Dr. Sandeep Sharma ◽  
Karan Sharma ◽  
Flansha Jain ◽  
Shreyanshu Kumar Jena

A Power System is actually a vast system that requires an outstanding plan for maintaining the continual flow of electricity. When a fault occurs at the power system, number of difficulties arises because of transients in system. so to attenuate these transients, power electronics based devices like FACTS are utilized. A unified power flow controller (UPFC) is one among different power electronics controller which can dispense VAR compensation, line impedance control and phase shifting. The thought is to see potential of UPFC to require care of active and reactive power movement within the compensated line (including UPFC) and to shrink the falloff of the bus voltage in case of grounding fault within the cable. power system block consisting of simulink is used for numerical analysis. Simulation outcomes from MATLAB reflects major improvement in the overall system’s behaviour with UPFC in sustain the voltage and power flow even under severe line faults by proper injection of series voltage into the cable at the point of connection. outcomes shows how the UPFC contributes effectively to a faster regaining of the power system to the pre-fault conditions.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2268 ◽  
Author(s):  
Dong-Hee Yoon ◽  
Sang-Kyun Kang ◽  
Minseong Kim ◽  
Youngsun Han

We present a novel architecture of parallel contingency analysis that accelerates massive power flow computation using cloud computing. It leverages cloud computing to investigate huge power systems of various and potential contingencies. Contingency analysis is undertaken to assess the impact of failure of power system components; thus, extensive contingency analysis is required to ensure that power systems operate safely and reliably. Since many calculations are required to analyze possible contingencies under various conditions, the computation time of contingency analysis increases tremendously if either the power system is large or cascading outage analysis is needed. We also introduce a task management optimization to minimize load imbalances between computing resources while reducing communication and synchronization overheads. Our experiment shows that the proposed architecture exhibits a performance improvement of up to 35.32× on 256 cores in the contingency analysis of a real power system, i.e., KEPCO2015 (the Korean power system), by using a cloud computing system. According to our analysis of the task execution behaviors, we confirmed that the performance can be enhanced further by employing additional computing resources.


2019 ◽  
Vol 11 (6) ◽  
pp. 1744 ◽  
Author(s):  
Qais Alsafasfeh ◽  
Omar Saraereh ◽  
Imran Khan ◽  
Sunghwan Kim

As the unconstrained integration of distributed photovoltaic (PV) power into a power grid will cause changes in the power flow of the distribution network, voltage deviation, voltage fluctuation, and so on, system operators focus on how to determine and improve the integration capacity of PV power rationally. By giving full consideration to the static security index constraints and voltage fluctuation, this paper proposes a maximum integration capacity optimization model of the PV power, according to different power factors for the PV power. Moreover, the proposed research analyzes the large-scale PV grid access capacity, PV access point, and multi-PV power plant output, by probability density distribution, sensitivity analysis, standard deviation analysis, and over-limit probability analysis. Furthermore, this paper establishes accessible capacity maximization problems from the Institute of Electrical and Electronics Engineers (IEEE) standard node system and power system analysis theory for PV power sources with constraints of voltage fluctuations. A MATLAB R2017B simulator is used for the performance analysis and evaluation of the proposed work. Through the simulation of the IEEE 33-node system, the integration capacity range of the PV power is analyzed, and the maximum integration capacity of the PV power at each node is calculated, providing a rational decision-making scheme for the planning of integrating the distributed PV power into a small-scale power grid. The results indicate that the fluctuations and limit violation probabilities of the power system voltage and load flow increase with the addition of the PV capacity. Moreover, the power loss and PV penetration level are influenced by grid-connected spots, and the impact of PV on the load flow is directional.


2020 ◽  
Vol 40 (3) ◽  
pp. 21-31
Author(s):  
Mohamed Nassim Kraimia ◽  
Mohamed Boudour

In this paper a study of the impact of the harmonics generated by a static Var compensator (SVC) is presented. The SVC is modeled, in the harmonic domain, as a coupled current source by using the complex Fourier transforms. Then, this model is converted to polar form to be integrated into the harmonic power flow program. This approach has been carried out on the IEEE 14 bus test power system, in order to show its effectiveness in evaluating the impact of harmonics, injected by the shunt compensating devices, and its interaction with the AC transmission system, in meshed power networks. Since the SVC consists of a thyristorcontrolled reactor (TCR) and a fixed capacitor, the harmonic currents are functions of the TCR thyristors firing angles. The variation of the total voltage harmonic distortion as function of firing angle changes and location of nonlinear loads is clearly presented and discussed.


Sign in / Sign up

Export Citation Format

Share Document