scholarly journals Review on Contingency and its Effects in Transmission Lines

2021 ◽  
pp. 56-60
Author(s):  
Jayprakash Giri ◽  
Sh. Rajiv Chauhan ◽  
Smt. Nidhi Mishra
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Transmission System ◽  
Correction Factors ◽  
Contingency Analysis ◽  
Transmission Systems ◽  
Component Failure ◽  
Contingent Liabilities ◽  
Different Types

A component failure in a power system is known as a contingency. The system must return to an acceptable state of equilibrium after the contingency. Post-contingency correction factors are important for maintaining reliability. Correction factors require analysis of contingent liabilities. Various methods are used to perform contingency analysis. Control of the transmission system has been described in this document. The pricing conditions and associated parameters for the different types of transmission lines have been described. The article focuses on all the parameters necessary for the analysis of transmission systems and their limits.

scholarly journals STUDY ON EFFECT OF UPFC DEVICE IN ELECTRICAL TRANSMISSION SYSTEM: POWER FLOW ASSESSMENT

2013 ◽  
pp. 70-74
Author(s):  
CH. CHENGAIAH ◽  
R.V.S. SATYANARAYANA ◽  
G.V. MARUTHESWAR MARUTHESWAR
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Power Transmission ◽  
Stability Limit ◽  
Transmission System ◽  
Real Time Control ◽  
Electrical Transmission ◽  
Transmission Systems ◽  
Time Control

The power transfer capability of electric transmission lines are usually limited by large signals ability. Economic factors such as the high cost of long lines and revenue from the delivery of additional power gives strong intensive to explore all economically and technically feasible means of raising the stability limit. On the other hand, the development of effective ways to use transmission systems at their maximum thermal capability. Fast progression in the field of power electronics has already started to influence the power industry. This is one direct out come of the concept of FACTS aspects, which has become feasible due to the improvement realized in power electronic devices in principle the FACTS devices should provide fast control of active and reactive power through a transmission line. The UPFC is a member of the FACTS family with very attractive features. This device can independently control many parameters. This device offers an alternative mean to mitigate transmission system oscillations. It is an important question is the selection of the input signals and the adopted control strategy for this device in order to damp power oscillations in an effective and robust manner. The UPFC parameters can be controlled in order to achieve the maximal desire effect in solving first swing stability problem. This problem appears for bulky power transmission systems with long transmission lines. In this paper a MATLAB Simulink Model is considered with UPFC device to evaluate the performance of Electrical Transmission System of 22 kV and 33kV lines. In the simulation study, the UPFC facilitates the real time control and dynamic compensation of AC transmission system. The dynamic simulation is carried out in conjunction with the N-R power flow solution sequence. The updated voltages at each N-R iterative step are interpreted as dynamic variables. The relevant variables are input to the UPFC controllers.

scholarly journals Security Constrained Stochastic Power System Scheduling Algorithms - With Wind Electric Generators

2021 ◽  
Author(s):  
Yu Peng
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Output ◽  
Unit Commitment ◽  
System Security ◽  
Transmission System ◽  
Short Term ◽  
Transmission Systems ◽  
Probabilistic Distribution ◽  
Ac Transmission

Power systems worldwide are embracing diverse supply mixes that incorporate a significant portion from renewables such as wind and solar energy. Wind energy is characterised by reliable equipment, but with an output that is uncertain and intermittent. In addition to equipment unreliability (system N-1 criterion), output uncertainties of wind electric generators (WEGs) introduce risk into daily power system schedules. This risk from the uncertainty of output from WEGs can be quantified as expected energy not served (EENS). Furthermore, the introduction of new forms of generation changes the methods of operating transmission systems, further necessitating the use of transmission security constraints in power systems optimization algorithms. This dissertation explores new approaches to stochastically model the real power output of WEGs and to efficiently tackle AC transmission system security constraints for power system optimization algorithms such as optimal power flow (OPF) and day-ahead unit commitment (UC). Usually, normal probabilistic distribution is used to model uncertainty in short-term wind power output forecast and compute EENS. In this dissertation, a new triangular approximate distribution (TAD) model is proposed which is a linear approximation of normal probabilistic distribution to model short-term wind power output forecast and compute EENS. This TAD model is used to formulate a practical risk-constrained fast OPF for transmission systems to simultaneously minimize: 1) risk due to uncertainties in power output from WEGs, and 2) the total operating cost. The integration of new energy resources causes transmission systems to operate in new, challenging, and often unforeseen operating states. Thus, it is imperative that UC algorithms incorporate AC transmission system security constraints and stochastically model output of WEGs to ensure reliable operation of transmission systems. As a first step, a successive mixed integer linear programming (MILP) method is proposed for AC transmission system security constrained unit commitment (SCUC) challenge. Fuzzy sets theory is used to model infeasible constraints in this MILP formulation. As a next step, the TAD model of WEGs is integrated into the MILP formulation of SCUC to create a fast security and risk constrained probabilistic UC algorithm. The two UC algorithms are tested on large systems.

scholarly journals Subsynchronous Resonance and FACTS-Novel Control Strategy for Its Mitigation

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Doan Duc Tung ◽  
Le Van Dai ◽  
Le Cao Quyen
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Control Strategy ◽  
Power Plants ◽  
Thermal Power ◽  
Transmission System ◽  
Static Synchronous Compensator ◽  
Turbine Generator ◽  
Subsynchronous Resonance ◽  
Ac Transmission

The subsynchronous resonance (SSR) is an important problem in the power system, and especially the series compensated transmission lines may cause SSR in the turbine generators, such that it leads to the electrical instability at subsynchronous frequencies and potential turbine-generator shaft failures. Taking the Vietnamese Vungang thermal plants as an example, a shaft failure of Vungang I thermal power unit has occurred on November 24, 2015, due to SSR. The main cause for this failure is a resonance caused by the series capacitors on the 500 kV grid. This paper analyzes the SSR based on the location of shaft cracks and turbine generator mode shape for Vungang I and II thermal power plants. On the basis of that, it develops a novel control strategy for each Flexible AC Transmission system (FACTS) device as the thyristor controlled series compensator (TCSC), static VAR compensator (SVC), and static synchronous compensator (STATCOM). Then they are comparable to one another in order to choose a feasible solution for mitigating the SSR. The effectiveness of the proposed control strategy is verified via time domain simulation of the Vietnamese 500/220 kV transmission system using EMTP-RV and PSS/E programs. The obtained results show that the proposed strategy for SVC can be applied to immediately solve the difficulties encountering in the Vietnamese power system.

Intelligent Approach for Fault Diagnosis in Power Transmission Systems Using Support Vector Machines

2007 ◽  
Vol 8 (4) ◽  
Author(s):  
Ravikumar B. ◽  
Thukaram Dhadbanjan ◽  
H. P. Khincha
Keyword(s):  
Fault Diagnosis ◽  
Support Vector Machines ◽  
Power Systems ◽  
Power System ◽  
Transmission System ◽  
Fault Analysis ◽  
Support Vector ◽  
Transmission Systems ◽  
Vector Machines ◽  
The Impact

This paper presents an approach for identifying the faulted line section and fault location on transmission systems using support vector machines (SVMs) for diagnosis/post-fault analysis purpose. Power system disturbances are often caused by faults on transmission lines. When fault occurs on a transmission system, the protective relay detects the fault and initiates the tripping operation, which isolates the affected part from the rest of the power system. Based on the fault section identified, rapid and corrective restoration procedures can thus be taken to minimize the power interruption and limit the impact of outage on the system. The approach is particularly important for post-fault diagnosis of any mal-operation of relays following a disturbance in the neighboring line connected to the same substation. This may help in improving the fault monitoring/diagnosis process, thus assuring secure operation of the power systems. In this paper we compare SVMs with radial basis function neural networks (RBFNN) in data sets corresponding to different faults on a transmission system. Classification and regression accuracy is reported for both strategies. Studies on a practical 24-Bus equivalent EHV transmission system of the Indian Southern region is presented for indicating the improved generalization with the large margin classifiers in enhancing the efficacy of the chosen model.

Composite Severity Indices Based Contingency Management of Power System: A Comparative Study

2016 ◽  
Vol 26 ◽  
pp. 132-141 ◽  
Author(s):  
Akanksha Mishra ◽  
Gundavarapu Venkata Nagesh Kumar
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Contingency Management ◽  
Probabilistic Approach ◽  
Proper Solution ◽  
Contingency Analysis ◽  
System A ◽  
Composite Indices ◽  
Line Overload ◽  
Ranking Technique

Severity assessment of transmission lines is a very important aspect of contingency analysis of a power system. Thereafter, a proper solution needs to be provided to ensure a secured power supply. In this paper, rapid contingency ranking technique (RCRT) has been introduced for the contingency assessment of a power system. Several composite indices have been designed by forming different combinations of line overload indices and voltage stability indices and the results have been compared. Deterministic and probabilistic approach have been used for the placement of IPFC and the results have been compared. While, the probability approach protects the system against most of the contingencies, the deterministic approach protects the system against the severe-most contingency. Thereafter, the IPFC is tuned using the differential evolution method. A multi-objective function has been formulated for tuning the device. The use of IPFC to overcome the post-contingency problems has been reinforced by implementing the proposed strategy on an IEEE 57 bus system.

scholarly journals Shunt Compensaton of the Integrated Nigeria’s 330KV Transimission Grid System

2020 ◽  
Vol 5 (9) ◽  
pp. 537-540
Author(s):  
Engr. Obi, Fortunatus Uche ◽  
Aghara, Jachimma ◽  
Prof. Atuchukwu John
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Power Flow ◽  
Research Work ◽  
Load Flow ◽  
Sudden Increase ◽  
Grid System ◽  
Voltage Profile ◽  
Contingency Analysis ◽  
Shunt Compensation

The Nigerian Power system is complex and dynamic, as a result of this it is characterized by frequent faults and outages resulting to none steady supply of power to the teaming consumers. This has great effect on the activities and mode of living of Nigerians. The research work was carried out on contingency analysis on the existing integrated 330KV Nigeria grid system and to carry out a shunt compensation on the violated buses, the shutdown of Eket-Ibom line being the case study so as to determine the following; uncertainties and effects of changes in the power system, to recognize limitations that can affect the power reliability and minimize the sudden increase or decrease in the voltage profile of the buses through shunt compensation of buses. Determine tolerable voltages and thermal violation of +5% and -5% of base voltage 330 KV (0.95-1.05) PU and to determine the critical nature and importance of some buses. This is aimed at bridging the gap of proposing further expansion of the grid system which is not only limited by huge sum of finance and difficulties in finding right – of- way for new lines but also which faces the challenges of fixed land and longtime of construction. The data of the network was gotten and modeled. The power flow and contingency analysis of the integrated Nigeria power system of 51 buses (consisting of 16 generators and 35 loads) and 73 transmission lines were carried out using Newton-Raphson Load Flow (NRLF) method in Matlab environment, simulated with PSAT software. Shunt compensation of the weak buses were done using Static Var Compensator (SVC) with Thyristor Controlled Reactor- Fixed capacitor (TCR-FC) technique. Results obtained showed that the average voltage for base simulation was 326.25KV, contingency 323.67KV and compensation was 322.37 KV. Voltage violations for lower limit were observed at Itu as 309KV and Eket as 306.81 KV while violations for upper limit were recorded at Damaturu as 352.85KV, Yola as 353.62 KV, Gombe as 355.98KV, and Jos as 342.97 KV. However after shunt compensation there were improvements for the violations at lower limits and that of higher limit were drastically brought down as recorded below: Damaturu 329.93 KV, Jos 330 KV, Eket 327.2 KV, Gombe 333.55KV, Itu 330KV, and Yola 330.52KV

scholarly journals Congestion Management and Transmission Line Loss Reduction using TCSC and Market Split Based

2019 ◽  
Vol 8 (9S) ◽  
pp. 339-346
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Congestion Management ◽  
Transmission System ◽  
System Stability ◽  
Deregulated Power System ◽  
Congestion Effect ◽  
Flexible Alternating Current Transmission

Due to increasing power demand in a deregulated power system, the stability of the power system may get affected and sometimes it may also cause congestion in the transmission lines of power networks. It is a major issue for a deregulated power system and its management provides a competition environment to different market players. In this paper, market split based approach is used to tackle the problem of congestion which split the system into zones. Locational Marginal Pricing (LMP) method is used to access the prices at different buses. The objective is to minimize the congestion effect. DC optimal power flow based system is used to solve such type of problem. TCSC (Thyristor-Controlled Series Compensation), FACTS (Flexible Alternating Current Transmission System) device is used to reduce the losses in a transmission system. Market splitting based approach is effective to manage the prices at different buses and system stability is increased by using TCSC. The whole work is carried out on IEEE 14 bus system.

scholarly journals Considering FACTS in Optimal Transmission Expansion Planning

2017 ◽  
Vol 7 (5) ◽  
pp. 1987-1995 ◽  
Author(s):  
K. Soleimani ◽  
J. Mazloum
Keyword(s):  
Power Systems ◽  
Transmission Lines ◽  
Power Transmission ◽  
Transmission System ◽  
Optimal Number ◽  
Transmission Systems ◽  
Expansion Planning ◽  
Facts Devices ◽  
Transmission Expansion ◽  
Expansion Plan

The expansion of power transmission systems is an important part of the expansion of power systems that requires enormous investment costs. Since the construction of new transmission lines is very expensive, it is necessary to choose the most efficient expansion plan that ensures system security with a minimal number of new lines. In this paper, the role of Flexible AC Transmission System (FACTS) devices in the effective operation and expansion planning of transmission systems is examined. Effort was taken to implement a method based on sensitivity analysis to select the optimal number and location of FACTS devices, lines and other elements of the transmission system. Using this method, the transmission expansion plan for a 9 and a 39 bus power system was performed with and without the presence of FACTS with the use of DPL environment in Digsilent software 15.1. Results show that the use of these devices reduces the need for new transmission lines and minimizes the investment cost.

scholarly journals Contingency Analysis and Ranking of Kurdistan Region Power System Using Voltage Performance Index

2021 ◽  
Vol 5 (1) ◽  
pp. 73-79
Author(s):  
Ali Abdulqadir Rasool ◽  
Najimaldin M. Abbas ◽  
Kamal Sheikhyounis
Keyword(s):  
Power System ◽  
Transmission Lines ◽  
Performance Index ◽  
Large Scale ◽  
Flow Analysis ◽  
Severe Case ◽  
Load Flow ◽  
Kurdistan Region ◽  
Contingency Analysis ◽  
Voltage Performance

In this paper, analysis and ranking of single contingency due to the outage of transmission lines for a large scale power system of the Kurdistan Region (KR) are presented. Power System Simulator software (PSS®E33) is used to simulate the Kurdistan Region power system network and perform the contingency analysis for single line outage. This analysis is essential in order to predict and evaluate the voltage stability in case of contingency occurrence to know the most severe case and plan for managing it. All possible transmission line outages of the network are tested individually. After each branch disconnects, load flow analysis are applied by using Newton Raphson method then all bus voltages are recorded, and compared with them before the contingency. Voltage performance index is calculated for all possible contingencies to rank them according to their severity and determine the most severe contingency which is corresponding to the highest value of performance index. Also, the contingencies which cause load loss and amount of this load are observed.

scholarly journals Contingency Analysis of Fault and Minimization of Power System Outage using Fuzzy Controller

2019 ◽  
Vol 9 (1) ◽  
pp. 4111-4115
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Line ◽  
Power Flow ◽  
Power Transmission ◽  
Fuzzy Controller ◽  
Transmission System ◽  
Load Flow ◽  
Contingency Analysis ◽  
Additional Advantage

In power systems, voltage stability perform the major role in design and its operation. Major system failures are occur due to voltage variability and breakdown. To meet and compensate the rising power demand of regular usage in modern trends, transmission networks are enormously loaded which create the voltage instability. Contingency analysis is a recognized energy managing tool. It calculate the violation in the transmission line. In this paper a computational controller fuzzy system is suggested to handle the transmission line outage and overload in other branch kind of problems in Power system. The efficiency of power transmission system with fuzzy controller is inveterate by computation of various parameters of transmission bus under different loading situations. For the contingency analysis the transmission power flow several methods have been developed. Fast Decoupled load flow program is the effective method which provides a fast and effective solution to the contingency analysis in the transmission system and also it is incorporate with matrix alteration formula which gives additional advantage for the system.

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