scholarly journals Voltage Stability Indices: Formulation and Classification Perspectives

2019 ◽  
Vol 8 (12) ◽  
pp. 5777-5785
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Stability Margin ◽  
Stability Evaluation ◽  
Chronological Order ◽  
Real Time Control ◽  
Voltage Instability ◽  
Time Control ◽  
Voltage Stability Margin ◽  
Stability Indices

Voltage instability had been observed as the foremost cause of blackout incidents worldwide in last three decades. In order to deploy an appropriate countermeasure and enhance voltage stability margin, voltage stability predictor is of utmost importance. Therefore, much research had been focussed to propose voltage stability indices (VSIs) that can identify weak areas and overall condition of power systems. In this paper systematic review covering imperative aspects of formulation theory, expressions, critical values and applicability of VSIs has been presented in chronological order. A broad categorization of VSIs is also addressed. An inclusive review provides a strong foundation for further research in the perspective of voltage stability evaluation for real-time control applications.

scholarly journals Decentralized Load Shedding Method Based on Voltage Stability Margin Index Using Synchrophasor Measurement Technology

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 277 ◽  
Author(s):  
Yunhwan Lee ◽  
Hwachang Song
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Stability Margin ◽  
Load Shedding ◽  
Measurement Technology ◽  
Dynamic Simulations ◽  
Stability Margins ◽  
Voltage Instability ◽  
Voltage Stability Margin ◽  
Simulation Results

This study develops an analytical method for assessing the voltage stability margins of a decentralized load shedding scheme; it then examines the challenges related to the existing load shedding scheme. It also presents a practical application for implementing the proposed method, based on the synchrophasor measurement technology in modern power grid operations. By applying the concept of a continuously-computed voltage stability margin index to the configuration of the Thévenin equivalent system, the maximum transfer power could be used as an index to monitor the voltage instability phenomenon and thus determine the required load shedding amount. Thus, the calculated voltage stability margin might be a useful index for system operators in the critical decision-making process of load shedding. Dynamic simulations are performed on real Korean power systems as case studies. Simulation results, when comparing the existing and proposed methods, showed that there was a considerable reduction in the amount of load shedding in the voltage instability scenario. This indicates that the synchrophasor measurement technology has a considerable effect on the proposed load shedding method. The simulation results have validated the performance of the proposed method.

scholarly journals Implementation of Static Line Voltage Stability Indices for Improved Static Voltage Stability Margin

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Natakorn Thasnas ◽  
Apirat Siritaratiwat
Keyword(s):  
Optimal Power Flow ◽  
Voltage Stability ◽  
Stability Margin ◽  
Stability Index ◽  
System Stability ◽  
Line Voltage ◽  
Voltage Stability Index ◽  
Static Voltage Stability ◽  
Voltage Stability Margin ◽  
Stability Indices

Nowadays, the changes of economic, environment, and regulations are forcing the electric utilities to operate systems at maximum capacity. Therefore, the operation and control of power system to improve the system stability has been receiving a great deal of attention. This paper presents an approach for enhancing the static voltage stability margin and reducing the power losses of the system with voltage security-constrained optimal power flow (VSC-OPF) that is based on static line voltage stability indices. The control approaches incorporate the voltage stability criteria into the conventional OPF. The minimization of the summation of fast voltage stability index (FVSI), line stability index (Lmn), and line voltage stability index (LVSI) is used as the objective functions. The performance and effectiveness of the proposed control approaches are evaluated on the standard IEEE 30-bus, 57-bus, and 118-bus test systems under normal and contingency conditions. The comparison analysis is carried out with different cases including minimization of generation cost. The proposed control approaches indicate the promising results and offer efficient countermeasures against the voltage instability of the system.

scholarly journals Power system voltage instability risk mitigation via emergency demand response-based whale optimization algorithm

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Mohammed Amroune ◽  
Tarek Bouktir ◽  
Ismail Musirin
Keyword(s):  
Power Systems ◽  
Power System ◽  
Demand Response ◽  
Optimization Algorithm ◽  
Voltage Stability ◽  
Risk Mitigation ◽  
Stability Margin ◽  
Whale Optimization Algorithm ◽  
Voltage Instability ◽  
Whale Optimization

AbstractIn recent years, due to the economic and environmental issues, modern power systems often operate proximately to the technical restraints enlarging the probable level of instability risks. Hence, efficient methods for voltage instability prevention are of great importance to power system companies to avoid the risk of large blackouts. In this paper, an event-driven emergency demand response (EEDR) strategy based on whale optimization algorithm (WOA) is proposed to effectively improve system voltage stability. The main objective of the proposed EEDR approach is to maintain voltage stability margin (VSM) in an acceptable range during emergency situations by driving the operating condition of the power system away from the insecure points. The optimal locations and amounts of load reductions have been determined using WOA algorithm. To test the feasibility and the efficiency of the proposed method, simulation studies are carried out on the IEEE 14-bus and real Algerian 114-bus power systems.

Research on Dynamic Stability Improvement by Using STATCOM in Power System

2014 ◽  
Vol 960-961 ◽  
pp. 1124-1127
Author(s):  
Si Yu Li ◽  
Jia Dong Huang ◽  
Cui Ma
Keyword(s):  
Power Systems ◽  
Power Quality ◽  
Voltage Stability ◽  
Reactive Power ◽  
Stability Margin ◽  
Test System ◽  
Nonlinear Loads ◽  
Static Voltage Stability ◽  
Voltage Stability Margin ◽  
Unbalanced Loads

Nowadays, unbalanced loads or nonlinear loads produce a bad effect on the power quality of utility mains. Also, it is necessary for reactive power to be compensated because the most of industrial loads is inductive and make a lagging displacement power factor. Reactive power compensation utilizing STATCOM is one of the most important methods to improve power quality. In this paper, the technical feature of STATCOM is introduced and then a comparison with SVC is made. The effect of STATCOM on static voltage stability in power systems has been studied. Based on PSD-BPA software, effect of STATCOM is determined. Static voltage stability margin enhancement using STATCOM and SVC is compared in the modified IEEE 14-bus test system. Test results show very encouraging result.

scholarly journals Improvement the voltage stability margin of Iraqi power system using the optimal values of FACTS devices

2021 ◽  
Vol 11 (2) ◽  
pp. 984
Author(s):  
Ghassan Abdullah Salman ◽  
Hatim G. Abood ◽  
Mayyadah Sahib Ibrahim
Keyword(s):  
Power Systems ◽  
Power System ◽  
Voltage Stability ◽  
Stability Margin ◽  
Voltage Collapse ◽  
Voltage Profile ◽  
Heavy Load ◽  
Transmission Grid ◽  
Facts Devices ◽  
Voltage Stability Margin

The detection of potential voltage collapse in power systems is essential to maintain the voltage stability in heavy load demand. This paper proposes a method to detect weak buses in power systems using two stability indices: the voltage stability margin factor (dS/dY) and the voltage collapse prediction index (VCPI). Hence, the paper aims to improve the voltage stability of Iraqi transmission grid by allocating FACTS devices in the optimal locations and optimal sizes. Two types of FACTS are used in this paper which are Thyristor controlled series compensator (TCSC) and static var compensator (SVC). The objective function of the problem is fitted using particle swarm optimization (PSO). The proposed method is verified using simulation test on Diyala-132 kV network which is a part of the Iraqi power system. The results observed that improvement the voltage stability margin, the voltage profile of Diyala-132 kV is increased and the power losses is decreased.

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