scholarly journals Maximum Loadability Enhancement with a Hybrid Optimization Method

2018 ◽  
Vol 7 (3) ◽  
pp. 323-330
Author(s):  
E. E. Hassan ◽  
T. K. A. Rahman ◽  
Z. Zakaria ◽  
N. Bahaman ◽  
M. H. Jifri

Nowadays, a power system is operating in a stressed condition due to the increase in demand in addition to constraint in building new power plants. The economics and environmental constraints to build new power plants and transmission lines have led the system to operate very close to its stability limits. Hence, more researches are required to study the important requirements to maintain stable voltage condition and hence develop new techniques in order to address the voltage stability problem. As an action, most Reactive Power Planning (RPP) objective is to minimize the cost of new reactive resources while satisfying the voltage stability constraints and labeled as Secured Reactive Power Planning (SCRPP). The new alternative optimization technique called Adaptive Tumbling Bacterial Foraging (ATBFO) was introduced to solve the RPP problems in the IEEE 57 bus system. The comparison common optimization Meta-Heuristic Evolutionary Programming and original Bacterial Foraging techniques were chosen to verify the performance using the proposed ATBFO method. As a result, the ATBFO method is confirmed as the best suitable solution in solving the identified RPP objective functions.

2020 ◽  
Author(s):  
Stefanie Samaan ◽  
Markus Knittel ◽  
Spyridon Iason Dizes ◽  
Albert Moser

The ongoing decommissioning of conventional power plants decreases the installed reactive power reserves for voltage control in transmission grids. Hence, an efficient planning of compensation devices substituting this lack of reactive power is required. Grid operators must allocate these devices for steady-state voltage control and for dynamic voltage control ensuring voltage stability. A separate determination of this static and dynamic VAR demand, however, fails to exploit synergies and disregards that VAR compensation in steady-state reduces the reserves for dynamic compensation. This paper proposes a coupled determination of the system static and dynamic VAR demand. An optimisation method applying mixed-integer programming identifies an efficient allocation and portfolio consisting of different compensation technologies. It includes constraints for voltage limits during steady-state and contingencies as well as for long-term voltage stability. Results emphasise that the method identifies an efficient portfolio for various operation and fault scenarios, while providing the required voltage stability margin.


2016 ◽  
Vol 65 (4) ◽  
pp. 789-802 ◽  
Author(s):  
Biplab Bhattacharyya ◽  
Shweta Rani ◽  
Ram Ishwar Vais ◽  
Indradeo Pratap Bharti

Abstract This paper presents a novel approach for reactive power planning of a connected power network. Reactive power planning is nothing but the optimal usage of all reactive power sources i.e., transformer tap setting arrangements, reactive generations of generators and shunt VAR compensators installed at weak nodes. Shunt VAR compensator placement positions are determined by a FVSI (Fast Voltage Stability Index) method. Optimal setting of all reactive power reserves are determined by a GA (genetic algorithm) based optimization method. The effectiveness of the detection of the weak nodes by the FVSI method is validated by comparing the result with two other wellknown methods of weak node detection like Modal analysis and the L-index method. Finally, FVSI based allocation of VAR sources emerges as the most suitable method for reactive power planning.


2020 ◽  
Author(s):  
Stefanie Samaan ◽  
Markus Knittel ◽  
Spyridon Iason Dizes ◽  
Albert Moser

The ongoing decommissioning of conventional power plants decreases the installed reactive power reserves for voltage control in transmission grids. Hence, an efficient planning of compensation devices substituting this lack of reactive power is required. Grid operators must allocate these devices for steady-state voltage control and for dynamic voltage control ensuring voltage stability. A separate determination of this static and dynamic VAR demand, however, fails to exploit synergies and disregards that VAR compensation in steady-state reduces the reserves for dynamic compensation. This paper proposes a coupled determination of the system static and dynamic VAR demand. An optimisation method applying mixed-integer programming identifies an efficient allocation and portfolio consisting of different compensation technologies. It includes constraints for voltage limits during steady-state and contingencies as well as for long-term voltage stability. Results emphasise that the method identifies an efficient portfolio for various operation and fault scenarios, while providing the required voltage stability margin.


2012 ◽  
Vol 61 (2) ◽  
pp. 239-250 ◽  
Author(s):  
M. Kumar ◽  
P. Renuga

Application of UPFC for enhancement of voltage profile and minimization of losses using Fast Voltage Stability Index (FVSI)Transmission line loss minimization in a power system is an important research issue and it can be achieved by means of reactive power compensation. The unscheduled increment of load in a power system has driven the system to experience stressed conditions. This phenomenon has also led to voltage profile depreciation below the acceptable secure limit. The significance and use of Flexible AC Transmission System (FACTS) devices and capacitor placement is in order to alleviate the voltage profile decay problem. The optimal value of compensating devices requires proper optimization technique, able to search the optimal solution with less computational burden. This paper presents a technique to provide simultaneous or individual controls of basic system parameter like transmission voltage, impedance and phase angle, thereby controlling the transmitted power using Unified Power Flow Controller (UPFC) based on Bacterial Foraging (BF) algorithm. Voltage stability level of the system is defined on the Fast Voltage Stability Index (FVSI) of the lines. The IEEE 14-bus system is used as the test system to demonstrate the applicability and efficiency of the proposed system. The test result showed that the location of UPFC improves the voltage profile and also minimize the real power loss.


Author(s):  
Mogaligunta Sankaraiah ◽  
Sanna Suresh Reddy ◽  
M Vijaya Kumar

<p>Wind is available with free of cost anywhere in the world, this wind can be used for power generation due to many advantages. This attracts the researchers to work on wind power plants. The presence of wind power plants on distribution system causes major influence on voltage controlled devices (VCDs) in terms of life of the devices. Therefore, this paper proposes grey wolf optimization method (GWO) together with forecasted load one day in advance. VCDs are on load tap changer (ULTC) and capacitors (CS), there are two main objectives first one is curtail of distribution network (DN) loss and second one is curtailing of ULTC and CS switching’s. Objectives are achieved by controlling the reactive power of DFIG in coordination with VCDs. The proposed method is planned and applied in Matlab/Simulink on 10KV practical system with DFIG located at different locations. To validate the efficacy of GWO, results are compared with conventional and dynamic programming methods without profane grid circumstances.</p>


2019 ◽  
Vol 16 (8) ◽  
pp. 3455-3460
Author(s):  
Chun Lim Hiew ◽  
Jacqueline Lukose

Nowadays, voltage stability issues are the main problems around the world and therefore it is important that to maintain stable voltage stability. Series capacitor compensation plays an important role in the transmission line because it can improve the voltage stability as compared to shunt compensation. The Thyristor-Controlled Series Capacitor (TCSC) is selected in this project for providing capacitor compensation because its ability to control the amount of compensation in the transmission line, and operating in three different mode of region, which are resonance, capacitive, and inductive regions. The Fast Voltage Stability Index (FVSI) is used to determine the system’s stability and determine the weakest line in the system for TCSC placement. The TCSC sizing is optimized by using Differential Evolution (DE) optimization technique. All these processes are simulated on Institute of Electrical and Electronics Engineer (IEEE) 14-bus test system by using MATLAB. The proposed methodology was carried out in few tests, which are system contingency test, line outage test, power loss test, voltage profile improvement test and variable TCSC location. Based on the results, the overall voltage stability of the system was improved. The voltage magnitude for each bus had improved and the total power losses also reduced. Therefore, the optimization is successful and the study’s aim is achieved.


2017 ◽  
Vol 2 (6) ◽  
pp. 27 ◽  
Author(s):  
Rayudu Katuri ◽  
Guduri Yesuratnam ◽  
Askani Jayalaxmi

One of the important tasks of a power system engineer is to run the system in safe and reliable mode for secure operation with increase in loading. So, it is significant to perform voltage stability analysis by optimal reactive power dispatch with Artificial Intelligence (AI) techniques. This paper presents the application of Ant Colony Optimization (ACO) and BAT algorithms for Optimal Reactive Power Dispatch (ORPD) to enhance voltage stability. The proposed ACO and BAT algorithms are used to find the optimal settings of On-load Tap changing Transformers (OLTC), Generator excitation and Static Var Compensators (SVC) to minimize the sum of the squares of the voltage stability L– indices of all the load buses. By calculating system parameters like L-Index, voltage error/deviation and real power loss for the practical Equivalent of Extra High Voltage (EHV) Southern Region Indian 24 bus system, voltage profile is improved and voltage stability is enhanced. A comparative analysis is done with the conventional optimization technique like Linear Programming (LP) for the given objective function to demonstrate the effectiveness of proposed ACO and BAT algorithms. 


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