Application of UPFC for enhancement of voltage profile and minimization of losses using Fast Voltage Stability Index (FVSI)

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):  
Nur Zahirah Mohd Ali ◽  
Ismail Musirin ◽  
Hasmaini Mohamad

<span>In this paper, a new hybrid optimization technique is proposed namely Adaptive Embedded Clonal Evolutionary Programming (AECEP). This idea comes from the combination part of the clone in an Artificial Immune System (AIS) and then combined with Evolutionary Programming (EP). This technique was implemented to determine the optimal sizing of Flexible AC Transmission Systems (FACTS) devices. This study focused on the ability of Static Var Compensator (SVC) is used for the optimal operation of the power system as well as in reducing congestion in power system. In order to determine the location of SVC, the previous study has been done using pre-developed voltage stability index, Fast Voltage Stability Index (FVSI). Congested lines or buses will be identified based on the highest FVSI value for the purpose of SVC placement. The optimizations were conducted for the SVC sizing under single contingency, where SVC was modeled in steady state analysis. The objective function of this study is to minimize the power loss and improve the voltage profile along with the reduction of congestion with the SVC installation in the system. Validation on the IEEE 30 Bus RTS and IEEE 118 Bus RTS revealed that the proposed technique managed to reduce congestion in power system.</span>


Author(s):  
Mostafa Elshahed ◽  
Mahmoud Dawod ◽  
Zeinab H. Osman

Integrating Distributed Generation (DG) units into distribution systems can have an impact on the voltage profile, power flow, power losses, and voltage stability. In this paper, a new methodology for DG location and sizing are developed to minimize system losses and maximize voltage stability index (VSI). A proper allocation of DG has to be determined using the fuzzy ranking method to verify best compromised solutions and achieve maximum benefits. Synchronous machines are utilized and its power factor is optimally determined via genetic optimization to inject reactive power to decrease system losses and improve voltage profile and VSI. The Augmented Lagrangian Genetic Algorithm with nonlinear mixed-integer variables and Non-dominated Sorting Genetic Algorithm have been implemented to solve both single/multi-objective function optimization problems. For proposed methodology effectiveness verification, it is tested on 33-bus and 69-bus radial distribution systems then compared with previous works.


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.


Author(s):  
Mahmood Khalid Zarkani ◽  
Ahmed Sahib Tukkee ◽  
Mohammed Jasim Alali

<p>The rapid and enormous growths of the power electronics industries have made the flexible AC transmission system (FACTS) devices efficient and viable for utility application to increase power system operation controllability as well as flexibility. This research work presents the application of an evolutionary algorithm namely differential evolution (DE) approach to optimize the location and size of three main types of FACTS devices in order to minimize the power system losses as well as improving the network voltage profile. The utilized system has been reactively loaded beginning from the base to 150% and the system performance is analyzed with and without FACTS devices in order to confirm its importance within the power system. Thyristor controlled series capacitor (TCSC), unified power flow controller (UPFC) and static var compensator (SVC) are used in this research work to monitor the active and reactive power of the carried out system. The adopted algorithm has been examined on IEEE 30-bus test system. The obtained research findings are given with appropriate discussion and considered as quite encouraging that will be valuable in electrical grid restructuring.</p>


Power system is a largely inter connected network, due to this interconnection some of the lines may get over loaded and voltage collapse will occur , hence these lines are called weak lines, this causes serious voltage instability at the particular lines of the power system. The improvement of stability will achieve by controlling the reactive power flow. The Flexible Alternating Current Transmission Systems (FACTS) devices have been proposed to effectively controlling the power flow in the lines and to regulate the bus voltages in electrical power systems, resulting in an increased power transfer capability, low system losses and improved stability. In FACTS devices the Unified Power Flow Controller (UPFC) is one of the most promising device for power flow control. It can either simultaneously or selectively control both real and reactive flow and bus voltage. UPFC is a combination of shunt and series compensating devices. Optimal location of UPFC is determined based on Voltage Stability Index (VSI). GA and PSO techniques are used to set the parameters of UPFC [6]. The objective function formulated here is fitness function, which has to be maximized for net saving. The results obtained using PSO on IEEE 14 Bus is compared with that of results obtained using GA, to show the validity of the proposed techniques and for comparison purposes


Author(s):  
J. P. Sridhar ◽  
R. Prakash

Huge need in electricity causes placement of Distribution Generation (DG)s like Photovoltaics (PV) systems in distribution side for enhancing the loadability by improving the voltage stability and minimization of loss with minimum cost. Many optimal placements of DG have done in focus of minimum loss and improving voltage profile. This Whale optimization is a new optimization technique framed with mathematics of spiral bubble-net feeding behavior of humpback whales for solving a power system multi-objective problem considering cost of the power tariff and DG. Here main objectives are minimizing loss and cost with maximization of voltage stability index. IEEE 69 power system data is used for solution of the proposed method.


2016 ◽  
Vol 36 (2) ◽  
pp. 43
Author(s):  
Sandra Pérez ◽  
Karol López ◽  
Luis Rodríguez

This paper presents a methodology for under voltage load shedding using a metaheuristic optimization technique and a stability criterion. Two strategies are proposed to find the minimal size and location of load to shed for the recovery of normal operation conditions. The first one is based on a classical criterion for the under voltage load shedding, identifying the load to disconnect by considering bus voltage level; the second includes a simplified voltage stability index SVSI, which identifies critical buses in the system. The proposed methodology is implemented in an IEEE 14 bus test system, considering a heavy loading condition with andwithout contingency to validate its efficiency.


Author(s):  
Aziz Oukennou ◽  
Abdelhalim Sandali

This paper aims to develop a novel voltage stability index (NVSI) to evaluate and detect the voltage collapse proximity in the power system. This NVSI is based on the combination of two indices and the approximation made on the difference in angle between the sending bus and the receiving one in the power system. Compared to indices developed in the literature, the advantage of the new voltage stability index (NVSI) is that it can be computed very quickly and easily from power flow results, such as voltages, magnitudes and angles. The static and dynamic studies have been carried out on the IEEE 14-bus test system using PSAT Software. The proposed index has shown more sensitivity and simplicity, and that it can be used as a monitoring tool.


2020 ◽  
Vol 152 ◽  
pp. 03002
Author(s):  
Mohamad Khairuzzaman Mohamad Zamani ◽  
Ismail Musirin ◽  
Saiful Izwan Suliman ◽  
Sharifah Azma Syed Mustaffa ◽  
Nur Zahirah Mohd Ali ◽  
...  

As the load demand in a power system increases, power system operators struggle to maintain the power system to be operated within its acceptable limits. If no mitigation actions are taken, a power system may suffer from voltage collapse, which in turn leads to blackout. Flexible AC Transmission System (FACTS) devices can be employed to help improve the voltage profile of the power system. This paper presents the implementation of Chaotic Immune Symbiotic Organism Search (CISOS) optimization technique to solve optimal Thyristor Controlled Series Compensator (TCSC) in a power system for voltage profile improvement. Validation process are conducted on IEEE 26-bus RTS resulting in the capability of CISOS in solving the allocation problem with a better voltage profile. Comparative studies conducted with respect to Particle Swarm Optimization (PSO) and Evolutionary Programming (EP) has revealed the superiority of CISOS over PSO and EP in solving the optimal allocation problem by producing optimal solution with a better voltage profile. The results and information obtained from this study can help power system operator in terms of optimal compensation in power system as well as improving the operation of a power system.


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