Pallavi Choudekar

Prediction of Voltage Collapse in Power System Using Voltage Stability Indices

Voltage collapse is the possible outcome of voltage instability. Voltage collapse occurs when the transmission lines are operating very close to their maximum capacity limits. This paper focuses on the usefulness of two voltage stability indices to find out the weak bus so that the appropriate measures can be taken in advance to avoid voltage collapse. In this paper, WSCC 3 Machine, nine bus test system has been considered and comparison of different voltage stability indices is done to predict voltage collapse.

Series Smart Wire—Managing Load and Congestion in Transmission Line

Nowadays, congestion management is a major problem in power system deregulation. With the continuous increase in load demand, there is continuous requirement for different new technologies resulting in advanced network operation. This paper presents a solution for congestion management by developing a series smart wire module which operates with the increment in load. The circuitry is bypassed if it does not detects congestion in line else with the detection of congestion series smart wire module is operated. This method improves the reliability of the system by reducing active power losses. The effectiveness of this module is demonstrated in standard IEEE 15 bus system model using MATLAB/Simulink and the results are formulated with graphical representations.

Power flow study and contingency status of WSCC 9 Bus test system using MATLAB

Power flow study is the initial step which provides voltage magnitudes, phase angles, active and reactive power flows at respective buses under normal operating conditions. It helps in analyzing the current state of the power system and effective alternative options for expanding the existing system in order to meet with the increasing load demand. Contingency Analysis is also a major part of study for reliable and planned operation of power system. It is very significant function in modern Energy Management Systems. The objective of contingency analysis is to give operator the information about the static security. There are several factors which may lead to the contingency in power system, for example line outage, transformer outage, generator outage and overloads resulting the extreme situations such as voltage collapse, over loads in other branches and/or sudden system voltage rise or drop. Contingency analysis is used to calculate parameters violations. In this paper, maximum loading parameter is calculated and contingency status of Western System Coordinating Council 3 Machine, 9 Bus test system is done using PSAT toolbox in MATLAB.

Optimal location of TCSC using sensitivity and stability indices for reduction in losses and improving the voltage profile

Major problem of heavily loaded system is, transmission networks are operating close to their limit which causes increase in stress on transmission lines. This problem was solved by the addition of isolated and individually controlled devices such as FACTS to the existing networks. This paper focuses on FACTS device-TCSC (Thyristor Controlled Series Capacitor) and its optimal location in the power system network. To decide optimal location of TCSC sensitivity factor methods and stability indices are used. These methods are applied on IEEE-14 bus system and its power flow analysis is done using PSAT (Power System Analysis Tool Box) software. Reactive and real power loss sensitivities, and line voltage stability indexes are calculated for each line and power flow results are compared with and without TCSC in sensitive and critical lines.

Transmission line efficiency improvement and congestion management under critical contingency condition by optimal placement of TCSC

In this paper placement of thyristor controlled series compensators (TCSC) at optimal location of a power system for maintaining voltage stability, improving transmission efficiency, steady state stability limit and mitigating congestion under single line critical contingency condition is discussed. Optimal location is found out by line voltage stability index and sensitivity analysis. Performance index (PI) is used for finding critical contingency. Under critical contingency condition which is single line outage in this case, congested transmission lines are found. TCSC is a FACTS device which can reduce power loss in overloaded transmission lines, increase loadability, reduce system loss and maintain stability of power systems. This work has been tested on IEEE 14 bus test system using MATLAB.

Optimal Location of Thyristor Controlled Series Compensator to Assuage Congestion in Transmission Network

To assuage the increasing electrical power demand, power plants make use of sophisticated technologies to generate a much larger amount of electrical energy. But the archaic transmission lines have their material limits because of which they are unable to transmit the increased energy generation successfully, and get overloaded and cause major losses of electrical power. There are numerous ways to tackle this problem of congestion and losses. Changing millions of kilometres of transmission lines would not be an economical solution. Keeping this in mind, we intend to find a better solution for the congestion problem with the help of FACTS devices. The results show significant improvement in bus voltages when the observations and calculations are obtained on a standard IEEE 30 bus system, which has been simulated with the help of MATLAB software.

Mitigation of Congestion in Transmission Line Using Series Smart Wire

In the deregulated power system market, congestion management is one of significant technical issues. Congestion management demands for decrease in load in a particular line, installation of flexible AC transmission system (FACTS) devices in transmission line for reliability and the addition of new renewable generation unit. Various new technologies have been developed so far to mitigate congestion within the network without construction of any new line. This paper presents an idea of mitigating congestion by using Smart Wire (SW) in series. SW series module operates whenever congestion is detected and during normal condition, the smart wire circuitry is bypassed. This technology supports the efficacy of the system by decreasing relevant losses also. Proposed system utilises 15 bus IEEE system in MATLAB/Simulink to demonstrate the working of smart wire, and the results are formulated graphically.

Improvement of Power System Security Under Single Line Critical Contingency Condition by Optimal Placement of Multiple TCSCs

Transmission congestion occurs in a power system due to increase in load demand. This mainly occurs in restructured power system because of restrictions of transmission line capacity. Due to this power system does not remain in secure condition. Ranking of contingency is done using performance index and critical contingency is found. In this paper, placement of multiple TCSCs for reducing transmission line congestion under single line critical contingency condition is done. Optimal location for placement of TCSCs is found out by using sensitivity analysis. By placing two TCSCs, there is reduction in line loading, improvement in voltage profile and reduction in reactive power loss, thus keeping power system in secure condition under critical contingency. Proposed work is carried out on IEEE 14 bus test system using MATLAB.

Minimizing Fuel Cost of Generators Using GA-OPF

In the current scenario of deregulated power system congestion in the network is one of the critical issues, which need to be resolved for better economic and system efficiency. Several measures have been adopted to relieve the system from congestion for maximization of social benefit. Fuel cost minimization is considered as the key factor for social welfare maximization, which provides benefits to both buyer and consumer of electricity. The fuel cost minimization for power system is achieved based on many parameters one of them being generator allocation. This paper uses GA-based optimization algorithm to obtain optimal generator allocation to find the best fit having minimum fuel cost. The proposed approach for fuel cost minimization is tested on IEEE 14 bus standard system.

Optimal placement of thyristor controlled series compensators for mitigation of congestion under critical contingency condition

In unbundled electricity market managing transmission congestion is a real challenge for independent system operator. This paper presents placement of thyristor controlled series compensators (TCSC) at optimal location for maintaining voltage stability and mitigating congestion under single line contingency condition. Optimal location is found out by Line voltage stability index calculation. Congested lines are found out under contingency condition (single line outage). Critical contingencies are found out by finding performance index. Effect of placement of TCSC under critical contingency can be observed. TCSC is a member of Flexible AC Transmission Systems devices can reduce power loss in overloaded transmission lines, have ability to increase loadability, reduce system loss and maintains stability of power systems. Work is carried out on IEEE 14 bus test system using MATLAB.