In radial distribution systems, the voltages at buses
reduces when moved away from the substation, also the losses
are high. The reason for decrease in voltage and high losses is
the insufficient amount of reactive power, which can be
provided by the shunt capacitors. For this purpose, in this
paper, two stage methodologies are used. In first stage, the
load flow of pre-compensated distribution system is carried
out using ‘Dimension reducing distribution load flow
algorithm’. In the second stage, Differential Evolution (DE)
technique is used to determine the optimal location and size
of the capacitors. The above method is tested on IEEE 69 bus
system. In this paper a new method is proposed to improve the
power factor of those buses having low power factor (less than
0.8lag) to unity power factor simultaneously by placing the
capacitors.
In power engineering the power flow analysis (also known as load flow study) is an important tool involving numerical analysis applied to a powe r system. This project deals with a model of existing power system using the actual data taking care of all parameters required for the simulation and analysis. With the help of Maharasht ra State Electricity Transmission co. Ltd.,a model of 220KV lines,of Solapur District grid usin g MATLAB software will be modeled. In this project,an algorithm will be used for power f low study and data collection and coding required for modeling. Load flow studies will be ca rried out using Newton Raphson method and voltage profile of buses will be analyzed. New meth od for the improvement of voltage profile will be suggested and analyze using the developed m odel. The optimization techniques include power factor compensation,tap changing,up gradati on of substation,up gradation of line and load shifting will be analyzed. Importance of power flow or Load flow studies is in planning future expansion of power system as well as determi ning the best operation of existing systems. From results of simulation buses with low voltage p rofile will be identified and possible solutions can be suggested.
In this paper, a Wavelet modulated isolated two-stage three-phase bidirectional AC-DC converter is proposed for electric vehicle (EV) charging systems. Half-bridge resonant CLLC converter is proposed due to its high efficiency, wide gain range, galvanic isolation and bidirectional power flow. Wavelet modulation technique is used for three-phase six leg AC-DC converter due to its benefits of high DC component and lower harmonic contents. The proposed two-stage converter is developed and simulated in MATLAB Simulink environment. The contribution of this paper is on the implementation and performance analysis of Wavelet modulation in bidirectional AC-DC converters. The results show that Wavelet modulation is suitable to be implemented for the proposed bidirectional converter. The performance of the proposed converter delivers very low output voltage ripple and total harmonic distortion output current of less than 10% which is within the expected results.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
DISTRIBUTION LOAD FLOW ANALYSIS FOR RDIAL & MESH DISTRIBUTION SYSTEMIAEME Publication
Power flow analysis is the backbone of power system analysis and design. They are necessary for planning, operation, economic scheduling and exchange of power between utilities. Power flow analysis is required for many other analyses such as transient stability, optimal power flow and contingency studies. The principal information of power flow analysis is to find the magnitude and phase angle of voltage at each bus and the real and reactive power flowing in each transmission lines. Power flow analysis is an importance tool involving numerical analysis applied to a power system. In this analysis, iterative techniques are used due to there no known analytical method to solve the problem. This resulted nonlinear set of equations or called power flow equations are generated.
In power engineering the power flow analysis (also known as load flow study) is an important tool involving numerical analysis applied to a powe r system. This project deals with a model of existing power system using the actual data taking care of all parameters required for the simulation and analysis. With the help of Maharasht ra State Electricity Transmission co. Ltd.,a model of 220KV lines,of Solapur District grid usin g MATLAB software will be modeled. In this project,an algorithm will be used for power f low study and data collection and coding required for modeling. Load flow studies will be ca rried out using Newton Raphson method and voltage profile of buses will be analyzed. New meth od for the improvement of voltage profile will be suggested and analyze using the developed m odel. The optimization techniques include power factor compensation,tap changing,up gradati on of substation,up gradation of line and load shifting will be analyzed. Importance of power flow or Load flow studies is in planning future expansion of power system as well as determi ning the best operation of existing systems. From results of simulation buses with low voltage p rofile will be identified and possible solutions can be suggested.
In this paper, a Wavelet modulated isolated two-stage three-phase bidirectional AC-DC converter is proposed for electric vehicle (EV) charging systems. Half-bridge resonant CLLC converter is proposed due to its high efficiency, wide gain range, galvanic isolation and bidirectional power flow. Wavelet modulation technique is used for three-phase six leg AC-DC converter due to its benefits of high DC component and lower harmonic contents. The proposed two-stage converter is developed and simulated in MATLAB Simulink environment. The contribution of this paper is on the implementation and performance analysis of Wavelet modulation in bidirectional AC-DC converters. The results show that Wavelet modulation is suitable to be implemented for the proposed bidirectional converter. The performance of the proposed converter delivers very low output voltage ripple and total harmonic distortion output current of less than 10% which is within the expected results.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
DISTRIBUTION LOAD FLOW ANALYSIS FOR RDIAL & MESH DISTRIBUTION SYSTEMIAEME Publication
Power flow analysis is the backbone of power system analysis and design. They are necessary for planning, operation, economic scheduling and exchange of power between utilities. Power flow analysis is required for many other analyses such as transient stability, optimal power flow and contingency studies. The principal information of power flow analysis is to find the magnitude and phase angle of voltage at each bus and the real and reactive power flowing in each transmission lines. Power flow analysis is an importance tool involving numerical analysis applied to a power system. In this analysis, iterative techniques are used due to there no known analytical method to solve the problem. This resulted nonlinear set of equations or called power flow equations are generated.
SIMULTANEOUS OPTIMIZATION OF STANDBY AND ACTIVE ENERGY FOR SUB-THRESHOLD CIRC...VLSICS Design
Increased downscaling of CMOS circuits with respect to feature size and threshold voltage has a result of dramatically increasing in leakage current. So, leakage power reduction is an important design issue for active and standby modes as long as the technology scaling increased. In this paper, a simultaneous active and standby energy optimization methodology is proposed for 22 nm sub-threshold CMOS circuits. In the first phase, we investigate the dual threshold voltage design for active energy per cycle minimization. A
slack based genetic algorithm is proposed to find the optimal reverse body bias assignment to set of noncritical
paths gates to ensure low active energy per cycle with the maximum allowable frequency at the optimal supply voltage. The second phase, determine the optimal reverse body bias that can be applied to all gates for standby power optimization at the optimal supply voltage determined from the first phase.
Therefore, there exist two sets of gates and two reverse body bias values for each set. The reverse body bias is switched between these two values in response to the mode of operation. Experimental results are obtained for some ISCAS-85 benchmark circuits such as 74L85, 74283, ALU74181, and 16 bit RCA. The optimized circuits show significant energy saving ranged (from 14.5% to 42.28%) and standby power
saving ranged (from 62.8% to 67%)
Convergence analysis of the triangular-based power flow method for AC distribu...IJECEIAES
This paper addresses the convergence analysis of the triangular-based power flow (PF) method in alternating current radial distribution networks. The PF formulation is made via upper-triangular matrices, which enables finding a general iterative PF formula that does not require admittance matrix calculations. The convergence analysis of this iterative formula is carried out by applying the Banach fixed-point theorem (BFPT), which allows demonstrating that under an adequate voltage profile the triangular-based PF always converges. Numerical validations are made, on the well-known 33 and 69 distribution networks test systems. Gauss-seidel, newton-raphson, and backward/forward PF methods are considered for the sake of comparison. All the simulations are carried out in MATLAB software.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
A Particle Swarm Optimization for Reactive Power Optimizationijceronline
This paper presents implementation of new algorithm Particle Swarm Optimization (PSO) for Energy Saving through minimizing power losses. The PSO Algorithm Solution is tested in standard IEEE 30 Bus system. The objective is to optimize the reactive power dispatch with optimal setting of control variables without violating inequality constraints and satisfying equality constraint. Control Variables are of both types: Continuous and Discrete. The continuous control variables are generator bus voltage magnitudes;whereas the discrete variables are transformer tap settings and reactive power of shunt compensators (Capacitor banks) .
INTRODUCTION BASIC TECHNIQUES TYPE OF BUSES
Y BUS MATRIX POWER SYSTEM COMPONENTS BUS ADMITTANCE MATRIX
Power (Load) flow study is the analysis of a power system in normal steady-state operation
This study will determine:
Comparative power flow analysis of 28 and 52 buses for 330 kv power grid netw...Onyebuchi nosiri
Newton-Raphson technique was formulated and used to evaluate the electrical performances of the existing 28-bus and improved 52-bus Nigerian 330kV power networks. The Jacobian matrix for both the existing 28-bus and the improved 52-bus Nigerian power system was derived using Newton-Raphson power flow solution method. The steady-state critical bus voltages, voltage and angle profiles at each bus, active and reactive power flows, transformer tap settings, component or circuit loading, generator exciter regulator voltage set points and system losses of these networks were determined to ascertain their effectiveness and proper network reconfiguration. The results obtained showed a better performance of the 52-Bus system in power quality, voltage and angle profiles over the conventional 28-bus system
1 ijaems oct-2015-3-design and development of novel matrix converter performanceINFOGAIN PUBLICATION
Matrix converter is a direct AC-AC converter topology that directly converts energy from an AC source to an AC load without the need of a bulky and limited lifetime energy storage element. Due to the significant advantages offered by matrix converter, such as adjustable power factor, capability of regeneration and high quality sinusoidal input/output waveforms. Matrix converter has been one of the AC–AC topologies that hasreceived extensive research attention for being an alternative to replace traditional AC-DC-AC converters in the variable voltage and variable frequency AC drive applications. In the present paper an indirect space vector modulated matrix converter is proposed. The basic idea of an indirect modulation scheme is to separately apply SVM to the rectification and inversion stages, before combining their switching states to produce the final gating signals. The paper encompasses development of a laboratory prototype of 230V, 250VA three phase to three phase DSP controlled matrix converter fed induction motor drive. The observations and real time testings have been carried out to evaluate and improve the stability of system under various typical abnormal input voltage conditions
Efficient Optimal Sizing And Allocation Of Capacitors In Radial Distribution ...IDES Editor
A distribution system is an interface between the
bulk power system and the consumers. The radial distribution
system is popular among these because of its low cost and
simple design. The voltage instability in the power system is
characterized by a monotonic voltage drop, which is slow at
first and becomes abrupt after some time when the system is
unable to meet the increasing power demand. Therefore to
overcome these problems capacitors are used. The installation
of the shunt capacitors on the radial distribution system is
essential for power flow control, improving system stability,
pf correction, voltage profile management and losses
minimization. But the placement of the capacitors with
appropriate size is always a challenge. Therefore for this
purpose, in this paper along with Differential Evolution (DE)
Algorithm, Dimension Reducing Distribution Load Flow
(DRDLF) is used. This load flow identifies the location of the
capacitors and the Differential Algorithm determines the size
of the capacitors such that the cost of the energy loss and the
capacitor to be minimum. In this problem the installation
cost of the capacitors is also included. The above method is
tested on IEEE 69 bus system and was found to be better
compared to other methods like Genetic Algorithm and PSO
Optimal Power Flow with Reactive Power Compensation for Cost And Loss Minimiz...ijeei-iaes
One of the concerns of power system planners is the problem of optimum cost of generation as well as loss minimization on the grid system. This issue can be addressed in a number of ways; one of such ways is the use of reactive power support (shunt capacitor compensation). This paper used the method of shunt capacitor placement for cost and transmission loss minimization on Nigerian power grid system which is a 24-bus, 330kV network interconnecting four thermal generating stations (Sapele, Delta, Afam and Egbin) and three hydro stations to various load points. Simulation in MATLAB was performed on the Nigerian 330kV transmission grid system. The technique employed was based on the optimal power flow formulations using Newton-Raphson iterative method for the load flow analysis of the grid system. The results show that when shunt capacitor was employed as the inequality constraints on the power system, there is a reduction in the total cost of generation accompanied with reduction in the total system losses with a significant improvement in the system voltage profile
Performance Improvement of the Radial Distribution System by using Switched C...idescitation
Distribution system is the major link which provides supply to the consumers
from the high voltage transmission system. The load on the distribution system is not
constant and it changes with respect to time throughout the working period. The voltage
drop and power losses occur in the distribution system mainly depends on the nature of the
load which is applied on the system. The voltage drop and power losses frequently occurs
mainly on those systems which are supplying load to the industrial areas, this is mainly
because of the existence of more reactive power. To overcome these problems shunt
compensation is employed to reduce or suppress those effects to an extent. The main aim of
this paper is to determine the specific value of the shunt capacitance required to achieve the
permissible voltage tolerance limits and maximum percentage of power loss reduction in a
sample two feeder radial distribution system.
SIMULTANEOUS OPTIMIZATION OF STANDBY AND ACTIVE ENERGY FOR SUB-THRESHOLD CIRC...VLSICS Design
Increased downscaling of CMOS circuits with respect to feature size and threshold voltage has a result of dramatically increasing in leakage current. So, leakage power reduction is an important design issue for active and standby modes as long as the technology scaling increased. In this paper, a simultaneous active and standby energy optimization methodology is proposed for 22 nm sub-threshold CMOS circuits. In the first phase, we investigate the dual threshold voltage design for active energy per cycle minimization. A
slack based genetic algorithm is proposed to find the optimal reverse body bias assignment to set of noncritical
paths gates to ensure low active energy per cycle with the maximum allowable frequency at the optimal supply voltage. The second phase, determine the optimal reverse body bias that can be applied to all gates for standby power optimization at the optimal supply voltage determined from the first phase.
Therefore, there exist two sets of gates and two reverse body bias values for each set. The reverse body bias is switched between these two values in response to the mode of operation. Experimental results are obtained for some ISCAS-85 benchmark circuits such as 74L85, 74283, ALU74181, and 16 bit RCA. The optimized circuits show significant energy saving ranged (from 14.5% to 42.28%) and standby power
saving ranged (from 62.8% to 67%)
Convergence analysis of the triangular-based power flow method for AC distribu...IJECEIAES
This paper addresses the convergence analysis of the triangular-based power flow (PF) method in alternating current radial distribution networks. The PF formulation is made via upper-triangular matrices, which enables finding a general iterative PF formula that does not require admittance matrix calculations. The convergence analysis of this iterative formula is carried out by applying the Banach fixed-point theorem (BFPT), which allows demonstrating that under an adequate voltage profile the triangular-based PF always converges. Numerical validations are made, on the well-known 33 and 69 distribution networks test systems. Gauss-seidel, newton-raphson, and backward/forward PF methods are considered for the sake of comparison. All the simulations are carried out in MATLAB software.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
A Particle Swarm Optimization for Reactive Power Optimizationijceronline
This paper presents implementation of new algorithm Particle Swarm Optimization (PSO) for Energy Saving through minimizing power losses. The PSO Algorithm Solution is tested in standard IEEE 30 Bus system. The objective is to optimize the reactive power dispatch with optimal setting of control variables without violating inequality constraints and satisfying equality constraint. Control Variables are of both types: Continuous and Discrete. The continuous control variables are generator bus voltage magnitudes;whereas the discrete variables are transformer tap settings and reactive power of shunt compensators (Capacitor banks) .
INTRODUCTION BASIC TECHNIQUES TYPE OF BUSES
Y BUS MATRIX POWER SYSTEM COMPONENTS BUS ADMITTANCE MATRIX
Power (Load) flow study is the analysis of a power system in normal steady-state operation
This study will determine:
Comparative power flow analysis of 28 and 52 buses for 330 kv power grid netw...Onyebuchi nosiri
Newton-Raphson technique was formulated and used to evaluate the electrical performances of the existing 28-bus and improved 52-bus Nigerian 330kV power networks. The Jacobian matrix for both the existing 28-bus and the improved 52-bus Nigerian power system was derived using Newton-Raphson power flow solution method. The steady-state critical bus voltages, voltage and angle profiles at each bus, active and reactive power flows, transformer tap settings, component or circuit loading, generator exciter regulator voltage set points and system losses of these networks were determined to ascertain their effectiveness and proper network reconfiguration. The results obtained showed a better performance of the 52-Bus system in power quality, voltage and angle profiles over the conventional 28-bus system
1 ijaems oct-2015-3-design and development of novel matrix converter performanceINFOGAIN PUBLICATION
Matrix converter is a direct AC-AC converter topology that directly converts energy from an AC source to an AC load without the need of a bulky and limited lifetime energy storage element. Due to the significant advantages offered by matrix converter, such as adjustable power factor, capability of regeneration and high quality sinusoidal input/output waveforms. Matrix converter has been one of the AC–AC topologies that hasreceived extensive research attention for being an alternative to replace traditional AC-DC-AC converters in the variable voltage and variable frequency AC drive applications. In the present paper an indirect space vector modulated matrix converter is proposed. The basic idea of an indirect modulation scheme is to separately apply SVM to the rectification and inversion stages, before combining their switching states to produce the final gating signals. The paper encompasses development of a laboratory prototype of 230V, 250VA three phase to three phase DSP controlled matrix converter fed induction motor drive. The observations and real time testings have been carried out to evaluate and improve the stability of system under various typical abnormal input voltage conditions
Efficient Optimal Sizing And Allocation Of Capacitors In Radial Distribution ...IDES Editor
A distribution system is an interface between the
bulk power system and the consumers. The radial distribution
system is popular among these because of its low cost and
simple design. The voltage instability in the power system is
characterized by a monotonic voltage drop, which is slow at
first and becomes abrupt after some time when the system is
unable to meet the increasing power demand. Therefore to
overcome these problems capacitors are used. The installation
of the shunt capacitors on the radial distribution system is
essential for power flow control, improving system stability,
pf correction, voltage profile management and losses
minimization. But the placement of the capacitors with
appropriate size is always a challenge. Therefore for this
purpose, in this paper along with Differential Evolution (DE)
Algorithm, Dimension Reducing Distribution Load Flow
(DRDLF) is used. This load flow identifies the location of the
capacitors and the Differential Algorithm determines the size
of the capacitors such that the cost of the energy loss and the
capacitor to be minimum. In this problem the installation
cost of the capacitors is also included. The above method is
tested on IEEE 69 bus system and was found to be better
compared to other methods like Genetic Algorithm and PSO
Optimal Power Flow with Reactive Power Compensation for Cost And Loss Minimiz...ijeei-iaes
One of the concerns of power system planners is the problem of optimum cost of generation as well as loss minimization on the grid system. This issue can be addressed in a number of ways; one of such ways is the use of reactive power support (shunt capacitor compensation). This paper used the method of shunt capacitor placement for cost and transmission loss minimization on Nigerian power grid system which is a 24-bus, 330kV network interconnecting four thermal generating stations (Sapele, Delta, Afam and Egbin) and three hydro stations to various load points. Simulation in MATLAB was performed on the Nigerian 330kV transmission grid system. The technique employed was based on the optimal power flow formulations using Newton-Raphson iterative method for the load flow analysis of the grid system. The results show that when shunt capacitor was employed as the inequality constraints on the power system, there is a reduction in the total cost of generation accompanied with reduction in the total system losses with a significant improvement in the system voltage profile
Performance Improvement of the Radial Distribution System by using Switched C...idescitation
Distribution system is the major link which provides supply to the consumers
from the high voltage transmission system. The load on the distribution system is not
constant and it changes with respect to time throughout the working period. The voltage
drop and power losses occur in the distribution system mainly depends on the nature of the
load which is applied on the system. The voltage drop and power losses frequently occurs
mainly on those systems which are supplying load to the industrial areas, this is mainly
because of the existence of more reactive power. To overcome these problems shunt
compensation is employed to reduce or suppress those effects to an extent. The main aim of
this paper is to determine the specific value of the shunt capacitance required to achieve the
permissible voltage tolerance limits and maximum percentage of power loss reduction in a
sample two feeder radial distribution system.
Abstract: In this paper three phase load flow analysis on four bus system using Mi Power software is reformed. As power system never operates under steady state condition therefore single phase load flow analysis doesn’t provide accurate results. Hence three phase load flow analysis which can be performed under different contingencies, provide data when system is unbalanced. The system is analysing on the basis of parameter values in MW & MVAR for transmission line and generator buses. Harmonic values of resistance, reactance, and susceptance can predict the condition of small and large kind of system network. This type of analysis is useful for solving the power flow problem in different power systems which will useful to calculate the unknown parameter.
Optimal Capacitor Placement in Distribution System using Fuzzy TechniquesIDES Editor
To improve the overall efficiency of power system,
the performance of distribution system must be improved. It
is done by installing shunt capacitors in radial distribution
system. The problem of capacitor allocation in electric
distribution systems involves maximizing “energy and peak
power (demand) loss reductions” by means of capacitor
installations. As a result power factor of distribution system
improves. There is also lots of saving in terms of money. A 10
bus radial distribution system is taken as the model. Then a
load flow programs is executed on MATLAB. Then by using
load flow data & fuzzy techniques the determination of suitable
location of capacitor placement and its size is done. Shunt
capacitors to be placed at the nodes of the system will be
represented as reactive power injections. Fuzzy techniques have
advantages of simplicity, less computations & fast results. The
same techniques can be applied to complex distribution systems
& dynamic loads.
A Novel Distribution System Power Flow Algorithm using Forward Backward Matri...iosrjce
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
The effect of load modelling on phase balancing in distribution networks usin...IJECEIAES
Due to the unequal loads in phases and different customer consumption, the distribution network is unbalanced. Unbalancing in the distribution network, in addition to increasing power losses, causes unbalancing in voltages and increases operating costs. To reduce this unbalancing, various methods and algorithms have been presented. In most studies and even practical projects due to lack of information about the network loads, load models such as constant power model, constant current or constant impedance are used to model the loads. Due to the changing and nonlinear behaviours of today's loads, these models cannot show results in accordance with reality. This paper while introducing an optimal phase-balancing method, discusses the effect of load modelling on phase balancing studies. In this process the re-phasing method for balancing the network and the harmony search algorithm for optimizing the phase displacement process have been used. The simulation was carried out on an unbalanced distribution network of 25 buses. The results show well the effect of this comprehensive modelling on phase balancing studies. It also shows that in the re-phasing method for balancing the network and in the absence of a real load model, the use of which model offers the closest answer to optimal solutions.
Load Balancing of Modern Distribution Networks by Genetic AlgorithmITIIIndustries
The main purpose of this paper is to establish a multi-objective function for optimal load balancing in modern distribution networks. The proposed approach can reduce the three-phase voltage unbalance ratio and system power loss; furthermore, the system operation performance will be improved. The genetic algorithm and three-phase power flow algorithm are coded in Matlab. Finally, the IEEE 37-Bus test system is used as the sample system to verify the accuracy of the proposed approach. The simulation results demonstrate that the proposed approach is systematic and efficient for solving the load balancing problem in active distribution networks
Selective localization of capacitor banks considering stability aspects in po...IAEME Publication
The issue of voltage stability has become predominant in larger power systems, since the
system is operated close to its capabilities in recent years. Addressing this concern considering the
economic constraints is a challenge .This draws attention towards the localization of the reactive
components that can improve the overall voltage profile in the system. This paper discusses a
methodology for suitable selection of position (bus) for the placement of capacitor bank wherein the
injection of fixed amount of reactive power is made to depict a picture of the overall improved
voltage in the system considering the stability aspect for respective injection at that bus. The reduced
jacobian is used to determine the impact of reactive power injection in the form of system voltage
improvement.
In recent days, due to advancement in technology, the end users are facing severe power quality issues. Load flow analysis is one of the fundamental methodologies in solving power network problems. The key importance of Load flow analysis is to improve the performance of distribution network. The main intention of this reserach is to carry out the load flow and voltage stability analysis of 10 bus loop distribution network energized by a generator. Load flow analysis is carried out by using Newton Raphson method. The per unit voltage and angle of the proposed network is determined in all 10 buses by load flow analysis. The voltage stability analysis is implemented by introducing a fault in the network. Here, a power fault is injected at bus 4 between the time interval of 2 to 3 sec to analyse the stability of the system. The voltage stability of the system is analysed for the network with and without automatic voltage regulator (AVR). The AVR unit is tuned by using power system stabilizer (PSS). The results are examined by simulating the network using open modelica connection editor. From the simulation results the per unit voltages and angles at all 10 buses are determined for the network with and without AVR. By comparing both the results it is proved that the network with AVR has better voltage stability than the other. Thus, the voltage stability of the system is improved by connecting the generator with AVR and PSS.
Particle Swarm Optimization based Network Reconfiguration in Distribution Sys...theijes
The International Journal of Engineering & Science is aimed at providing a platform for researchers, engineers, scientists, or educators to publish their original research results, to exchange new ideas, to disseminate information in innovative designs, engineering experiences and technological skills. It is also the Journal's objective to promote engineering and technology education. All papers submitted to the Journal will be blind peer-reviewed. Only original articles will be published.
The papers for publication in The International Journal of Engineering& Science are selected through rigorous peer reviews to ensure originality, timeliness, relevance, and readability.
Theoretical work submitted to the Journal should be original in its motivation or modeling structure. Empirical analysis should be based on a theoretical framework and should be capable of replication. It is expected that all materials required for replication (including computer programs and data sets) should be available upon request to the authors.
The International Journal of Engineering & Science would take much care in making your article published without much delay with your kind cooperation
Three-phase four-wire shunt hybrid active power filter model with model pred...IJECEIAES
This paper presents a harmonic reduction and load imbalance model in a three-phase four-wire distribution network. This model uses a hybrid active power filter, a passive inductor and capacitor filter, and an active power filter in the form of a three-phase, four-leg connected grid inverter. The switching of the voltage source converter on this filter uses finite control set model predictive control (FCS-MPC). Control of this hybrid active power filter uses model predictive control (MPC) with a cost function, comparing the reference current and prediction current with mathematical modelling of the circuit. The reference current is taken from the load current by extracting dq, and the predicted current is obtained from the iteration of the voltage source converter (VSC) switching pattern. Each combination is compared with the reference current in the cost function to get the smallest error used as a power switching signal. Modelling was validated by using MATLAB Simulink. The simulation results prove a decrease in harmonics at a balanced load from 22.16% to 4.2% and at an unbalanced load, reducing the average harmonics to 4.74%. The simulation also decreases the load current imbalance in the distribution network. Reducing the current in the neutral wire from 62.01%-0.42% and 11.29-0.3 A.
Power Flow Analysis for Four Buses System by NR Methodijtsrd
Power flow studies provide a systematic mathematical approach for determination of various bus voltages, there phase angle, active and reactive power flows through different branches, generators and loads under steady state condition. In this paper, the purpose of power flow analysis is to determine four bus system power flows. Case studies have been performed on Lawpita Taungoo Kamarnat Hlawga 230kV Line Myanmar . This paper presents a reliable method to meet the requirements by developing a Newton Raphson based load flow calculation program through which control setting of Shunt Compensator can be determined directly. This program computes the voltage magnitude and angle at each bus in a power system under balanced steady state conditions. Real and reactive power flows for all buses, as well as line flow and line losses, are also computed. And then the compensation of shunt capacitor is proposed for load flow analysis and also for overall loss minimization and improvement in system voltage profile. Wint Yu Yu Zaw ""Power Flow Analysis for Four Buses System by NR Method"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23472.pdf
Paper URL: https://www.ijtsrd.com/engineering/electronics-and-communication-engineering/23472/power-flow-analysis-for-four-buses-system-by-nr-method/wint-yu-yu-zaw
Similar to Differential Evolution Based Optimization Approach for Power Factor Correction (20)
Power System State Estimation - A ReviewIDES Editor
The aim of this article is to provide a comprehensive
survey on power system state estimation techniques. The
algorithms used for finding the system states under both static
and dynamic state estimations are discussed in brief. The
authors are opinion that the scope of pursuing research in the
area of state estimation with PMU and SCADA measurements
is the state of the art and timely.
Artificial Intelligence Technique based Reactive Power Planning Incorporating...IDES Editor
Reactive Power Planning is a major concern in the
operation and control of power systems This paper compares
the effectiveness of Evolutionary Programming (EP) and
New Improved Differential Evolution (NIMDE) to solve
Reactive Power Planning (RPP) problem incorporating
FACTS Controllers like Static VAR Compensator (SVC),
Thyristor Controlled Series Capacitor (TCSC) and Unified
power flow controller (UPFC) considering voltage stability.
With help of Fast Voltage Stability Index (FVSI), the critical
lines and buses are identified to install the FACTS controllers.
The optimal settings of the control variables of the generator
voltages,transformer tap settings and allocation and parameter
settings of the SVC,TCSC,UPFC are considered for reactive
power planning. The test and Validation of the proposed
algorithm are conducted on IEEE 30–bus system and 72-bus
Indian system.Simulation results shows that the UPFC gives
better results than SVC and TCSC and the FACTS controllers
reduce the system losses.
Design and Performance Analysis of Genetic based PID-PSS with SVC in a Multi-...IDES Editor
Damping of power system oscillations with the help
of proposed optimal Proportional Integral Derivative Power
System Stabilizer (PID-PSS) and Static Var Compensator
(SVC)-based controllers are thoroughly investigated in this
paper. This study presents robust tuning of PID-PSS and
SVC-based controllers using Genetic Algorithms (GA) in
multi machine power systems by considering detailed model
of the generators (model 1.1). The effectiveness of FACTSbased
controllers in general and SVC-based controller in
particular depends upon their proper location. Modal
controllability and observability are used to locate SVC–based
controller. The performance of the proposed controllers is
compared with conventional lead-lag power system stabilizer
(CPSS) and demonstrated on 10 machines, 39 bus New England
test system. Simulation studies show that the proposed genetic
based PID-PSS with SVC based controller provides better
performance.
Optimal Placement of DG for Loss Reduction and Voltage Sag Mitigation in Radi...IDES Editor
This paper presents the need to operate the power
system economically and with optimum levels of voltages has
further led to an increase in interest in Distributed
Generation. In order to reduce the power losses and to improve
the voltage in the distribution system, distributed generators
(DGs) are connected to load bus. To reduce the total power
losses in the system, the most important process is to identify
the proper location for fixing and sizing of DGs. It presents a
new methodology using a new population based meta heuristic
approach namely Artificial Bee Colony algorithm(ABC) for
the placement of Distributed Generators(DG) in the radial
distribution systems to reduce the real power losses and to
improve the voltage profile, voltage sag mitigation. The power
loss reduction is important factor for utility companies because
it is directly proportional to the company benefits in a
competitive electricity market, while reaching the better power
quality standards is too important as it has vital effect on
customer orientation. In this paper an ABC algorithm is
developed to gain these goals all together. In order to evaluate
sag mitigation capability of the proposed algorithm, voltage
in voltage sensitive buses is investigated. An existing 20KV
network has been chosen as test network and results are
compared with the proposed method in the radial distribution
system.
Line Losses in the 14-Bus Power System Network using UPFCIDES Editor
Controlling power flow in modern power systems
can be made more flexible by the use of recent developments
in power electronic and computing control technology. The
Unified Power Flow Controller (UPFC) is a Flexible AC
transmission system (FACTS) device that can control all the
three system variables namely line reactance, magnitude and
phase angle difference of voltage across the line. The UPFC
provides a promising means to control power flow in modern
power systems. Essentially the performance depends on proper
control setting achievable through a power flow analysis
program. This paper presents a reliable method to meet the
requirements by developing a Newton-Raphson based load
flow calculation through which control settings of UPFC can
be determined for the pre-specified power flow between the
lines. The proposed method keeps Newton-Raphson Load Flow
(NRLF) algorithm intact and needs (little modification in the
Jacobian matrix). A MATLAB program has been developed to
calculate the control settings of UPFC and the power flow
between the lines after the load flow is converged. Case studies
have been performed on IEEE 5-bus system and 14-bus system
to show that the proposed method is effective. These studies
indicate that the method maintains the basic NRLF properties
such as fast computational speed, high degree of accuracy and
good convergence rate.
Study of Structural Behaviour of Gravity Dam with Various Features of Gallery...IDES Editor
The size and shape of opening in dam causes the
stress concentration, it also causes the stress variation in the
rest of the dam cross section. The gravity method of the analysis
does not consider the size of opening and the elastic property
of dam material. Thus the objective of study is comprises of
the Finite Element Method which considers the size of
opening, elastic property of material, and stress distribution
because of geometric discontinuity in cross section of dam.
Stress concentration inside the dam increases with the opening
in dam which results in the failure of dam. Hence it is
necessary to analyses large opening inside the dam. By making
the percentage area of opening constant and varying size and
shape of opening the analysis is carried out. For this purpose
a section of Koyna Dam is considered. Dam is defined as a
plane strain element in FEM, based on geometry and loading
condition. Thus this available information specified our path
of approach to carry out 2D plane strain analysis. The results
obtained are then compared mutually to get most efficient
way of providing large opening in the gravity dam.
Assessing Uncertainty of Pushover Analysis to Geometric ModelingIDES Editor
Pushover Analysis a popular tool for seismic
performance evaluation of existing and new structures and is
nonlinear Static procedure where in monotonically increasing
loads are applied to the structure till the structure is unable
to resist the further load .During the analysis, whatever the
strength of concrete and steel is adopted for analysis of
structure may not be the same when real structure is
constructed and the pushover analysis results are very sensitive
to material model adopted, geometric model adopted, location
of plastic hinges and in general to procedure followed by the
analyzer. In this paper attempt has been made to assess
uncertainty in pushover analysis results by considering user
defined hinges and frame modeled as bare frame and frame
with slab modeled as rigid diaphragm and results compared
with experimental observations. Uncertain parameters
considered includes the strength of concrete, strength of steel
and cover to the reinforcement which are randomly generated
and incorporated into the analysis. The results are then
compared with experimental observations.
Secure Multi-Party Negotiation: An Analysis for Electronic Payments in Mobile...IDES Editor
This paper is an attempt to base on auctions which
presents a frame work for the secure multi-party decision
protocols. In addition to the implementations which are very
light weighted, the main focus is on synchronizing security
features for avoiding agreements manipulations and reducing
the user traffic. Through this paper one can understand that
this different auction protocols on top of the frame work can
be collaborated using mobile devices. This paper present the
negotiation between auctioneer and the proffered and this
negotiation shows that multiparty security is far better than
the existing system.
Selfish Node Isolation & Incentivation using Progressive ThresholdsIDES Editor
The problems associated with selfish nodes in
MANET are addressed by a collaborative watchdog approach
which reduces the detection time for selfish nodes thereby
improves the performance and accuracy of watchdogs[1]. In
the related works they make use of credit based systems, reputation
based mechanisms, pathrater and watchdog mechanism
to detect such selfish nodes. In this paper we follow an approach
of collaborative watchdog which reduces the detection
time for selfish nodes and also involves the removal of such
selfish nodes based on some progressively assessed thresholds.
The threshold gives the nodes a chance to stop misbehaving
before it is permanently deleted from the network.
The node passes through several isolation processes before it
is permanently removed. Another version of AODV protocol
is used here which allows the simulation of selfish nodes in
NS2 by adding or modifying log files in the protocol.
Various OSI Layer Attacks and Countermeasure to Enhance the Performance of WS...IDES Editor
Wireless sensor networks are networks having non
wired infrastructure and dynamic topology. In OSI model each
layer is prone to various attacks, which halts the performance
of a network .In this paper several attacks on four layers of
OSI model are discussed and security mechanism is described
to prevent attack in network layer i.e wormhole attack. In
Wormhole attack two or more malicious nodes makes a covert
channel which attracts the traffic towards itself by depicting a
low latency link and then start dropping and replaying packets
in the multi-path route. This paper proposes promiscuous mode
method to detect and isolate the malicious node during
wormhole attack by using Ad-hoc on demand distance vector
routing protocol (AODV) with omnidirectional antenna. The
methodology implemented notifies that the nodes which are
not participating in multi-path routing generates an alarm
message during delay and then detects and isolate the
malicious node from network. We also notice that not only
the same kind of attacks but also the same kind of
countermeasures can appear in multiple layer. For example,
misbehavior detection techniques can be applied to almost all
the layers we discussed.
Responsive Parameter based an AntiWorm Approach to Prevent Wormhole Attack in...IDES Editor
The recent advancements in the wireless technology
and their wide-spread deployment have made remarkable
enhancements in efficiency in the corporate and industrial
and Military sectors The increasing popularity and usage of
wireless technology is creating a need for more secure wireless
Ad hoc networks. This paper aims researched and developed
a new protocol that prevents wormhole attacks on a ad hoc
network. A few existing protocols detect wormhole attacks but
they require highly specialized equipment not found on most
wireless devices. This paper aims to develop a defense against
wormhole attacks as an Anti-worm protocol which is based on
responsive parameters, that does not require as a significant
amount of specialized equipment, trick clock synchronization,
no GPS dependencies.
Cloud Security and Data Integrity with Client Accountability FrameworkIDES Editor
The Cloud based services provide much efficient
and seamless ways for data sharing across the cloud. The fact
that the data owners no longer possess data makes it very
difficult to assure data confidentiality and to enable secure
data sharing in the cloud. Despite of all its advantages this
will remain a major limitation that acts as a barrier to the
wider deployment of cloud based services. One of the possible
ways for ensuring trust in this aspect is the introduction of
accountability feature in the cloud computing scenario. The
Cloud framework requires promotion of distributed
accountability for such dynamic environment[1]. In some
works, there‘s an accountable framework suggested to ensure
distributed accountability for data sharing by the generation
of only a log of data access, but without any embedded feedback
mechanism for owner permission towards data
protection[2].The proposed system is an enhanced client
accountability framework which provides an additional client
side verification for each access towards enhanced security of
data. The integrity of content of data which resides in the
cloud service provider is also maintained by secured
outsourcing. Besides, the authentication of JAR(Java Archive)
files are done to ensure file protection and to maintain a safer
environment for data sharing. The analysis of various
functionalities of the framework depicts both the
accountability and security feature in an efficient manner.
Genetic Algorithm based Layered Detection and Defense of HTTP BotnetIDES Editor
A System state in HTTP botnet uses HTTP protocol
for the creation of chain of Botnets thereby compromising
other systems. By using HTTP protocol and port number 80,
attacks can not only be hidden but also pass through the
firewall without being detected. The DPR based detection
leads to better analysis of botnet attacks [3]. However, it
provides only probabilistic detection of the attacker and also
time consuming and error prone. This paper proposes a Genetic
algorithm based layered approach for detecting as well as
preventing botnet attacks. The paper reviews p2p firewall
implementation which forms the basis of filtering.
Performance evaluation is done based on precision, F-value
and probability. Layered approach reduces the computation
and overall time requirement [7]. Genetic algorithm promises
a low false positive rate.
Enhancing Data Storage Security in Cloud Computing Through SteganographyIDES Editor
in cloud computing data storage is a significant issue
because the entire data reside over a set of interconnected
resource pools that enables the data to be accessed through
virtual machines. It moves the application software’s and
databases to the large data centers where the management of
data is actually done. As the resource pools are situated over
various corners of the world, the management of data and
services may not be fully trustworthy. So, there are various
issues that need to be addressed with respect to the
management of data, service of data, privacy of data, security
of data etc. But the privacy and security of data is highly
challenging. To ensure privacy and security of data-at-rest in
cloud computing, we have proposed an effective and a novel
approach to ensure data security in cloud computing by means
of hiding data within images following is the concept of
steganography. The main objective of this paper is to prevent
data access from cloud data storage centers by unauthorized
users. This scheme perfectly stores data at cloud data storage
centers and retrieves data from it when it is needed.
The main tasks of a Wireless Sensor Network
(WSN) are data collection from its nodes and communication
of this data to the base station (BS). The protocols used for
communication among the WSN nodes and between the WSN
and the BS, must consider the resource constraints of nodes,
battery energy, computational capabilities and memory. The
WSN applications involve unattended operation of the network
over an extended period of time. In order to extend the lifetime
of a WSN, efficient routing protocols need to be adopted. The
proposed low power routing protocol based on tree-based
network structure reliably forwards the measured data towards
the BS using TDMA. An energy consumption analysis of the
WSN making use of this protocol is also carried out. It is
found that the network is energy efficient with an average
duty cycle of 0:7% for the WSN nodes. The OmNET++
simulation platform along with MiXiM framework is made
use of.
Permutation of Pixels within the Shares of Visual Cryptography using KBRP for...IDES Editor
The security of authentication of internet based
co-banking services should not be susceptible to high risks.
The passwords are highly vulnerable to virus attacks due to
the lack of high end embedding of security methods. In order
for the passwords to be more secure, people are generally
compelled to select jumbled up character based passwords
which are not only less memorable but are also equally prone
to insecurity. Multiple use of distributed shares has been
studied to solve the problem of authentication by algorithms
based on thresholding of pixels in image processing and visual
cryptography concepts where the subset of shares is considered
for the recovery of the original image for authentication using
correlation function[1][2].The main disadvantage in the above
study is the plain storage of shares and also one of the shares
is being supplied to the customer, which will lead to the
possibility of misuse by a third party. This paper proposes a
technique for scrambling of pixels by key based random
permutation (KBRP) within the shares before the
authentication has been attempted. Total number of shares to
be created is dependent on the multiplicity of ownership of
the account. By this method the problem of uncertainty among
the customers with regard to security, storage, retrieval of
holding of half of the shares is minimized.
This paper presents a trifocal Rotman Lens Design
approach. The effects of focal ratio and element spacing on
the performance of Rotman Lens are described. A three beam
prototype feeding 4 element antenna array working in L-band
has been simulated using RLD v1.7 software. Simulated
results show that the simulated lens has a return loss of –
12.4dB at 1.8GHz. Beam to array port phase error variation
with change in the focal ratio and element spacing has also
been investigated.
Band Clustering for the Lossless Compression of AVIRIS Hyperspectral ImagesIDES Editor
Hyperspectral images can be efficiently compressed
through a linear predictive model, as for example the one
used in the SLSQ algorithm. In this paper we exploit this
predictive model on the AVIRIS images by individuating,
through an off-line approach, a common subset of bands, which
are not spectrally related with any other bands. These bands
are not useful as prediction reference for the SLSQ 3-D
predictive model and we need to encode them via other
prediction strategies which consider only spatial correlation.
We have obtained this subset by clustering the AVIRIS bands
via the clustering by compression approach. The main result
of this paper is the list of the bands, not related with the
others, for AVIRIS images. The clustering trees obtained for
AVIRIS and the relationship among bands they depict is also
an interesting starting point for future research.
Microelectronic Circuit Analogous to Hydrogen Bonding Network in Active Site ...IDES Editor
A microelectronic circuit of block-elements
functionally analogous to two hydrogen bonding networks is
investigated. The hydrogen bonding networks are extracted
from â-lactamase protein and are formed in its active site.
Each hydrogen bond of the network is described in equivalent
electrical circuit by three or four-terminal block-element.
Each block-element is coded in Matlab. Static and dynamic
analyses are performed. The resultant microelectronic circuit
analogous to the hydrogen bonding network operates as
current mirror, sine pulse source, triangular pulse source as
well as signal modulator.
Texture Unit based Monocular Real-world Scene Classification using SOM and KN...IDES Editor
In this paper a method is proposed to discriminate
real world scenes in to natural and manmade scenes of similar
depth. Global-roughness of a scene image varies as a function
of image-depth. Increase in image depth leads to increase in
roughness in manmade scenes; on the contrary natural scenes
exhibit smooth behavior at higher image depth. This particular
arrangement of pixels in scene structure can be well explained
by local texture information in a pixel and its neighborhood.
Our proposed method analyses local texture information of a
scene image using texture unit matrix. For final classification
we have used both supervised and unsupervised learning using
K-Nearest Neighbor classifier (KNN) and Self Organizing
Map (SOM) respectively. This technique is useful for online
classification due to very less computational complexity.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202