The document analyzes and compares the impact of different shunt compensation devices (shunt capacitor, synchronous phase modifier (SPM), and static VAR compensator (SVC)) on voltage stability enhancement. It identifies the most critical contingency using indices like P-V curves, L-index, and fast voltage stability index (FVSI) for the IEEE 9-bus, 30-bus, and 118-bus test systems. The optimal location and size of the shunt compensator is determined by placing a fictitious generator at the weakest bus. Simulation results show that all three devices can improve voltage stability against load variations, with SPM having slightly higher losses than the other options.
This document discusses voltage stability in power systems. It defines voltage stability as the ability of a power system to maintain acceptable voltage levels under normal conditions and after being subjected to a disturbance. Voltage stability can be analyzed through static or dynamic analysis. Static analysis assumes steady-state conditions while dynamic analysis solves differential equations over time. The document focuses on concepts like P-V and Q-V curves, which relate active/reactive power to voltage. It examines how different load types like constant MVA loads affect stability. Sensitivity analysis is introduced as a static analysis method to determine stability by examining how bus voltages change with reactive power injections.
There are two broad classes of power system stability:
1) Steady state stability - The ability of a system to maintain equilibrium after a small disturbance.
2) Transient stability - The ability to maintain synchronism during large disturbances like faults.
Factors influencing transient stability include generator loading, fault conditions, clearing time, reactances, and inertia. Methods to improve it include high-speed excitation, series capacitors, fault clearing and independent pole operation.
Voltage stability using Series FACTS devicesSAI SREE
This document discusses various FACTS devices and their use in enhancing voltage stability. It first defines voltage stability and FACTS devices. FACTS devices are classified as either series or shunt devices depending on their connection type. Series compensation devices like TCSC and SSSC inject voltage in quadrature with line current to control active power flow and reduce line losses. TCSC allows rapid changes to transmission line impedance. SSSC can control both active and reactive power with capacitive and inductive modes of operation. The document concludes that FACTS devices like TCSC and SSSC can improve voltage stability through controlling parameters like voltage, reactance, and power flow in transmission lines.
Power System Stability Enhancement Using Static Synchronous Series Compensato...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Voltage collapse mitigation by reactive power compensation at the load sideeSAT Journals
Abstract Power system stability may be defined as the property of a power system that enables it to remain in a state of operating equilibrium under normal operating conditions and to regain an acceptable state of equilibrium after being subjected to a disturbance. A general and formal definition is given below. The IEEE/CIGRE Joint Task Force has proposed the following definition-“Power system stability is the ability of an electric power system, for a given initial operating condition, to regain a state of operating equilibrium after being subjected to a physical disturbance, with most system variables bounded, so that practically the entire system remains intact.” The challenge faced in the modern power system is the collapse of voltages at heavy loads at the load buses of a power system. The voltage collapse will in turn will effect the stability of the power system. In this paper a novel way of mitigating the voltage collapse by supplying the reactive power at load buses is discussed and encouraging simulation results are obtained. The method employed is as fallows. Simulation is done without SVC and STATCOM at load buses. On comparison of the results at the load buses it is seen that with SVC and STATCOM at the load buses voltage collapse is mitigated in spite of heavily loading the system. Keywords: Voltage Collapse, Reactive Power Management, Load Bus, Power System Stability.
This document discusses voltage stability in power systems. It defines voltage stability as the ability of a power system to maintain acceptable voltage levels under normal conditions and after being subjected to a disturbance. Voltage stability can be analyzed through static or dynamic analysis. Static analysis assumes steady-state conditions while dynamic analysis solves differential equations over time. The document focuses on concepts like P-V and Q-V curves, which relate active/reactive power to voltage. It examines how different load types like constant MVA loads affect stability. Sensitivity analysis is introduced as a static analysis method to determine stability by examining how bus voltages change with reactive power injections.
There are two broad classes of power system stability:
1) Steady state stability - The ability of a system to maintain equilibrium after a small disturbance.
2) Transient stability - The ability to maintain synchronism during large disturbances like faults.
Factors influencing transient stability include generator loading, fault conditions, clearing time, reactances, and inertia. Methods to improve it include high-speed excitation, series capacitors, fault clearing and independent pole operation.
Voltage stability using Series FACTS devicesSAI SREE
This document discusses various FACTS devices and their use in enhancing voltage stability. It first defines voltage stability and FACTS devices. FACTS devices are classified as either series or shunt devices depending on their connection type. Series compensation devices like TCSC and SSSC inject voltage in quadrature with line current to control active power flow and reduce line losses. TCSC allows rapid changes to transmission line impedance. SSSC can control both active and reactive power with capacitive and inductive modes of operation. The document concludes that FACTS devices like TCSC and SSSC can improve voltage stability through controlling parameters like voltage, reactance, and power flow in transmission lines.
Power System Stability Enhancement Using Static Synchronous Series Compensato...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Voltage collapse mitigation by reactive power compensation at the load sideeSAT Journals
Abstract Power system stability may be defined as the property of a power system that enables it to remain in a state of operating equilibrium under normal operating conditions and to regain an acceptable state of equilibrium after being subjected to a disturbance. A general and formal definition is given below. The IEEE/CIGRE Joint Task Force has proposed the following definition-“Power system stability is the ability of an electric power system, for a given initial operating condition, to regain a state of operating equilibrium after being subjected to a physical disturbance, with most system variables bounded, so that practically the entire system remains intact.” The challenge faced in the modern power system is the collapse of voltages at heavy loads at the load buses of a power system. The voltage collapse will in turn will effect the stability of the power system. In this paper a novel way of mitigating the voltage collapse by supplying the reactive power at load buses is discussed and encouraging simulation results are obtained. The method employed is as fallows. Simulation is done without SVC and STATCOM at load buses. On comparison of the results at the load buses it is seen that with SVC and STATCOM at the load buses voltage collapse is mitigated in spite of heavily loading the system. Keywords: Voltage Collapse, Reactive Power Management, Load Bus, Power System Stability.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Evolve the Controller for Static Synchronous Series Compensator Based on Cont...IJPEDS-IAES
Real and Reactive power flow in an alternating current transmission line can be independently controlled by connecting, to the transmission line, a series- compensating voltage, which is variable in magnitude and phase angle. The Static Synchronous Series Compensator (SSSC), a solid-state voltage source inverter (VSC) coupled with a transformer, is connected in series with a transmission line. An SSSC injects an almost sinusoidal voltage, of variable magnitude, in series with a transmission line. This injected voltage is almost in quadrature with the line current, thereby emulating an inductive or a capacitive reactance in series with the transmission line. This emulated variable reactance, inserted by the injected voltage source, influences the electric power flow in the transmission line. In this report, an attempt is made to evolve the model of SSSC and VSC with preliminary studies for the controller design.
This document discusses flexible alternating current transmission systems (FACTS) and focuses on shunt compensators. It covers the objectives of shunt compensation including midpoint voltage regulation to segment transmission lines, end of line voltage support to prevent instability, improving transient stability, and damping power oscillations. Midpoint compensation regulates voltage to allow lines to be treated as multiple segments. End of line support maintains receiving end voltages and prevents instability during disturbances. Shunt devices provide fast reactive power to damp out angle and power oscillations following events. The document examines these topics through mathematical analysis and diagrams.
This document provides an overview of a course on Flexible AC Transmission Systems (FACTS) controllers. The course covers various topics including:
- Introduction to FACTS controllers and their benefits in controlling power flow.
- Operation of voltage source converters and current source converters, including single-phase and three-phase bridge converters.
- Methods of shunt compensation using static VAR compensators and thyristor controlled reactors to improve stability and reduce oscillations.
- Series compensation methods to control power flow using thyristor controlled series capacitors and reactors.
- Combined controllers like the Unified Power Flow Controller (UPFC) that can control both series and shunt compensation simultaneously.
The objectives
The document discusses unified power flow controllers (UPFCs) and their benefits for power systems. It provides the following key points:
1) A UPFC consists of two voltage-source converters connected by a DC link, allowing one converter to operate as a static synchronous compensator (STATCOM) to provide reactive power support and the other to function as a static synchronous series compensator (SSSC) to control real power flow.
2) UPFCs offer benefits like regulating power flows, reducing the need for new transmission infrastructure, improving transient stability, and independently controlling real and reactive power flows.
3) The document describes the basic configuration and circuit of a UPFC installed between a sending and receiving end
A Review on Power System Voltage Stability and Optimization TechniquesIJERA Editor
Power system voltage stability is a one of the major focused areas in recent days due to mismatch between generation and demand. Maintenance of voltage stability is a challenging issue in planning and security assessment of power systems. Voltage stability is the ability of a power system to maintain steady acceptable voltages at all buses in the power system under normal operating conditions and after being subjected to a disturbance. Long-term voltage instability problems can occur in heavily loaded systems where the electrical distance is large between the generator and the load. Timely application of reactive power compensation or load shedding may prevent this type of voltage instability. System reactive power handling capacity can be improved with Flexible AC Transmission System (FACTS) devices. Identification of critical system locations to undertake appropriate remedial measures in operation is the concern. This paper reviews the performance of various types FACTS controllers in power system voltage stability problem and focuses on different optimization methods implemented for optimal placement and sizing of FACTS devices to minimize power losses.
This document provides an overview of Flexible AC Transmission Systems (FACTS) technology. It outlines 6 units that will be covered: introduction to FACTS, voltage and current source converters, shunt compensators, series compensators, and combined controllers. The introduction discusses power flow limitations in AC systems and how FACTS devices can control parameters like voltage and impedance to improve power transfer capacity and stability. Key FACTS benefits are listed as well as the characteristics and tradeoffs of high power semiconductor devices used. The document aims to explain how FACTS controllers work and their applications in improving power system performance.
A flexible alternating current transmission system (FACTS) is a system composed of static equipment used for the AC transmission of electrical energy. It is meant to enhance controllability and increase power transfer capability of the network. It is generally a power electronics-based system.
In conventional AC transmission system, the ability to transfer AC power is limited by several factors like thermal limits, transient stability limit, voltage limit, short circuit current limit etc. These limits define the maximum electric power which can be efficiently transmitted through the transmission line without causing any damage to the electrical equipments and the transmission lines. This is normally achieved by bringing changes in the power system layout. However this is not feasible and another way of achieving maximum power transfer capability without any changes in the power system layout. Also with the introduction of variable impedance devices like capacitors and inductors, whole of the energy or power from the source is not transferred to the load, but a part is stored in these devices as reactive power and returned back to the source. Thus the actual amount of power transferred to the load or the active power is always less than the apparent power or the net power. For ideal transmission the active power should be equal to the apparent power. In other words, the power factor (the ratio of active power to apparent power) should be unity. This is where the role of Flexible AC transmission System comes.
This document discusses FACTS (Flexible AC Transmission System) devices. It defines FACTS as using static power electronics controllers to control reactive power and enhance AC transmission system controllability. The document outlines the necessity of FACTS devices to compensate for reactive power and improve power transmission efficiency. It describes different types of FACTS controllers including shunt controllers like STATCOM, TCR, TSR, and TSC. The benefits of FACTS in providing fast, flexible control of transmission parameters and improving power flow capability are also summarized.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Stability Modeling Of Storage Devices In FACTS Applicationspreeti naga
The document discusses modeling of storage devices like SMES and BESS for stability applications in FACTS. It describes the need for storage devices to improve controllability in FACTS. It explains SMES, with the superconducting coil producing large fringe fields and power conversion through a VSC and DC-DC chopper. Steady state models are used in power flow studies to maintain real and reactive power injections. State of operation models storage devices as quasi-steady interfaces with dynamic controls. Static VAR compensators are also discussed with thyristor controlled reactors and capacitors to regulate voltage. Dynamic models of the superconducting inductor and battery are also presented.
Comparison of facts devices for two area power system stability enhancement u...IAEME Publication
This document summarizes a research paper that compares the performance of SVC and STATCOM FACTS devices for enhancing transient stability in a two area power system modelled in MATLAB. The paper reviews previous research on using FACTS controllers like SVC, STATCOM, SSSC, TCSC and UPFC to improve power system stability. Simulation results from the paper indicate that a two machine system installed with STATCOM provided better damping of rotor angle oscillations compared to an SVC installation, demonstrating improved transient stability when using a STATCOM.
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.
This document is a project report submitted by four students for their Bachelor of Engineering degree. The project investigates the optimal location of Interline Power Flow Controllers (IPFC) in power transmission systems. The objectives are to maintain voltage profiles and real and reactive power flows. The scope involves improving voltage profiles and power transfer capabilities using IPFCs. Recently, FACTS devices like IPFCs have attracted interest for applications like congestion management and cost reduction. The problem is that few publications have investigated IPFC locations in power systems and their effects. The report is organized into chapters covering theory, location determination methods, IPFC performance simulation and results.
Static Synchronous Series Compensator (SSSC) with Superconducting Magnetic En...IDES Editor
Static Synchronous Series Compensator (SSSC) has
been designed with Superconducting Magnetic Energy Storage
(SMES) system. A closed loop control scheme has been
proposed with PI controller and real and reactive powers are
taken as references. A 48 pulse voltage source inverter is
designed for the SSSC. Control scheme for the chopper circuit
of SMES coil is also designed. A three area system is taken as
the test system and the operation of SSSC with SMES is
analysed for various transient disturbances. Test results under
different disturbances and operating conditions show the
proposed SSSC with SMES is effective in damping out the
power system oscillations.
Transient Stability of Power System using Facts Device-UPFCijsrd.com
This paper is based on Occurrence of a fault in a power system causes transients. To stabilize the system, The Flexible Alternating Current Transmission (FACTS) devices such as UPFC are becoming important in suppressing power system oscillations and improving system damping. The UPFC is a solid-state device, which can be used to control the active and reactive power.. By using a UPFC the oscillation introduced by the faults, the rotor angle and speed deviations can be damped out quickly than a system without a UPFC. The effectiveness of UPFC in suppressing power system oscillation is investigated by analyzing their oscillation in rotor angle and change in speed occurred in the two machine system considered in this work. A proportional integral (PI) controller has been employed for the UPFC. It is also shown that a UPFC can control independently the real and reactive power flow in a transmission line. A MATLAB simulation has been carried out to demonstrate the performance of the UPFC in achieving transient stability of the two-machine five-bus system.
##CONTENT##
Introduction
Voltage control
Power system control
Control of reactive power and power factor
Interconnected control and frequency ties
Supervisory control
Line compensation
Series compensation
Series and shunt compensation schemes for ac transmission system
Comparison of Shunt Facts Devices for the Improvement of Transient Stability ...IJSRD
This paper presents, the performance of STATCOM placed at midpoint of the two machine power system and compared with the performance of SVC. The comparison of various results found for the different type of faults (single line, double line & three phase fault) occur in long transmission line, and their removal by using shunt FACTS devices is analysed. Computer simulation results under a severe disturbance condition (three phase fault) for different fault clearing times, and different line lengths are analyzed. Both controllers are implemented using MATLAB/SIMULINK. Simulation results shows that the STATCOM with conventional PI controller installed with two machine three bus systems provides better damping oscillation characteristics in rotor angle as compared to two machine power system installed with SVC. The transient stability of two machine system installed with STATCOM has been improved considerably and post settling time of the system after facing disturbance is also improved.
Comparison of 60GHz CSRRs Ground Shield and Patterned Ground Shield On-chip B...IOSR Journals
This document compares two 60GHz on-chip bandpass filters designed using a 0.18μm CMOS technology. The first filter uses complementary split ring resonators (CSRRs) as the ground shield, while the second uses a patterned ground shield. Simulation results show that the CSRR ground shield filter has slightly lower insertion loss of -2.682dB, a narrower 3dB bandwidth of 10.8GHz, and a smaller chip size of 0.651mm^2. The patterned ground shield filter has a higher insertion loss of -2.77dB but a wider 3dB bandwidth of 14GHz and slightly smaller chip size of 0.527mm^2. Both filters demonstrate good return loss and
High Performance Error Detection with Different Set Cyclic Codes for Memory A...IOSR Journals
The document presents a proposed error detection method using majority logic decoding with difference set cyclic codes. The proposed method can detect up to five bit errors in the first three decoding cycles, improving performance over traditional majority logic decoding approaches. It uses a control unit to evaluate parity check sums over the first three cycles, and can detect errors without fully decoding the codeword when no errors are found. This reduces decoding time compared to approaches that fully decode each codeword. The proposed method is also less complex than alternatives using syndrome calculation for error detection. Simulation results showed the proposed method can detect errors faster while using less memory and power than traditional approaches.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Evolve the Controller for Static Synchronous Series Compensator Based on Cont...IJPEDS-IAES
Real and Reactive power flow in an alternating current transmission line can be independently controlled by connecting, to the transmission line, a series- compensating voltage, which is variable in magnitude and phase angle. The Static Synchronous Series Compensator (SSSC), a solid-state voltage source inverter (VSC) coupled with a transformer, is connected in series with a transmission line. An SSSC injects an almost sinusoidal voltage, of variable magnitude, in series with a transmission line. This injected voltage is almost in quadrature with the line current, thereby emulating an inductive or a capacitive reactance in series with the transmission line. This emulated variable reactance, inserted by the injected voltage source, influences the electric power flow in the transmission line. In this report, an attempt is made to evolve the model of SSSC and VSC with preliminary studies for the controller design.
This document discusses flexible alternating current transmission systems (FACTS) and focuses on shunt compensators. It covers the objectives of shunt compensation including midpoint voltage regulation to segment transmission lines, end of line voltage support to prevent instability, improving transient stability, and damping power oscillations. Midpoint compensation regulates voltage to allow lines to be treated as multiple segments. End of line support maintains receiving end voltages and prevents instability during disturbances. Shunt devices provide fast reactive power to damp out angle and power oscillations following events. The document examines these topics through mathematical analysis and diagrams.
This document provides an overview of a course on Flexible AC Transmission Systems (FACTS) controllers. The course covers various topics including:
- Introduction to FACTS controllers and their benefits in controlling power flow.
- Operation of voltage source converters and current source converters, including single-phase and three-phase bridge converters.
- Methods of shunt compensation using static VAR compensators and thyristor controlled reactors to improve stability and reduce oscillations.
- Series compensation methods to control power flow using thyristor controlled series capacitors and reactors.
- Combined controllers like the Unified Power Flow Controller (UPFC) that can control both series and shunt compensation simultaneously.
The objectives
The document discusses unified power flow controllers (UPFCs) and their benefits for power systems. It provides the following key points:
1) A UPFC consists of two voltage-source converters connected by a DC link, allowing one converter to operate as a static synchronous compensator (STATCOM) to provide reactive power support and the other to function as a static synchronous series compensator (SSSC) to control real power flow.
2) UPFCs offer benefits like regulating power flows, reducing the need for new transmission infrastructure, improving transient stability, and independently controlling real and reactive power flows.
3) The document describes the basic configuration and circuit of a UPFC installed between a sending and receiving end
A Review on Power System Voltage Stability and Optimization TechniquesIJERA Editor
Power system voltage stability is a one of the major focused areas in recent days due to mismatch between generation and demand. Maintenance of voltage stability is a challenging issue in planning and security assessment of power systems. Voltage stability is the ability of a power system to maintain steady acceptable voltages at all buses in the power system under normal operating conditions and after being subjected to a disturbance. Long-term voltage instability problems can occur in heavily loaded systems where the electrical distance is large between the generator and the load. Timely application of reactive power compensation or load shedding may prevent this type of voltage instability. System reactive power handling capacity can be improved with Flexible AC Transmission System (FACTS) devices. Identification of critical system locations to undertake appropriate remedial measures in operation is the concern. This paper reviews the performance of various types FACTS controllers in power system voltage stability problem and focuses on different optimization methods implemented for optimal placement and sizing of FACTS devices to minimize power losses.
This document provides an overview of Flexible AC Transmission Systems (FACTS) technology. It outlines 6 units that will be covered: introduction to FACTS, voltage and current source converters, shunt compensators, series compensators, and combined controllers. The introduction discusses power flow limitations in AC systems and how FACTS devices can control parameters like voltage and impedance to improve power transfer capacity and stability. Key FACTS benefits are listed as well as the characteristics and tradeoffs of high power semiconductor devices used. The document aims to explain how FACTS controllers work and their applications in improving power system performance.
A flexible alternating current transmission system (FACTS) is a system composed of static equipment used for the AC transmission of electrical energy. It is meant to enhance controllability and increase power transfer capability of the network. It is generally a power electronics-based system.
In conventional AC transmission system, the ability to transfer AC power is limited by several factors like thermal limits, transient stability limit, voltage limit, short circuit current limit etc. These limits define the maximum electric power which can be efficiently transmitted through the transmission line without causing any damage to the electrical equipments and the transmission lines. This is normally achieved by bringing changes in the power system layout. However this is not feasible and another way of achieving maximum power transfer capability without any changes in the power system layout. Also with the introduction of variable impedance devices like capacitors and inductors, whole of the energy or power from the source is not transferred to the load, but a part is stored in these devices as reactive power and returned back to the source. Thus the actual amount of power transferred to the load or the active power is always less than the apparent power or the net power. For ideal transmission the active power should be equal to the apparent power. In other words, the power factor (the ratio of active power to apparent power) should be unity. This is where the role of Flexible AC transmission System comes.
This document discusses FACTS (Flexible AC Transmission System) devices. It defines FACTS as using static power electronics controllers to control reactive power and enhance AC transmission system controllability. The document outlines the necessity of FACTS devices to compensate for reactive power and improve power transmission efficiency. It describes different types of FACTS controllers including shunt controllers like STATCOM, TCR, TSR, and TSC. The benefits of FACTS in providing fast, flexible control of transmission parameters and improving power flow capability are also summarized.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
Stability Modeling Of Storage Devices In FACTS Applicationspreeti naga
The document discusses modeling of storage devices like SMES and BESS for stability applications in FACTS. It describes the need for storage devices to improve controllability in FACTS. It explains SMES, with the superconducting coil producing large fringe fields and power conversion through a VSC and DC-DC chopper. Steady state models are used in power flow studies to maintain real and reactive power injections. State of operation models storage devices as quasi-steady interfaces with dynamic controls. Static VAR compensators are also discussed with thyristor controlled reactors and capacitors to regulate voltage. Dynamic models of the superconducting inductor and battery are also presented.
Comparison of facts devices for two area power system stability enhancement u...IAEME Publication
This document summarizes a research paper that compares the performance of SVC and STATCOM FACTS devices for enhancing transient stability in a two area power system modelled in MATLAB. The paper reviews previous research on using FACTS controllers like SVC, STATCOM, SSSC, TCSC and UPFC to improve power system stability. Simulation results from the paper indicate that a two machine system installed with STATCOM provided better damping of rotor angle oscillations compared to an SVC installation, demonstrating improved transient stability when using a STATCOM.
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.
This document is a project report submitted by four students for their Bachelor of Engineering degree. The project investigates the optimal location of Interline Power Flow Controllers (IPFC) in power transmission systems. The objectives are to maintain voltage profiles and real and reactive power flows. The scope involves improving voltage profiles and power transfer capabilities using IPFCs. Recently, FACTS devices like IPFCs have attracted interest for applications like congestion management and cost reduction. The problem is that few publications have investigated IPFC locations in power systems and their effects. The report is organized into chapters covering theory, location determination methods, IPFC performance simulation and results.
Static Synchronous Series Compensator (SSSC) with Superconducting Magnetic En...IDES Editor
Static Synchronous Series Compensator (SSSC) has
been designed with Superconducting Magnetic Energy Storage
(SMES) system. A closed loop control scheme has been
proposed with PI controller and real and reactive powers are
taken as references. A 48 pulse voltage source inverter is
designed for the SSSC. Control scheme for the chopper circuit
of SMES coil is also designed. A three area system is taken as
the test system and the operation of SSSC with SMES is
analysed for various transient disturbances. Test results under
different disturbances and operating conditions show the
proposed SSSC with SMES is effective in damping out the
power system oscillations.
Transient Stability of Power System using Facts Device-UPFCijsrd.com
This paper is based on Occurrence of a fault in a power system causes transients. To stabilize the system, The Flexible Alternating Current Transmission (FACTS) devices such as UPFC are becoming important in suppressing power system oscillations and improving system damping. The UPFC is a solid-state device, which can be used to control the active and reactive power.. By using a UPFC the oscillation introduced by the faults, the rotor angle and speed deviations can be damped out quickly than a system without a UPFC. The effectiveness of UPFC in suppressing power system oscillation is investigated by analyzing their oscillation in rotor angle and change in speed occurred in the two machine system considered in this work. A proportional integral (PI) controller has been employed for the UPFC. It is also shown that a UPFC can control independently the real and reactive power flow in a transmission line. A MATLAB simulation has been carried out to demonstrate the performance of the UPFC in achieving transient stability of the two-machine five-bus system.
##CONTENT##
Introduction
Voltage control
Power system control
Control of reactive power and power factor
Interconnected control and frequency ties
Supervisory control
Line compensation
Series compensation
Series and shunt compensation schemes for ac transmission system
Comparison of Shunt Facts Devices for the Improvement of Transient Stability ...IJSRD
This paper presents, the performance of STATCOM placed at midpoint of the two machine power system and compared with the performance of SVC. The comparison of various results found for the different type of faults (single line, double line & three phase fault) occur in long transmission line, and their removal by using shunt FACTS devices is analysed. Computer simulation results under a severe disturbance condition (three phase fault) for different fault clearing times, and different line lengths are analyzed. Both controllers are implemented using MATLAB/SIMULINK. Simulation results shows that the STATCOM with conventional PI controller installed with two machine three bus systems provides better damping oscillation characteristics in rotor angle as compared to two machine power system installed with SVC. The transient stability of two machine system installed with STATCOM has been improved considerably and post settling time of the system after facing disturbance is also improved.
Comparison of 60GHz CSRRs Ground Shield and Patterned Ground Shield On-chip B...IOSR Journals
This document compares two 60GHz on-chip bandpass filters designed using a 0.18μm CMOS technology. The first filter uses complementary split ring resonators (CSRRs) as the ground shield, while the second uses a patterned ground shield. Simulation results show that the CSRR ground shield filter has slightly lower insertion loss of -2.682dB, a narrower 3dB bandwidth of 10.8GHz, and a smaller chip size of 0.651mm^2. The patterned ground shield filter has a higher insertion loss of -2.77dB but a wider 3dB bandwidth of 14GHz and slightly smaller chip size of 0.527mm^2. Both filters demonstrate good return loss and
High Performance Error Detection with Different Set Cyclic Codes for Memory A...IOSR Journals
The document presents a proposed error detection method using majority logic decoding with difference set cyclic codes. The proposed method can detect up to five bit errors in the first three decoding cycles, improving performance over traditional majority logic decoding approaches. It uses a control unit to evaluate parity check sums over the first three cycles, and can detect errors without fully decoding the codeword when no errors are found. This reduces decoding time compared to approaches that fully decode each codeword. The proposed method is also less complex than alternatives using syndrome calculation for error detection. Simulation results showed the proposed method can detect errors faster while using less memory and power than traditional approaches.
Cash Flow Valuation Mode Lin Discrete TimeIOSR Journals
This document summarizes key concepts related to cash flow valuation in discrete time using discounted cash flow analysis. It introduces probability spaces, stochastic processes, martingales, and defines cash flow, discounting, and discount rate processes. The value of a cash flow is modeled as the expected discounted sum of future cash flows. Discounting links future cash flows to their present value using a discount factor that accounts for the time value of money and risk. The discount rate captures the cost of capital and risk of non-payment implied by the discount process.
Nutritional Analysis of Edible Wild Fruit (Zizyphus Jujuba Mill.) Used By Rur...IOSR Journals
Wild edible plants form an important constituent of traditional diets in Himalayas. People of Hamirpur District are very close to Nature wild fruits like Zizyphus jujuba Mill. are one of the important natural resources in the district. The indigenous people of the district have direct dependence on the wild plants for their sustenance. Hundreds of wild edible plants are present in the north- western Himalayas, out of which the ‘Ber’ Zizyphus jujuba Mill. has its religious as well as nutritional advantage over the others. Because of the easy accessibility the fruits are very commonly eaten by the rural populace and the travellers. Biochemical analysis of the dried fruits showed remarkable presence of Carbohydrates 69.12%, Total sugars 27.75%, Phosphorus 133mg/100g, Calcium 199.19mg/100g, Magnesium 84.69mg/100g and Iron 4.15mg/100g on dry weight basis. In other words an important supplementary diet for giving strength to otherwise poor and deprived lot. The present communication aims to highlight the fruits eaten by the inner country side people and what nutritional components are they getting in return
The Effects of Rauwolfia Vomitoria Extract on the Liver Enzymes of Carbon Tet...IOSR Journals
This study investigated the effects of Rauwolfia vomitoria extract on liver enzymes in rats with carbon
tetrachloride-induced hepatotoxicity. Rats were divided into four groups: a control, Rauwolfia vomitoria extract,
carbon tetrachloride, and carbon tetrachloride with Rauwolfia vomitoria extract. Liver enzymes and weights
were measured after treatment. Carbon tetrachloride significantly increased liver enzymes and weight compared
to controls, while Rauwolfia vomitoria prevented these increases, indicating it has a protective effect against
carbon tetrachloride-induced liver damage.
Study of Boron Based Superconductivity and Effect of High Temperature Cuprate...IOSR Journals
This paper illustrates the main normal and Boron superconducting state temperature properties of magnesium diboride, a substance known since early 1950's, but lately graded to be superconductive at a remarkably high critical temperature Tc=40K for a binary synthesis. What makes MgB2 so special? Its high Tc, simple crystal construction, large coherence lengths, high serious current densities and fields, lucidity of surface boundaries to current promises that MgB2 will be a good material for both large scale applications and electronic devices. Throughout the last seven month, MgB2 has been fabricated in various shape, bulk, single crystals, thin films, ribbons and wires. The largest critical current densities >10MA/cm2 and critical fields 40T are achieved for thin films. The anisotropy attribution inferred from upper critical field measurements is still to be resolved, a wide range of values being reported, γ = 1.2 ÷ 9. Also there is no consensus about the existence of a single anisotropic or double energy cavity. One central issue is whether or not MgB2 represents a new class of superconductors, being the tip of an iceberg that waits to be discovered. Until now MgB2 holds the record of the highest Tc among simple binary synthesis. However, the discovery of superconductivity in MgB2 revived the interest in non-oxides and initiated a search for superconductivity in related materials, several synthesis being already announced to become superconductive: TaB2, BeB2.75, C-S composites, and the elemental B under pressure.
This document summarizes a survey paper that examines workflow signatures for business process compliance.
The paper discusses how cryptographic signature schemes are not well-suited for representing logical relationships in workflows, such as AND-joins and AND-splits. It proposes using a multi-key hierarchical encryption scheme for workflow signatures instead.
The paper provides an example of a business travel workflow involving multiple tasks and agents. It also briefly describes identity-based, hierarchical identity-based, and multi-level hierarchical identity-based digital signature schemes. The main goal of the survey is to examine workflows and encryption techniques that can provide authentication, integrity, and representation of logical workflow relationships.
IOSR Journal of Mathematics(IOSR-JM) is an open access international journal that provides rapid publication (within a month) of articles in all areas of mathemetics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mathematics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Nasal Parameters of Ibibio and Yakurr Ethnic Groups of South South NigeriaIOSR Journals
The study involved 400 subjects, 200 each of the two ethnic groups(100 males and 100 females). The age range was 18-35years. Subjects with facial deformities or surgeries that involved the nasal region were excluded from the study. Subjects that have both parents and grandparents of each ethnic group and who have lived in that environment for at least the first 18years of their lifetime were selected for the study. The nasal length and width were measured using spreading calipers and nasal indices deducted from these measurements. Test for significance was done using the students’ t-test. Results showed the nasal indices of the Ibibio males and females to be 86.58±1.20 and 81.75±1.14 respectively and for the Yakurr males and females, it was 77.76±0.82 and 102.27±1.13 respectively. There was significant ethnic and gender differences in all the nasal parameters (nasal length, nasal width and nasal indices) at p<0.05. From the nasal indices the nose type of the Ibibio males is platyrrhine while that of the Ibibio females is mesorrhine, the Yakurr males also have mesorrhine nose type while the Yakurr females have platyrrhine nose type. With this result, nasal parameters could be a useful tool in gender and ethnic differentiation between the Ibibio and Yakurr ethnic groups.
Spectral Studies of Some Transition Metal Ion complexes with 4-[(E)-(Ferrocen...IOSR Journals
Several new complexes of some transition metal ions with organometallic compounds were derived from ferrocencecarboxylaldehyde and 4-amino-2-hydroxy pyridine. These organometallic complexes were investigated by using some analytical techniques like infrared, mass spectra, electronic spectra, electron spin resonance, thermal analysis, magnetic moment, conductivity and antimicrobial activity. From the obtained elemental analysis data, organometallic compounds complexes shows 1:2 [M: L] ratio and general formula of the complex is [ML2.2H2O]. These complexes revealed a non-electrolytic nature. The magnetic moment values of the complexes exhibited the paramagnetic as well as diamagnetic in nature. The coordination behavior of the metal ions towards to the investigated organometallic compounds takes place through >C=N- and –OH groups. The electronic spectral data shows that all the complexes are covalent in nature, octahedral structure with co-ordination number six. Organometallic compound complexes were loses two water molecules subjected to simultaneous thermo gravimetric analysis, to study their decomposition mechanism and thermal stability. Mass spectra of the organometallic compound and their complexes are matched with theoretical values of the masses. The prepared organometallic compounds and their metal complexes were screened for their antibacterial activity against some bacterial species, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus Pyogones. The Antimicrobial activity data show the metal complexes to be more active than the parent organometallic compounds.
Increase In Electrical And Thermal Conductivities Of Doped Polymers Dependent...IOSR Journals
Most Polymers do not possess natural intrinsic properties that will be enough for them to be used as semi- conductors. In the world trend of industrial growth where polymers seem to be replacing all semi-conductors because of their availability, durability, recyclability and reduced cost, attention is being strongly given to their improvement them for this essential function hence the need for this research.Eight samples each of four polymers; polyethylene (PE), polystyrene (PS), poly propylene (PP),nylon 66 were prepared by doping with different concentrationsof graphite to enhance their electrical and thermal conductivities, considering the fact that they are of different intrinsic properties. The samples were testedfor their electrical and thermal conductivities.It was evident that as the concentration of the graphite dopantincreases, the electrical and thermal conductivities of all the polymers increased although not at the same rate.The most interesting fact is that all polymers that showed highly favorable results in electrical conductivity, showed the least for thermal conductivities which can be attributed to their intrinsic properties.
Effects of Eccentric Strength Training’s Time on Daily Plasma Testosterone Le...IOSR Journals
This study aims to evaluate the effects of the eccentric physical training’s time on daily plasma concentrations of testosterone among sedentary athletes. Sixty male athletes, with homogeneous age, size and weight were selected for the study during three months. They were subjects to a strength training of the extensor and flexor muscles of the knee. After they were divided in two groups of thirty subjects and then had physical training either in the morning between 6 and 7, or in the evening, between 16 and 17. The dosage of testosterone on each athlete was performed before and after submission to an eccentric physical program at the antecubital vein in a restful sitting. Our results have shown that eccentric physical training induces the increase of this steroid hormone in the two groups of athletes and the training in the evening promotes better its production. Our results also showed that the rate of this androgen drop significantly during the day in both groups of athletes trained in the morning or in the evening as well as their respective controls. However, the decline was even more pronounced for subjects trained in the morning
IOSR journal of VLSI and Signal Processing (IOSRJVSP) is an open access journal that publishes articles which contribute new results in all areas of VLSI Design & Signal Processing. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced VLSI Design & Signal Processing concepts and establishing new collaborations in these areas.
This document describes linking design and manufacturing on a PLM (Product Lifecycle Management) platform. Specifically, an automobile fuel tank cap was modeled in Creo Parametric. An injection mold was then developed for the part. The complete design data was integrated into Windchill PLM software for data and process management. Operations were generated to manufacture the mold cavities and core. The fuel tank cap design was then reviewed in the PLM software by a guest reviewer. This case study demonstrates how PLM software can efficiently manage product design and manufacturing data throughout the entire product lifecycle.
Seismic Study and Spatial Variation of b-value in Northeast IndiaIOSR Journals
Study of recent seismicity and b-value estimation by Least Square and Maximum Likelihood Estimation methods in five tectonic blocks of Northeast India demarcates indo Burma Belt, Main Central Thrust, Main Boundary Thrust, Shilling Plateau, Mikir Hills and Kopili Lineament as active seismic source of the region. Spatial variation of b-value is observed by dividing the study area into 10×10 grids. Higher b-value contours depict the highly seismic area with structural heterogeneity, while lower b-value contours indicate the areas under high stress. b-values are observed in the range of 0.437 - 0.908 and mostly concentrated around 0.7, indicating high stress accumulation.
Lean and Agile Manufacturing as productivity enhancement techniques - a compa...IOSR Journals
This document provides an overview of lean and agile manufacturing as techniques to enhance productivity. It defines lean manufacturing as focusing on eliminating waste to improve productivity, while agile manufacturing emphasizes responsiveness and flexibility to meet customer needs. The document compares the two approaches, noting they both aim to improve competitiveness but have different origins, goals, and implementation processes. Lean focuses on efficiency and waste removal, while agile prioritizes flexibility and responsiveness to change. Both can benefit organizations but require overcoming cultural barriers to successful adoption.
A Review: Machine vision and its ApplicationsIOSR Journals
Abstract:The machine vision has been used in the industrial machine designing by using the intelligent character recognition. Due to its increased use, it makes the significant contribution to ensure the competitiveness in modern development. The state of art in machine vision inspection and a critical overview of applications in various industries are presented in this paper. In its restricted sense it is also known as the computer vision or the robot vision. This paper gives the overview of Machine Vision Technology in the first section, followed by various industrial application and thefuture trends in Machine Vision. Keywords:CCD- charged coupled devices, Fruit harvesting system, HIS- Hue Saturation Intensity, Image analysis, Image enhancement, Image feature extraction, Image feature classification processing, Intelligent Vehicle tracking , Isodiscriminationn Contour, Machine Vision
Distributed Path Computation Using DIV AlgorithmIOSR Journals
This document summarizes research on distributed path computation algorithms that aim to prevent routing loops. It introduces the Distributed Path Computation with Intermediate Variables (DIV) algorithm, which can operate with any routing algorithm to guarantee loop-freedom. DIV generalizes previous loop-free algorithms and provably outperforms them by reducing synchronous updates and helping maintain paths during network changes. The document also reviews link-state routing, distance-vector routing, and existing loop-prevention techniques like the Diffusing Update Algorithm and Loop Free Invariance algorithms.
Rainy and Dry Days as a Stochastic Process (Albaha City)IOSR Journals
1) The document presents a mathematical model using Markov chains to represent rainy and dry days in Albaha City, Saudi Arabia based on weather data from 1431-1434 Hijri.
2) A two-state Markov chain is constructed with states 0 (dry day) and 1 (rainy day) and the transition probabilities between states are estimated from historical weather data.
3) The Markov chain is used to determine probability distributions of the number of consecutive rainy/dry days, time until returning to each state, and the long-term probabilities of being in each state.
4) The model is tested by comparing its 4-step transition probabilities to actual weather data and found to accurately represent
This document summarizes a research paper that studied the abrasion resistance of geopolymer concrete at varying temperatures. The paper prepared geopolymer concrete samples using fly ash as the source material and an alkaline solution of sodium hydroxide and sodium silicate. Samples were cured at 25°C, 60°C, and 80°C and tested for abrasion resistance at 5-25 minutes using a tile abrasion testing machine. Results showed that abrasion resistance increased with higher curing temperature, with samples cured at 80°C showing the highest resistance. The paper concluded that geopolymer concrete has good abrasion resistance properties and further research is needed on mixtures with higher alkaline liquid ratios.
An Optimal Power Flow (OPF) Method withImproved Voltage Stability AnalysisNiraj Solanki
This document discusses an optimal power flow method with improved voltage stability analysis. It introduces voltage stability and instability concepts. It then describes a voltage stability indicator L derived from fundamental circuit laws that can predict proximity to voltage collapse. The document outlines the formulation of an optimal power flow problem to minimize generation costs and indicator L. It applies this method to the 9-bus WSCC test system in MATLAB and concludes the indicator can accurately predict voltage stability problems and vulnerable locations.
Enhancement of Voltage Stability on IEEE 14 Bus Systems Using Static Var Comp...paperpublications3
Abstract: This paper investigates the effects of Static Var Compensator (SVC) on voltage stability of a power system. One of the major causes of voltage instability is the reactive power limit of the system. Improving the system’s reactive power handling capacity via Flexible AC transmission system (FACTS) devices is a remedy for prevention of voltage instability and hence voltage collapse. The effects of Static Var Compensator (SVC) in static voltage stability margin enhancement will be studies. Prediction of the stability margin or distance to voltage collapse is based on the reactive power load demand. The load is connected to several selected buses. The analysis is performed for IEEE 14 Bus system. Then, the most critical mode is identified for each system. IEEE standard test system has been considered and Load flows were computed by using Newton Raphson method with the help of MATLAB and a weak bus is identified.
Online Voltage Stability Analysis using Synchrophasor Technologyijsrd.com
Voltage instability has been a major problem in all the emerging power systems across the world. Several instances of blackouts in North America, including the 1996 Western Interconnection and the 2003 North East US /Canada blackout are primarily due to voltage collapse. So Monitoring and maintaining voltage stability in real-time is extremely important for operating a power system reliably. In this paper Synchrophasor technology is introduced. Synchrophasor technology has the capability to monitor voltage stability over a wide area in real time. In this paper different methods are introduced for finding the voltage collapse point in the system and also one new method given for identification of voltage collapse point.
IRJET- Voltage Stability Analysis using Voltage Stability IndicesIRJET Journal
This document discusses voltage stability analysis using the Fast Voltage Stability Index (FVSI). It analyzes the IEEE 30-bus test system to identify the most sensitive method to detect the weakest line and bus. The FVSI is calculated for different reactive power loadings at various buses. Increasing the load at bus 26 identifies line 34 as critical. For bus 30, line 38 is most critical. And for bus 29, line 37 is identified. Analysis of the FVSI helps determine the point of voltage instability and the weakest elements in the system.
IRJET- Voltage Stability Analysis using Voltage Stability IndicesIRJET Journal
1) The document discusses using the Fast Voltage Stability Index (FVSI) to analyze voltage stability on the IEEE 30-bus test system and identify weak lines and buses.
2) FVSI was calculated for different levels of reactive power loading at three buses. Higher FVSI values indicate lines closer to instability.
3) For bus 26, line 34 was found to be most critical with an FVSI of 0.9571. For bus 30, line 38 was most critical at 0.9325. For bus 29, line 37 was most critical at 0.8421.
4) Analysis of FVSI identified bus 26 as the weakest bus, able to withstand the
IJERD (www.ijerd.com) International Journal of Engineering Research and Devel...IJERD Editor
This document summarizes a study on identifying weaker elements in a power system that are prone to voltage collapse. It introduces two voltage stability indices: FVSI (Fast Voltage Stability Index) and LQP (Line Quadratic Programming). These indices are calculated using power flow values and indicate how close an element is to voltage instability. The indices are used to rank elements in the IEEE 14 bus system based on different contingency scenarios like changing real or reactive load at a single bus or multiple buses. The results from FVSI are validated by comparing with LQP. FVSI provides feasible and fast results for identifying weak elements and determining maximum loading limits to maintain voltage stability.
1. The document discusses voltage stability in power systems. Voltage instability can occur when voltage decreases below normal levels and does not recover after disturbances, potentially leading to voltage collapse.
2. It classifies voltage stability dynamics as either short-term (seconds) or long-term (minutes to hours) and discusses factors that influence each type.
3. A simple two-bus power system model is used to illustrate basic concepts of voltage stability analysis.
This presentation is about power system voltage stability.
What is voltage stability?
How voltage instability occurs?
How to improve voltage stability of the system?
The document presents a study on optimizing the placement and sizing of static VAR compensators (SVCs) in power systems to improve voltage stability. It uses the harmony search algorithm (HSA) to determine the optimal SVC sizes and locations to minimize real power losses, voltage deviation at load buses, and L-index values, which indicate voltage stability. The methodology is demonstrated on the IEEE 14-bus test system under normal and overloading conditions. The results show that locating optimally sized SVCs at buses 9 and 14 reduces losses and voltage deviations while improving voltage profiles and stability.
International Journal of Engineering Research and DevelopmentIJERD Editor
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Aerospace Engineering.
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.
Influence of Static VAR Compensator for Undervoltage Load Shedding to Avoid V...IJAPEJOURNAL
In the recent years, operation of power systems at lower stability margins has increased the importance of system protection methods that protect the system stability against various disturbances. Among these methods, the load shedding serves as an effective and last-resort tool to prevent system frequency/voltage instability. The analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, voltage also needs to be taken into account in load shedding schemes. This paper considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location .The amount of load to be shed from each bus is decided using the fixed step size method and it’s location has been identified by using voltage collapse proximity index method. SVC is shunt connected FACTS device used to improve the voltage profile of the system. In this paper impact of SVC on load shedding for IEEE 14 bus system has been presented and analyzed.
International Journal of Engineering and Science Invention (IJESI)inventionjournals
This document summarizes a research paper on improving voltage stability and reducing losses in distribution networks through distributed generation. The paper analyzes how distributed generation capacity and location can enhance voltage stability in a real distribution network. It presents a method to determine the steady-state voltage stability region of each bus in a distribution system. Simulation results show that distributed generation can reduce line losses by supplying power locally, with losses decreasing as generation is placed closer to loads. Both the capacity and location of distributed generation significantly impact line losses.
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.
“An Assessment of Voltage Stability based on Line Voltage Stability Indices a...iosrjce
The issue of voltage instability is becoming a matter of concern throughout the world. It is of
absolute importance to maintain the stability of the power system or it would lead to a condition of total
collapse of the system and ultimately blackout of the whole network. This paper analyses the performance of
line voltage stability indices, Fast Voltage Stability index (FVSI), Line index (LQP), Reactive Power Index
(VQI) and line Stability Index (LMN). These indices are used to identify the most critical line and bus of the
system. Under a condition of single line outage a TCSC is installed at the most critical line and its effect has
been observed. An IEEE 14 bus system is used for simulation purpose.
This document analyzes voltage stability in power systems using line voltage stability indices and proposes enhancing stability with a TCSC. It discusses four indices - Fast Voltage Stability Index (FVSI), Line Quadratic Programming (LQP), Reactive Power Index (VQI), and Line Stability Index (LMN) - that can identify the most critical line and bus. Under a single line outage, a TCSC is installed at the critical line identified by the indices. Simulation results on the IEEE 14-bus system show that a TCSC can improve voltage stability by modifying the line reactance. The TCSC provides both inductive and capacitive compensation depending on its firing angle to enhance power transfer and voltage profiles.
Voltage Stability Assessment Using the Concept of GVSMiosrjce
To assessment of voltage stability of multi bus power system, the main requirement is equivalent twobus
network models, which is fulfilled by lumping all the series impedances and shunt admittances of
transmission lines within a series equivalent impedance. This paper shows the development of an equivalent pi
network model using a new technology or methodology called generalized global voltage stability margin
(GVSM). This is used to assess the overall voltage stability status of the system accurately. Simulation results
for IEEE 14 Test bus system, IEEE 30 Test bus system , IEEE 118 Test bus system are establish that the piequivalent
model obtained by the proposed method is highly accurate for assessing voltage stability of any
power system at any operating point in a better way as compared to series equivalent model
This document presents a new methodology called generalized global voltage stability margin (GVSM) to assess voltage stability in power systems. The methodology develops an equivalent pi-network model of the power system by lumping all series impedances and shunt admittances of transmission lines. Simulation results on IEEE 14, 30, and 118 test systems show the pi-equivalent model accurately represents the system and allows assessment of voltage stability at any operating point. The GVSM value indicates how close the system is to voltage collapse, and decreases as load increases, becoming zero at the point of collapse. The methodology provides a better representation of voltage stability compared to a traditional series equivalent model.
This document presents a student project on interpreting voltage instability and collapse using various voltage stability analysis techniques. The project will classify voltage stability, characterize past voltage collapses, examine prevention methods, analyze different voltage stability indices, simulate P-V and Q-V curves, and apply continuation power flow analysis. The outline includes introductions to concepts, classifications, calculations, simulations, and conclusions with references.
This document discusses a proposed tool using support vector regression (SVR) and fuzzy logic controller (FLC) for online voltage stability monitoring and estimation of reactive power (VAR) support in deregulated power systems. The tool uses bus voltage angle and reactive power load as inputs to SVR to predict the voltage stability margin index (VSMI) and voltage stability factor (VSF) of the most critical bus. The results of SVR are compared to artificial neural networks in terms of accuracy and computation time on IEEE 14 bus and 30 bus test systems. The tool estimates voltage stability margins for different transactions and contingencies and determines the minimum VAR support needed to enhance stability.
This document provides a technical review of secure banking using RSA and AES encryption methodologies. It discusses how RSA and AES are commonly used encryption standards for secure data transmission between ATMs and bank servers. The document first provides background on ATM security measures and risks of attacks. It then reviews related work analyzing encryption techniques. The document proposes using a one-time password in addition to a PIN for ATM authentication. It concludes that implementing encryption standards like RSA and AES can make transactions more secure and build trust in online banking.
This document analyzes the performance of various modulation schemes for achieving energy efficient communication over fading channels in wireless sensor networks. It finds that for long transmission distances, low-order modulations like BPSK are optimal due to their lower SNR requirements. However, as transmission distance decreases, higher-order modulations like 16-QAM and 64-QAM become more optimal since they can transmit more bits per symbol, outweighing their higher SNR needs. Simulations show lifetime extensions up to 550% are possible in short-range networks by using higher-order modulations instead of just BPSK. The optimal modulation depends on transmission distance and balancing the energy used by electronic components versus power amplifiers.
This document provides a review of mobility management techniques in vehicular ad hoc networks (VANETs). It discusses three modes of communication in VANETs: vehicle-to-infrastructure (V2I), vehicle-to-vehicle (V2V), and hybrid vehicle (HV) communication. For each communication mode, different mobility management schemes are required due to their unique characteristics. The document also discusses mobility management challenges in VANETs and outlines some open research issues in improving mobility management for seamless communication in these dynamic networks.
This document provides a review of different techniques for segmenting brain MRI images to detect tumors. It compares the K-means and Fuzzy C-means clustering algorithms. K-means is an exclusive clustering algorithm that groups data points into distinct clusters, while Fuzzy C-means is an overlapping clustering algorithm that allows data points to belong to multiple clusters. The document finds that Fuzzy C-means requires more time for brain tumor detection compared to other methods like hierarchical clustering or K-means. It also reviews related work applying these clustering algorithms to segment brain MRI images.
1) The document simulates and compares the performance of AODV and DSDV routing protocols in a mobile ad hoc network under three conditions: when users are fixed, when users move towards the base station, and when users move away from the base station.
2) The results show that both protocols have higher packet delivery and lower packet loss when users are either fixed or moving towards the base station, since signal strength is better in those scenarios. Performance degrades when users move away from the base station due to weaker signals.
3) AODV generally has better performance than DSDV, with higher throughput and packet delivery rates observed across the different user mobility conditions.
This document describes the design and implementation of 4-bit QPSK and 256-bit QAM modulation techniques using MATLAB. It compares the two techniques based on SNR, BER, and efficiency. The key steps of implementing each technique in MATLAB are outlined, including generating random bits, modulation, adding noise, and measuring BER. Simulation results show scatter plots and eye diagrams of the modulated signals. A table compares the results, showing that 256-bit QAM provides better performance than 4-bit QPSK. The document concludes that QAM modulation is more effective for digital transmission systems.
The document proposes a hybrid technique using Anisotropic Scale Invariant Feature Transform (A-SIFT) and Robust Ensemble Support Vector Machine (RESVM) to accurately identify faces in images. A-SIFT improves upon traditional SIFT by applying anisotropic scaling to extract richer directional keypoints. Keypoints are processed with RESVM and hypothesis testing to increase accuracy above 95% by repeatedly reprocessing images until the threshold is met. The technique was tested on similar and different facial images and achieved better results than SIFT in retrieval time and reduced keypoints.
This document studies the effects of dielectric superstrate thickness on microstrip patch antenna parameters. Three types of probes-fed patch antennas (rectangular, circular, and square) were designed to operate at 2.4 GHz using Arlondiclad 880 substrate. The antennas were tested with and without an Arlondiclad 880 superstrate of varying thicknesses. It was found that adding a superstrate slightly degraded performance by lowering the resonant frequency and increasing return loss and VSWR, while decreasing bandwidth and gain. Specifically, increasing the superstrate thickness or dielectric constant resulted in greater changes to the antenna parameters.
This document describes a wireless environment monitoring system that utilizes soil energy as a sustainable power source for wireless sensors. The system uses a microbial fuel cell to generate electricity from the microbial activity in soil. Two microbial fuel cells were created using different soil types and various additives to produce different current and voltage outputs. An electronic circuit was designed on a printed circuit board with components like a microcontroller and ZigBee transceiver. Sensors for temperature and humidity were connected to the circuit to monitor the environment wirelessly. The system provides a low-cost way to power remote sensors without needing battery replacement and avoids the high costs of wiring a power source.
1) The document proposes a model for a frequency tunable inverted-F antenna that uses ferrite material.
2) The resonant frequency of the antenna can be significantly shifted from 2.41GHz to 3.15GHz, a 31% shift, by increasing the static magnetic field placed on the ferrite material.
3) Altering the permeability of the ferrite allows tuning of the antenna's resonant frequency without changing the physical dimensions, providing flexibility to operate over a wide frequency range.
This document summarizes a research paper that presents a speech enhancement method using stationary wavelet transform. The method first classifies speech into voiced, unvoiced, and silence regions based on short-time energy. It then applies different thresholding techniques to the wavelet coefficients of each region - modified hard thresholding for voiced speech, semi-soft thresholding for unvoiced speech, and setting coefficients to zero for silence. Experimental results using speech from the TIMIT database corrupted with white Gaussian noise at various SNR levels show improved performance over other popular denoising methods.
This document reviews the design of an energy-optimized wireless sensor node that encrypts data for transmission. It discusses how sensing schemes that group nodes into clusters and transmit aggregated data can reduce energy consumption compared to individual node transmissions. The proposed node design calculates the minimum transmission power needed based on received signal strength and uses a periodic sleep/wake cycle to optimize energy when not sensing or transmitting. It aims to encrypt data at both the node and network level to further optimize energy usage for wireless communication.
This document discusses group consumption modes. It analyzes factors that impact group consumption, including external environmental factors like technological developments enabling new forms of online and offline interactions, as well as internal motivational factors at both the group and individual level. The document then proposes that group consumption modes can be divided into four types based on two dimensions: vertical (group relationship intensity) and horizontal (consumption action period). These four types are instrument-oriented, information-oriented, enjoyment-oriented, and relationship-oriented consumption modes. Finally, the document notes that consumption modes are dynamic and can evolve over time.
The document summarizes a study of different microstrip patch antenna configurations with slotted ground planes. Three antenna designs were proposed and their performance evaluated through simulation: a conventional square patch, an elliptical patch, and a star-shaped patch. All antennas were mounted on an FR4 substrate. The effects of adding different slot patterns to the ground plane on resonance frequency, bandwidth, gain and efficiency were analyzed parametrically. Key findings were that reshaping the patch and adding slots increased bandwidth and shifted resonance frequency. The elliptical and star patches in particular performed better than the conventional design. Three antenna configurations were selected for fabrication and measurement based on the simulations: a conventional patch with a slot under the patch, an elliptical patch with slots
1) The document describes a study conducted to improve call drop rates in a GSM network through RF optimization.
2) Drive testing was performed before and after optimization using TEMS software to record network parameters like RxLevel, RxQuality, and events.
3) Analysis found call drops were occurring due to issues like handover failures between sectors, interference from adjacent channels, and overshooting due to antenna tilt.
4) Corrective actions taken included defining neighbors between sectors, adjusting frequencies to reduce interference, and lowering the mechanical tilt of an antenna.
5) Post-optimization drive testing showed improvements in RxLevel, RxQuality, and a reduction in dropped calls.
This document describes the design of an intelligent autonomous wheeled robot that uses RF transmission for communication. The robot has two modes - automatic mode where it can make its own decisions, and user control mode where a user can control it remotely. It is designed using a microcontroller and can perform tasks like object recognition using computer vision and color detection in MATLAB, as well as wall painting using pneumatic systems. The robot's movement is controlled by DC motors and it uses sensors like ultrasonic sensors and gas sensors to navigate autonomously. RF transmission allows communication between the robot and a remote control unit. The overall aim is to develop a low-cost robotic system for industrial applications like material handling.
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H010335459
1. IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
e-ISSN: 2278-1676,p-ISSN: 2320-3331, Volume 10, Issue 3 Ver. III (May – Jun. 2015), PP 54-59
www.iosrjournals.org
DOI: 10.9790/1676-10335459 www.iosrjournals.org 54 | Page
Comparative analysis of Shunt Compensation Devices Impact on
Voltage Stability Enhancement
Dr.Venu Yarlagadda1
, Spandana Bitla2
1Associate Professor, VNR VJIET
2Asst.Prof, ARTI
Abstract: The voltage stability can be assessed accurately using different methods viz. P-V curves, L-index and
Fast Voltage Stability Index (FVSI). These indices can either reveal the critical bus or line of a power system. P-
V curves, FVSI and L indices are used to identify the most critical n-1 contingency. The optimal location of the
shunt compensator can be identified with maximum value of stability indices of all buses and lines.
The optimal capacity of the shunt compensator is computed using fictitious Generator at weakest bus. Power
flow is carried out by placing the optimal sized shunt compensator at weakest bus and results shows the
effectiveness of the shunt compensator. The comparative analyses have been carried out for the fixed shunt
compensator, Synchronous Phase Modifier and Static Var Compensator against load variations.
Index Terms: Voltage Stability, SPM,SVC, Voltage stability indices, Comparative analysis of Shunt
Compensation Devices, Shunt Compensation, Fast Voltage Stability Index, L-index, Impact of shunt
compensation & Losses reduction with shunt devices.
I. Introduction
Power system stability is defined as a characteristic for a power system to remain in a state of
equilibrium at normal operating conditions and to restore an acceptable state of equilibrium after a disturbance.
Traditionally, the stability problem has been the rotor angle stability [1], i.e., maintaining synchronous
operation. Instability may also occur without loss of synchronism, in which case of concern is the control and
stability of voltage. “The voltage stability [2-3] is the ability of a power system to maintain steady acceptable
voltages at all buses in the system at normal operating conditions and after being subjected to a disturbance.”
Power system is voltage stable if voltages after a disturbance are close to voltages uncontrollably decrease due
to outage of equipment (generator, line, transformer, bus bar, etc.), increment of load, decrement of production
and/or weakening of voltage control.
The Voltage instability is nothing but under the stressed conditions a power system can exhibit new
type of unstable behavior characterized by slow (or sudden) voltage drops, sometimes escalating to form a
collapse. When the system crosses the maximum deliverable power limit the mechanism of load power
restoration becomes unstable, reducing the power consumed instead of increasing. Voltage control and
instability are local problems. However, the consequences of voltage instability may have a widespread impact.
Voltage stability can also be called “load stability”. The main factor causing Voltage instability is the
inability of the power system to meet the demands for reactive power in the heavily stressed systems to keep
desired voltages. Other factors contributing to voltage instability are the generator reactive power limits, the
load characteristics, the characteristics of the reactive power compensation devices and the action of the voltage
control devices.
The condition of voltage stability in a power system can be known using voltage stability indices[4-8].
These indices can either reveal the critical bus of a power system or the stability of each line connected between
two bus in an interconnected network or evaluate the voltage stability margins of a system. They provide
important information about proximity of the system to voltage instability and can be used to identify the
weaker bus as well as the critical line with respect to a bus of a system. Usually their values change between
0(No Load) to 1 (Voltage Collapse).
The tools used to assess the voltage stability are P-V curves, FVSI and L-Indices.
1. P-V curves
The P-V curves are the most used method of predicting voltage security. They are used to determine the loading
margin of a power system[5]. The power system load is gradually increased and, at each increment, is necessary
recomputed power flows until the nose of the PV curve is reached. The margin between the voltage collapse
point and the current operating point is used as voltage stability criterion.
2. L Index
The L index[5] is a quantitative measure for the estimation of the distance of the actual state of the system to the
stability limit. The L index describes the stability of the complete system and is given by:
2. Comparative analysis of Shunt Compensation Devices Impact on Voltage Stability Enhancement
DOI: 10.9790/1676-10335459 www.iosrjournals.org 55 | Page
L =
max
j ∈ αL{Lj} =
max
j ∈ αL 1 −
∑i∈αG Fji Vi
Vj
Where αL is the set of consumer nodes and G is the set of generator nodes. Lj is a local indicator that
determinates the bus bars from where collapse may originate. The L index varies in a range between 0 (no load)
and 1 (voltage collapse).
3. Line Stability Index FVSI
The line stability index FVSI [6] is based on a concept of power flow through a single line. For a typical
transmission line, the stability index is calculated by:
FVSIij =
4Z2Qj
ViX
Where Z is the line impedance, X is the line reactance, Qj is the reactive power flow at the receiving
end and Vi is the sending end voltage. The line that gives index value closest to 1 will be the most critical line of
the bus and may lead to the whole system instability. The calculated FVSI can also be used to determine the
weakest bus on the system. The determination of the weakest bus is based on the maximum load allowed on a
load bus. The most vulnerable bus in the system corresponds to the bus with the smallest maximum permissible
load.
II. Contingency Based Voltage Stability Improvement
Voltage stability is defined as the ability of a power system to maintain steadily acceptable bus voltage
at each node under normal operating conditions, after load variation following a change in system configuration
or when the system is subjected to contingencies [7] like line outage or generator outage. Single or multiple
contingencies cause voltage violations which are known as voltage contingencies. The line outages may lead to
the most severe violations in line flow which necessitates the line over load alleviation of the network.
Line outage in power system lead to the voltage collapse which implies the contingency in the system.
Line outage contingencies are ranked so that the line which highly affects the system when there is an outage
occurs in this line in terms of voltage instability could be identified. The contingency ranking process can be
conducted by computing the line stability index of each line for a particular line outage and sort them in
descending order. The contingency which is ranked the highest implies that it contributed to system instability.
A. Contingency ranking based on voltage stability indices
Contingencies are ranked according to their margins to voltage collapse. A margin to voltage collapse
is defined as the largest load change that the power system may sustain at a bus or collection of buses from a
well defined operating point. The margin may be measured in MVA, MW, or MVAR.
A new contingency ranking technique using a voltage stability index. The study involved voltage
stability analysis and line outages simulation which subsequently derived the correlation between critical line
outages and sensitive or weak lines obtained from the voltage stability analysis.
The results have shown that there is a correlation between critical line outages and sensitive lines
obtained from voltage stability analysis. The technique was tested on the IEEE Reliability Test System and
verified by comparing the results obtained from other techniques. The results from this study could also identify
the weak cluster in a power system network.
Here is this paper IEEE 9 Bus, 30 Bus, 118 Bus Test Systems are simulated in POWER WORLD and
MATLAB software. By the outage of transmission line between two buses and simulated for all the cases. By
considering the severe most contingency which is ranked first is taken and connected shunt compensation at
buses. By this connection of shunt compensation there is an improvement in voltage magnitude & stability.
B. Optimal Placement of Shunt Compensator
The severe most n-1 contingency is identified based on P-V Curves, L-Index & FVSI. The weakest bus
is detected based on the same indices, which can be used for the optimal placement of shunt compensator (Shunt
Capacitor, SPM and SVC).
1. IEEE 9 Bus System
Contingency ranking is made based on P-V curves, L-Index and FVSI for (n-1) contingency. The 7-5
line outage is severe most (n-1) contingency based on P-V curves, L-Index and FVSI. The 8th
bus is most critical
bus based on P-V curves, L-Index and FVSI.
2. IEEE 30 Bus System
Contingency ranking is made based on L-Index and FVSI values for (n-1) contingency. The 25-27 line
outage is severe most (n-1) contingency based on P-V curves & L-Index. The 1-3 line outage is severe most (n-
1) contingency based on FVSI. The 26th
bus is most critical bus based on P-V curves & L-Index and 27th
bus is
most critical bus based on FVSI.
3. Comparative analysis of Shunt Compensation Devices Impact on Voltage Stability Enhancement
DOI: 10.9790/1676-10335459 www.iosrjournals.org 56 | Page
3. IEEE 118 Bus System
Contingency ranking is made based on P-V curves, L-Index and FVSI for (n-1) contingency. The 53-54
line outage is severe most (n-1) contingency based on P-V curves, L-Index and FVSI. The 53rd
bus is most
critical bus based on P-V curves, L-Index and FVSI.
C. Optimal Capacity of Shunt Compensator
The optimal location and size of FACTS devices [8-10] has retained the interest of worldwide
researchers in power systems. In the stationary mode, FACTS devices are used to control the power flow in the
transmission lines as well as the bus voltages. The required objectives can be of technical order or of an
economic nature. Various mathematical methods and criteria are used to optimal allocation of these devices in
the power systems.
We have concluded that optimal placement should be done at critical point where the values are near to
the collapse point. In order to calculate the size of the compensator The Capacity of the Shunt Compensator is
obtained by using P-Q bus to P-V bus Conversion Method. In this method the weakest bus can be converted to
Voltage Controlled bus by placing a Fictitious Generator, which generates only Reactive Power corresponding
to the Reference Voltage i.e. 1 P.U. After connecting a Fictitious Generator at weakest bus, the power flow is
performed using N-R Method. The capacity or Size of the Compensator is obtained at that bus corresponding to
reference voltage (1 p.u.).
When Fictitious Generator is connected in shunt to IEEE 9 bus system based upon P-V Curves, L-
index & FVSI values at 8th
bus we get 207 MVAr. Again the load flow is done, at 5th
bus voltage value is near to
the critical point the same process is repeated i.e., calculation of P-V Curves L-index and FVSI values. Now the
Fictitious Generator is connected in shunt to IEEE 9 bus system at 8th
& 5th
buses now we get 205 MVAr &
97MVAr values respectively i.e., size or capacity of shunt compensator.
When Fictitious Generator is connected in shunt to IEEE 30 bus system based upon P-V Curves & L-
index values at 26th
bus we get 37 MVAr. Again the load flow is done, at 25th
bus voltage value is near to the
critical point the same process is repeated i.e., calculation of P-V Curves & L-index values. Now the Fictitious
Generator is connected in shunt to IEEE 30 bus system at 8th
& 5th
buses now we get 37 MVAr & 5 MVAr
values respectively i.e., size or capacity of shunt compensator. When Fictitious Generator is connected in shunt
to IEEE 30 bus system based upon FVSI values at 27th
bus we get 35 MVAr value respectively i.e., size or
capacity of shunt compensator.
When Fictitious Generator is connected in shunt to IEEE 118 bus system based upon L-index & FVSI
values at 53rd
bus we get 31 MVAr value respectively i.e., size or capacity of shunt compensator.
III. Optimal Placement Of Static Var Compensator
A. Optimal Shunt Compensation
The severe most n-1 contingency is identified based on P-V Curves, L-Index & FVSI. The weakest bus
is detected based on the same indices, which can be used for the optimal placement of shunt compensator (Shunt
Capacitor, SPM and SVC). Voltage Stability can be improved by placing shunt compensator at weakest bus,
capacity or size of the compensator equal to the value which is obtained from the Fictitious Generator.
B. Synchronous Phase Modifier (SPM)
Synchronous Phase Modifier[11] is an effective method of achieving variable shunt compensation, but
it has -10% active power losses (Iron and Mechanical). In second case a synchronous phase modifier is
connected at the weakest bus, the results shows the effectiveness of the SPM on mitigating voltage variations
and stability indices against load variations with a small increment in the power losses.
C. Static Var Compensator (SVC)
In steady state an SVC [10] can be treated as a reactive power injection source, which can be presented
as the following mathematical statement:
QSVC = Vt (Vt - Vref ) XSL
Where XSL is the slope of voltage control characteristic, Vt is the terminal voltage of SVC and Vref is the
reference voltage. Doing some calculation the above Equation can be rewritten as:
QSVC = BSVC × Vref
2
The value of BSVC can be varied between minimum and maximum susceptance the so-called capacitive
susceptance and inductive susceptance, where the desired reactive power can be maintained.
The reactive power generated by SVC is given by
QSVC
min
≤QSVC ≤QSVC
max
IEEE 9, 30 and 118 Bus test systems have been simulated in Power World software and MATLAB
programming. Simulation results have been presented below.
4. Comparative analysis of Shunt Compensation Devices Impact on Voltage Stability Enhancement
DOI: 10.9790/1676-10335459 www.iosrjournals.org 57 | Page
IV. Comparative Analysis Of Simulation Results: Shunt Capacitor, Spm & Svc On Voltage
Stability Improvement
Comparative Analysis of Simulation Results: Shunt Capacitor, SPM & SVC on Voltage Stability Improvement
A IEEE 9 Bus System Results
IEEE 9 Bus test system is simulated in power world software the compensator is connected at the
severe most bus for voltage stability enhancement. Three kinds of compensators viz. shunt capacitor, SPM and
SVC have been connected and comparative bar graphs of these controllers have been drawn using simulation
results as shown below.
Figure 1: Comparison bar chart of voltages for C, SPM & SVC against load decrement of 25%
Figure 2: Comparison bar chart of L - Index for C, SPM & SVC against load decrement of 25%
Figure3: Comparison bar chart of FVSI for C, SPM & SVC against load decrement of 25%
Table 1: Comparison of Losses of Shunt Capacitor, SPM & SVC against load variations
∆Load 0.25↓ 0.25↑ 0.5↓ 0.5↑
Device MW MVAr MW MVAr MW MVAr MW MVAr
C 36 71.8 32 90.6 41 83 32 127
SPM 35 68.9 31 97.3 38 75 32 134
SVC 36 69.4 32 90.5 40 78.9 32 127
0.9
0.92
0.94
0.96
0.98
1
1.02
1.04
1.06
Bus4
Bus5
Bus6
Bus7
Bus8
Bus9
Voltage
Magnitude with
C 25%↓
Voltage
Magnitude with
SPM 25%↓
Voltage
Magnitude with
SVC 25%↓
0
0.01
0.02
0.03
0.04
0.05
Bus4
Bus5
Bus6
Bus7
Bus8
Bus9
L-Index with C
25%↓
L-Index with
SPM 25%↓
L-Index with
SVC 25%↓
0
0.1
0.2
0.3
0.4
0.5
5 to
4
6 to
4
7 to
5
9 to
6
7 to
8
8 to
9
FVSI with C
25%↓
FVSI with SPM
25%↓
FVSI with SVC
25%↓
5. Comparative analysis of Shunt Compensation Devices Impact on Voltage Stability Enhancement
DOI: 10.9790/1676-10335459 www.iosrjournals.org 58 | Page
Figure 4: Comparison bar chart of Losses of Shunt Capacitor, SPM & SVC against load variations
B. IEEE 30 Bus System Results
IEEE 30 Bus test system is simulated in power world software and the compensator is connected at the
severe most bus for voltage stability enhancement. Three kinds of compensators viz. shunt capacitor, SPM and
SVC have been connected and comparative bar graphs of these controllers have been drawn using simulation
results as shown below. Figure 6.5 shows the Comparison bar chart of voltages for C, SPM & SVC against load
decrement of 25%.Figure 6.6 shows the Comparison bar chart of L - Index for C, SPM & SVC against load
decrement of 25%.
Figure 5: Comparison bar chart of voltages for C, SPM & SVC against load decrement of 25%
Figure 6: Comparison bar chart of L - Index for C, SPM & SVC against load decrement of 25%
C. IEEE 118 Bus System Results
IEEE 118 Bus test system is simulated in power world software and the compensator is connected at
the severe most bus for voltage stability enhancement. Three kinds of compensators viz. shunt capacitor, SPM
and SVC have been connected and comparative bar graphs of these controllers have been drawn using
simulation results as shown below.
0
20
40
60
80
100
120
140
MW
Mvar
MW
Mvar
MW
Mvar
MW
Mvar
0.25↓ 0.25↑ 0.5↓ 0.5↑
C
SPM
SVC
0.9
0.92
0.94
0.96
0.98
1
1.02
Voltage
magnitude with C
25↓
Voltagemagnitud
e with SPM 25↓
Voltagemagnitud
ewith SVC 25↓
0
0.01
0.02
0.03
0.04
0.05
0.06
L-Index withC
25↓
L-Index with
SPM 25↓
L-Index
withSVC 25↓
0.92
0.93
0.94
0.95
0.96
0.97
0.98
0.99
1
1.01
Bus
7
Bus
31
Bus
74
Bus
105
Voltage
magnitude with C
25↓
Voltagemagnitud
e with SPM 25↓
Voltagemagnitud
ewith SVC 25↓
6. Comparative analysis of Shunt Compensation Devices Impact on Voltage Stability Enhancement
DOI: 10.9790/1676-10335459 www.iosrjournals.org 59 | Page
Figure 7: Comparison bar chart of voltages for C, SPM & SVC against load decrement of 25%
Figure 8: Comparison bar chart of L - Index for C, SPM & SVC against load decrement of 25%
Figure 9: Comparison bar chart of Losses of Shunt Capacitor, SPM & SVC against load variations
V. Conclusions
The simulation result shows the effectiveness of shunt compensator on voltage stability improvement,
since FVSI and L-Index have been decreased considerably. The fixed shunt compensator is quite effective for
the base load conditions and it is most economical method but it is ineffective against load variations i.e. off
peak and peak load intervals. Load variations lead to voltage variations in fixed compensated systems; in order
to minimize these variations variable compensators are most essential. SPM (Synchronous Phase modifier) and
SVC are quiet effective for providing such variable compensation which will minimize voltage variations.
Simulation result also shows that the SVC is more advantageous than Shunt Capacitor and SPM since
losses are minimum and it has effectively mitigated the voltage variations against the load variations hence it is
quiet effective compensator for off peak and peak loads.
References
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[3]. Dynamic Voltage Collapse Prediction on a Practical Power System Using Power Transfer Stability Index Muhammad Nizam,
Student Member, IEEE, Azah Mohamed, Senior Member, IEEE, Aini Hussain, Member, IEEE.
[4]. Evaluation of Voltage Stability Indices (VSI) Using Genetic Algorithm, 2010 IEEE International Energy Conference by
Muhammad Tami Al-Hajri and M. A. Abido.
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Iranian Journal of Electrical & Electronic Engineering, Vol. 7, No. 2, June 2011.
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[13]. stability”, IEEE Trans. Power Syst., Vol.13, No. 1, pp. 115-125, February 1998.
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[15]. Indicators by Renuga Verayiah and Izham Zainal Abidin presented at 2nd IEEE International Conference on Power and Energy
(PECon 08), December 1-3, 2008, Johor Baharu, Malaysia.
0
0.01
0.02
0.03
0.04
0.05
0.06
Bus7
Bus16
Bus31
Bus53
Bus74
Bus90
Bus105
Bus118
L-Index withC
25↓
L-Index with SPM
25↓
L-Index withSVC
25↓
0
50
100
150
200
250
MW
MVAr
MW
MVAr
MW
MVAr
MW
MVAr0.25↓ 0.25↑ 0.5↓ 0.5↑
C
SPM
SVC