This presentation discusses an anomaly encountered during the Cartosat-2C Earth observation satellite program. Testing revealed that switching noise from one of the satellite's solar array strings was coupling onto signal lines and preventing commands from being executed properly. Analysis showed the noise coupling was due to a long wire harness routing both strings in close proximity. To address this, the harness routing was modified to reduce the shared wire length from 8.2m to 4.2m, eliminating the noise coupling issue. The satellite was then successfully launched with on-orbit performance meeting specifications.
Power System Simulation Laboratory Manual Santhosh Kumar
This document outlines experiments related to power system simulation laboratory. It includes 10 experiments covering topics like computation of transmission line parameters, modeling of transmission lines, formation of bus admittance and impedance matrices, load flow analysis using different methods, fault analysis, stability analysis of single machine and multimachine systems, electromagnetic transients, load-frequency dynamics, and economic dispatch. The document provides theoretical background and procedures for conducting each experiment using MATLAB software. Sample problems are also included for some experiments to demonstrate the modeling and simulation of different power system components and analysis.
This document presents a single phase to three phase matrix converter topology for electric traction drives. The matrix converter replaces the conventional AC-DC-AC conversion stages with a single direct AC-AC conversion stage, removing the need for an intermediate DC link. The operation and control of the matrix converter is analyzed using a separation and link approach, treating it as two equivalent circuits during the positive and negative periods of the source voltage. Sinusoidal pulse width modulation control is used to generate switching signals to control the bi-directional switches and regulate the output voltage and frequency delivered to the three phase traction motor. Simulation results indicate this matrix converter is a feasible replacement for existing traction drive systems.
Analysis of harmonics and resonances in hvdc mmc link connected to AC gridBérengère VIGNAUX
High-frequency responses of HVDC-MMC links are essential to study because harmonic and resonance phenomena may impact the AC grid. In this paper, EMT-type simulations are used to analyze converter station’s frequency response.
Power System Simulation Lab (Formation of Y-Bus & Z-Bus Matrix)Mathankumar S
This document provides information and instructions for an experiment on power system simulation involving the formation of bus admittance and impedance matrices. It includes:
- The objective to understand the formation of network matrices and solve sample networks.
- Data for a 3-bus, 3-line power system including line parameters, transformer data if present, and shunt element information.
- Instructions for students to input the data, run simulations in power system software to form the bus admittance matrix, and output the results.
- The document is an exam paper for the subject Power System I. It contains two sections - Section A and Section B, with 4 questions each. Students have to answer any 3 questions from each section.
- The questions cover various topics related to power systems including transformer and transmission line modeling, fault analysis, symmetrical components, load flow analysis, relay protection and power flow through transmission lines.
- The questions involve derivations, calculations, explanations and numerical problems related to the power system topics. Diagrams and data are provided with some questions.
This document presents a single phase to three phase matrix converter topology for electric traction drives. The matrix converter replaces the multiple conversion stages of a conventional AC-DC-AC converter with a single stage direct AC-AC conversion. The converter analysis is presented using a separation and link approach, which treats the converter as two equivalent circuits during the positive and negative periods of the AC source voltage. Sinusoidal pulse width modulation control is used to control the bi-directional switches in the converter in order to obtain the desired three phase output voltage and frequency for driving an induction traction motor. Simulation results indicate this matrix converter is a feasible replacement for the conversion stages in existing AC traction drive systems.
This presentation discusses an anomaly encountered during the Cartosat-2C Earth observation satellite program. Testing revealed that switching noise from one of the satellite's solar array strings was coupling onto signal lines and preventing commands from being executed properly. Analysis showed the noise coupling was due to a long wire harness routing both strings in close proximity. To address this, the harness routing was modified to reduce the shared wire length from 8.2m to 4.2m, eliminating the noise coupling issue. The satellite was then successfully launched with on-orbit performance meeting specifications.
Power System Simulation Laboratory Manual Santhosh Kumar
This document outlines experiments related to power system simulation laboratory. It includes 10 experiments covering topics like computation of transmission line parameters, modeling of transmission lines, formation of bus admittance and impedance matrices, load flow analysis using different methods, fault analysis, stability analysis of single machine and multimachine systems, electromagnetic transients, load-frequency dynamics, and economic dispatch. The document provides theoretical background and procedures for conducting each experiment using MATLAB software. Sample problems are also included for some experiments to demonstrate the modeling and simulation of different power system components and analysis.
This document presents a single phase to three phase matrix converter topology for electric traction drives. The matrix converter replaces the conventional AC-DC-AC conversion stages with a single direct AC-AC conversion stage, removing the need for an intermediate DC link. The operation and control of the matrix converter is analyzed using a separation and link approach, treating it as two equivalent circuits during the positive and negative periods of the source voltage. Sinusoidal pulse width modulation control is used to generate switching signals to control the bi-directional switches and regulate the output voltage and frequency delivered to the three phase traction motor. Simulation results indicate this matrix converter is a feasible replacement for existing traction drive systems.
Analysis of harmonics and resonances in hvdc mmc link connected to AC gridBérengère VIGNAUX
High-frequency responses of HVDC-MMC links are essential to study because harmonic and resonance phenomena may impact the AC grid. In this paper, EMT-type simulations are used to analyze converter station’s frequency response.
Power System Simulation Lab (Formation of Y-Bus & Z-Bus Matrix)Mathankumar S
This document provides information and instructions for an experiment on power system simulation involving the formation of bus admittance and impedance matrices. It includes:
- The objective to understand the formation of network matrices and solve sample networks.
- Data for a 3-bus, 3-line power system including line parameters, transformer data if present, and shunt element information.
- Instructions for students to input the data, run simulations in power system software to form the bus admittance matrix, and output the results.
- The document is an exam paper for the subject Power System I. It contains two sections - Section A and Section B, with 4 questions each. Students have to answer any 3 questions from each section.
- The questions cover various topics related to power systems including transformer and transmission line modeling, fault analysis, symmetrical components, load flow analysis, relay protection and power flow through transmission lines.
- The questions involve derivations, calculations, explanations and numerical problems related to the power system topics. Diagrams and data are provided with some questions.
This document presents a single phase to three phase matrix converter topology for electric traction drives. The matrix converter replaces the multiple conversion stages of a conventional AC-DC-AC converter with a single stage direct AC-AC conversion. The converter analysis is presented using a separation and link approach, which treats the converter as two equivalent circuits during the positive and negative periods of the AC source voltage. Sinusoidal pulse width modulation control is used to control the bi-directional switches in the converter in order to obtain the desired three phase output voltage and frequency for driving an induction traction motor. Simulation results indicate this matrix converter is a feasible replacement for the conversion stages in existing AC traction drive systems.
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document discusses using artificial neural networks (ANNs) for fault detection and location in extra high voltage transmission lines. It presents a fault detector and locator trained on data from power system simulations of different fault scenarios. The fault detector identifies faults based on current and voltage signals. Three ANN-based fault locators are evaluated that use different inputs like current magnitudes, voltage and current magnitudes, and voltage magnitudes. Test results show the ANN approach can accurately detect and locate faults, with the best performance from the locator using both current and voltage phasor magnitudes. This neural network method provides high-speed fault protection for transmission lines.
Design of Two CMOS Differential Amplifiersbastrikov
High performance, 0.6u process CMOS differential amplifiers were designed in Cadence. Design specifications included differential gain, 3-db bandwidth, output swing, input common mode range, phase margin, total static power consumption, slew rate, and common mode rejection ratio.
This document describes a base station system that uses multiple carrier frequency bands and transmission diversity time delay operation between pairs of co-located control units (CUs). The CUs are connected via an antenna combiner such that even numbered CUs use one primary antenna and odd numbered CUs use a secondary antenna. Each CU pair transmits the same carrier frequency simultaneously, with the slave CU transmitting a delayed signal to provide diversity. Transmission diversity may be disabled for certain timing-sensitive signal bursts.
This document contains a practical work book for a power system analysis course. It includes 10 experiments on topics like analysis of three phase star and delta connected systems under balanced and unbalanced loads, demonstration of the single phase equivalent of a three phase star connected network, simulation of three phase short circuits using MATLAB, selection of circuit breakers for three phase faults, and analysis of transients in power systems. The experiments are designed to help students learn and apply concepts related to power system modeling, analysis, and protection.
This document describes a proposed unified power quality conditioner (UPQC) topology that can compensate for voltage sags, swells and current harmonics with a reduced DC-link voltage without compromising performance. The UPQC uses a capacitor in series with the interfacing inductor of the shunt active filter and connects the system neutral to the negative DC-link terminal. This allows the DC-link voltage requirements of the series and shunt active filters to be matched with a common DC-link capacitor. The performance of the proposed topology is evaluated through MATLAB/Simulink simulation.
This document discusses transmission lines and their parameters. It begins by introducing transmission lines as guided structures that direct the propagation of energy from a source to a load. It then discusses the key parameters used to describe transmission lines - resistance, inductance, conductance and capacitance per unit length. It provides examples of how electromagnetic waves propagate through transmission lines and derives the transmission line equations. It also covers input impedance, standing wave ratio, power, and gives examples of calculating transmission line properties. The document concludes by discussing microstrip transmission lines.
Wind parks are made up of a large number of
saturable inductances (power transformers, inductive voltage
transformers (IVTs)), as well as capacitors (cables, wind turbine
harmonic filters, capacitor voltage transformers (CVTs), voltage
grading capacitors in circuit-breakers). Therefore, they may
present scenarios in which ferroresonance occurs. This paper
presents the scenarios that can lead to ferroresonant circuits in
doubly fed induction generator (DFIG) based wind parks.
This document proposes and analyzes a reversible three-phase switching mode rectifier consisting of four active switches. It derives a closed-form pulse width modulation duty cycle control law to achieve sinusoidal input currents, controllable power factor, bidirectional power flow capability, and adjustable DC output voltage without using current sensors. The rectifier is modeled using state space averaging techniques and space vector representation. Both steady-state and small signal analyses are performed. Experimental results demonstrate the rectifier achieves the desired properties and bidirectional power flow. Guidelines for determining component parameters and controller gains are also described.
- Basic overview of transmission line analysis
-How transmission line analysis differs from basic circuit analysis
- How distributed circuit element differs from Lumped elements
-Links to be referred for Smith Chart
This document contains 5 problems related to transmission lines and circuits. Problem 1 asks to calculate the ABCD parameters of a transmission line system including transformers. Problem 2 gives the ABCD parameters and asks for the sending end voltage, current, and power factor. Problem 3 asks for the sending end voltage given two lines in parallel. Problem 4 asks for the ABCD parameters and characteristic impedance of a pi network transmission line. Problem 5 asks for the resistances of an equivalent T-network model of a two-port resistive circuit.
Modeling and Simulation of a Carrier-based PWM Voltage Source Inverter for a ...IAES-IJPEDS
The analysis of a carrier-based PWM two level voltage source inverter for a nine phase induction machine drive system is presented in this paper. Methods for generating zero-sequence signals during balanced and unbalanced condition are established. Simulation results for the analysis are presented. Two fault conditions involving the voltage source inverter and the nine-phase squirrel cage induction machine load are investigated. For the two fault scenarios considered, the effects on the performance characteristics of the induction machine load are highlighted. The simulation results obtained show that the two imbalance conditions considered result in substantial oscillations on the electromagnetic torque of the machine with attendant reduction in the torque rating. There is also large slip in the rotor speed.
The effect of ripple steering on control loop stability for ac cm pfc boost c...Murray Edington
This document discusses the effect of ripple steering on control loop stability for continuous conduction mode (CCM) power factor correction (PFC) boost converters. It presents an average switch model approach to modeling the power stage, feedback compensation, and dynamics. Transfer functions are derived for a conventional boost converter and then a PFC boost converter with coupled magnetic filter. Experimental and simulation results from a 1.8 kW prototype verify the analytical work and model's ability to predict steady-state and dynamic behavior of CCM PFC boost converters with coupled magnetic filters. Ripple steering is shown to improve EMI filtering and reduce component sizes while allowing similar control strategies to conventional boost converters.
The document provides technical information about a base station system. It discusses:
1) Using on-air combining to combine carrier signals from multiple combining devices and antennas if transmission combining is needed beyond a single rack.
2) Obtaining better than standard receiver sensitivity by using combining devices or pre-amplifiers at antennas, with pre-amplifiers ensuring sensitivity at the antenna connector.
3) Enabling transmission diversity time delay to combine output signals from standard carriers fed the same signal to increase output power and provide diversity downlinks, reducing signal fading effects.
Laboratory Setup for Long Transmission LineIRJET Journal
This document describes the design and development of a laboratory model for a long transmission line. Key aspects include:
1) The model is based on scaled down parameters of an actual 351km, 375MVA, 400kV transmission line between Koradi and Bhushawal.
2) The line is represented by 7 pi sections, with each section modeling 50km. Components like inductors, capacitors, contactors, and meters were selected based on calculations.
3) Hardware implementation includes the physical construction of the model along with automation using PLC and SCADA for online monitoring.
4) Testing showed the model demonstrated phenomena like Ferranti effect similarly to the actual line. The model can be
The differential phase shifter is an interesting four-port passive microwave network composed of two separate lines, the main line and the reference line, and providing stable phase difference between the two output signals over the specified bandwidth of interest. The most common differential phase shifter is the coupled-line Schiffman phase shifter. In this paper, a novel 90 degrees differential microstrip phase shifter configuration employing a half wavelength transmission line loaded with three open stubs is presented, the proposed design could achieve excellent performance with low phase variation over a wide bandwidth compared to the standard Schiffman phase shifter. The simulated results accomplished with the use of CST Microwave Studio and advanced design system (ADS), were found to be in good agreement and have shown that the proposed loaded-stub phase shifter achieved less than 1.1 dB insertion loss, greater than 13 dB return loss and constant 90±5 degrees phase shift over an 89 percent bandwidth.
This document provides an overview of transmission line basics and concepts. It discusses key transmission line parameters like characteristic impedance, propagation delay, per-unit-length capacitance and inductance. It covers transmission line equivalent circuit models and relevant equations. It also discusses transmission line structures, parallel plate approximations, reflection coefficients, and discontinuities. The goal is to understand transmission line behavior and analysis techniques.
The document discusses antenna diversity techniques used in base station systems, including switched combining and maximum ratio combining. It describes the key components used for transmitting and receiving paths, including antennas, combiners, multicouplers and duplexers. Antenna diversity provides a second receive path to improve quality by using techniques like switched combining that select the best receiver path, or maximum ratio combining that optimally combines both paths.
This document describes an AC-DC matrix converter based on a Cockcroft-Walton voltage multiplier circuit. The converter uses a four bidirectional-switch matrix converter between an AC source and a CW circuit to provide high power factor, adjustable output voltage, and low output ripple. The matrix converter operates at two frequencies - one for power factor correction control and one to set the output frequency. Simulation results show the converter improves efficiency and power factor while reducing output voltage ripple compared to a conventional CW circuit. A 10V AC to 50V DC prototype was built and tested.
The document is a court decision from the Supreme Court of the Philippines regarding a petition filed by the Metropolitan Waterworks and Sewerage System (MWSS) assailing a Court of Appeals ruling on employee retirement benefits. Specifically, the key issue is whether employees who served over 30 years were entitled to additional separation pay of 0.5 months salary for each year of service under MWSS's ERIP II retirement program for employees affected by the agency's privatization. The Supreme Court denies the petition, finding that based on relevant laws and MWSS policies, employees who served over 30 years were in fact still owed that additional 0.5 months of separation pay per year of service.
This document provides an overview of the history and development of banking in India. It discusses how the earliest banks originated in the late 18th century, and how foreign banks started establishing branches in India in the 1860s, with Calcutta becoming an important banking center. The document outlines the nationalization of India's banks in 1969 and 1980, and the subsequent liberalization of the banking sector in the 1990s with the introduction of private banks. It also provides context on the current state of India's banking industry and expected future growth.
IOSR Journal of Electrical and Electronics Engineering(IOSR-JEEE) is an open access international journal that provides rapid publication (within a month) of articles in all areas of electrical and electronics engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in electrical and electronics engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document discusses using artificial neural networks (ANNs) for fault detection and location in extra high voltage transmission lines. It presents a fault detector and locator trained on data from power system simulations of different fault scenarios. The fault detector identifies faults based on current and voltage signals. Three ANN-based fault locators are evaluated that use different inputs like current magnitudes, voltage and current magnitudes, and voltage magnitudes. Test results show the ANN approach can accurately detect and locate faults, with the best performance from the locator using both current and voltage phasor magnitudes. This neural network method provides high-speed fault protection for transmission lines.
Design of Two CMOS Differential Amplifiersbastrikov
High performance, 0.6u process CMOS differential amplifiers were designed in Cadence. Design specifications included differential gain, 3-db bandwidth, output swing, input common mode range, phase margin, total static power consumption, slew rate, and common mode rejection ratio.
This document describes a base station system that uses multiple carrier frequency bands and transmission diversity time delay operation between pairs of co-located control units (CUs). The CUs are connected via an antenna combiner such that even numbered CUs use one primary antenna and odd numbered CUs use a secondary antenna. Each CU pair transmits the same carrier frequency simultaneously, with the slave CU transmitting a delayed signal to provide diversity. Transmission diversity may be disabled for certain timing-sensitive signal bursts.
This document contains a practical work book for a power system analysis course. It includes 10 experiments on topics like analysis of three phase star and delta connected systems under balanced and unbalanced loads, demonstration of the single phase equivalent of a three phase star connected network, simulation of three phase short circuits using MATLAB, selection of circuit breakers for three phase faults, and analysis of transients in power systems. The experiments are designed to help students learn and apply concepts related to power system modeling, analysis, and protection.
This document describes a proposed unified power quality conditioner (UPQC) topology that can compensate for voltage sags, swells and current harmonics with a reduced DC-link voltage without compromising performance. The UPQC uses a capacitor in series with the interfacing inductor of the shunt active filter and connects the system neutral to the negative DC-link terminal. This allows the DC-link voltage requirements of the series and shunt active filters to be matched with a common DC-link capacitor. The performance of the proposed topology is evaluated through MATLAB/Simulink simulation.
This document discusses transmission lines and their parameters. It begins by introducing transmission lines as guided structures that direct the propagation of energy from a source to a load. It then discusses the key parameters used to describe transmission lines - resistance, inductance, conductance and capacitance per unit length. It provides examples of how electromagnetic waves propagate through transmission lines and derives the transmission line equations. It also covers input impedance, standing wave ratio, power, and gives examples of calculating transmission line properties. The document concludes by discussing microstrip transmission lines.
Wind parks are made up of a large number of
saturable inductances (power transformers, inductive voltage
transformers (IVTs)), as well as capacitors (cables, wind turbine
harmonic filters, capacitor voltage transformers (CVTs), voltage
grading capacitors in circuit-breakers). Therefore, they may
present scenarios in which ferroresonance occurs. This paper
presents the scenarios that can lead to ferroresonant circuits in
doubly fed induction generator (DFIG) based wind parks.
This document proposes and analyzes a reversible three-phase switching mode rectifier consisting of four active switches. It derives a closed-form pulse width modulation duty cycle control law to achieve sinusoidal input currents, controllable power factor, bidirectional power flow capability, and adjustable DC output voltage without using current sensors. The rectifier is modeled using state space averaging techniques and space vector representation. Both steady-state and small signal analyses are performed. Experimental results demonstrate the rectifier achieves the desired properties and bidirectional power flow. Guidelines for determining component parameters and controller gains are also described.
- Basic overview of transmission line analysis
-How transmission line analysis differs from basic circuit analysis
- How distributed circuit element differs from Lumped elements
-Links to be referred for Smith Chart
This document contains 5 problems related to transmission lines and circuits. Problem 1 asks to calculate the ABCD parameters of a transmission line system including transformers. Problem 2 gives the ABCD parameters and asks for the sending end voltage, current, and power factor. Problem 3 asks for the sending end voltage given two lines in parallel. Problem 4 asks for the ABCD parameters and characteristic impedance of a pi network transmission line. Problem 5 asks for the resistances of an equivalent T-network model of a two-port resistive circuit.
Modeling and Simulation of a Carrier-based PWM Voltage Source Inverter for a ...IAES-IJPEDS
The analysis of a carrier-based PWM two level voltage source inverter for a nine phase induction machine drive system is presented in this paper. Methods for generating zero-sequence signals during balanced and unbalanced condition are established. Simulation results for the analysis are presented. Two fault conditions involving the voltage source inverter and the nine-phase squirrel cage induction machine load are investigated. For the two fault scenarios considered, the effects on the performance characteristics of the induction machine load are highlighted. The simulation results obtained show that the two imbalance conditions considered result in substantial oscillations on the electromagnetic torque of the machine with attendant reduction in the torque rating. There is also large slip in the rotor speed.
The effect of ripple steering on control loop stability for ac cm pfc boost c...Murray Edington
This document discusses the effect of ripple steering on control loop stability for continuous conduction mode (CCM) power factor correction (PFC) boost converters. It presents an average switch model approach to modeling the power stage, feedback compensation, and dynamics. Transfer functions are derived for a conventional boost converter and then a PFC boost converter with coupled magnetic filter. Experimental and simulation results from a 1.8 kW prototype verify the analytical work and model's ability to predict steady-state and dynamic behavior of CCM PFC boost converters with coupled magnetic filters. Ripple steering is shown to improve EMI filtering and reduce component sizes while allowing similar control strategies to conventional boost converters.
The document provides technical information about a base station system. It discusses:
1) Using on-air combining to combine carrier signals from multiple combining devices and antennas if transmission combining is needed beyond a single rack.
2) Obtaining better than standard receiver sensitivity by using combining devices or pre-amplifiers at antennas, with pre-amplifiers ensuring sensitivity at the antenna connector.
3) Enabling transmission diversity time delay to combine output signals from standard carriers fed the same signal to increase output power and provide diversity downlinks, reducing signal fading effects.
Laboratory Setup for Long Transmission LineIRJET Journal
This document describes the design and development of a laboratory model for a long transmission line. Key aspects include:
1) The model is based on scaled down parameters of an actual 351km, 375MVA, 400kV transmission line between Koradi and Bhushawal.
2) The line is represented by 7 pi sections, with each section modeling 50km. Components like inductors, capacitors, contactors, and meters were selected based on calculations.
3) Hardware implementation includes the physical construction of the model along with automation using PLC and SCADA for online monitoring.
4) Testing showed the model demonstrated phenomena like Ferranti effect similarly to the actual line. The model can be
The differential phase shifter is an interesting four-port passive microwave network composed of two separate lines, the main line and the reference line, and providing stable phase difference between the two output signals over the specified bandwidth of interest. The most common differential phase shifter is the coupled-line Schiffman phase shifter. In this paper, a novel 90 degrees differential microstrip phase shifter configuration employing a half wavelength transmission line loaded with three open stubs is presented, the proposed design could achieve excellent performance with low phase variation over a wide bandwidth compared to the standard Schiffman phase shifter. The simulated results accomplished with the use of CST Microwave Studio and advanced design system (ADS), were found to be in good agreement and have shown that the proposed loaded-stub phase shifter achieved less than 1.1 dB insertion loss, greater than 13 dB return loss and constant 90±5 degrees phase shift over an 89 percent bandwidth.
This document provides an overview of transmission line basics and concepts. It discusses key transmission line parameters like characteristic impedance, propagation delay, per-unit-length capacitance and inductance. It covers transmission line equivalent circuit models and relevant equations. It also discusses transmission line structures, parallel plate approximations, reflection coefficients, and discontinuities. The goal is to understand transmission line behavior and analysis techniques.
The document discusses antenna diversity techniques used in base station systems, including switched combining and maximum ratio combining. It describes the key components used for transmitting and receiving paths, including antennas, combiners, multicouplers and duplexers. Antenna diversity provides a second receive path to improve quality by using techniques like switched combining that select the best receiver path, or maximum ratio combining that optimally combines both paths.
This document describes an AC-DC matrix converter based on a Cockcroft-Walton voltage multiplier circuit. The converter uses a four bidirectional-switch matrix converter between an AC source and a CW circuit to provide high power factor, adjustable output voltage, and low output ripple. The matrix converter operates at two frequencies - one for power factor correction control and one to set the output frequency. Simulation results show the converter improves efficiency and power factor while reducing output voltage ripple compared to a conventional CW circuit. A 10V AC to 50V DC prototype was built and tested.
The document is a court decision from the Supreme Court of the Philippines regarding a petition filed by the Metropolitan Waterworks and Sewerage System (MWSS) assailing a Court of Appeals ruling on employee retirement benefits. Specifically, the key issue is whether employees who served over 30 years were entitled to additional separation pay of 0.5 months salary for each year of service under MWSS's ERIP II retirement program for employees affected by the agency's privatization. The Supreme Court denies the petition, finding that based on relevant laws and MWSS policies, employees who served over 30 years were in fact still owed that additional 0.5 months of separation pay per year of service.
This document provides an overview of the history and development of banking in India. It discusses how the earliest banks originated in the late 18th century, and how foreign banks started establishing branches in India in the 1860s, with Calcutta becoming an important banking center. The document outlines the nationalization of India's banks in 1969 and 1980, and the subsequent liberalization of the banking sector in the 1990s with the introduction of private banks. It also provides context on the current state of India's banking industry and expected future growth.
This document contains answers to questions about Informatica and data warehousing concepts. It defines key Informatica components like the Designer, Server Manager and Repository Manager. It describes how to create mappings, sessions, transformations and reusable objects. It also covers data warehousing topics such as the differences between OLTP and data warehousing systems, and between views and materialized views in a data warehouse.
This document provides a case study analysis of the brand positioning of Zoom TV, an Indian television channel focused on Bollywood entertainment. It begins with an executive summary that outlines the objective of analyzing Zoom TV's brand positioning compared to other lifestyle and entertainment channels. It then discusses concepts related to branding, positioning, and developing a positioning statement. The document provides background on the television industry and Bollywood entertainment channels in India. It introduces Zoom TV and discusses its target audience, programming, competitors, and distribution. It analyzes threats to the entertainment channel industry and opportunities for mobile platforms. The document concludes with recommendations to strengthen Zoom TV's brand positioning.
This document is a 16-page decision from the Supreme Court of the Philippines regarding a dispute between Shinryo (Philippines) Company, Inc. and RRN Incorporated over unpaid accounts and overpayment from a construction project. The Construction Industry Arbitration Commission ruled in favor of RRN, awarding unpaid accounts plus interest. Shinryo appealed, arguing that RRN should pay for use of equipment and that the materials and completion costs awards were incorrect. However, the Court of Appeals and now the Supreme Court affirmed the CIAC's decision, finding that Shinryo did not prove its claims or present sufficient evidence to overturn the factual findings of the arbitration body.
This document provides information about the MA English Literature and Linguistics program offered by the Faculty of FELL&AL at the Department of English. The 2-year program covers both literature and linguistics and introduces students to seminal works in both disciplines. It includes courses in areas such as history of English language and literature, poetry, drama, novels, linguistics, grammar, teaching English as a foreign language, and literary criticism. The program aims to develop students' analytical abilities and make them proficient in teaching literature and linguistics.
The document provides information about English as a second language resources including preparing for exams like IELTS and TOEFL. It lists exam study resources and links to websites for tutoring, test preparation courses, and connecting with classrooms internationally. The document also includes advertisements for English learning websites and test preparation services.
Tinjauan pustaka mendiskusikan definisi, etiologi, dan faktor risiko infark miokard dengan ST elevasi (STEMI). STEMI terjadi karena ruptur atau diseksi plak aterosklerosis yang mengurangi aliran darah ke jantung. Faktor risiko termasuk usia, jenis kelamin, riwayat keluarga, lipid tinggi, hipertensi, merokok, dan diabetes. Merokok meningkatkan risiko STEMI 50%.
This document provides information about homework help resources from the website homeworkping.com, including research paper help, online tutoring, and different subject specific homework help like math, algebra, calculus, accounting, paper writing, and more. It also includes an exercise sheet for appraising a scientific paper on the relationship between environmental health and human health in the UK. The exercise sheet evaluates aspects of the paper like its format, research validity, importance, and applicability.
This document provides information on courses for the MBA program at Jawaharlal Nehru Technological University Kakinada in Kakinada, India. It lists 8 courses for the first semester: Management Theory and Practice, Perspectives on Management, Planning, Organizing, Leading, Controlling, Total Quality Management, and Managerial Economics. For each course, it provides a brief description of topics covered. It also lists textbooks and references for each course.
Load Flow and PV Curve Analysis of a 220kV SubstationIRJET Journal
This document discusses load flow analysis and PV curve analysis of a 220kV substation. It presents the methodology used, which includes collecting data from the substation, developing a bus network model, performing load flow analysis using the Newton-Raphson method in MATLAB, and generating PV curves in PowerWorld simulator. The analysis was conducted on two cases with different circuit configurations. The results show voltages, power flows, line losses and identify the knee point of PV curves. Capacitor compensation is also analyzed, showing it can improve voltage stability. The study highlights the importance of load flow analysis for maintaining power system stability and performance.
Application of SVM Technique for Three Phase Three Leg Ac/Ac Converter TopologyIOSR Journals
This paper presents a simulation of a three-phase three-leg AC/AC converter topology using nine IGBTs and space vector pulse width modulation (SVM) technique. The proposed topology reduces the number of switches compared to conventional back-to-back and matrix converters. Simulation results show the converter provides sinusoidal input and output voltages with unity power factor under constant frequency and variable frequency operation. Experimental results from a 5kVA prototype verify the validity of the proposed scheme.
This document contains a question bank for an EHV AC transmission exam. It includes descriptive questions divided into short answer questions and long answer questions across 5 units. The short answer questions test understanding and remembering key concepts. The long answer questions require applying, analyzing, evaluating, and creating explanations related to EHV AC transmission topics like line parameters, corona effects, radio interference, traveling waves, and compensation methods. Multiple choice questions at the end cover additional concepts from Unit 1.
EXPERIMENTAL DETERMINATION AND ANALYSIS OF TRANSMISSION LINE PERFORMANCEijiert bestjournal
It is necessary to calculate the voltage,current a nd power at any point on a transmission line provided the values at one point are known. We are aware that in three phase circuit problems it is sufficient to compute results in one phase and subsequently predict results in the other two phases by exploiting the three phase symm etry. Although the lines are not spaced equilaterally and not transposed,the resulting asy mmetry is slight and the phases are considered to be balanced. As such the transmission line calcu lations are also carried out on per phase basis. For that purpose in the transmission line demo pane l we will be designed to �To study the performance of the line.1)e.g. Relation between sen ding end quantity and receiving end quantity,Ferranti effect,efficiency of power line etc.2) To demonstrate fault clearing process using distance relay(Future Scope)
EE6501 Power System Analysis Rejinpaul_Important_QuestionsSanthosh Kumar
This document provides sample exam questions for a 5th semester power systems analysis course. It covers topics like power flow analysis, fault analysis, sequence networks, transient stability, and swing equations. The questions involve calculating fault currents, drawing impedance diagrams, solving load flows, determining critical clearing angles, and more. In total, there are 5 units covering different power systems analysis concepts, and each unit provides 5 sample exam questions related to those concepts for review.
High Voltage Direct Current Transmission Systems 2Mark MaterialsSanthosh Kumar
The document provides information about HVDC transmission, including:
1. It lists two merits of AC transmission (power can be generated at high voltages, maintenance of AC substations is easy and cheaper) and two merits of DC transmission (it requires only two conductors, there is no skin effect).
2. It discusses types of DC link including monopolar, bipolar, and homopolar links.
3. It lists types of power devices used for HVDC transmission including thyristor, IGBT, GTO, LTT, and MCT.
4. It provides advantages and disadvantages of HVDC transmission such as full control over power, reduced transmission lines, and inability to change voltage
Capacitive voltage and current induction phenomena in GIS substationIOSR Journals
This document summarizes a study that simulated capacitive voltage and current induction in a 420kV GIS substation. The substation and transmission lines were modeled in EMTP-RV software. Single-phase and three-phase faults were applied to lines to observe induced voltage and current. For a single-phase fault, the maximum induced current was 0.41A and maximum voltage matched measured substation values. For a three-phase fault, the maximum induced current was 0.48A and maximum voltage also matched measured substation values. The results validate the accuracy of the substation and transmission line models used in the study.
Three phase bridge controlled by microprocessor(eee499.blogspot.com)slmnsvn
This document summarizes a student project to build a three-phase thyristor bridge controlled by a microprocessor. A PIC 16F877 microcontroller was programmed to trigger thyristors at specific firing angles to control the output voltage. Testing showed the bridge could control DC motor speed by varying the firing angle and output voltage. Harmonics in the input current were reduced using passive low-pass filters. Applications include power electronic labs, motor speed control, battery charging, and uninterruptible power systems.
This document describes the design and development of a laboratory model for a long transmission line. Key aspects include:
1) The model is based on scaled down parameters of an actual 351km, 375MVA, 400kV transmission line between Koradi and Bhushawal.
2) The line is represented by 7 pi sections, with each section modeling 50km. Components like inductors and capacitors were selected based on the scaled parameters.
3) Hardware implementation includes a control panel with instruments, contactors, and a PLC-SCADA system for online monitoring.
4) Both MATLAB simulation and hardware testing were done to observe the Ferranti effect voltage increase along the line. The model can
International Journal of Engineering Research and DevelopmentIJERD Editor
The document proposes a new multi-string inverter topology for photovoltaic systems connected to the electric grid. It connects multiple PV strings in parallel through diodes before boosting the DC voltage and converting it to AC with an inverter. Simulations show the multi-string topology offers higher efficiency compared to traditional string inverters by reducing losses.
This document contains questions and answers related to power electronics devices and converters. It begins with definitions of key power electronics terms:
- IGBT is popular due to lower switching losses and smaller snubber circuit requirements.
- Thyristors can be turned on through forward voltage, gate, dv/dt, temperature, or light triggering.
- Power diodes have higher voltage, current, and power ratings than signal diodes due to a drift region construction.
- IGBTs, power MOSFETs, and power BJTs are voltage, voltage, and current controlled devices respectively due to how their output current is controlled by their input signals.
- There are N-channel and P-channel
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
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This document summarizes a research paper that proposes a dual active bridge inverter topology with one floating bridge to eliminate the need for an isolation transformer. It allows for multilevel output voltage waveforms by charging the floating bridge capacitor to half the main DC link voltage. The paper presents the operating principles and analyzes the available switching states. It also describes a model predictive control scheme to independently control the load current and floating capacitor voltage by predicting their behavior for each switching state over the next sampling period.
This document contains 54 questions related to electromechanical energy conversion, DC machines, transformers, and parallel operation of transformers. The questions cover topics such as magnetic field energy, armature reaction, commutation, DC generator characteristics, transformer tests, efficiency calculations, and load sharing between parallel transformers.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Physical designing of low power operational amplifierDevendra Kushwaha
The document provides details about a master's thesis project to design a novel low power operational amplifier. It begins with an introduction to operational amplifiers, describing their basic structure and ideal characteristics. The literature review discusses previous work on designing low power and low noise operational amplifiers using techniques like current driven bulk, Miller compensation, and class AB amplifiers. Key inferences from the literature are that most work has been done on 120nm CMOS technology, noise can be reduced by adjusting transconductance, and cascoded structures provide better gain than cascaded structures. The document outlines the scope of work, methodology, expected outcomes, and software requirements for the thesis project.
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
International Journal of Engineering Research and Development (IJERD)IJERD Editor
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
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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.
ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Leveraging Generative AI to Drive Nonprofit InnovationTechSoup
In this webinar, participants learned how to utilize Generative AI to streamline operations and elevate member engagement. Amazon Web Service experts provided a customer specific use cases and dived into low/no-code tools that are quick and easy to deploy through Amazon Web Service (AWS.)
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Main Java[All of the Base Concepts}.docxadhitya5119
This is part 1 of my Java Learning Journey. This Contains Custom methods, classes, constructors, packages, multithreading , try- catch block, finally block and more.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
This document provides an overview of wound healing, its functions, stages, mechanisms, factors affecting it, and complications.
A wound is a break in the integrity of the skin or tissues, which may be associated with disruption of the structure and function.
Healing is the body’s response to injury in an attempt to restore normal structure and functions.
Healing can occur in two ways: Regeneration and Repair
There are 4 phases of wound healing: hemostasis, inflammation, proliferation, and remodeling. This document also describes the mechanism of wound healing. Factors that affect healing include infection, uncontrolled diabetes, poor nutrition, age, anemia, the presence of foreign bodies, etc.
Complications of wound healing like infection, hyperpigmentation of scar, contractures, and keloid formation.
LAND USE LAND COVER AND NDVI OF MIRZAPUR DISTRICT, UPRAHUL
This Dissertation explores the particular circumstances of Mirzapur, a region located in the
core of India. Mirzapur, with its varied terrains and abundant biodiversity, offers an optimal
environment for investigating the changes in vegetation cover dynamics. Our study utilizes
advanced technologies such as GIS (Geographic Information Systems) and Remote sensing to
analyze the transformations that have taken place over the course of a decade.
The complex relationship between human activities and the environment has been the focus
of extensive research and worry. As the global community grapples with swift urbanization,
population expansion, and economic progress, the effects on natural ecosystems are becoming
more evident. A crucial element of this impact is the alteration of vegetation cover, which plays a
significant role in maintaining the ecological equilibrium of our planet.Land serves as the foundation for all human activities and provides the necessary materials for
these activities. As the most crucial natural resource, its utilization by humans results in different
'Land uses,' which are determined by both human activities and the physical characteristics of the
land.
The utilization of land is impacted by human needs and environmental factors. In countries
like India, rapid population growth and the emphasis on extensive resource exploitation can lead
to significant land degradation, adversely affecting the region's land cover.
Therefore, human intervention has significantly influenced land use patterns over many
centuries, evolving its structure over time and space. In the present era, these changes have
accelerated due to factors such as agriculture and urbanization. Information regarding land use and
cover is essential for various planning and management tasks related to the Earth's surface,
providing crucial environmental data for scientific, resource management, policy purposes, and
diverse human activities.
Accurate understanding of land use and cover is imperative for the development planning
of any area. Consequently, a wide range of professionals, including earth system scientists, land
and water managers, and urban planners, are interested in obtaining data on land use and cover
changes, conversion trends, and other related patterns. The spatial dimensions of land use and
cover support policymakers and scientists in making well-informed decisions, as alterations in
these patterns indicate shifts in economic and social conditions. Monitoring such changes with the
help of Advanced technologies like Remote Sensing and Geographic Information Systems is
crucial for coordinated efforts across different administrative levels. Advanced technologies like
Remote Sensing and Geographic Information Systems
9
Changes in vegetation cover refer to variations in the distribution, composition, and overall
structure of plant communities across different temporal and spatial scales. These changes can
occur natural.
This presentation was provided by Steph Pollock of The American Psychological Association’s Journals Program, and Damita Snow, of The American Society of Civil Engineers (ASCE), for the initial session of NISO's 2024 Training Series "DEIA in the Scholarly Landscape." Session One: 'Setting Expectations: a DEIA Primer,' was held June 6, 2024.
Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Chapter 4 - Islamic Financial Institutions in Malaysia.pptx
174072012 ee2404-lm
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EXPERIMENT 1
COMPUTATION OF PARAMETERS AND MODELLING OF TRANSMISSION LINES
1.1 AIM
(i) To determine the positive sequence line parameters L and C per phase per kilometer of a three phase
single and double circuit transmission lines for different conductor arrangements.
(ii) To understand modelling and performance of short, medium and long lines.
1.2 OBJECTIVES
i. To become familiar with different arrangements of conductors of a three phase single and double circuit
transmission lines and to compute the GMD and GMR for different
arrangements.
ii. To compute the series inductance and shunt capacitance per phase, per km of a three phase single and
double circuit overhead transmission lines with solid and bundled conductors.
iii. To become familiar with per phase equivalent of a three phase short and medium lines and to evaluate
the performances for different load conditions.
iv. (a) To become familiar with the theory of long transmission line and study the effect of distributed
parameters on voltage and currents, along the line, (b) calculate the surge
Impedance and surge impedance loading.
Three Phase - Symmetrical Spacing:
2. Three Phase - Asymmetrical Transposed:
Nominal П-Model
Bundle conductors
3. Equivalent П-Model
1 EXERCISES:
1.1 A three-phase transposed line composed of one ACSR, 1,43,000 cmil, 47/7 Bobolink conductor
per phase with flat horizontal spacing of 11m between phases a and b and between phases b and c. The
conductors have a diameter of 3.625 cm and a GMR of
1.439 cm. The line is to be replaced by a three conductor bundle of ACSR 477,000-cmil,
26/7 Hawk conductors having the same cross sectional area of aluminum as the single conductor line. The
conductors have a diameter of 2.1793 cm and a GMR of 0.8839 cm.
The new line will also have a flat horizontal configurations, but it is to be operated at a
Higher voltage and therefore the phase spacing is increased to 14m as measured from the
Centre of the bundles. The spacing between the conductors in the bundle is 45 cm.
(a) Determine the inductance and capacitance per phase per kilometer of the above two
Lines.
(b) Verify the results using the available program.
(c) Determine the percentage change in the inductance and capacitance in the bundle
4. Conductor system. Which system is better and why?
1.2 A single circuit three phase transposed transmission line is composed of four ACSR 1,272,000 cmil
conductors per phase with flat horizontal spacing of 14 m between
Phases a and b and between phases b and c. The bundle spacing is 45 cm. The
Conductor diameter is 3.16 cm.
a) Determine the inductance and capacitance per phase per kilometer of the line.
b) Verify the results using available program.
1.3 A 345 kV double circuit three phase transposed line is composed of two ACSR,
1,431,000 cmil, 45/7 bobolink conductors per phase with vertical conductor configuration
as shown in Fig. 1.13. The conductors have a diameter of 1.427 in and the bundle spacing
is 18 in.
a) Find the inductance and capacitance per phase per kilometer of the line.
b) Verify the results using the available program.
c) If we change the relative phase position to acb-a’b’c’, determine the inductance and
Capacitance per unit length using available program.
d) Which relative phase position is better and why?
1.4 A 230 kV, 60 HZ three phase transmissions is 160 km long. The per phase resistance is 0.124 Ω per
km and the reactance is 0.497 Ω per km and the shunt admittance is 3.30 x 10-6
∟900
seimens per km It
delivers 40MW at 220 KV with 0.9 power factor lagging. Use medium line П model
i. Determine the voltage and current at sending end and also compute voltage
regulation and efficiency.
ii. Verify the results using the available program
1.5 A three phase transmission line has a per phase impedance of Z=0.03+j0.04 Ω per km and a per phase
shunt admittance of y=j4.0 x 10-6
Simens per km. The line is 200
km long. Obtain ABCD parameters of the transmission line. The line is sending 407 MW
and 7.833 MVAR at 350KV.Use medium П model
1.6 A three phase 50 Hz, 400 kV transmission line is 250 km long. The line parameters per phase per unit
length are found to be
r=0.02 Ω/km L=1.06mH/km C=0.011 µF/km
Determine the following using the program available use long line model.
(a) The sending end voltage, current and efficiency when the load at the receiving end is
640 MW at 0.8 power factor logging at 400 kV.
5. (b) The receiving end voltage, current, efficiency and losses when 480 MW and 320
MVAR are being transmitted at 400 kV from the sending end.
c) The sending end voltage, current and efficiency and losses when the receiving end load
Impedance is 230 Ω at 400KV
(d) The receiving end voltage when the line is open circuited and is energized with
400kV at the sending end. Also, determine the reactance and MVAR of a three phase shunt reactor to be
installed at the receiving end in order to limit the no load receiving end voltage to 400 kV.
(e) The MVAR and capacitance to be installed at the receiving end for the loading
Condition in (a) to keep the receiving end voltage at 400 kV when the line is
Energized with 400 kV at the sending end.
(f) The line voltage profile along the line for the following cases: no load, rated load of
800 MW at 0.8 power factor at sending end at 400 kV, line terminated in the SIL and
Short circuited line.
EXPERIMENT 2
FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRICES AND SOLUTION OF
NETWORKS
6. 1. Using a text editor create an input file in the sequence given below for formation of
Y and Z matrix for the 6-bus system. Check the results obtained using the available Software. Run the
program and print the modified Y matrix for the 6 bus system for the removal
of the following components, one at-a-time:
a. Line 4-6
b. Transformer 4-3
SYSTEM DATA
NO OF BUSES : 6 NO OF TRANSMISSION LINES: 5
NO OF TRANSFORMERS : 2 NO OF SHUNT ELEMENTS : 2
SYSTEM BASE MVA : 100.00
TRANSMISSION LINE DATA
To understand the formation of network matrices, the bus admittance matrix Y and the bus impedance
2.1 AIM
solution using these matrices.
matrix Z of a power network, to effect certain required changes on these matrices and to obtain network
2.2 OBJECTIVES
i. To write a computer program to form bus admittance matrix Y, given the impedances of
the elements of a power network and their connectivity (mutual coupling between elements
neglected)
ii. To modify the matrix Y to effect specified changes in the configuration of the network.
iii. To obtain network solution, that is, to determine the bus voltages given bus current injections.
iv. To obtain certain specified columns of the bus impedance matrix Z or the full matrix Z using the
factors of Y or the inverse of Y.
7. L NO S BUS R BUS R_IN_PU X_IN_PU HBC_IN_PU RAT
1 1 6 .1230 .5180 .0000 55.0000
2 1 4 .0800 .3700 .0000 65.0000
3 4 6 .0870 .4070 .0000 30.0000
4 5 2 .2820 .6400 .0000 55.0000
5 2 3 .7230 1.0500 .0000 40.0000
TRANSFORMER DATA
TNO S BUS R BUS R_IN_PU X_IN_PU TAP_IN_PU RAT
1 6 5 .0000 .3000 1.0000 30.0000
2 4 3 .0000 1330 1.0000 55.0000
SHUNT CAP/REACTOR DATA
S NO BUS NO SHUNT_MVAR
1 4 2.0000
2 6 2.5000
EXPERIMENT 3
LOAD FLOW ANALYSIS - I: SOLUTION OF LOAD FLOW AND RELATED
PROBLEMS USING GAUSS-SEIDEL METHOD
AIM
8. (i) To understand, the basic aspects of steady state analysis of power systems that are
required for effective planning and operation of power systems.
(ii) To understand, in particular, the mathematical formulation of load flow model in complex form and a
simple method of solving load flow problems of small sized system using Gauss-Seidel iterative
algorithm
OBJECTIVES
i. To write a computer program to solve the set of non-linear load flow equations using Gauss-Seidel Load
Flow (GSLF) algorithm and present the results in the format required for system studies.
ii. To investigate the convergence characteristics of GSLF algorithm for normally loaded small system for
different acceleration factors.
iii. To investigate the effects on the load flow results, load bus voltages and line transformer loadings, due
to the following control actions:
a. Variation of voltage settings of P-V buses
b. Variation of shunt compensation at P-Q buses
c. Variation of tap settings of transformer
d. Generation shifting or rescheduling.
INPUT FILE:
POWER FLOW ANALYSIS I: SOLUTION OF POWER FLOW RELATED PROBLEMS BY GAUSS-
SEIDEL
CASE:1 6-BUS SYSTEM-BASE CASE-POOR VOLTAGE PROFILE:
ACCN FACTOR=1
NAME:
ROLL NO:
VII SEMESTER
DATE:
6 2 4 5 2 1 2 100 100.00 .0001 1.0000
1 0.0000 .0000 .0000 0.0 0.00 1.020
2 50.0000 .0000 .0000 100.0 -20.00 1.020
3 55.000 13.000 1.000
4 0.000 0.000 1.000
5 30.000 18.000 1.000
6 50.000 5.000 1.000
1 1 6 0.1230 0.518 0.000 55.0
2 1 4 0.0800 0.370 0.000 65.0
3 4 6 0.0870 0.407 0.000 30.0
4 5 2 0.2820 0.640 0.000 55.0
5 2 3 0.7230 1.050 0.000 40.0
1 4 3 0.0000 0.1330 1.000 30.0
2 6 5 0.0000 0.3000 1.000 55.0
1 4 2.0
9. 2 6 2.5
EXPERIMENT 4
PROBLEMS USING NEWTON-RAPHSON AND FAST DECOUPLED
METHOD
AIM:
(i} To understand the following for medium and large scale power systems.
10. a) Mathematical formulation of load flow problem in real variable form.
b) Newton Raphson method of load flow (NRLF) solution.
c) Fast decoupled method of load flow (FDLP) solution.
(ii) To become proficient in the usage of software for practical problem solving in the
areas of power system planning and operation.
(iii) To become proficient in the usage of software in solving problems using Newton-
Raphson and Fast decoupled load flow methods.
OBJECTIVES:
(i) To investigate the convergence characteristics of load flow solutions using NRLF and FDLP
algorithms for different sized systems and compare the same with that of GSLF algorithm.
(ii) To investigate the effect of variation of voltage control parameters such as generator voltage
magnitude setting, off nominal tap ratio of transformer and MVAR injections of shunt
capacitors/inductor on the voltage profile and transmission loss of the system.
(iii) To assess the effect of single outage contingencies such as a line outages and generator
outages.
(iv) To investigate the convergence of load flow solution of a two bus system for different load
conditions, understand the existence of maximum load ability condition and to verify the both,
numerically (using load flow package) analytically using the two bus system equations.
EXERCISE:
1. Obtain the load flow solution for the given 6 bus 5 line power system shown in experiment 2
using NRLF method using AU POWER LAB SOFTWARE.
EXPERIMENT 5
FAULT ANALYSIS
AIM:
11. To become familiar with modeling and analysis of power system under faulted condition and to
compute the fault level post fault voltage and current for different types of fault both symmetrical and
unsymmetrical.
OBJECTIVES:
1. To carryout fault analysis for symmetrical and unsymmetrical faults in small systems using the
Thevenin’s equivalent circuit in the sequences and phase domains at the faulted bus but without
the use of software.
2. To conduct fault analysis on a given system using software available and obtain fault analysis
report with fault level and current at the faulted point and post-fault voltages and currents in the
network for the following faults
(a) Three-phase-to-ground
(b) Line-to-ground
(c) Line-to-Line
(d) Double-line-to-ground
3. To study the variation in fault levels and currents in the system when it is interconnected to
neighboring systems.
EXERCISE:
1. It is proposed to conduct fault analysis on two alternative configurations of 4-bus system given in
fig shown below.
G1, G2: 100MVA, 20KV, x+
= x-
=xd” = 20%; x0
=4%; xn = 5%
T1, T2: 100MVA, 20KV/345KV; xleak = 8%
L1, L2: x+
=x-
=15%; x0
=50% on the base of 100MVA
The first configuration, case (a), comprises star-star transformers and the second configuration, case
(b), comprises star-delta transformers.
i. For a three phase to ground (solid) fault, line to line fault, line to ground fault, double line to
ground fault at bus 4, determine the fault current and MVA at faulted bus, post fault bus voltages,
fault current distribution in different elements of the network using Thevenin equivalent circuit.
Draw a single-line diagram showing the above results.
ii. Check the results obtained in (i) using available fault analysis software.
12. The 4-bus system in (i) above is interconnected to a neighboring system at tie bus 5, through a tie-line 3-
5, whose parameters are the same as that of lines L1 and L2. The fault level at bus 5 in the neighboring
system is 500MVA. Recompute the fault distribution in different elements of the network using available
software.
2. (i) For the system given in the figure apply a line-to-ground (solid) fault at bus 4 and determine the
fault current and fault MVA at faulted bus, post-fault bus voltages and fault current contribution by each
generator, both in sequences and phase domain using the available software.
(ii) Check the fault current at bus 4 computed in (i) above using Thevenin equivalent and the
respective sequence network connection.
EXPERIMENT 6
TRANSIENT AND SMALL SIGNAL STABILITY ANALYSIS OF
13. SINGLE-MACHINE INFINITE BUS SYSTEM
AIM :
To become familiar with various aspects of the transient and small signal stability analysis of
Single-Machine Infinite Bus (SMIB) system.
OBJECTIVES :
(i) To understand modeling and analysis of transient and small signal stability of a SMIB power
system.
(ii) To examine the transient stability of a SMIB and determine the critical clearing time of the system
through simulation by trial and error.
(iii) To determine transient stability margin (MW) for different fault conditions.
(iv) To obtain linearised swing equation and to determine the roots of characteristic equation ,
damped frequency of oscillation and undamped natural frequency.
EXERCISE :
(i) A power system comprising a thermal generating plant with four 555 MVA,
24kV, 60HZ units supplies power to an infinite bus through a transformer and two transmission
lines. The data for the system in p.u on a base of 2220 MVA, 24 kV is given below. An equivalent
generator representing the 4 units, characterized by classical model:
Xd’ = 0.3 p.u H= 3.5 MW-s/MVA Transformer : X = 0.15 p.u
Line 1 : X = 0.5 p.u Line 2 : X = 0.93 p.u
Plant operating condition: P = 0.9 p.u ; pf= 0.9(lag) ; Et = 1.0 p.u
It is proposed to examine the transient stability of the system for a three-phase-to ground fault at
the end of line 2 near H.T bus occurring at time t= 0 sec. The fault is cleared at 0.07 sec. by
simultaneous opening of the two circuit breakers at both the ends of line 2.(case1)
(a) Calculate the initial conditions necessary for the classical model of the
machine for the above pre-fault operating condition, determine the
critical clearing angle and time for the fault using “Equal Area Criterion”
and hence comment on the stability of the system for this fault.
14. SOLUTION:
Computation of stator current
It = S*
/ E * T = (0.9-j0.436) / 1.0 = 0.9- j0.436
Computation of the terminal voltage
E’
= Et + jXd’
It = 1.1305 + j0.27
Computation of infinite bus voltage
EB = Et –Jx4(i4+Ji)
X4 = Xtr + X3 = 0.47 p.u.
Ir = P / Et = 0.9 p.u.
I = -Q / E = - 0.435p.u.
Eb = 0.7933-j0.4275
Computation of angle of separation between E’
and Eb
δ = ∟E1’
- ∟Eb = 0.7282 rad
If the infinite bus is taken as reference then
E’
= 1.16 ∟41074
It = 0.99∟2.52 Et =1∟28.31
Critical clearing angle:
Cosδ = {PM(δMAX – δ0) + P3MAXcosδMAX – P2MAXcosδ0 } / { P3MAX – P2MAX}
P3MAX = Eb E’
/ (Xd’
+ Xtr + Xline-1) = 1.098
P2MAX = 0
To find δMAX :
After the fault clearance
δMAX = 180 – sin-1
(Pe / P3max) = 124.94 degree = 2.18 rad
Substituting in the above formula
Cos δc= (0.9(2.18-0.728) + 1.09 * cos124.94)/1.09
δc = 51.88 deg = 0.905 rad
To find critical clearing time:
Tc = √(2H(δc – δ0)) / Π f0 PM = 0.085s
b) Simulate the above sequence of fault occurrence and clearance using the
Software available and plot the swing curve (rotor angle versus time) as
well as the curves showing angular velocity and real power delivered by
the plant versus time
(c) Determine the critical clearing angle and time for the above fault through
trial and error method by repeating the simulation in (b) for different fault
clearing times and compare the critical clearing angle and time obtained.(case2)
Case 3:
Three-phase-to-ground fault at the mid point of line 2 occurs at t=0 sec and is
cleared at t=0.07 sec by the simultaneous opening of two breakers in line 2.
Comment on the transient stability of the system under case 2 and case 3 and
compare the severity of the faults; cases 1,2 and 3 from the point of view of
maximum rotor swing and also by comparing the clearing time margin available.
15. 3. Determine the steady-state stability margin (MW) available for the system
under the given operating condition in exercise 6.5.1. Also determine the
transient stability margin (MW) available for the operating condition given in
exercise 6.5.1. for the three cases of fault, case 1, case 2 and case 3. Can the
severity of the fault be measured using this margin?
Steady state stability margin = (Pmax – P0)* base .MW.
Pmax = EV / X = E’
Eb / X
= 1.16 * 0.9 / (0.328 + 0.3 + 0.15 )
= 1.347 M.W.
Substituting the value in the above formula
Stability margin = (1.347 – 0.9) * 2220
= 992.34 M.W.
Transient stability margin = (Pmax (stable) – P0) M.W.
4. Is proposed to examine the small-signal stability characteristics of the
system given in exercise 1. about the steady-state operating condition
following the loss of line 2; Assume the damping coefficient KD = 1.5 p.u
torque / p.u speed deviation.
(a) Write the linearized swing equation of the system. Obtain the
characteristic equation, its roots, damped frequency of oscillation in Hz,
damping ratio and undamped natural frequency. Obtain also the force-free
time response Δδ (t) for an aintial condition perturbation Δδ = 5 degree and Δω(t) = 0.
5. Repeat the small-signal stability analysis carried out using the software
package in exercise 4 with the following parameters and comment on the
relative stability of each case:
(a) KD = 0 p.u and –1.5 p.u
(b) KD = 1.5 p.u but with P = 1.2, 1.5 and 2.0 p.u
EXPERIMENT 7
16. TRANSIENT STABILITY ANALYSIS OF MULTIMACHINE POWER SYSTEMS
AIM:
(i) To become familiar with modelling aspects of synchronous machines and network for
transient stability analysis of multi-machine power systems.
(ii) To become familiar with the state-of-the-art algorithm for simplified transient stability
simulation involving only classical machine models for synchronous machines.
(iii) To understand system behaviour when subjected to large disturbances in the presence of
synchronous machine controllers.
(iv) To become proficient in the usage of the software to tackle real life problems
encountered in the areas of power system planning and operation.
OBJECTIVES
(i) To assess the transient stability of a multimachine power system when subjected to a
common disturbance sequence: fault application on a transmission line followed by fault
removal and line opening.
(ii) To determine the critical clearing time.
(iii) To observe system response and understand its behaviour during a full load rejection at a
substation with and without controllers.
(iv) To observe system response and understand its behaviour during loss of a major
generating station.
(v) To understand machine and system behaviour during loss of excitation.
(vi) To study the effect of load relief provided by under frequency load shedding scheme.
SOFTWARE REQUIRED
MULTIMACHINE TRANSIENT STABILITY module of AU Power lab or equivalent
EXERCISES
1.. Transient stability analysis of a 9-bus, 3-machine, 60 Hz power system with the following system
modelling requirements:
i. Classical model for all synchronous machines, models for excitation and speed
governing systems not included.
(a) Simulate a three-phase fault at the end of the line from bus 5 to bus 7 near bus 7 at time = 0.0 sec. Assume
that the fault is cleared successfully by opening the line 5-7 after 5 cycles
( 0.083 sec) . Observe the system for 2.0 seconds
(b) Obtain the following time domain plots:
- Relative angles of machines 2 and 3 with respect to machine 1
- Angular speed deviations of machines 1, 2 and 3 from synchronous speed
- Active power variation of machines 1, 2 and 3.
(c) Determine the critical clearing time by progressively increasing the fault clearing
time.
17.
18. EXPERIMENT 8
ELECTROMAGNETIC TRANSIENTS IN POWER SYSTEMS
AIM:
a. To study and understand the electromagnetic transient phenomena in power systems caused due to
switching and fault by using Electromagnetic Transients Program (EMTP).
b. To become proficient in the usage of EMTP to address problems in the areas of over voltage
protection and mitigation and insulation coordination of EHV systems.
OBJECTIVES:
(i) To study the transients due to energization of a single-phase and three-phase load from a non-
ideal source with line represented by Π – model.
(ii) To study the transients due to energization of a single-phase and three-phase load from a non-
ideal source and line represented by distributed parameters.
(iii) To study the transient over voltages due to faults for a SLG fault at far end of a line.
(iv) To study the Transient Recovery Voltage (TRV) associated with a breaker for a three-phase
fault.
SOFTWARE REQUIRED: ELECTROMAGNETIC TRANSIENTS PROGRAM –
UBC version module of AU Power lab or equivalent
EXCERCISE:
Prepare the data for the network given in the Annexure and run EMTP. Obtain the plots of source
voltage, load bus voltage and load current following the Energization of a single-phase load. Comment on
the results. Double the source inductance and obtain the plots of the variables mentioned earlier.
Comment on the effect of doubling the source inductance.
Energization of a single phase 0.95 pf load from a non ideal source and a more realistic line
representation (lumped R, L, C):
Circuit Diagram:
Exercise
1 Prepare the data for the network given in the Annexure 8.1 and run EMTP. Obtain the plots of
source voltage, load bus voltage and load current following the energisation of a single-phase load
and obtain the plots
19. Output
2. Prepare the data for the network given in the Annexure 8.2 and run EMTP. Obtain the plots of
voltages of phases a, b, c at the load bus and switch A current of phase a following energisation of
22. 3. Prepare the data for the network given in the Annexure 8.3 and run EMTP. Obtain the plots of
voltages at source, Bus 1 and Bus 12 following the energisation of the single phase open ended line
represented by distributed parameters. Obtain the plot of voltage at Bus 12 by expanding the time
scale by a factor of ten, i.e, plot the voltage for the first 2.5 millisecond.
23. Output
4 Prepare the data for energisation of a three-phase load fed by a three-phase distributed
parameter line as given in the Annexure 8.4 and run EMTP. Obtain the plots of voltages at source,
Bus 1 and phase a voltage at Bus 12 following the energisation by simultaneous closing of all the
three phases
Output
24. 5 Prepare the data for the network given in the Annexure 8.5 and run EMTP. Obtain the plots of
voltages at source, Bus 1 and Bus 2 following a single lineto- ground fault at the far end, Bus 2.
25. Output
6. Prepare the data for the network given in Annexure 8.6 and run EMTP. Obtain the transient
recovery voltage (TRV) in each phase for a three-phase fault at Bus 1. The TRVs are the voltages
across the switches between Bus1 and BKR1.
29. EXPERIMENT 9
LOAD-FREQUENCY DYNAMICS OF SINGLE-AREA AND TWO AREA POWER
SYSTEMS
AIM:
To become familiar with the modeling and analysis of load-frequency and tie-line flow dynamics
of a power system with load-frequency controller (LFC) under different control modes and to design
improved controllers to obtain the best system response.
OBJECTIVES:
1. To study the time response (both steady state and transient) of area frequency deviation and
transient power output change of regulating generator following a small load change in a single-
area power system with the regulating generator under “free governor action”, for different
operating conditions and different system parameters.
2. To study the time response (both steady state and transient) of area frequency deviation and
turbine power output change of regulating generator following a small load change in a single-
area power system provided with an integral frequency controller, to study the effect of changing
the gain of the controller and to select the best gain for the controller to obtain the best response.
3. To analyze the time response of area frequency deviations and net interchange deviation
following a small load change in one of the areas in an inter connected two-area power system
under different control modes, to study the effect of changes in controller parameters on the
response and to select the optimal set of parameters for the controller to obtain the best response
under different operating conditions.
SOFTWARE REQUIRED:
‘LOAD FREQUENCY CONTROL’ module of AU Power Lab or equivalent
EXERCISES
1. It is proposed to simulate using the software available the load-frequency dynamics of a single-
area power system whose data are given below:
Rated capacity of the area = 2000 MW
Normal operating load = 1000 MW
Nominal frequency = 50 Hz
Inertia constant of the area = 5.0 s
Speed regulation (governor droop)
of all regulating generators = 4 percent
Governor time constant = 0.08 s
Turbine time constant = 0.3 s
Assume linear load–frequency characteristics which means the connected system load increases by one
percent if the system frequency increases by one percent. The area has a governor control but not a load-
frequency controller. The area is subjected to a load increase of 20 MW.
(a) Simulate the load-frequency dynamics of this area using available software and check the following:
30. (i) Steady – state frequency deviation ∆fs in Hz. Compare it with the hand-calculated value using “Area
Frequency Response Coefficient” (AFRC).
(ii) Plot the time response of frequency deviation ∆f in Hz and change in turbine power ∆PT in p.u MW
upto 20 sec. What is value of the peak overshoot in ∆f?
(b) Repeat the simulation with the following changes in operating condition, plot the time
response of ∆f and compare the steady-state error and peak overshoot.
(i) Speed regulation = 3 percent
(ii) Normal operating load = 1500 MW
Hz
MANUAL CALCULATION: A)LOAD FREQ SINGLE AREA- PROBLEM 1(a)
Steady State frequency deviation Δfs=-(M/β) Hz
where
β=Area Frequency Response Coefficient(AFRC)=D+(1/R) Hz/p.u.M.W.
M is in p.u.MW =20/2000=0.01 p.u.MW/Hz
HzMWD /20
50*
100
1
1000*
100
1
=
= D =20/2000=0.01 p.u.MW/Hz
HzMW
R
/1000
50*
100
4
20001
=
=
1/R=1000/2000=0.5 p.u.MW/Hz
β=0.01+0.5=0.51 p.u MW/Hz
Δfs = -(M/β)Hz = -(0.01)/(0.51)
Δfs = -0.0196 Hz
MANUAL CALCULATION: B)LOAD FREQ SINGLE AREA- PROBLEM 1(b)
Steady State frequency deviation Δfs=-(M/β) Hz
where
β=Area Frequency Response Coefficient(AFRC)=D+(1/R) Hz/p.u.M.W.
M is in p.u.MW =20/2000=0.01 p.u.MW/Hz
HzMWD /30
50*
100
1
1500*
100
1
=
= D =30/2000=0.015 p.u.MW/Hz
HzMW
R
/1333
50*
100
3
20001
=
=
1/R=1333/2000=0.666 p.u.MW/Hz
β=0.015+0.666=0.681 p.u MW/Hz
Δfs = -(M/β)Hz = -(0.01)/(0.681)
Δfs = -0.01467 Hz
COMPARISON OF A AND B:
D R Δfs Hz Δf peak Hz
31. 0.01 4% -0.0196 -0.0256
0.015 3% -0.0155 -0.0215
2. Assume that the single-area power system given in exercise 9.5.1 is provided with a load frequency
controller (an integral controller) whose gain KI can be tuned.
(a) Carryout the simulation for the same disturbance of load change of 20 MW for different values of KI,
obtain the time response ∆f for each case, critically compare these responses and comment on their
suitability for practical application.
9-13
(Hint: For choosing different values of KI, first set the governor and turbine time
constants to zero and determine analytically the value of integral gain KI,cr to have
critical damping on the response ∆f (t). Choose the range of KI to include
KI,cr as 0 ≤ KI ≤ ( KI,cr + 1.0 ) )
(b) From the investigations made in (a) above, choose the best value of KI which gives an “optimal”
response ∆f (t) with regard to peak overshoot, settling time, steady-state error and Mean Sum- Squared-
Error (MSSE).
3 It is proposed to simulate the load frequency dynamics of a two-area power system. Both the areas are
identical and has the system parameters given in exercise 9.5.1. Assume that the tie-line has a capacity of
Pmax 1-2 = 200 MW and is operating at a power angle of ( δ01- δ20 ) = 300. Assume that both the areas do
not have load –frequency controller. Area 2 is subjected to a load increase of 20 MW.
(a) Simulate the load-frequency dynamics of this system using available software and
check the following:(i). Steady-State frequency deviation ∆fs in Hz and tie-line flow deviation, ∆P12,S
inp.u. MW. Compare them with hand-calculated values using AFRC’s
(ii) Compare result ∆fs with that obtained in single area simulation in exercise 1
(a), and comment on the support received from area 1 and the advantages of
interconnecting with neighbouring areas .
(iii) Plot the time responses, ∆f1(t), ∆f2 (t), ∆PT1(t) , ∆PT2(t) and ∆P12(t). Comment
on the peak overshoot of ∆f1, and ∆f2.
MANUAL CALCULATION:TWO AREA LOAD FREQUENCY CONTROL PROGRAM
OUTPUT
Δfs = -(M1+M2)/( β1+β2)
M1 =0;M2=0.01 p.u .MW/Hz
β1 =β2=0.51 p.u .MW/Hz (identical areas)
Δfs = - (0.01)/(0.51+0.51)= - 0.0098 Hz
ΔP1-2s = - ΔP1-2s = ( β1M2- β2M1)/ ( β1+β2) p.u .MW
= (0.51*0.01)/(0.51+0.51)
= 10 MW.
Comparison of manual calculation and simulated values.
MANUALY CALCULATED VALUES SIMULATED VALUES
32. Δfs = - 0.0098 Hz
ΔP1-2s=10MW
EXPERIMENT 10
ECONOMIC DISPATCH IN POWER SYSTEM
AIM:
To understand the basics of the problem of Economic Dispatch of optimally adjusting the
generation schedules of thermal generating units to meet the system load which are required for unit
commitment & Economic operation of power systems.
To understand the development of co-ordination equation (the mathematical model for ED)
without and with losses & operating constraints and solution of these equations using direct and iterative
methods.
OBJECTIVE:
To write a program for solving ED problem without and with transmission losses for a given load
condition/daily load cycle using
(a)Direct method
(b)Lambda-iteration method
To study the effect of reduction in operation cost resulting due to changing from simple load
dispatch to economic load dispatch.
To study the effect of change in fuel cost on the economic dispatch for a given load.
To study the use of ED in finalizing the unit commitment for tomorrow’s operating conditions of
power system.
EXERCISE:
1. The system load in a power system varies from 250MW to 1250MW. Two thermal units are
operating at all times and meeting the system load. Incremental fuel cost in hundreds of rupees per Megawatt
hour for the units are
dF1/dP1 = 0.0056P1 + 5.6 ; P1 in MW
dF2/dP2 = 0.0067P2 + 4.5 ; P2 in MW
The operating limits of both the units are given by
100<=P1, P2<=625MW
Assume that the transmission loss is negligible.
a) Determine the economic (minimum fuel cost) generation schedule of each unit, the incremental
fuel cost of each unit and the incremental cost of received power for different load levels from 250
to 1250MW in steps of 100MW.
b) Draw the following characteristics from the results obtained in (a)
i. Incremental cost of received power in hundreds of rupees per MW hr versus system load
in MW.
ii. Unit outputs P1 and P2 in MW versus system load in MW.
33. c) Determine the saving in fuel cost in hundreds of rupees per hour for the economic distribution of a
total load of 550MW between the two units compared with equal distribution of that load between
the two units.
INPUT:
Economic Dispatch - Lambda Iteration Method Without Loss
AU Power lab
VII
0.001 0.05 10
2 $/hr $/MWhr
0.0028 5.6 0 100 625
0.00335 4.5 0 100 625
1
250 1250 100
OUTPUT:
Manual Calculation:
λ = (PD + b1/2a1 +b2/2a2)/(1/2a1+1/2a2)
For PD = 550 MW
λ= 550 + ((5.6/0.0056 + 4.5/0.0067)/(1/0.0056 + 1/0.0067))
⇒ λ = 6.77691 Rs MW/Hr
PG1
*
= λ-b1/2a1 = (6.77691-5.6)/0.0056 = 210.626 MW
PG2
*
= λ-b2/2a2 = (6.77691-4.5)/0.0067 = 339.8374 MW
Fuel Cost:
FC1 = 0.0028 PG12 + 5.6 PG1 + C1 Rs/Hr
FC2 = 0.00335 PG12 + 4.5 PG1 + C2 Rs/Hr
Where C1 & C2 are unknown constants
Fuel Cost for optimal schedule (PG1
*
, PG2
*
)
FC1 = 0.0028(210.1626) 2+5.6(210.1626) + C1 Rs/Hr
FC2 = 0.00335(339.8374) 2 + 4.5(339.8374) + C2 Rs/Hr
FC
*
=FC1+FC2=3216.74+C1C2 Rs/Hr
Fuel Cost for equal Sharing: [PG1 = 275 = PG2]
FC1 = 0.0028(275) 2+5.6(275) + C1 Rs/Hr
FC2 = 0.00335(275) 2 + 4.5(275) + C2 Rs/Hr
FC1 + FC2 = 3242.59 + C1C2 Rs/Hr
Total Saving:
FC = FC – FC
*
= 3242.59 – 3216.74 = 25.85 Rs/Hr
EXERCISE :
2. For the system in exercise 4.3 take into account the transmission loss.
a. Determine the economic loading of each unit to meet a total customer load of 550MW, using
the program developed in 4.2
b. What is transmission loss of the system at the economic loading?
c. Determine the penalty factor for each unit and the incremental fuel cost at each generating bus.
34. d. Determine also the incremental cost of received power (or system λ).Assume that the loss
coefficient in per unit on a 100MVA base of customer load level of 550MW are given by
B11 = 0.008383183
B12 = B21 = -0.000049448
B10/2 = 0.000375082
B22 = 0.005963568
B20/2 = 0.000194971
B00 = 0.000090121
INPUT:
Economic Dispatch - Lambda Iteration Method With Loss
AU Powerlab
2001399126
VII
0.01 0.05 10
2 $/hr $/MWhr
0.0028 5.6 0 100 625
0.00335 4.5 0 100 625
0.008383183 -0.000049448
0.000049448 0.005963568
0.000375082 0.000194971
0.000090121 100
0
550OUTPUT :
Manual Calculation:
B11 = 8.38*10-3
B12 = -0.049*10-3
B21 = 0
B22 = 5.96*10-3
PL = B11P1
2
+ P2
2
B22 + P1P2B12
PD = P1 + P2 – PL
PD = 550 MW
λ = (550 + 5.6/0.0056 + 4.5/0.0067) / (1/0.0056 + 1/0.0067)
⇒ λ = 6.7767 Rs/MW-Hr
For First Iteration
Assume P2 = 0
P1 = [1-(b1/λ)-(2B12P2)]/[(2a1/λ)+2B11]
P1 = [1-(5.6/6.776)-0]/[(0.0056/6.776)+0.01676]
P1 = 9.8686 MW
P2 = [1-(b2/λ)-(2B21P1)]/[(2a2/λ)+2B22]
35. P2 = [1-(4.5/6.776)-0]/[(0.0067/6.776)+0.01192]
P2 = 23.02 MW
PL = P1
2
B11 + P2
2
B22 + P1P2B12
= [(9.8686)2
*(0.00838) + (26.02)2
*(0.00596) + 9.8686*26.02*-0.049*10-3
]
PL = 4.8387 MW
PD = P1 + P2 – PL
= 9.8686 + 26.02 – 4.838
PD = 31.04 MW
: 3292.06 $/hr
EXERCISE :
3. A power system with negligible transmission loss, the system load varies from a peak of 1200MW
to a valley of 500MW. There are three thermal generating units which can be committed to take
the system load. The fuel cost data and generation operation limit data are given below
In hundreds of rupees per hour:
F1 = 392.7 + 5.544P1 + 0.001093P1
2
; P1 in MW
F2 = 217.0 + 5.495P2 + 0.001358P2
2
; P2 in MW
F3 = 65.5 + 6.695P3 + 0.004049P3
2
; P3 in MW
Generation Limit:
150<=P1<=600 MW
100<=P2<=400 MW
50<=P3<=200 MW
There are no other constant on system operation. Obtain an optimum (minimum fuel cost)
with commitment table for each load level taken in steps of 100 MW from 1200 to 500.Adopt
“Brute force enumeration” technique. For each load level obtain economic schedule using
economic dispatch program developed in ex 4.3 for each feasible combination of units and choose
the lowest fuel cost schedule among the combination.
Show the details of economic schedule and the component and total cost of operation for
each feasible combination of unit for the load level of 900MW.
INPUT:
Economic Dispatch - Lambda Iteration Method
Without Loss
AU Power lab
2003557
VII
0.001 0.05 5
3 $/hr $/MWhr