This video describes the Torque - Slip / Torque- Speed Characteristics of three phase squirrel cage induction motor and slip ring induction motor- also describes the Condition for the maximum torque - Pullout torque and Pullout torque equation
This document describes a project to control the speed of a single-phase induction motor. It uses components like op-amps, opto-isolators, SCRs, and a potentiometer. An op-amp operates in comparator mode to generate pulses that trigger SCRs connected in series with the motor. This allows adjusting the firing angle to control motor speed or lamp brightness. Single-phase induction motors are widely used because they are inexpensive and can operate from a single-phase power supply.
Pulse-Width Modulation (PWM) techniques are used to control output voltages of power converters. There are three main PWM methods: Sine PWM uses a reference sine wave compared to a triangular carrier wave to generate PWM signals; Hysteresis PWM uses a feedback control loop with variable switching frequency to maintain output within a hysteresis band; Space Vector PWM approximates the reference voltage vector using combinations of the eight switching states and their durations to reduce harmonic distortion and improve voltage utilization.
This document discusses equations governing the dynamics of a motor load system. It defines key terms like moment of inertia (J), angular velocity (ωm), motor torque (T), and load torque (Tl). It explains that during acceleration, the motor supplies the load torque plus an additional torque (Jdωm/dt) to overcome inertia. Load torques can include friction torque (TF), windage torque (Tw), and torque required for useful work (TL). Load torques are classified as either active if they can drive the motor, or passive if they always oppose motion. Different load types can have torque proportional to speed, speed squared, or inversely with speed.
This document discusses control of electrical drives using variable frequency drives (VFDs). It explains how VFDs work by converting alternating current (AC) power to direct current (DC) power using a rectifier, and then converting the DC back to adjustable frequency AC power using an inverter to control motor speed. Diagrams show the block diagram of a VFD and sections including the converter, inverter, and control. The document presents equations showing the relationships between motor speed, frequency, poles and torque. It also describes simulation results showing voltage, current, speed-torque and total harmonic distortion waveforms. In conclusion, it states that VFDs can provide both speed control and energy savings for induction motors.
Functions and Performance Requirements
Elements of an Excitation System
Types of Excitation Systems
Control and Protection Functions
Modeling of Excitation Systems
The functions of an excitation system are
to provide direct current to the synchronous generator field winding, and
to perform control and protective functions essential to the satisfactory operation of the power system
The performance requirements of the excitation system are determined by
Generator considerations:
supply and adjust field current as the generator output varies within its continuous capability
respond to transient disturbances with field forcing consistent with the generator short term capabilities:
rotor insulation failure due to high field voltage
rotor heating due to high field current
stator heating due to high VAR loading
heating due to excess flux (volts/Hz)
Power system considerations:
contribute to effective control of system voltage and improvement of system stability
V/F control of Induction Motor - Variable voltage and Variable frequencyCitharthan Durairaj
This presentation describes Principle of Variable voltage and Variable frequency- the open loop & closed loop Voltage/Frequency (V/F) control of Induction motor with torque speed characteristics -
This document discusses DC motor drives. It provides an overview of DC drives, including their applications, advantages, and types. It describes the basic characteristics and operating modes of shunt, series, and separately excited DC motors, including motoring, regenerative braking, dynamic braking, and plugging modes. It also discusses four quadrant operation of DC motors.
The document discusses current-fed inverters that use a constant current source input. It describes two operation modes for inverters - load-commutated and force-commutated, which depend on the thyristor firing angle. Load-commutated mode requires leading power factor load, while force-commutated mode requires lagging VAR load. Self-commutated devices like GTOs allow direct control of the six-step waveform without needing load commutation. However, their use can potentially cause resonance issues between motor inductance and capacitor networks unless PWM is carefully implemented.
This document describes a project to control the speed of a single-phase induction motor. It uses components like op-amps, opto-isolators, SCRs, and a potentiometer. An op-amp operates in comparator mode to generate pulses that trigger SCRs connected in series with the motor. This allows adjusting the firing angle to control motor speed or lamp brightness. Single-phase induction motors are widely used because they are inexpensive and can operate from a single-phase power supply.
Pulse-Width Modulation (PWM) techniques are used to control output voltages of power converters. There are three main PWM methods: Sine PWM uses a reference sine wave compared to a triangular carrier wave to generate PWM signals; Hysteresis PWM uses a feedback control loop with variable switching frequency to maintain output within a hysteresis band; Space Vector PWM approximates the reference voltage vector using combinations of the eight switching states and their durations to reduce harmonic distortion and improve voltage utilization.
This document discusses equations governing the dynamics of a motor load system. It defines key terms like moment of inertia (J), angular velocity (ωm), motor torque (T), and load torque (Tl). It explains that during acceleration, the motor supplies the load torque plus an additional torque (Jdωm/dt) to overcome inertia. Load torques can include friction torque (TF), windage torque (Tw), and torque required for useful work (TL). Load torques are classified as either active if they can drive the motor, or passive if they always oppose motion. Different load types can have torque proportional to speed, speed squared, or inversely with speed.
This document discusses control of electrical drives using variable frequency drives (VFDs). It explains how VFDs work by converting alternating current (AC) power to direct current (DC) power using a rectifier, and then converting the DC back to adjustable frequency AC power using an inverter to control motor speed. Diagrams show the block diagram of a VFD and sections including the converter, inverter, and control. The document presents equations showing the relationships between motor speed, frequency, poles and torque. It also describes simulation results showing voltage, current, speed-torque and total harmonic distortion waveforms. In conclusion, it states that VFDs can provide both speed control and energy savings for induction motors.
Functions and Performance Requirements
Elements of an Excitation System
Types of Excitation Systems
Control and Protection Functions
Modeling of Excitation Systems
The functions of an excitation system are
to provide direct current to the synchronous generator field winding, and
to perform control and protective functions essential to the satisfactory operation of the power system
The performance requirements of the excitation system are determined by
Generator considerations:
supply and adjust field current as the generator output varies within its continuous capability
respond to transient disturbances with field forcing consistent with the generator short term capabilities:
rotor insulation failure due to high field voltage
rotor heating due to high field current
stator heating due to high VAR loading
heating due to excess flux (volts/Hz)
Power system considerations:
contribute to effective control of system voltage and improvement of system stability
V/F control of Induction Motor - Variable voltage and Variable frequencyCitharthan Durairaj
This presentation describes Principle of Variable voltage and Variable frequency- the open loop & closed loop Voltage/Frequency (V/F) control of Induction motor with torque speed characteristics -
This document discusses DC motor drives. It provides an overview of DC drives, including their applications, advantages, and types. It describes the basic characteristics and operating modes of shunt, series, and separately excited DC motors, including motoring, regenerative braking, dynamic braking, and plugging modes. It also discusses four quadrant operation of DC motors.
The document discusses current-fed inverters that use a constant current source input. It describes two operation modes for inverters - load-commutated and force-commutated, which depend on the thyristor firing angle. Load-commutated mode requires leading power factor load, while force-commutated mode requires lagging VAR load. Self-commutated devices like GTOs allow direct control of the six-step waveform without needing load commutation. However, their use can potentially cause resonance issues between motor inductance and capacitor networks unless PWM is carefully implemented.
Solved Examples for Three - Phase Induction MotorsAli Altahir
This document provides solutions to two academic examples involving calculations related to induction motors. The first example calculates motor slip percentage, induced torque, operating speed if torque is doubled, and gross power if torque is doubled for a given induction motor setup. The second example calculates maximum torque, corresponding speed and slip, starting torque, effect of doubling rotor resistance, sketches torque-slip curves, and checks motor stability at different speeds. Review questions are also provided related to torque-speed characteristics, torque development, starting torque control, speed control, maximum torque conditions, full load torque, self-starting behavior, slip never being zero, effects of rotor resistance, reasons for high starting torque, and motors with high starting torque.
This document discusses using a cycloconverter to provide self-control of a synchronous motor drive. A cycloconverter can directly convert AC power to a variable frequency that can control the speed of AC motors. For synchronous motor drives, cycloconverters are useful because they allow four-quadrant operation and smooth low-speed control with good dynamic response and low harmonic distortion, making them suitable for large, low-speed applications like mills and mine hoists. However, cycloconverters have limitations in that they can only vary the output frequency in steps and not smoothly, and are economically only suitable for high power applications due to their complex control circuitry and high cost.
The document discusses different types of inverters including their history, applications, classifications, and characteristics. It describes how inverters work by changing DC input to AC output and their uses in applications like UPS, induction heating, electric vehicles. Inverters are classified as static or dynamic based on mobility and as voltage source or current source based on their input/output characteristics. The key aspects of a good inverter are its output waveform quality, efficiency, and reliability.
An inverter is a device that converts DC power from batteries into AC power. It allows appliances that run on AC power to operate from a DC power source. There are different types of inverters based on their output waveform: square wave, modified sine wave, and pure sine wave. Square wave inverters are the cheapest but produce a less stable output. Modified sine wave inverters produce a three-step waveform and are suitable for basic appliances. Pure sine wave inverters have the best waveform quality but are the most expensive. Inverters are commonly used in UPS systems, with solar panels, for backup power, and in HVDC transmission.
The load dispatch center monitors and controls the power system to ensure reliable power supply. It collects data using a SCADA system and oversees elements like generators, transformers, and transmission lines. The load dispatch center performs economic and secure operation of the power system, and works to restore power lines after faults. It is responsible for functions like load forecasting, outage monitoring, voltage regulation, load scheduling, and coordination between grids.
This document summarizes different types of excitation systems for alternators. It discusses the function of excitation systems to supply direct current to the field winding and control the voltage and reactive power of alternators. The three main types covered are DC excitation systems, AC excitation systems, and static excitation systems. DC excitation systems use two small DC generators as exciters but are not commonly used for large alternators now. AC excitation systems include brushless and rotating thyristor types and have advantages like eliminating brushes. Static excitation systems have no rotating parts, are suitable for medium and high capacity alternators, and have benefits like smaller size and no windage losses. The document concludes that the selection of an excitation system depends on factors like the altern
Vector control is a more advanced and precise method of controlling AC induction motors compared to scalar control. It involves transforming the motor currents and voltages into a rotating reference frame to obtain decoupled control similar to a DC motor. This allows for independent control of flux and torque for faster dynamic response and better performance than scalar control. The basic implementation of vector control uses Clarke and Park transformations to convert between stationary and rotating reference frames in the controller. It provides DC motor-like precision in speed and torque control of induction motors.
The document discusses power system stability, including classifications of stability (steady state, transient, and dynamic) and factors that affect transient stability. It also covers topics like the swing equation, equal area criterion, critical clearing angle, and multi-machine stability studies. Some key points:
1) Power system stability refers to a system's ability to return to normal operating conditions after disturbances like faults or load changes.
2) Transient stability depends on factors like fault duration and location, generator inertia, and pre-fault loading conditions.
3) The equal area criterion states that a system will remain stable if the accelerating and decelerating area segments on the power-angle curve are equal.
4)
Module 3 electric propulsion electric vehicle technology pptDrCVMOHAN
The document discusses electric propulsion systems for electric vehicles. It describes how electric motors convert electrical energy to mechanical energy to propel vehicles. Power converters supply electric motors with proper voltage and current, while electronic controllers command the power converter and control motor operation. Common types of electric motors used in electric vehicles include DC motors, induction motors, permanent magnet motors, and switched reluctance motors. The document provides details on the operation and control of these different motor types.
This presentation describes the per-phase equivalent circuit of induction motor - Power flow diagram - Ratio of air gap power, rotor copper loss and mechanical power developed.
This document discusses different types of motor starters used for AC and DC motors. It describes the necessity of starters to limit inrush current and protect motors. The main types covered are DOL, star-delta, and autotransformer starters. It provides information on their wiring diagrams, motor starting characteristics, advantages and disadvantages, suitable motor sizes and applications. Current ratings for motors used with different starters are also included.
This document discusses electrical drives. It defines an electrical drive as a system that uses an electric motor to control motion for various industrial processes. The key components of an electrical drive system are a power source, power modulator, controller, motor, sensing unit, and mechanical load. The power source provides energy, typically from a 3-phase AC supply. The power modulator interfaces the motor to the power source and provides adjustable voltage, current and frequency. Common types of power modulators include controlled rectifiers, inverters, AC voltage regulators, DC choppers, and cycloconverters. Electrical drives offer advantages like flexible control, easy starting and braking, wide speed and torque ranges, and no exhaust emissions.
INTERVIEW QUESTIONS ON POWER ELECTRONICS BY RAJ RAJKUMAR TIWARI
This document provides answers to questions about power electronics components and concepts. It defines terms like holding current, latching current, and turn-on methods for SCRs. It also discusses snubber circuits, firing angle, safe operating area, components for isolating power circuits, current-controlled and voltage-controlled devices, duty cycle, characteristics of ideal op-amps, factors for choosing MOSFETs vs IGBTs, topologies like buck converters, parameters for designing converters, and commutation types. The document provides high-level information on many common topics in power electronics.
Torque Production & Control of Speed in Synchronous Motor.
Speed of synchronous motors can be controlled using two methods called open loop and close loop control.
Open loop contol is the simplest scalar control method where motor speed is controlled by independent frequency control of the converter.
In case of close loop self control mode, instead of controlling the inverter frequency independentaly, the frequency and the phase of the output waveform are controlled by an absolute position encoder mounted on the machine shaft giving an account of position of the rotor.
Electrical Isolation procedure onboard shipShoaib Ahmed
Electricity is a hidden and soundless killer. So, dealing with electricity is inherently hazardous and it is tough to assure that safe working conditions are in place. Undoubtedly, safe electrical isolation is the first prior onboard ship. Both the seafarer and the company have responsibilities to ensure a safe working environment.
Shipboard employees face various problems that can make servicing operations more
challenging, such as:
# Large and complex vessel and vessel machinery, facilities, and systems;
# Machinery, equipment, and systems having multiple power sources, insulating points
and energy types; and
# Difficulty in identifying all energy sources due to faulty engineering drawings and
schematics.
Lead-Acid Battery Simplified Simulink Model using MATLAB Tsuyoshi Horigome
This document describes a simplified Simulink model of a lead-acid battery that can be used to simulate charge and discharge characteristics. The model accounts for battery voltage (Vbat) versus state of charge (SOC) and can simulate charge/discharge times at various current rates. It includes example simulations for a 50Ah battery showing charge time, discharge time waves at different discharge rates, and Vbat vs SOC curves. Instructions are provided on adjusting the model for different battery specifications by editing parameters like capacity and number of cells.
Input output , heat rate characteristics and Incremental costEklavya Sharma
This document discusses the input-output, heat rate, and incremental cost characteristics of thermal power plants. It defines input-output characteristics as a plot of fuel input versus power output. Heat rate is the ratio of fuel input to energy output and is the slope of the input-output curve. An incremental fuel rate curve plots the incremental fuel rate, or change in input divided by change in output, versus output. The incremental cost curve multiplies incremental fuel rate by fuel cost to determine incremental cost in monetary terms per unit of output. Economic dispatch of power plants aims to minimize total incremental costs while meeting demand.
This document contains 68 questions and answers related to power electronics interview questions. It covers topics like IGBTs, thyristors, power diodes, MOSFETs, BJTs, snubber circuits, choppers, controlled rectifiers, inverters, and PWM control. The questions define key power electronics terms and concepts and discuss the advantages and applications of different power devices and converter topologies.
This document discusses voltage source inverter (VSI) and current source inverter (CSI) fed induction motor drives. It explains that the torque produced by an induction motor is proportional to the slip at stable operation, and inversely proportional to the slip at unstable operation. It also notes that induction motors should always be operated at or near zero slip for normal operation. The document describes how VSI and CSI topologies work, including using PWM inverters to vary frequency and voltage. It discusses reasons why MOSFET or IGBT devices are preferred over SCRs. In addition, it explains that CSI drives control torque by varying the DC link current to change output voltage.
Impulse generators are used to test electrical equipment by generating high voltage surges over short durations, simulating events like lightning strikes. A single-stage impulse generator uses capacitors and resistors to charge then discharge through a spark gap, producing an impulse. However, they are large and inefficient. A Marx generator improves on this design using multiple capacitors charged in parallel and discharged in series, multiplying the output voltage. While more compact and powerful, Marx generators still have long charge times and loss of efficiency due to the charging resistors.
This document discusses shafts, axles, and other rotating machine elements. It provides definitions and key differences between shafts and axles. Shafts are rotating members that transmit power and experience bending, torsional, and axial stresses, while axles are stationary members that support rotating components and only experience bending and axial stresses. The document also covers power transmission equations, stresses in shafts, deflection of shafts, and examples calculating stress and shaft dimensions.
18 me54 turbo machines module 03 question no 6a & 6bTHANMAY JS
Modal 03: Question Number 5 a & 5 b
i. Reaction Turbine (Parsons’s turbine)
ii. Degree of Reaction for Parsons’s turbine
iii. Condition for maximum utilization factor,
iv. Reaction staging.
v. Numerical Problems.
Previous Year Question papers
Solved Examples for Three - Phase Induction MotorsAli Altahir
This document provides solutions to two academic examples involving calculations related to induction motors. The first example calculates motor slip percentage, induced torque, operating speed if torque is doubled, and gross power if torque is doubled for a given induction motor setup. The second example calculates maximum torque, corresponding speed and slip, starting torque, effect of doubling rotor resistance, sketches torque-slip curves, and checks motor stability at different speeds. Review questions are also provided related to torque-speed characteristics, torque development, starting torque control, speed control, maximum torque conditions, full load torque, self-starting behavior, slip never being zero, effects of rotor resistance, reasons for high starting torque, and motors with high starting torque.
This document discusses using a cycloconverter to provide self-control of a synchronous motor drive. A cycloconverter can directly convert AC power to a variable frequency that can control the speed of AC motors. For synchronous motor drives, cycloconverters are useful because they allow four-quadrant operation and smooth low-speed control with good dynamic response and low harmonic distortion, making them suitable for large, low-speed applications like mills and mine hoists. However, cycloconverters have limitations in that they can only vary the output frequency in steps and not smoothly, and are economically only suitable for high power applications due to their complex control circuitry and high cost.
The document discusses different types of inverters including their history, applications, classifications, and characteristics. It describes how inverters work by changing DC input to AC output and their uses in applications like UPS, induction heating, electric vehicles. Inverters are classified as static or dynamic based on mobility and as voltage source or current source based on their input/output characteristics. The key aspects of a good inverter are its output waveform quality, efficiency, and reliability.
An inverter is a device that converts DC power from batteries into AC power. It allows appliances that run on AC power to operate from a DC power source. There are different types of inverters based on their output waveform: square wave, modified sine wave, and pure sine wave. Square wave inverters are the cheapest but produce a less stable output. Modified sine wave inverters produce a three-step waveform and are suitable for basic appliances. Pure sine wave inverters have the best waveform quality but are the most expensive. Inverters are commonly used in UPS systems, with solar panels, for backup power, and in HVDC transmission.
The load dispatch center monitors and controls the power system to ensure reliable power supply. It collects data using a SCADA system and oversees elements like generators, transformers, and transmission lines. The load dispatch center performs economic and secure operation of the power system, and works to restore power lines after faults. It is responsible for functions like load forecasting, outage monitoring, voltage regulation, load scheduling, and coordination between grids.
This document summarizes different types of excitation systems for alternators. It discusses the function of excitation systems to supply direct current to the field winding and control the voltage and reactive power of alternators. The three main types covered are DC excitation systems, AC excitation systems, and static excitation systems. DC excitation systems use two small DC generators as exciters but are not commonly used for large alternators now. AC excitation systems include brushless and rotating thyristor types and have advantages like eliminating brushes. Static excitation systems have no rotating parts, are suitable for medium and high capacity alternators, and have benefits like smaller size and no windage losses. The document concludes that the selection of an excitation system depends on factors like the altern
Vector control is a more advanced and precise method of controlling AC induction motors compared to scalar control. It involves transforming the motor currents and voltages into a rotating reference frame to obtain decoupled control similar to a DC motor. This allows for independent control of flux and torque for faster dynamic response and better performance than scalar control. The basic implementation of vector control uses Clarke and Park transformations to convert between stationary and rotating reference frames in the controller. It provides DC motor-like precision in speed and torque control of induction motors.
The document discusses power system stability, including classifications of stability (steady state, transient, and dynamic) and factors that affect transient stability. It also covers topics like the swing equation, equal area criterion, critical clearing angle, and multi-machine stability studies. Some key points:
1) Power system stability refers to a system's ability to return to normal operating conditions after disturbances like faults or load changes.
2) Transient stability depends on factors like fault duration and location, generator inertia, and pre-fault loading conditions.
3) The equal area criterion states that a system will remain stable if the accelerating and decelerating area segments on the power-angle curve are equal.
4)
Module 3 electric propulsion electric vehicle technology pptDrCVMOHAN
The document discusses electric propulsion systems for electric vehicles. It describes how electric motors convert electrical energy to mechanical energy to propel vehicles. Power converters supply electric motors with proper voltage and current, while electronic controllers command the power converter and control motor operation. Common types of electric motors used in electric vehicles include DC motors, induction motors, permanent magnet motors, and switched reluctance motors. The document provides details on the operation and control of these different motor types.
This presentation describes the per-phase equivalent circuit of induction motor - Power flow diagram - Ratio of air gap power, rotor copper loss and mechanical power developed.
This document discusses different types of motor starters used for AC and DC motors. It describes the necessity of starters to limit inrush current and protect motors. The main types covered are DOL, star-delta, and autotransformer starters. It provides information on their wiring diagrams, motor starting characteristics, advantages and disadvantages, suitable motor sizes and applications. Current ratings for motors used with different starters are also included.
This document discusses electrical drives. It defines an electrical drive as a system that uses an electric motor to control motion for various industrial processes. The key components of an electrical drive system are a power source, power modulator, controller, motor, sensing unit, and mechanical load. The power source provides energy, typically from a 3-phase AC supply. The power modulator interfaces the motor to the power source and provides adjustable voltage, current and frequency. Common types of power modulators include controlled rectifiers, inverters, AC voltage regulators, DC choppers, and cycloconverters. Electrical drives offer advantages like flexible control, easy starting and braking, wide speed and torque ranges, and no exhaust emissions.
INTERVIEW QUESTIONS ON POWER ELECTRONICS BY RAJ RAJKUMAR TIWARI
This document provides answers to questions about power electronics components and concepts. It defines terms like holding current, latching current, and turn-on methods for SCRs. It also discusses snubber circuits, firing angle, safe operating area, components for isolating power circuits, current-controlled and voltage-controlled devices, duty cycle, characteristics of ideal op-amps, factors for choosing MOSFETs vs IGBTs, topologies like buck converters, parameters for designing converters, and commutation types. The document provides high-level information on many common topics in power electronics.
Torque Production & Control of Speed in Synchronous Motor.
Speed of synchronous motors can be controlled using two methods called open loop and close loop control.
Open loop contol is the simplest scalar control method where motor speed is controlled by independent frequency control of the converter.
In case of close loop self control mode, instead of controlling the inverter frequency independentaly, the frequency and the phase of the output waveform are controlled by an absolute position encoder mounted on the machine shaft giving an account of position of the rotor.
Electrical Isolation procedure onboard shipShoaib Ahmed
Electricity is a hidden and soundless killer. So, dealing with electricity is inherently hazardous and it is tough to assure that safe working conditions are in place. Undoubtedly, safe electrical isolation is the first prior onboard ship. Both the seafarer and the company have responsibilities to ensure a safe working environment.
Shipboard employees face various problems that can make servicing operations more
challenging, such as:
# Large and complex vessel and vessel machinery, facilities, and systems;
# Machinery, equipment, and systems having multiple power sources, insulating points
and energy types; and
# Difficulty in identifying all energy sources due to faulty engineering drawings and
schematics.
Lead-Acid Battery Simplified Simulink Model using MATLAB Tsuyoshi Horigome
This document describes a simplified Simulink model of a lead-acid battery that can be used to simulate charge and discharge characteristics. The model accounts for battery voltage (Vbat) versus state of charge (SOC) and can simulate charge/discharge times at various current rates. It includes example simulations for a 50Ah battery showing charge time, discharge time waves at different discharge rates, and Vbat vs SOC curves. Instructions are provided on adjusting the model for different battery specifications by editing parameters like capacity and number of cells.
Input output , heat rate characteristics and Incremental costEklavya Sharma
This document discusses the input-output, heat rate, and incremental cost characteristics of thermal power plants. It defines input-output characteristics as a plot of fuel input versus power output. Heat rate is the ratio of fuel input to energy output and is the slope of the input-output curve. An incremental fuel rate curve plots the incremental fuel rate, or change in input divided by change in output, versus output. The incremental cost curve multiplies incremental fuel rate by fuel cost to determine incremental cost in monetary terms per unit of output. Economic dispatch of power plants aims to minimize total incremental costs while meeting demand.
This document contains 68 questions and answers related to power electronics interview questions. It covers topics like IGBTs, thyristors, power diodes, MOSFETs, BJTs, snubber circuits, choppers, controlled rectifiers, inverters, and PWM control. The questions define key power electronics terms and concepts and discuss the advantages and applications of different power devices and converter topologies.
This document discusses voltage source inverter (VSI) and current source inverter (CSI) fed induction motor drives. It explains that the torque produced by an induction motor is proportional to the slip at stable operation, and inversely proportional to the slip at unstable operation. It also notes that induction motors should always be operated at or near zero slip for normal operation. The document describes how VSI and CSI topologies work, including using PWM inverters to vary frequency and voltage. It discusses reasons why MOSFET or IGBT devices are preferred over SCRs. In addition, it explains that CSI drives control torque by varying the DC link current to change output voltage.
Impulse generators are used to test electrical equipment by generating high voltage surges over short durations, simulating events like lightning strikes. A single-stage impulse generator uses capacitors and resistors to charge then discharge through a spark gap, producing an impulse. However, they are large and inefficient. A Marx generator improves on this design using multiple capacitors charged in parallel and discharged in series, multiplying the output voltage. While more compact and powerful, Marx generators still have long charge times and loss of efficiency due to the charging resistors.
This document discusses shafts, axles, and other rotating machine elements. It provides definitions and key differences between shafts and axles. Shafts are rotating members that transmit power and experience bending, torsional, and axial stresses, while axles are stationary members that support rotating components and only experience bending and axial stresses. The document also covers power transmission equations, stresses in shafts, deflection of shafts, and examples calculating stress and shaft dimensions.
18 me54 turbo machines module 03 question no 6a & 6bTHANMAY JS
Modal 03: Question Number 5 a & 5 b
i. Reaction Turbine (Parsons’s turbine)
ii. Degree of Reaction for Parsons’s turbine
iii. Condition for maximum utilization factor,
iv. Reaction staging.
v. Numerical Problems.
Previous Year Question papers
This document contains calculations for various mechanical, electrical, and computer systems for a device called MARTHA. The calculations are organized by system and include analyses of materials like PVC, steel, aluminum, and various fasteners used. Stress, strain, load, and separation number calculations are shown for components like the chassis, motor mount, screws, and wheels to ensure the design meets strength and safety requirements.
The document discusses AC motor drives and induction motor drives. It provides details on:
1. AC motor drives are commonly used in industrial and domestic applications due to their light weight, low cost, and low maintenance requirements. Their power control is relatively complex.
2. There are two main types of AC motor drives - induction motor drives and synchronous motor drives. Induction motors are commonly used in adjustable speed drives.
3. Speed control of induction motors can be achieved by varying the stator voltage and frequency. Rotor resistance control using an external resistor is also described for wound rotor induction motors.
it describes: 1- What is AC/AC Converter and its applilcation?
2- AC Converter in resistive and inductive load with equations
3- using phase control and Time Proportional Control
This is the basic lecture on gears ( 2nd lecture, please check my 1st lecture) It includes simple gear train, compound gear train and epicyclic gear train. In the end, it includes explanation of analytical method to solve rpms of all the gears in planetery gear system
Module 02: Energy exchange in Turbo machines
Modal 02: Question Number 3 a & 3 b
i. Basic Introduction
ii. Euler’s turbine equation
iii. Alternate form of Euler’s turbine equation
iv. Components of energy transfer
v. Degree of Reaction
vi. Velocity triangles for different values of degree of reaction
vii. Utilization factor
viii. Relation between degree of reaction and Utilization factor
ix. List of Formulas
x. Previous Year Question papers
1. The document discusses the velocity and acceleration analysis of a crank and slotted lever quick return motion mechanism.
2. It provides the given data of a crank angle of 60 degrees and crank speed of 100 rpm.
3. It then calculates the velocity and acceleration of the ram (J) as well as the angular acceleration of the slotted lever using graphical methods like velocity diagrams and acceleration diagrams.
This document discusses bevel gears, which are useful for changing the direction of shaft rotation by 90 degrees. Bevel gears can have straight, spiral, or hypoid teeth and are commonly used in applications like locomotives, marine vessels, automobiles, and industrial machinery. The document explains the components of bevel gears like the pitch cone and cone center. It also discusses how to develop involute teeth on the cone surface of bevel gears. The advantages of bevel gears are also summarized, such as their quiet operation and high efficiency compared to other gear types.
EEE 411 power system stability analysis .pptxShoilieChakma
Power system stability refers to the ability of a power system to maintain synchronous operation of generators after experiencing a disturbance such as a fault, load change, or generator loss. There are several types of stability depending on the size of disturbance and time frame. Rotor angle stability concerns maintaining synchronism after small or large disturbances and can be classified as small-signal or transient stability. Transient stability analyzes the ability of the system to maintain synchronism in the seconds after a large disturbance like a fault, using tools like the equal area criterion to determine the critical clearing angle and time.
This document provides information about a course on turbo machines taught by Mr. Thanmay J. S. at VVIET Mysore. The course aims to analyze the energy transfer in radial and axial flow turbo machines using the degree of reaction and utilization factor. It covers general analysis of radial flow compressors and pumps, including velocity triangles and expressions for power, degree of reaction, and the effect of blade discharge angle on performance. It also discusses general analysis of axial flow pumps and compressors, and expressions for degree of reaction and utilization factor in axial flow turbines.
The document summarizes the engineering analysis of a senior design project involving a hydraulic lift table. It includes:
1) Governing equations for the hydraulic lift, pistons, lazy susan bearings and shaft stress.
2) Results of calculations showing the hydraulic force required is 4445 pounds to lift the table weighing 222 pounds and bulk pack weighing 45 pounds.
3) The hydraulic pistons must provide over 2200 pounds of force each.
4) Calculations to determine the torque and friction forces on the lazy susan bearing assembly when rotating the table.
Ejercicios resueltos en clase de fundaciones ayudante CALCULO DE ZAPATASGABRIEL COCA
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Torque speed characteristics of Squirrel cage & Slip ring induction motors
1. TORQUE- SPEED CHARACTERISTICS OF SQUIRREL CAGE & SLIP RING IM
(OR)
TORQUE- SLIP CHARACTERISTICS OF SQUIRREL CAGE & SLIP RING IM
Basic Torque Equation of DC motor
𝐓 = 𝐤 ∗ ∅ ∗ 𝐈
Basic Torque Equation of AC motor
𝐓 = 𝐤 ∗ ∅ ∗ 𝐈 * cos
Power in DC Circuit
V* I
Power in AC Circuit
V* I * cos
Torque - Multiplication of
2 magnetic fluxes
Power – Multiplication of
Voltage and Current