1. The document describes experiments to study the characteristics of various power electronics devices like SCR, TRIAC, MOSFET, IGBT using different circuit connections and varying parameters.
2. Procedures to study half wave and full wave rectification using RC triggering circuit are provided along with the relevant circuit diagram and waveforms. Readings are noted in a tabular column and graphs are plotted.
3. Signatures of staff conducting the experiments are included indicating the experiments were performed in the power electronics lab.
This document provides the procedure to study the performance and waveforms of half wave rectifier (HWR) and full wave rectifier (FWR) using an RC triggering circuit. The experiment involves making connections of the circuit and noting voltage and current readings at different resistor (R) values. Graphs of output voltage, current and power vs firing/conduction angle are plotted. The practical output is compared with the theoretical output voltage calculation.
The document describes experiments to be performed in an Electronics Lab. It includes:
1. Characterization of semiconductor diodes and Zener diodes, including measurement of their forward and reverse bias characteristics.
2. Measurement of transistor characteristics under common emitter, collector, and base configurations.
3. Characterization of other electronic devices like FETs, UJTs, SCRs, DIACs, TRIACs, photodiodes, and thermistors.
4. Design and analysis of rectifier, amplifier, and filter circuits using these devices. Experiments will also involve use of an oscilloscope to examine electronic circuits.
The manual is very useful for UG EEE students for the subject Power Electronics
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
The document is a lab manual for a Power Electronics course that provides instructions on how to perform experiments to characterize various power semiconductor devices. The summary is:
[1] The manual contains 15 experiments to characterize devices like SCRs, TRIACs, MOSFETs, IGBTs and experiments on triggering circuits, choppers, AC voltage control and motor speed control.
[2] Experiment 2 involves characterizing a TRIAC in different modes of operation to determine its breakover voltages, holding current and latching current. Connections are made in circuit diagrams for modes I, II and measurements taken.
[3] Procedures, connections diagrams, calculations and questions are provided to guide students in
This document provides information about a power electronics laboratory manual for a fifth semester electrical engineering course. It includes a list of 10 experiments on topics like the characteristics of SCRs, TRIACs, MOSFETs, and IGBTs. It also covers experiments on AC to DC converters, choppers, and PWM inverters. The document provides circuit diagrams, procedures, and sample questions for each experiment. It is intended to guide students in learning about and conducting various experiments related to power electronics components and applications.
This document provides the contents of a practical work book for the course EE-444 Electrical Drives at NED University of Engineering and Technology. The contents include 15 lab sessions that cover topics such as introduction to devices like diodes, SCRs, IGBTs and MOSFET switches. The lab sessions also cover experiments on AC/DC single phase and three phase controlled and non-controlled rectifiers, DC/DC chopper, characteristics of DC generators and motors, and starting of synchronous and induction motors. Safety rules for the electrical drives lab are also provided.
This document provides information about experiments to characterize various power electronics devices like SCR, MOSFET, and IGBT. It includes circuit diagrams, procedures to obtain characteristics like V-I, transfer and output, and questions for a viva voce. The experiments aim to determine characteristics like latching current, holding current for SCR, and transfer and output curves for MOSFET and IGBT. Gate triggering circuits using RC and resistance triggering for SCR are also described.
This document provides the procedure to study the performance and waveforms of half wave rectifier (HWR) and full wave rectifier (FWR) using an RC triggering circuit. The experiment involves making connections of the circuit and noting voltage and current readings at different resistor (R) values. Graphs of output voltage, current and power vs firing/conduction angle are plotted. The practical output is compared with the theoretical output voltage calculation.
The document describes experiments to be performed in an Electronics Lab. It includes:
1. Characterization of semiconductor diodes and Zener diodes, including measurement of their forward and reverse bias characteristics.
2. Measurement of transistor characteristics under common emitter, collector, and base configurations.
3. Characterization of other electronic devices like FETs, UJTs, SCRs, DIACs, TRIACs, photodiodes, and thermistors.
4. Design and analysis of rectifier, amplifier, and filter circuits using these devices. Experiments will also involve use of an oscilloscope to examine electronic circuits.
The manual is very useful for UG EEE students for the subject Power Electronics
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
The document is a lab manual for a Power Electronics course that provides instructions on how to perform experiments to characterize various power semiconductor devices. The summary is:
[1] The manual contains 15 experiments to characterize devices like SCRs, TRIACs, MOSFETs, IGBTs and experiments on triggering circuits, choppers, AC voltage control and motor speed control.
[2] Experiment 2 involves characterizing a TRIAC in different modes of operation to determine its breakover voltages, holding current and latching current. Connections are made in circuit diagrams for modes I, II and measurements taken.
[3] Procedures, connections diagrams, calculations and questions are provided to guide students in
This document provides information about a power electronics laboratory manual for a fifth semester electrical engineering course. It includes a list of 10 experiments on topics like the characteristics of SCRs, TRIACs, MOSFETs, and IGBTs. It also covers experiments on AC to DC converters, choppers, and PWM inverters. The document provides circuit diagrams, procedures, and sample questions for each experiment. It is intended to guide students in learning about and conducting various experiments related to power electronics components and applications.
This document provides the contents of a practical work book for the course EE-444 Electrical Drives at NED University of Engineering and Technology. The contents include 15 lab sessions that cover topics such as introduction to devices like diodes, SCRs, IGBTs and MOSFET switches. The lab sessions also cover experiments on AC/DC single phase and three phase controlled and non-controlled rectifiers, DC/DC chopper, characteristics of DC generators and motors, and starting of synchronous and induction motors. Safety rules for the electrical drives lab are also provided.
This document provides information about experiments to characterize various power electronics devices like SCR, MOSFET, and IGBT. It includes circuit diagrams, procedures to obtain characteristics like V-I, transfer and output, and questions for a viva voce. The experiments aim to determine characteristics like latching current, holding current for SCR, and transfer and output curves for MOSFET and IGBT. Gate triggering circuits using RC and resistance triggering for SCR are also described.
POWER ELECTRONICS LAB MANUAL, DR. B G SHIVALEELAVATHI, JSSATEBShivaleelavathi B G
The static characteristics of an SCR were measured. The forward V-I characteristics were plotted for different gate currents which showed the threshold voltage. The forward resistance was calculated from the characteristics. The holding and latching currents were also determined by applying different anode currents and observing the SCR state with the gate open.
The manual is useful for PG students belongs to ME power Electronics and Drives
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
The document contains short questions and answers related to power electronics topics like IGBTs, thyristors, power diodes, power MOSFETs, choppers, inverters, and AC voltage controllers. Some key points covered include:
- IGBT is popular due to lower heat requirements and switching losses compared to other power devices.
- Thyristors can be turned on through various methods including forward voltage, gate, and light triggering.
- Power diodes have higher voltage, current, and power ratings than signal diodes.
- Power devices like IGBT, MOSFET and thyristor are voltage controlled while BJT is current controlled.
- Choppers provide
This document contains instructions for performing experiments on electrical machines in a lab. It provides safety guidelines and procedures for two experiments: 1) Speed control of a DC shunt motor using armature and field control methods. Graphs of speed vs armature voltage and speed vs field current are to be plotted. 2) Open circuit and short circuit tests on a single-phase transformer to determine its equivalent circuit parameters and efficiency. Calculations are to be shown to find the transformer's resistance, reactance, regulation, and efficiency at different loads. Precautions for working in the machine lab and sample viva questions are also included.
This manual is very much useful for PG students belongs to ME Power Electronics and Drives
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
The document describes an experiment to draw the magnetization characteristics of a DC shunt generator in order to determine the critical resistance (Rc) and critical speed (Nc). It provides the nameplate details of a motor and generator, as well as a list of apparatus required including rheostats, ammeters, voltmeters and a tachometer. The procedure will involve varying the field resistance and measuring the corresponding field current, armature current and speed to plot the magnetization characteristics curve.
This document is a lab manual for an Electrical and Electronics Engineering course. It provides instructions and details for 12 experiments related to house wiring, ceiling fans, motors, and lighting equipment. The first experiment discusses assembling basic house wiring including components like switches, sockets, and an energy meter. The second experiment focuses on connecting a ceiling fan and varying its speed using a regulator. Circuit diagrams, component details, procedures, and expected results are outlined for safe and effective completion of the experiments.
Engineering practice lab manual for electronicsPadhu Ar
This document appears to be a lab manual for an electronics engineering course. It contains instructions and procedures for 5 experiments related to basic electronic components and measurements. The experiments include studying resistor color coding, measuring AC signal parameters using an oscilloscope, studying logic gates, generating a clock signal, soldering practice, and measuring ripple factor. The document provides background theory for components like resistors, capacitors, inductors, diodes, transistors, and logic gates. It also describes the use of oscilloscopes and multimeters. Tables list the experiments and apparatus required.
This document summarizes power semiconductor switches, including diodes, thyristors, bipolar junction transistors (BJTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), gate turn-off thyristors (GTOs), and other developing switching devices. It describes the characteristics, features, and operating principles of these different types of switches through diagrams, images, and brief explanations.
- The document is an electrical and electronics laboratory manual containing instructions for various experiments.
- It includes two parts - Part A contains experiments related to basic circuit theorems like superposition, reciprocity, Thevenin's, Norton's theorems. Part B includes experiments on basic electronic components like PN junction, diode characteristics.
- The given experiment is about verifying Thevenin's and Norton's theorems for a given circuit. It describes the circuit diagram, theoretical background, procedure to determine equivalent Thevenin's voltage and resistance or Norton's current and resistance.
This manual consists of some important experiments of ac electrical machines.This is prepared by satish babu and lokesh.They are working as staff in usha rama college,telaprolu.
Practical setup of power electronics lab power semicondutor devices [ scr, m...SHOEBSHAH
Some common power devices are the power diode, thyristor, power MOSFET, and IGBT. The power diode and power MOSFET operate on similar principles to their low-power counterparts, but are able to carry a larger amount of current and are typically able to support a larger reverse-bias voltage in the off-state.
Structural changes are often made in a power device in order to accommodate the higher current density, higher power dissipation, and/or higher reverse breakdown voltage. The vast majority of the discrete (i.e., non-integrated) power devices are built using a vertical structure, whereas small-signal devices employ a lateral structure. With the vertical structure, the current rating of the device is proportional to its area, and the voltage blocking capability is achieved in the height of the die. With this structure, one of the connections of the device is located on the bottom of the semiconductor die.
This document contains a lab manual for experiments in electronic circuit design using mechatronics engineering. It includes 10 listed experiments involving various components like SCRs, DIACs, TRIACs, op-amps, and filters. Experiment 1 details obtaining the V-I characteristics of an SCR to find the break over voltage and holding current. Experiment 4 involves designing inverting and non-inverting amplifiers using op-amps. Experiment 8 analyzes the effect of varying frequency on the output voltage of low-pass and high-pass filters.
This document contains questions and answers related to power electronics topics like phase controlled converters. Some key points:
- Phase controlled rectifiers convert fixed AC voltage to variable DC voltage by controlling the firing delay angle. Common applications include motor drives, traction systems, and process control.
- Freewheeling diodes improve input power factor and output current waveform quality in controlled rectifiers.
- Single phase bridge converters have advantages over midpoint converters like lower peak inverse voltages on SCRs and lower transformer ratings.
- Firing circuits for line commutated converters include UJT, cosine wave crossing pulse timing control, and digital schemes.
- Six-pulse converters have simpler commutation and reduced lower order
This article discusses different power electronics devices that are in use like power diodes, power thyristors, power transistors, IGBT, GTO, IGCT and others. This article will give a basic view of these devices and their operations.
This document describes experiments on measuring power in electrical circuits. The first experiment measures three-phase power using a two-wattmeter method. Connections are made to measure power under both balanced and unbalanced load conditions. The second experiment measures single-phase power using three-ammeter and three-voltmeter methods. Power is calculated from current and voltage measurements at different power factors. The third experiment tests a single-phase energy meter under power factors of 0.5, 0.866 and 1. The final experiment investigates the voltage-current relationship and locus diagram of a series R-L circuit by varying resistance at a fixed inductance.
This document provides guidelines for writing lab manuals and instructions for students conducting experiments. It includes details on drawing circuit diagrams, taking observations, completing calculations, and obtaining instructor signatures. It then provides the content for 5 sample lab experiments, including aims, apparatus required, theory, circuit diagrams, procedures, observations tables, calculations, precautions, and results. The experiments cover topics like half wave and full wave rectifiers, zener diodes as voltage regulators, the frequency response of a CE amplifier, and cascaded CE amplifiers with and without feedback.
The document provides instructions for experiments on power electronics laboratory equipment. It includes circuits and procedures to study the characteristics of SCR, MOSFET, IGBT using different firing circuits like R, RC and UJT. The objectives are to draw the output and transfer characteristics of these devices, determine threshold voltages and understand the operation of different firing circuits. Graphs are plotted from the observations and results are analyzed to understand the concepts of latching current, pinch-off voltage and voltage/current control of the devices.
The document provides details about the syllabus for the course EE2301 Power Electronics. It includes 5 units:
1) Power Semiconductor Devices
2) Phase-Controlled Converters
3) DC to DC Converters
4) Inverters
5) AC to AC Converters
It lists the topics that will be covered in each unit along with the total number of periods (45) and references textbooks that will be used. It also provides short questions and answers related to the first two units on power semiconductor devices and phase-controlled converters.
This document contains instructions for electronics experiments for first year BSc students. It lists 10 experiments including converting a meter to an ohmmeter, verifying Kirchoff's laws, measuring voltage and frequency using an oscilloscope, and verifying theorems like Thevenin's, Norton's and maximum power transfer. For each experiment, the aim, apparatus, circuit diagrams, observation tables and results are provided to help students perform the experiments.
This document provides instructions for students taking an Electrical and Electronics Engineering laboratory course on Power Electronics and Drives. It begins with general safety instructions for all EEE lab courses, such as being punctual and wearing proper attire. Next, it lists 13 experiments to be performed in the course, covering topics like gate pulse generation, characteristics of power electronic devices, and converter circuits. Finally, it provides details on the experiments, including circuit diagrams, procedures, expected waveforms, and requirements for recording observations and results. The document aims to prepare students for experiments examining key concepts in power electronics and motor drives.
The document is an electrical machines laboratory manual that provides instructions and procedures for various experiments involving DC machines. It includes circuit diagrams and procedures for open circuit and load tests on DC shunt generators and motors to obtain their characteristics curves. Procedures are also given for load tests on DC series motors and Swinburne's test to determine the efficiency of a DC machine working as both a motor and generator. The document lists the required equipment and provides formulas used in calculations along with sample tabulations and graphs.
POWER ELECTRONICS LAB MANUAL, DR. B G SHIVALEELAVATHI, JSSATEBShivaleelavathi B G
The static characteristics of an SCR were measured. The forward V-I characteristics were plotted for different gate currents which showed the threshold voltage. The forward resistance was calculated from the characteristics. The holding and latching currents were also determined by applying different anode currents and observing the SCR state with the gate open.
The manual is useful for PG students belongs to ME power Electronics and Drives
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
The document contains short questions and answers related to power electronics topics like IGBTs, thyristors, power diodes, power MOSFETs, choppers, inverters, and AC voltage controllers. Some key points covered include:
- IGBT is popular due to lower heat requirements and switching losses compared to other power devices.
- Thyristors can be turned on through various methods including forward voltage, gate, and light triggering.
- Power diodes have higher voltage, current, and power ratings than signal diodes.
- Power devices like IGBT, MOSFET and thyristor are voltage controlled while BJT is current controlled.
- Choppers provide
This document contains instructions for performing experiments on electrical machines in a lab. It provides safety guidelines and procedures for two experiments: 1) Speed control of a DC shunt motor using armature and field control methods. Graphs of speed vs armature voltage and speed vs field current are to be plotted. 2) Open circuit and short circuit tests on a single-phase transformer to determine its equivalent circuit parameters and efficiency. Calculations are to be shown to find the transformer's resistance, reactance, regulation, and efficiency at different loads. Precautions for working in the machine lab and sample viva questions are also included.
This manual is very much useful for PG students belongs to ME Power Electronics and Drives
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
The document describes an experiment to draw the magnetization characteristics of a DC shunt generator in order to determine the critical resistance (Rc) and critical speed (Nc). It provides the nameplate details of a motor and generator, as well as a list of apparatus required including rheostats, ammeters, voltmeters and a tachometer. The procedure will involve varying the field resistance and measuring the corresponding field current, armature current and speed to plot the magnetization characteristics curve.
This document is a lab manual for an Electrical and Electronics Engineering course. It provides instructions and details for 12 experiments related to house wiring, ceiling fans, motors, and lighting equipment. The first experiment discusses assembling basic house wiring including components like switches, sockets, and an energy meter. The second experiment focuses on connecting a ceiling fan and varying its speed using a regulator. Circuit diagrams, component details, procedures, and expected results are outlined for safe and effective completion of the experiments.
Engineering practice lab manual for electronicsPadhu Ar
This document appears to be a lab manual for an electronics engineering course. It contains instructions and procedures for 5 experiments related to basic electronic components and measurements. The experiments include studying resistor color coding, measuring AC signal parameters using an oscilloscope, studying logic gates, generating a clock signal, soldering practice, and measuring ripple factor. The document provides background theory for components like resistors, capacitors, inductors, diodes, transistors, and logic gates. It also describes the use of oscilloscopes and multimeters. Tables list the experiments and apparatus required.
This document summarizes power semiconductor switches, including diodes, thyristors, bipolar junction transistors (BJTs), metal-oxide-semiconductor field-effect transistors (MOSFETs), insulated-gate bipolar transistors (IGBTs), gate turn-off thyristors (GTOs), and other developing switching devices. It describes the characteristics, features, and operating principles of these different types of switches through diagrams, images, and brief explanations.
- The document is an electrical and electronics laboratory manual containing instructions for various experiments.
- It includes two parts - Part A contains experiments related to basic circuit theorems like superposition, reciprocity, Thevenin's, Norton's theorems. Part B includes experiments on basic electronic components like PN junction, diode characteristics.
- The given experiment is about verifying Thevenin's and Norton's theorems for a given circuit. It describes the circuit diagram, theoretical background, procedure to determine equivalent Thevenin's voltage and resistance or Norton's current and resistance.
This manual consists of some important experiments of ac electrical machines.This is prepared by satish babu and lokesh.They are working as staff in usha rama college,telaprolu.
Practical setup of power electronics lab power semicondutor devices [ scr, m...SHOEBSHAH
Some common power devices are the power diode, thyristor, power MOSFET, and IGBT. The power diode and power MOSFET operate on similar principles to their low-power counterparts, but are able to carry a larger amount of current and are typically able to support a larger reverse-bias voltage in the off-state.
Structural changes are often made in a power device in order to accommodate the higher current density, higher power dissipation, and/or higher reverse breakdown voltage. The vast majority of the discrete (i.e., non-integrated) power devices are built using a vertical structure, whereas small-signal devices employ a lateral structure. With the vertical structure, the current rating of the device is proportional to its area, and the voltage blocking capability is achieved in the height of the die. With this structure, one of the connections of the device is located on the bottom of the semiconductor die.
This document contains a lab manual for experiments in electronic circuit design using mechatronics engineering. It includes 10 listed experiments involving various components like SCRs, DIACs, TRIACs, op-amps, and filters. Experiment 1 details obtaining the V-I characteristics of an SCR to find the break over voltage and holding current. Experiment 4 involves designing inverting and non-inverting amplifiers using op-amps. Experiment 8 analyzes the effect of varying frequency on the output voltage of low-pass and high-pass filters.
This document contains questions and answers related to power electronics topics like phase controlled converters. Some key points:
- Phase controlled rectifiers convert fixed AC voltage to variable DC voltage by controlling the firing delay angle. Common applications include motor drives, traction systems, and process control.
- Freewheeling diodes improve input power factor and output current waveform quality in controlled rectifiers.
- Single phase bridge converters have advantages over midpoint converters like lower peak inverse voltages on SCRs and lower transformer ratings.
- Firing circuits for line commutated converters include UJT, cosine wave crossing pulse timing control, and digital schemes.
- Six-pulse converters have simpler commutation and reduced lower order
This article discusses different power electronics devices that are in use like power diodes, power thyristors, power transistors, IGBT, GTO, IGCT and others. This article will give a basic view of these devices and their operations.
This document describes experiments on measuring power in electrical circuits. The first experiment measures three-phase power using a two-wattmeter method. Connections are made to measure power under both balanced and unbalanced load conditions. The second experiment measures single-phase power using three-ammeter and three-voltmeter methods. Power is calculated from current and voltage measurements at different power factors. The third experiment tests a single-phase energy meter under power factors of 0.5, 0.866 and 1. The final experiment investigates the voltage-current relationship and locus diagram of a series R-L circuit by varying resistance at a fixed inductance.
This document provides guidelines for writing lab manuals and instructions for students conducting experiments. It includes details on drawing circuit diagrams, taking observations, completing calculations, and obtaining instructor signatures. It then provides the content for 5 sample lab experiments, including aims, apparatus required, theory, circuit diagrams, procedures, observations tables, calculations, precautions, and results. The experiments cover topics like half wave and full wave rectifiers, zener diodes as voltage regulators, the frequency response of a CE amplifier, and cascaded CE amplifiers with and without feedback.
The document provides instructions for experiments on power electronics laboratory equipment. It includes circuits and procedures to study the characteristics of SCR, MOSFET, IGBT using different firing circuits like R, RC and UJT. The objectives are to draw the output and transfer characteristics of these devices, determine threshold voltages and understand the operation of different firing circuits. Graphs are plotted from the observations and results are analyzed to understand the concepts of latching current, pinch-off voltage and voltage/current control of the devices.
The document provides details about the syllabus for the course EE2301 Power Electronics. It includes 5 units:
1) Power Semiconductor Devices
2) Phase-Controlled Converters
3) DC to DC Converters
4) Inverters
5) AC to AC Converters
It lists the topics that will be covered in each unit along with the total number of periods (45) and references textbooks that will be used. It also provides short questions and answers related to the first two units on power semiconductor devices and phase-controlled converters.
This document contains instructions for electronics experiments for first year BSc students. It lists 10 experiments including converting a meter to an ohmmeter, verifying Kirchoff's laws, measuring voltage and frequency using an oscilloscope, and verifying theorems like Thevenin's, Norton's and maximum power transfer. For each experiment, the aim, apparatus, circuit diagrams, observation tables and results are provided to help students perform the experiments.
This document provides instructions for students taking an Electrical and Electronics Engineering laboratory course on Power Electronics and Drives. It begins with general safety instructions for all EEE lab courses, such as being punctual and wearing proper attire. Next, it lists 13 experiments to be performed in the course, covering topics like gate pulse generation, characteristics of power electronic devices, and converter circuits. Finally, it provides details on the experiments, including circuit diagrams, procedures, expected waveforms, and requirements for recording observations and results. The document aims to prepare students for experiments examining key concepts in power electronics and motor drives.
The document is an electrical machines laboratory manual that provides instructions and procedures for various experiments involving DC machines. It includes circuit diagrams and procedures for open circuit and load tests on DC shunt generators and motors to obtain their characteristics curves. Procedures are also given for load tests on DC series motors and Swinburne's test to determine the efficiency of a DC machine working as both a motor and generator. The document lists the required equipment and provides formulas used in calculations along with sample tabulations and graphs.
This document contains instructions for conducting load tests on a self-excited DC shunt generator. It outlines the apparatus needed, including ammeters, voltmeters, rheostats, and a tachometer. The procedure describes adjusting the field rheostat to vary the field current and record open circuit voltage measurements. Load is then applied in steps using a rheostatic load, and armature current, voltage, and speed are measured to plot the generator's load characteristics curves. The goal is to determine the generator's performance under no load and varying load conditions.
The LM555 is an integrated circuit used for generating accurate time delays or oscillations. It can be used in monostable or astable configuration. In monostable mode, the time delay is controlled by one resistor and capacitor. In astable mode, the frequency and duty cycle are controlled by two resistors and one capacitor. The circuit can be triggered and reset. The output can source or sink up to 200mA. It has applications in precision timing, pulse generation, and sequential timing.
In this paper Low power low voltage CMOS analog multiplier circuit is proposed. It is based on flipped voltage
follower. It consists of four voltage adders and a multiplier core. The circuit is analyzed and designed in 0.18um
CMOS process model and simulation results have shown that, under single 0.9V supply voltage, and it
consumes only 31.8μW quiescent power and 110MHZ bandwidth.
IRJET- Speed Control of Brushless DC Motor using Pulse Width Modulation T...IRJET Journal
This document describes a speed control system for a brushless DC motor (BLDC) using pulse width modulation (PWM). It involves:
1. Generating PWM pulses from a microcontroller to control the duty cycle of a three-phase voltage source inverter that powers the BLDC motor. Higher duty cycles result in faster motor speeds.
2. Implementing the inverter using MOSFET switches to produce the three-phase voltages needed to electronically commutate the BLDC motor.
3. Testing the system and verifying that motor speed increases with higher PWM duty cycles, thus demonstrating effective speed control of the BLDC motor.
A 5-Level Single Phase Flying Capacitor Multilevel InverterIRJET Journal
This document presents a simulation and analysis of a single phase five level flying capacitor multilevel inverter. It explains the operating principle, topology, and components of the flying capacitor multilevel inverter. Simulations were conducted using Matlab/Simulink with both ideal switches and IGBT switches. The results show output voltage waveforms with five distinct levels that approximate a sinusoidal waveform. Triggering circuits using OR gates were also simulated to generate gate signals for the switches to produce the multilevel output.
This paper presents combinations of level shifted pulse-width modulation algorithm with conventional discontinuous pulse-width modulation methods for cascaded multilevel inverters. In the proposed DPWM a zero sequence signal is injected in sinusoidal reference signal to generate various modulators with easier implementation. The analysis four various control strategies namely Common Carrier (CC), Inverted Carrier (IC), Phase Shifted (PS) and Inverted Phase Shift (IPS) for cascaded multilevel inverter fed induction motor drive has been illustrated. To validate the proposed work experimental tests has been carried out using dSPACE controller. Experimental study proves that using proposed algorithms reduction in common-mode voltage with fewer harmonics along with reduced switching loss for a cascaded multilevel inverter fed motor drive has been achieved.
IRJET- Diode Clamped Multilevel Inverter for Induction Motor DriveIRJET Journal
1) The document describes a five-level diode clamped multilevel inverter fed induction motor drive system using solar energy as the renewable input source.
2) A multilevel boost converter is used to boost the voltage from the solar panels and balance the DC bus voltages of the diode clamped multilevel inverter.
3) Simulation results show that the five-level inverter provides reduced total harmonic distortion of 4.10% in the output current compared to 48.16% for a two-level inverter, demonstrating improved motor performance from use of the multilevel inverter topology.
This document describes an experiment to plot the VI characteristics of a TRIAC and determine its forward and reverse break over voltages at different gate currents. Key components used include a 2N5756 TRIAC, power supplies, voltmeters, ammeters, and resistors. The forward and reverse break over voltages are found to be 100V and 60V for various gate currents between 7.5mA to 9.9mA. The results characterize the static electrical behavior of the given TRIAC.
This document contains the syllabus and procedures for experiments in the Electrical Machines I Lab. The experiments focus on obtaining characteristics of DC machines like generators and motors, as well as transformers. Key experiments include open/load characteristics of DC generators and motors, efficiency tests, and open/short circuit tests for transformers. Precautions are outlined and tabular columns provided to record readings and calculate performance parameters like efficiency.
This document contains the syllabus and procedures for experiments in the Electrical Machines I Lab. The experiments focus on obtaining characteristics of DC machines like generators and motors, as well as load tests to determine efficiency. Key experiments include open/load characteristics of DC generators and motors, Swinburne's test on DC shunt motors, and load tests to find efficiency of DC shunt and compound motors. Procedures provide connections, precautions and step-by-step methods for collecting data and analyzing results for each experiment.
Soft Switched Multi-Output Flyback Converter with Voltage DoublerIJPEDS-IAES
A novel multi-output voltage doubler circuit with resonant switching
technique is proposed in this paper. The resonant topology in the primary
side of the flyback transformer switches the device either at zero voltage or
current thus optimizing the switching devices by mitigating the losses. The
voltage doubler circuit introduced in the load side increases the voltage by
twice the value thereby increasing the load power and density. The proposed
Multi-output Isolated Converter removes the need for mutiple SMPS units
for a particular application. This reduces the size and weight of the
converters considerably leading to a greater payload. This paper aims at
optimizing the proposed converter with some design changes. The results
obtained from the hardware prototype are given in a comprehensive manner
for a 3.5W converter operating at output voltages of 5V and 3.3V at 50 kHz
switching frequency. The converter output is regulated with the PI controller
designed with SG3523 IC. The effects of load and line regulation for ±20%
variations are analyzed in detail.
Transient Dynamic Analyzing for Induction Motor Design Based on combine Simul...IJERA Editor
The paper introduces an industrial application of field-circuit-mechanical combined simulation on the induction
motor design, which is driven with power electronic circuit, VFD(Varied Frequency Driver). The time variant
electromagnetic field is calculated with time stepping Finite Element method, while VFD circuit is simulated
real time with cSpice technology which have been implanted in the Maxwell software.
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This document discusses simulations of offline converters using cycle-by-cycle modeling. It summarizes a simulation of a 150W power factor correction (PFC) boost converter using the MC33262 controller. The simulation took 4 minutes and results matched theoretical calculations closely. It highlights that the input capacitor plays roles in both EMI and PFC operation and recommends a size of 3uF/kW. A bypass diode is suggested to absorb in-rush current and prevent stress on the catch diode.
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This presentation summarizes power electronic devices used in power systems, including the SCR and TRIAC. It describes the introduction, structure, operating modes, characteristics and applications of the SCR. The SCR's applications include motor starters and regulators. It also discusses the TRIAC's structure, operating quadrants, VI characteristics and applications such as LED drivers for street lighting. The presentation concludes with noting that power systems are networks for supplying, transferring and using electrical power to homes and industry.
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Power electronics is the application of electronics at high power levels and involves the conversion, control and conditioning of electric power. It has grown rapidly due to advances in power semiconductor switches, microelectronics, control algorithms and new applications. Power electronics systems range from a few watts to several megawatts and include power processors that control the flow of electric energy between input and output ports. Major applications of power electronics include industrial motor drives, transportation systems, utility systems, power supplies and residential appliances. Emerging topics in power electronics focus on improving efficiency, reducing size and cost, and minimizing negative impacts on power systems and the environment.
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1. FOR
IV SEMESTER B.E (EC / TC / ML)
(For private circulation only)
VISVESVARAYA TECHNOLOGICAL UNIVERSITY
Name
Reg no
:……………………………………………
:……………………………………………
DEPARTMENT OF ELECTRONICS & COMMUNICATION
SRI SIDDHARTHA INSTITUTE OF TECHNOLOGY
MARLUR, TUMKUR-572105
POWER ELECTRONICS LAB MANUAL
2. Power Electronics Lab manual
CONTENTS
Experiment No
Page. No
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
SCR Characteristics
TRIAC Characteristics
MOSFET Characteristics
IGBT Characteristics
RC Triggering Circuit – HWR & FWR
UJT Triggering of SCR
3
9
15
17
19
23
(LC Commutation Circuit) Oscillation Chopper Circuit 29
UJT Triggering of SCR – HWR & FWR
Digital Firing Circuit
AC Voltage control by using TRIAC & DIAC
Single Phase FWR
Impulse Commutated Chopper
Speed control of a 1 φ Induction motor
Speed Control of Universal motor
Series Inverter
Parallel Inverter
Question bank
Viva questions
Data sheets
33
39
41
45
49
51
53
55
57
58
59
64
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Dept. of ECE,KSSEM
3. Power Electronics Lab manual
Circuit Diagram: -
Ideal Graph: -
IL>IH
IL > IH
IL
IH
Base Diagrams of 2N3669/70 & TY616 : -
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Dept. of ECE,KSSEM
1ΚΩ/1W
4. Power Electronics Lab manual
Experiment No: 1
DATE: __/__/____
S.C.R. Characteristics
Aim: -
To study the V-I characteristics of S.C.R. and determine the Break over
voltage, on state resistance Holding current. & Latching current
Apparatus required: -
SCR – TY604, Power Supplies, Wattage Resistors, Ammeter, Voltmeter, etc.,
Procedure: -
1. Connections are made as shown in the circuit diagram.
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Dept. of ECE,KSSEM
9. Steps No.2, 3, 4, 5, 6, 7, 8 are repeated for another value of the gate current IG.
2. The value of gate current IG, is set to convenient value by adjusting VGG.
3. By varying the anode- cathode supply voltage VAA gradually in step-by- step, note down
the
corresponding values of VAK & IA. Note down VAK & IA at the instant of firing of SCR and
after4. The point at which SCR fires, gives the value of break over voltage VBO.
5. A graph of VAK V/S IA is to be plotted.
6. The on state resistance can be calculated from the graph by using a formula.
7. The gate supply voltage VGG is to be switched off
8. Observe the ammeter reading by reducing the anode-cathode supply voltage VAA. The
point
at which the ammeter reading suddenly goes to zero gives the value of Holding Current IH.
5. Power Electronics Lab manual
Wkt,
Let
Ia = 300mA
Vscr = 1v
Vaa = 30v
Vaa = Ia R L + Vscr
RL =
Vaa − Vscr
Ia
30− 1 = 96.66 Ω ≅ 100Ω
300× 10− 3
Vgg = Ig R g + Vgt
Rg =
Rg =
Vgg − Vgt
Ig
Let
Ig = 15mA
Vgt = 1v
Vgg = 15v
15 − 1 = 933Ω ≅ 1X Ω
15 × 10-3
Wattage:- Power in watts = I2Rg = (15x10-3)2x103 = 0.225w (select 1 watt)
∴Gate resistor = Rg = 1KΩ, 1 watts
Note: - Follow the same design procedure for TRIAC connection sting
-4-
Designing Equations:-
Dept. of ECE,KSSEM
RL =
Wattage:- Power in watts = I2RL = (300x10-3)2x100 = 9 watts (select 20 watts)
∴Λοαδ resistor = RL = 100Ω, 20watts
Gate Resistance (Rg):- Wkt,
Latching Current
6. Power Electronics Lab manual
Alternate Method: -
1. Connections are made as shown in the circuit diagram
2. Adjust the value of Ig to zero or some minimum value
3. By varying the voltage Vak from 0 to 10 volts with a step of 2 volts, note down
corresponding values of Ia
formula,
RON - STATE =
∆VAK
=______ Ω
∆I A
-5-
Dept. of ECE,KSSEM
4. Now apply the gate voltage gradually, until SCR fires, then note down the values of Ig
and
also the values of Ia and Vak
5. Increase Vaa to some value and note down Ia and Vak
6. Reduce gate voltage to zero, observe ammeter reading by reducing Vaa which gives
the
values of Ih (holding current) at the point at which, current suddenly drops to zero
7. Repeat the steps 2, 3, 4, 5 & 6 for different values of break over voltage
8. Plot a graph of Vak v/s Ia
9. The on state resistance can be calculated from the graph by using
7. Power Electronics Lab manual
Tabular column: -
Ig =
Sl.No
mA
VAK Volts
IA µΑ/µΑ/Α
Ig =
Sl.No
mA
VAK Volts
IA µΑ/µΑ/Α
-6-
Dept. of ECE,KSSEM
8. Power Electronics Lab manual
Procedure (Latching current)
1. connections one made as shown in the circuit diagram
2. Set Vgg at 7 volts
3. Set Vaa at particular value, observe Ia, by operating the switch (on & off).
if in goes to zero after opening of the switch, indicates Ia < IL
4. Repeat step 3 such that the current Ia should not go to zero after opening
of the switch. Then Ia gives the value of IL.
Viva questions: -
1. Explain the working operation of VI characteristics of S.C.R.
2. Define Holding current, Latching current on state resistance, Break down voltage
………………………….……………………..
Signature of the staff with date
-7-
Dept. of ECE,KSSEM
3. Explain the working operation of S.C.R. characteristics by using two transistor analogy
4. Write an expression for anode current
5. Mention the applications of S.C.R.?
9. Power Electronics Lab manual
CIRCUIT DIAGRAM: -
1 K Ω /1W
1 K Ω /1W
1 K Ω /1W
1 K Ω /1W
-8-
Dept. of ECE,KSSEM
10. Power Electronics Lab manual
Experiment No: 2
DATE: __/__/____
TRIAC Characteristics
Aim: -
To study the v-1 characteristics of a TRIAC in both directions and also in
different (1, 2, 3 & 4) modes op operation and determine break over voltages,
holding current, latching current and comment on sensitivities.
Apparatus required: -
TRIAC – BT 136, power supplies, wattage resistors, ammeter, voltmeter, etc.,
Procedure: -
I mode
1. Connections are made as shown in the circuit diagram (a)
2. The value of gate current ig is set to convenient value by adjusting vgg.
3. By varying the supply voltage Vm gradually in step-by-step, note down the
corresponding values of Vmt2t1 and i1. Note down Vmt2t1 and i1 at the instant
of firing of TRIAC and after firing (by reducing the voltmeter ranges and
increasing the ammeter ranges) then increase the supply voltage Vmt2mt1
and i1.
4. The point at which TRIAC fires gives the value of break over voltage vbo1
5. A graph of vmt2t1 v/s i1 is to be plotted.
6. The gates supply voltage. Vgg is to be switched off
7. Observe the am meter reading by reducing the supply voltage vmt. The
point at which the ammeter reading suddenly goes to zero gives the value
of holding current ih.
II mode: -
1. Connections are made as shown in the circuit diagram (b)
2. The gate current is set as same value as in i-mode
3. Repeat the step no. s 3, 4, 5, 6, & 7 of I-mode
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Dept. of ECE,KSSEM
11. Power Electronics Lab manual
Characteristic curve: -
Normal Method
Alternate Method
- 10 -
Dept. of ECE,KSSEM
12. Power Electronics Lab manual
III mode
1. Connections are mode as shown in the circuit diagram (c).
2. Step no. s 2, 3, 4, 5, 6, & 7 are to be repeated as in i-mode.
IV mode
1. Connections are mode as shown in the circuit diagram (d)
2. Repeat the step no. s 2, 3, 4, 5, 6, & 7 of i-mode.
Alternate Method: -
1. Connections are made as shown in the circuit diagram
2. Adjust the value of Ig to zero or some minimum value
3. By varying the voltage Vmt2mt1 from 0 to 10 volts with a step of 2 volts,
note down corresponding values of I1
4. Now apply the gate voltage gradually, until SCR fires, then note down the
values of Ig and also the values of I1 and Vmt2mt1.
5. Increase Vm to some value and note down I1 and Vmt2mt1.
6. Reduce gate voltage to zero, observe ammeter reading by reducing Vm
which gives the values of Ih (holding current) at the point at which,
current suddenly drops to zero
7. Repeat the steps 2, 3, 4, 5 & 6 for different values of break over voltages
8. Plot a graph of Vmt1mt2 v/s I1
9. Repeat the steps 1, 2, 3, 4, 5, 6 & 7 for different modes
10.Compare sensitivity of TRIAC and comment on sensitivities.
11.Refer same design procedure for selection of RL and Rg as that of SCR.
12.Follow the same procedure as that of SCR experiment to find latching
current.
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Dept. of ECE,KSSEM
13. Power Electronics Lab manual
Tabular column: -
I-mode
ig=
Sl.no
ma
volts
II-mode
Ig=
Sl.no
ma
volts
VTRIAC
ITRIAC ma
VTRIAC
ITRIAC ma
III-mode
ig=
Sl.no
VTRIAC
ma
volts
ITRIAC ma
IV-mode
Ig=
Sl.no
VTRIAC
ma
volts
ITRIAC ma
Base diagram of BT136:
- 12 -
Dept. of ECE,KSSEM
14. Power Electronics Lab manual
Viva questions: -
1. Explain
the different working modes of operations of a TRIAC?
2. Why i-mode is more sensitive among all modes?
3. What are the applications of TRIAC
4. Compare SCR, TRIAC & DIAC
5. Why I & II modes are operating in Ist quadrant and III & IV modes are
operating in IIIrd quadrant?
- 13 -
Dept. of ECE,KSSEM
………………………….……………………..
Signature of the staff with date
16. Power Electronics Lab manual
Experiment No: 3
DATE: __/__/____
MOSFET Characteristics
Aim: -
To study the characteristics of MOSFET
Apparatus required: -
MOSFET-IRF740, Power Supplies, Wattage Resistors, Ammeter, Voltmeter, etc.,
Procedure: -
Drain Characteristics
1. Connections are made as shown in the circuit diagram.
2. Adjust the value of VGS slightly more than threshold voltage Vth
3. By varying V1, note down ID & VDS and are tabulated in the tabular column
4. Repeat the experiment for different values of VGS and note down ID v/s VDS
5. Draw the graph of ID v/s VDS for different values of VGS.
Transconductance Characteristics
1. Connections are made as shown in the circuit diagram.
2. Initially keep V1 and V2 zero.
3. Set VDS = say 0.6 V
4. Slowly vary V2 (VGE) with a step of 0.5 volts, note down corresponding
and VDS readings for every 0.5v and are tabulated in the tabular column
ID
- 15 -
Dept. of ECE,KSSEM
17. Power Electronics Lab manual
5. Repeat the experiment for different values of VDS & draw the graph of ID v/s
VGS
6. Plot the graph of VGS v/s ID
…………..……………………………………..
Signature of the staff-in-charge
Circuit Diagram: -
Ideal Graphs: -
Collector Characteristics
Tabular Column
- 16 -
Transconductance Characteristics
Dept. of ECE,KSSEM
18. Power Electronics Lab manual
VGE =
VCE(V)
IC(mA)
VGE =
VCE(V)
IC(mA)
VCE =
VGE(V)
IC(mA)
VCE =
VGE(V)
IC(mA)
Experiment No: 4
DATE: __/__/____
IGBT Characteristics
Aim: -
To study the characteristics of IGBT
Apparatus required: -
IGBT-IRGBC 20S, Power Supplies, Wattage Resistors, Ammeter, Voltmeter, etc.,
Procedure: -
Collector Characteristics
1. Connections are mode as shown in the circuit diagram.
2. Initially set V2 to VGE1 = 5v (slightly more than threshold voltage)
3. Slowly vary V1 and note down IC and VCE
4. For particular value of VGE there is pinch off voltage (VP) between collector
and emitter
5. Repeat the experiment for different values of VGE and note down IC v/s VCE
6. Draw the graph of IC v/s VCE for different values of VGE.
Transconductance Characteristics
1. Connections are mode as shown in the circuit diagram.
2. Initially keep V1 and V2 at zero.
3. Set VCE1 = say 0.8 v
- 17 -
Dept. of ECE,KSSEM
19. Power Electronics Lab manual
4. Slowly vary V2 (VGE) and note down IC and VGE readings for every 0.5v and
enter tabular column
5. Repeat the experiment for different values of VCE and draw the graph of
IC v/s VGE
…………………..……………………………..
Signature of the staff-in-charge
Half Wave Rectifier using RC Triggering
Circuit diagram:-
R
Waveforms:-
- 18 -
Dept. of ECE,KSSEM
20. Power Electronics Lab manual
Graph: -
Experiment No: 5
DATE: __/__/____
RC Triggering Circuit – HWR & FWR
AIM: -
To study the performance & waveforms of HWR & FWR by using RC
triggering Circuit
APPARATUS REQUIRED: -
Transformer, SCR – TY604, BY127, Resistor, Capacitor, Ammeter,
Voltmeter
PROCEDURE: -
- 19 -
Dept. of ECE,KSSEM
21. Power Electronics Lab manual
Half Wave Rectifier
1. Connections are made as shown in the circuit diagram
2. By varying a resistance R gradually in step by step, note down the
corresponding values of Vn & Vm from CRO and Vodc from the DC
voltmeter. The readings are tabulated in the tabular column.
3. If the firing angle ranges from 0 to 90O, then the firing angle α is
calculated by using a formula α = sin-1 ⎜ n ⎟ in degrees.
⎜V ⎟
⎝ m⎠
4. The conduction angle β is calculated by using a formula, β = 180 - α.
5. The current and power is calculated by
2VodcVodc
=Watts respectively.A & Podc =
RR
⎛V ⎞
I odc
6. A graph of Vo v/s α, Vo v/s β, Io v/s α, Io v/s β, Podc v/s α, Podc v/s β are
to be plotted.
7. Compare practical output voltage with theoretical output voltage,
Voth =
Full Wave Rectifier
Vm
(1 + cosα) volts
2π
where Vm = 2Vrms
1. Repeat the above said procedure for full wave rectifier.
Voth =
Vm
(1 + cosα) volts
π
where Vm = 2Vrms
Full Wave Rectifier using RC Triggering
Circuit diagram:-
- 20 -
Dept. of ECE,KSSEM
22. Power Electronics Lab manual
Waveforms:-
Tabular Columns:-
Half Wave Rectifier
Sl. No.
Vn
Vm
(α<90O)
(α>90O)
Vodc
Voth
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Dept. of ECE,KSSEM
23. Power Electronics Lab manual
⎛V ⎞
α = sin-1 ⎜ n ⎟
⎜V ⎟
⎝ m⎠
⎛V
α = 180 − sin-1 ⎜ n
⎜V
⎝ m
⎞
⎟
⎟
⎠
Full Wave Rectifier
(α<90O)
Sl. No.
Vn
Vm
⎛V ⎞
α = sin-1 ⎜ n ⎟
⎜V ⎟
⎝ m⎠
(α>90O)
⎛V
α = 180 − sin-1 ⎜ n
⎜V
⎝ m
⎞
⎟
⎟
⎠
Vodc
Voth
Viva Questions: -
1. Explain the working operation of the circuit?
2. What are the limitations of R triggering circuit?
3. What are the limitations of RC triggering circuit?
4. Mention different methods of triggering SCR?
5. Why gate triggering is preferred?
……………………………….…………………
Signature of the staff-in-charge
- 22 -
Dept. of ECE,KSSEM
24. Power Electronics Lab manual
CIRCUIT DIAGRAM: -
Base Diagrams: -
SCR-TY604
UJT: -2N2646
Diode: - BY127
Pulse Transformer
- 23 -
Dept. of ECE,KSSEM
25. Power Electronics Lab manual
Experiment No: 6
DATE: __/__/____
U. J. T. Triggering of S. C. R
AIM: - To study the performance & waveforms of U.J.T triggering of S.C.R.
APPARATUS REQUIRED: -
SCR-TY604, Power supplies, Wattage Resistors, Ammeter, Voltmeter, UJT-
2N2646, Pulse Transformer, etc.,
PROCEDURE: -
1. Connections are mode as shown in the circuit diagram
2. By varying a resistance R gradually in step by step, note down the
corresponding values of Vn & Vm from CRO and VOdc from D.C voltmeter.
The readings are tabulated in the tabular column.
3. If firing angle ranges from 0 to 900, then firing angle can be calculated
from
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟
⎝ m⎠
in deg rees
If firing angle ranges from 900 to 1800, then firing angle can be calculated
by using a formula,
α = 180− Sin−1 ⎜
⎜
⎛ Vn ⎞
⎟
⎟
⎝ Vm ⎠
in degrees
4. The conduction angle β can be calculated by using a formula,
β= 180 - α
5. The current & power is calculated by
I dc =
Vdc
Amps
R
Pdc
2Vdc
=Watts respectively
R
6. A graph of Vdc v/s α, Vdc v/s β, Idc v/s α, Idc v/s β, Pdc v/s α , and Pdc v/s β
are to be plotted on a graph sheet.
- 24 -
DEPT. OF ECE,KSSEM
26. Power Electronics Lab manual
IDEAL WAVEFORMS: -
Tabular Column: -
FROM C.R.O
0 TO 900
Sl.
No
Vn
volts
Vm
volts
⎛V ⎞
α = Sin−1 ⎜ n ⎟
⎜V ⎟⎝ m⎠
ο
900 TO 1800
β=
180-α
Vm α = 180 − Sin−1 ⎛ Vn ⎞Vn
⎜β=180−α⎜V ⎟
⎟volts volts⎝ m⎠
ο
VDC
(Vload)
volts
Idc =
Vdc/R A
Pdc =
Vdc2/R
Watts
Voth
- 25 -
DEPT. OF ECE,KSSEM
27. Power Electronics Lab manual
7. For given frequency, the value of R can be calculated by using a formula,
T = 2.303RC. log10
R=
T
1
1−η
Ω
1
C2.303 .log10
1 −η
When
C = 0.1 mF & N = Intrinsic stand off ratio = 0.67
8. This value of R is set in the circuit, Step No S 3. 4. 5. & 6. are repeated
and waveforms are observed at different points as shown.
9. Compare Voth with VoPractical where Voth =
Vm
[1 + cos α]
π
VIVA QUESTIONS: -
1. Explain the working operation of U.J.T. triggering circuit waveforms?
2. Why U.J.T. Triggering circuit is superior when compared to R & RC
triggering circuit?
3. What is the use of pulse transformer?
4. Explain the design part of UJT?
5. Write equivalent circuit of UJT and show that Vpeak = Vemitter = Vγ+ηVBB.
6. Why do we require turn-on circuits for thyristors?
7. Why do we require turn-off circuits for thyristors?
8. Comment on Forced & Natural Commutation techniques.
………………………………………………….
Signature of the staff-in-charge
- 26 -
DEPT. OF ECE,KSSEM
31. Power Electronics Lab manual
Experiment No: 7
DATE: __/__/____
Oscillation Chopper Circuit
AIM: -
a) To convert variable D.C. voltage from a fixed D.C. input voltage.
b) Plot a graph of VDCOUT v/s Duty cycle (K)
APPARATUS REQUIRED: -
SCR-TY604, UJT-242646, Pulse Transformer, Power supplies, Wattage resistor,
Ammeter, Voltmeter, etc.,
PROCEDURE: -
A. Variable Frequency Operation
1. Connections are mode as shown in the circuit diagram.
2. The input D.C. voltage VDC is set as convenient value say 20 V
3. Select proper values of L, for a given duty cycle C is calculated so that
TON is constant.
4. By varying the variable resistor R1 in step-by-step gradually, note
down TON and T from CRO and VO or VDCout from D.C voltmeter.
5. The theoretical Ton and theoretical T are to be calculated by using a
formula.
TONth = Π LC
Where
Tth = 2.303R 1C 1 . log10
1
1−η
η = Intrinsic stand off ratio = 0.67
6. The theoretical output voltage VO or VDCOUT-th are to be calculated using
formula,
VOth = VDCout th =
TONth
Tth
×VDC
VOCRO = VDCoutCRO =
TONCRO
TCRO
×VDC
7. All observations and calculations are tabulated in a tabular column.
8. Compare Voth, VoCRO & VO d.c.voltmeter
9. Plot a graph of Vodc v/s duty cycle (k)
Turn-off Circuit Design: -
Ipeak = V
Toff =
C
L
Where Ipeak = 2I O
Toff = Device turn off time
- 30 -
π LC
2
DEPT. OF ECE,KSSEM
32. Power Electronics Lab manual
Tabular Column:- (A)
VDC
Sl.No
Volts
R1
Ω
C1
µΦ
L
H
C
µΦ
TONth =
Π LC
Tth = 2.303
RC. log10
1
1−η
TONCRO
TCRO
VOth =
TON th
Tth
×VDC
VOCRO =
TON CRO
TCRO
×VDC
VO
D.C.Voltmeter
Tabular Column:- (B)
VDC
Sl.No
Volts
R1
Ω
C1
µΦ
L
H
C
µΦ
TONth =
Π LC
Tth = 2.303
RC. log10
1
1−η
Duty cycle
T
K = ON
T
VO =
TON
×VDC
T
Let I O = 100 mA
I peak = 200 mA
V = 20 volts
T off = 50 µ s
I peak = V
C
L
I peak 200 ×10 /− 3 cC
== { ×10 /− 4 }1
L20Vl
C = 1 ×10 - 4 L − − − − (1 )
(
)
⎛ 2 ×50 ×10 −6⎛ 2Toff ⎞
Toff =∴ LC = ⎜⎟ =⎜
⎜
2π ⎠π⎝⎝
DEPT. OF ECE,KSSEM
34. Power Electronics Lab manual
For successful commutation, turn off time of the circuit should be greater than
turn off time of the device.
Select C = 1μF and L = 3mH.
∴Χιρχυιτ turn off time =
π LCπ
=1 ×10 −6 ×3 ×10 −3 = 86µs
22
∴Χιρχυιτ turn off time > turn off time of the device
i.e., 86μs > 50μs
B. Fixed Frequency Operation
1. The value of variable resistor R1 is set at some value is T is fixed
2. By varying L at different values, calculate the duty cycle K =
TON
Where
T
TONth = Π LC and T = 2.303RC. log10
3.
1
1−η
TONCRO
TCRO
Note down the corresponding o/p D.C. Voltage VDCOUT from D.C.Voltmeter
VOth = VDCoutth =
TONth
Tth
×VDC
VOCRO = VDCout CRO =
×VDC
4. Plot a graph of VDCOUT v/s Duty cycle (K)
VIVA QUESTIONS: -
1. Explain the working operation of oscillation chopper circuit?
2. What type of commutation circuit is employed in this circuit? Why it is
necessary?
3. Why UJT triggering is preferred?
4. Explain the working function of each component?
5. Explain the different types of commutation circuit
Note:- for T = 10 ms,
T = TON + TOFF
K = 30%
K = 50%
means
means
TON = 0.3 T
TON = 0.5 T
……………………………….………………...
Signature of the staff-in-charge
- 32 -
DEPT. OF ECE,KSSEM
35. Power Electronics Lab manual
CIRCUIT DIAGRAM: -
Half Wave Rectifier
Full Wave Rectifier
- 33 -
DEPT. OF ECE,KSSEM
36. Power Electronics Lab manual
Experiment No: 8
DATE: __/__/____
U. J. T. Triggering for HWR & FWR
AIM: - To study the performance & waveforms of U.J.T triggering of S.C.R.
APPARATUS REQUIRED: -
SCR-TY604, Power supplies, Wattage Resistors, Ammeter, Voltmeter, UJT-
2N2646, Pulse Transformer, etc.,
PROCEDURE: -
1. Connections are mode as shown in the circuit diagram
2. By varying a resistance R gradually in step by step, note down the
corresponding values of Vn & Vm from CRO and Vdc from D.C voltmeter.
The readings are tabulated in the tabular column.
3. If firing angle ranges from 0 to 900, then firing angle can be calculated
from
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟
⎝ m⎠
in deg rees .If firing angle ranges from 900 to 1800,
then firing angle can be calculated by using a formula,
⎛V
α = 180 − Sin −1 ⎜ n
⎜V
⎝ m
⎞
⎟
⎟
⎠
in deg rees
4. The conduction angle β can be calculated by using a formula,β= 180 - α
5. The current & power is calculated by
I dc
V
= dc Amps
R
Pdc
2Vdc
=Watts respectively
R
6. A graph of Vdc v/s α, Vdc v/s β, Idc v/s α, Idc v/s β, Pdc v/s α , and Pdc v/s β
are to be plotted on a graph sheet.
- 34 -
DEPT. OF ECE,KSSEM
38. Power Electronics Lab manual
7. For given frequency, the value of R can be calculated by using a formula,
T = 2.303RC. log10
1
1−η
R=
T
1
2.303 . log10C
1 −η
Ω
When
C = 0.1 mF & N = Intrinsic stand off ratio = 0.67
8. This value of R is set in the circuit, Step No S 3. 4. 5. & 6. are repeated
and waveforms are observed at different points as shown.
9. The practical o/p voltage (Vo meter) is compared with Voth
For HWR Voth =,
Vm
(1 + cosα ) voltswhereVm = 2Vin rms
2π
V
For FWR Voth = m (1 + cosα ) volts,
π
Graph: -
- 36 -
DEPT. OF ECE,KSSEM
39. Power Electronics Lab manual
Tabular Column:-
a) Half wave switches
FROM C.R.O
Idc =
Vdc/R
A
Pdc =
Vdc2/R
Watts
0 TO 900
Sl.No
Vn
volts
Vm
volts
⎛V ⎞
α = Sin−1 ⎜ n ⎟
⎜V ⎟⎝ m⎠
ο
900 TO 1800
α = 180−
⎛V ⎞
Sin ⎜ n ⎟
⎜V ⎟⎝ m⎠
−1
ο
β=180−
α
Vn
volts
Vm
volts
β=180−
α
VDC
(Vload)
volts
Full wave switches
FROM C.R.O
0 TO 900
Sl.
No
Vn
volts
Vm
volts
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟⎝ m⎠
ο
900 TO 1800
α = 180−
β=180−
α
Vn
volts
Vm
volts
⎛V ⎞
Sin ⎜ n ⎟
⎜V ⎟⎝ m⎠
−1
ο
β=180−
α
VDC
(Vload)
volts
Idc =
Vdc/R
A
Pdc =
Vdc2/R
Watts
Base Diagrams: -
SCR-TY604
UJT: -2N2646
Diode: - BY127
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DEPT. OF ECE,KSSEM
40. Power Electronics Lab manual
VIVA QUESTIONS: -
1. Explain the working operation of U.J.T. triggering circuit waveforms?
2. Why U.J.T. Triggering circuit is superior when compared to R & RC
triggering circuit?
3. What is the use of pulse transformer?
4. Explain the design part of UJT?
5. Write equivalent circuit of UJT and show that Vpeak = Vemitter = Vγ+ηVBB.
6. Why do we require turn-on circuits for thyristors?
7. Why do we require turn-off circuits for thyristors?
8. Comment on Forced & Natural Commutation techniques.
- 38 -
DEPT. OF ECE,KSSEM
41. Power Electronics Lab manual
………………………………………………….
Signature of the staff-in-charge
Circuit Diagram:
Wave form:-
Graph:-
Tabular Column:-
- 39 -
DEPT. OF ECE,KSSEM
42. Power Electronics Lab manual
Sl. No. Firing Angle ( ) Vα ODC
Experiment No: 9
DATE: __/__/____
Digital Firing Circuit
Aim: -
To demonstrate digital firing circuit to turn on SCR (HW) for R-Load and to
plot VODC v/s α.
Apparatus required: -
Digital Firing Module, SCR-TYN604, Resistor, etc.,
Procedure: -
1. Connections are made as shown in the circuit diagram.
2. Firing angle α is varied in steps gradually, note down corresponding values
of VODC (DC voltmeter reading) and tabulate.
3. A graph of α v/s VODC is plotted.
Result: -
Digital Firing Circuit to turn on SCR is studied and a graph of α v/s VODC is
plotted.
- 40 -
DEPT. OF ECE,KSSEM
43. Power Electronics Lab manual
………………………….……………………..
Signature of the staff with date
CIRCUIT DIAGRAM: -
- 41 -
DEPT. OF ECE,KSSEM
44. Power Electronics Lab manual
Experiment No: 10
DATE: __/__/____
AC Voltage Control by using
TRIAC-DIAC Combination
AIM: -
1. To study the AC voltage control by using TRIAC-DIAC combination
APPARATUS REQUIRED: -
TRIAC, DIAC, supply voltage, wattage resistors, Ammeter, Voltmeter, etc,.
PROCEDURE: -
A.
1. Connections are mode as shown in the circuit diagram (a)
2. By varying the variable resistance R1 in step by step, observe the
variation of intensity of light.
B.
1. Connections are mode as shown in the circuit diagram (b)
2. By varying the resistance R, in step-by-step note down the corresponding
vales of Vn & Vm from C.R.O. and Va.c from A.C. voltmeter the readings are
tabulated in the tabular column
- 42 -
DEPT. OF ECE,KSSEM
45. Power Electronics Lab manual
3. If delay angle ranges from 0 To 900, then firing angle can be calculated
from α = Sin − 1 ⎜ n ⎟ in degrees . If firing angle ranges from 900 To 1800 then
⎜V ⎟
⎝ m⎠
can be calculated by using a formula, α = 180 − Sin−1 ⎜
⎜
⎛ Vn ⎞
⎟ in degrees
Vm ⎟⎝⎠
⎛V ⎞
4. The conduction angle B can be calculated by using a formula,
β= 180 - α in degrees
5. The current can be calculated by I ac =
Vac
R
6. A graph of Iac v/s α, Vac or load voltage v/s α are to be plotted
7. Compare Voeter with Voth where Voth = Vin rms
1⎛sin 2α ⎞
⎜π − α +⎟
π⎝2 ⎠
Tabular Column: -
FROM C.R.O
0 TO 900
V ⎞
α = Sin ⎜ n ⎟
⎜V ⎟⎝ m⎠
−1 ⎛
ο
Sl.
No
Vn
volts
Vm
volts
900 TO 1800
L = 180 -
⎛V ⎞
Sin ⎜ n ⎟
⎜V ⎟⎝ m⎠
−1
Idc =
VDC
(Vload)
volts
Vdc/
R
A
Vin
Volt
s
Speed
rpm
β=180−
α
Vn
volts
Vm
volts
ο
β=180−
α
Waveforms:-
- 43 -
DEPT. OF ECE,KSSEM
46. Power Electronics Lab manual
VIVA QUESTIONS: -
1. Explain the features of TRIAC?
2. Explain the working operation of illumination control & various voltage
output waveforms by using TRIAC?
3. Compare S.C.R, DIAC & TRIAC?
4. What is universal motor?
5.
Comment on the different graphs of this experiment?
6. Mention the applications of TRIAC?
- 44 -
DEPT. OF ECE,KSSEM
47. Power Electronics Lab manual
………………………………………………..
Signature of the staff with date
CIRCUIT DIAGRAM: - (a) With R-load (Resistive load)
- 45 -
DEPT. OF ECE,KSSEM
48. Power Electronics Lab manual
GRAPHS: -
Experiment No: 11
DATE: __/__/____
Single Phase Full Wave Controlled Rectifier
AIM: -
1. To study the performance and waveforms of full wave controlled rectifier
with Resistance load and Inductive load
2. Plot a graph of VO v/s for R-load
APPARATUS REQUIRED: -
SCR-TY604, Power supplies, Wattage Resistors, Ammeter, Voltmeter, UJT-
2N2646, BY127, Inductor, Pulse Transformer, etc.,
PROCEDURE: -
1. Connections are made as shown in the circuit diagram for resistive load.
- 46 -
DEPT. OF ECE,KSSEM
49. Power Electronics Lab manual
2. By varying a variable resistor R in step-by-step gradually.
Note down
corresponding values of VN, VM, from C.R.O. and VO or Vload or VDC from
d.c.voltmeter for resistive load, the readings are tabulated in the tabular
column
3. If α varies from 0 To 900, then firing angle can be calculated from
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟
⎝ m⎠
If α varies from 900 to 1800 then α is
in deg rees
⎛V
α = 180 − Sin −1 ⎜ n
⎜V
⎝ m
⎞
⎟
⎟
⎠
in deg rees
4. The conduction angle β= 180 - α in degrees is calculated for each value of
α
5. Plot a graph of VDC or Vload or VO v/s firing angle α
6. Observe the waveforms at different points as shown and waveforms are
traced on tracing paper.
7. For Inductance load repeat step no. s 1,2,3,4,5 & 6.
- 47 -
DEPT. OF ECE,KSSEM
50. Power Electronics Lab manual
WAVEFORMS: -
TABULAR COLUMN: -
(a)
Sl.No
VN
volts
VM
volts
For Resistive load
0 – 90
0
0
O
From CRO
β=180 -
α
VN
volts
VM
volts
900 – 1800
⎛V
α = 180 − Sin −1 ⎜ n
⎜V⎝ m
⎞
⎟
⎟
⎠
O
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟⎝ m⎠
β=180 -
α
VO or VDC
or VLOAD
volts
- 48 -
DEPT. OF ECE,KSSEM
51. Power Electronics Lab manual
b) Inductive load:
00 – 900
Sl.No
VN
volts
VM
volts
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟⎝ m⎠
O
From CRO
900 – 1800
⎛V
α = 180 − Sin −1 ⎜ n
⎜V⎝ m
⎞
⎟
⎟
⎠
O
β=180 -
α
VN
volts
VM
volts
β=180 -
α
VO or VDC
or VLOAD
volts
C) R L with Free wheeling diode
00 – 900
Sl.No
VN
volts
VM
volts
⎛V ⎞
α = Sin −1 ⎜ n ⎟
⎜V ⎟⎝ m⎠
O
From CRO
β=180 -
α
VN
volts
VM
volts
900 – 1800
⎛V
α = 180 − Sin −1 ⎜ n
⎜V⎝ m
⎞
⎟
⎟
⎠
O
β=180 -
α
VO or VDC
or VLOAD
volts
VIVA QUESTIONS: -
1. Explain the performance and working operation of single-phase full
controlled rectifier with relevant waveforms for Resistive load, Inductive
load.
2. Compare H.C.R with F.C.R
3. In cyclo-converter, why H.C.R with Inductive load cannot be implemented
………………………………………………..
Signature of the staff with date
- 49 -
DEPT. OF ECE,KSSEM
52. Power Electronics Lab manual
Impulse Commutated Chopper:
VDC
Wave forms:-
Graph:-
- 50 -
DEPT. OF ECE,KSSEM
53. Power Electronics Lab manual
Experiment No: 12
DATE: __/__/____
Impulse Commutated Chopper
Aim: -
To study the performance of voltage commutated chopper for constant
frequency operations.
Apparatus required: -
Module, SCRs, Diodes, inductor, capacitors, etc.,
Procedure: -
1. Connections are made as shown in the circuit diagram.
2. Input DC voltage is set to convenient value (10v to 25v).
3. By varying duty cycle knob of triggering circuit module step by step
gradually note down corresponding Ton and T from the CRO and VO from
DC voltmeter and tabulate.
4. Duty cycle ‘K’ is calculated by using K =
5. A graph of VO v/s K is plotted.
6. Observe load and device voltage waveforms.
Tabular Column: -
Sl. No. Duty Cycle knobs TON cro TCRO
Ton
.
T
K=
TON
T
Vo (V)
………………………….……………………..
Signature of the staff with date
- 51 -
DEPT. OF ECE,KSSEM
54. Power Electronics Lab manual
Single Phase Induction Motor:
Graph:-
Tabular Column:-
Sl. No. Firing Angle ( ) Speed in RPMα
- 52 -
DEPT. OF ECE,KSSEM
55. Power Electronics Lab manual
Experiment No: 13
DATE: __/__/____
Speed Control of Single Phase
Induction Motor
Aim: -
To study speed control of Induction motor and plot speed v/s α.
Apparatus required: -
Module, TRIAC, Induction Motor, etc.,
Procedure: -
1. Connections are made as shown in the circuit diagram.
2. Firing angle α is varied in steps gradually, note down corresponding speed
of the induction motor using Tachometer and tabulate.
3. A graph of α v/s speed is plotted.
Result: -
Speed control of Induction Motor is studied and a graph of α v/s speed is
plotted.
………………………….……………………..
Signature of the staff with date
- 53 -
DEPT. OF ECE,KSSEM
56. Power Electronics Lab manual
Universal Motor (DC):
Universal Motor (AC):
Graph:-
Tabular Column:-
AC Motor
Sl.
No.
Firing Angle
( )α
Speed in
RPM
Sl.
No.
DC Motor
Firing Angle
( )α
Speed in
RPM
- 54 -
DEPT. OF ECE,KSSEM
57. Power Electronics Lab manual
Experiment No: 14
DATE: __/__/____
Speed Control of Universal Motor
Aim: -
To study speed control of Universal motor and plot speed v/s α.
Apparatus required: -
Module, TRIAC-BT136, Universal Motor, Diode-IN4001 etc.,
Procedure: -
DC Motor: -
1. Connections are made as shown in the circuit diagram.
2. Firing angle α is varied in steps gradually, note down corresponding speed
of the induction motor using Tachometer and tabulate.
3. A graph of α v/s speed is plotted.
AC Motor: -
1. Above procedure is repeated for AC Motor.
Result: -
Speed control of Universal Motor is studied and a graph of α v/s speed is
plotted.
………………………….……………………..
Signature of the staff with date
- 55 -
DEPT. OF ECE,KSSEM
59. Power Electronics Lab manual
Experiment No: 15
DATE: __/__/____
Series Inverter
Aim: -
To obtain variable AC from DC ripple input.
Apparatus required: -
Module, SCRs, Diodes, inductor, capacitors, etc.,
Procedure: -
1. To begin with switch on the power supply to the firing circuit check that
trigger pulses by varying the frequency.
2. Connections are made as shown in the circuit diagram.
3. Now connect trigger outputs from the firing circuits to gate and cathode of
SCRs T1 & T2.
4. Connect DC input from a 30v/2A regulated power supply and switch on
the input DC supply.
5. Now apply trigger pulses to SCRs and observe voltage waveform across
the load.
6. Measure Vorms & frequency of o/p voltage waveform.
Resonance frequency: -
11R2
fr =−
2π LC 4L2
L=10mH, C = 10μF, R = 20Ω, fth=477Hz, fp=250KHz
…………………………….…………………..
Signature of the staff with date
- 57 -
DEPT. OF ECE,KSSEM
60. Power Electronics Lab manual
Experiment No: 16
DATE: __/__/____
Parallel Inverter
…………………………….…………………..
Signature of the staff with date
- 58 -
DEPT. OF ECE,KSSEM
61. Power Electronics Lab manual
Parallel Inverter
Aim :-
To obtain variable AC from DC ripple input.
Apparatus required:-
Module, SCRs, Diodes, inductor, capacitors, etc,,
Procedure:-
1. Connecting are made as shown in the circuit diagram
2. Select values of c =
,L=
3. Set input voltage to 5 volts
4. Apply trigger voltage, observe corresponding output voltage ( ac voltage
and wave forms) at load terminal
5. Note down the voltage & frequency of out put wave form
6. The o/p ac voltage is almost equal to the two times of the dc i/p voltage.
…………………………….…………………..
Signature of the staff with date
- 59 -
DEPT. OF ECE,KSSEM
62. Power Electronics Lab manual
QUESTION BANK
4TH Semester EC/TC/ML
1. Obtain the VI characteristics of the SCR by conducting a suitable current
and hence determine the holding current, forward ON state resistance &
break over voltage.
2. Conduct a suitable experiment to obtain VI characteristics of the given
three layer bi-directional switch experimentally. Determine the holding
current and break over voltage in I and III quadrants and comment on its
sensitivity.
3. Conduct a suitable experiment to obtain collector and transfer
characteristics of IGBT.
4. Conduct a suitable experiment to obtain drain and transfer characteristics
of MOSFET.
5. Conduct an experiment to obtain synchronized triggering pulses to turn
ON SCR in full wave rectifier with resistive load. Show load voltage and
triggering pulse waveform. Plot average DC voltage v/s delay angle.
6. Conduct an experiment to obtain synchronized triggering pulses to turn
ON SCR in full wave rectifier with resistive and inductive load. Show load
voltage and triggering pulse waveform. Plot average DC voltage v/s delay
angle.
7. Conduct an experiment on controlled half wave rectifier to vary the DC
power fed to load by using RC triggering. Plot o/p voltage v/s firing angle.
8. Conduct an experiment on controlled full wave rectifier to vary the DC
power fed to load by using RC triggering. Plot o/p voltage v/s firing angle.
9. Conduct an experiment to control the illumination of incandescent lamp
using TRIAC, DIAC combination. Plot the graph of VORMS v/s α.
10.Conduct an experiment to produce variable DC o/p voltage (chopper), plot
o/p voltage v/s duty cycle for Variable frequency & Fixed Frequency.
11.Conduct an experiment to produce variable DC o/p voltage using voltage
commutated chopper, plot o/p voltage v/s duty cycle for Fixed frequency
operation.
12.Conduct a suitable experiment to control the speed of Induction motor.
Plot speed v/s α.
13.Conduct a suitable experiment to control the speed of Universal motor.
Plot speed v/s α.
14.Conduct a suitable experiment to obtain AC o/p using Series Inverter.
15.Demonstrate the digital firing circuit to turn ON SCR (HW) for R load. Plot
VODC v/s α
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DEPT. OF ECE,KSSEM
63. Power Electronics Lab manual
VIVA QUESTIONS
OF
POWR ELECTRONICS LAB
- 61 -
DEPT. OF ECE,KSSEM
64. Power Electronics Lab manual
Viva Questions Power Electronics Lab
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
What is power electronics?
Mention the different methods of varying the power?
What are the advantages of silicon over germanium?
What is power device?
Mention different types power devices?
What is SCR?
What are the features of SCR?
What are the features of Diac?
What is Diac?
What are the features of diac?
What are the applications of diac?
What is Triac?
What are the applications of Triac?
What are the applications of Triac?
What is power MOSFET?
What is power IGBT?
What are the applications of MOSFET & IGBT?
Compare SCR, Diac & Triac?
Compare MOSFET, BJT & IGBT?
What is turn of time?
What is turn off time?
What is static characteristics?
What is dynamic Characteristics?
What are the differences between static & dynamic Characteristics?
Explain gate characteristics & turn off characteristics of SCR?
Explain gate characteristics of SCR?
What is current controlled device?
What is voltage controlled device?
Explain o/p & transfer characteristics of MOSFET & IGBT?
What is the intention of using power device in power control circuit?
What is power control?
DEPT. OF ECE,KSSEM
65. Why SCR is called as bidirectional an controlled device?
Why Diac is called as bidirectional an controlled Device?
Why Triac is called as bidirectional controlled device?
What is rectifier?
What is an inverter?
What is steep down chopper? What is its o/p voltage equation?
What is step up chopper? What is its o/p voltage equation?
What is buck boost regulator? What is its o/p voltage equation?
- 62 -
66. Power Electronics Lab manual
40.
41.
42.
43.
44.
45.
What is cuck regulator? What is its/ o/p voltage equation?
Explain the working operation of single phase controlled half wave rectifier with
(a) R load
(b) RL load
(c) RL load with freewheeling diode
What is an intention of using freewheeling across inductive load in rectifier circuit?
What is pulse width?
Why turn off time of the circuit should be greater than turn off time of the device?
Explain the working operation of single phase Full wave controlled rectifier with
a) R load
b) RL load
c) RL load with freewheeling diode?
Explain the working operation of single phase Half controlled bridge rectifier with
a) R load
b) RL load
c) RL load with freewheeling diode?
Explain the working operation of single phase full controlled bridge rectifier with
a) R load
b) RL load
c) RL load with freewheeling diode?
Define average output voltage, Rms Voltage, peak or maximum voltage?
Derive an expression of average output voltage, Rms out voltage of any wave form
concerned to rectifier, ac voltage controller, chopper?
What is cyclo converter?
What is cyclo inverter?
Why forced commutation circuit is employed in case of cycle inverter?
What are the advantages of three phase circuit over single phase circuit?
What is firing angle or delay angle?
What is conduction period?
What is the meaning of triggering?
What are the different types of triggering methods (Can be used to trigger SCR)?
What is anode triggering, dv/dt triggering, temperature triggering, light triggering &
gate triggering?
Why gate triggering is preferred than other types?
Mention the different types of gate triggering circuits?
Explain the working operation of R- triggering circuit?
Why firing angle in case of R- triggering circuit is limited to 90 degrees?
Explain the working operation of RC triggering circuit?
Explain how firing angle will be extended to more than 900 by using RC triggering
circuit?
What is Uni-junction transistor (UJT)?
Write equivalent circuit of UJT?
Show that Vpeak = Vp= nVBB+ V diode Where n = intrinsic standoff ratio, V
applied or base voltage
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DEPT. OF ECE,KSSEM
68. Power Electronics Lab manual
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Why UJT triggering circuit is superior than R & RC triggering circuit?
What is UJT relaxation oscillator?
What is line synchronized UJT triggering circuit?
Explain the working operation of UJT relaxation oscillator?
Explain the working operation of line synchronized UJT triggering circuit with wave
forms at different points?
Design of UJT triggering circuit.
When UJT will conduct?
How UJT exhibits negative resistance property?
Why SCR, DIAC, TRIAC are called negative resistance devices?
Derive an expression of of frequency of UJT triggering pulse?
What is the function of pulse Transformer?
What are the different types of voltage ratings, current ratings & power ratings?
Explain each term
Why do we require protection circuits for power devices?
What is dv/dt rating? How do you protect SCR against high dv/dt rating? Explain
What is dv/dt rating? How do you protect SCR against high dv/dt rating? Explain
What is over current? How do you project SCR against over current? Explain
What is over voltage? How do you lprotect SCR against over voltage? Explain
How device will be protected against heavy power dissipation?
Why Triac has 4 modes of operations?
Why 1st & 2nd mode of operations are operating in 1st quadrant and 3rd & 4th mode of
operations are operating 3rd quadrant?
Why mode (1) is most sensitive among all modes?
What is commutation? What is commutation circuit?
Mention the different types of forced commutation circuit?
Explain the working operation of each forced commutation circuit with wave forms &
derivation of designed equations
(class A, Class B, class C, Class D, Class E & Class F commutation circuit)
What is Latching current? What is its significance?
What is Holding current? What is its significance?
What is dv/dt Rating? What is its significance?
What is dual converter?
Why full wave bridge controlled bridge rectifier with RL load (not with freewheeling
diode) is preferred in dual converter than half wave bridge controlled rectifier with RL
load (not with freewheeling diode).?
Why dual converter is called as four quadrant operator?
What is semi converter?
DEPT. OF ECE,KSSEM
69. What is full converter?
Why gate is preferred at base of NPN transistor & not at the base of PNP transistor in
SCR?
101. Derive an expression of anode current (SCR current)?
102. Explain the working operation of SCR with two transistor analogy?
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70. Power Electronics Lab manual
103.
Explain the working operation of each practical power electronics experiments with
circuit diagram, wave forms & designed equations?
104. Why output voltage is more at lesser value of firing angle?
105. What are the differences between uncontrolled output & controlled output?
106. How do you design zener voltage regulator?
107.
How do you select (design) the value of gate resistor and load resistor concerned to
SCR experiment?
108. How do you check SCR, Triac, Diac, Diode, Zener diode, wires by using ohm meter?
109. How do you check an ammeter, voltmeter & power supply?
110. Why load resistor has higher wattage?
111.
What is series inverter? Mention the advantages, disadvantages & applications of
series inverter? Explain its working operation?
What is continuous mode & discontinuous mode of operations concerned to rectifier
with (a). RL load (b) RL load with freewheeling diode.
Input voltage = device voltage + output voltage.
Prove above words
112. What is parallel inverter? Explain its working operation?
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115. What is blocking state or region?
116. What is forward blocking & reverse blocking?
117. What is reverse recovery time?
118. What is gate pulse?
119. Why gate pulses are preferred than continuous gate voltage?
120. S.T. turn on time =td + tr+ ts
121. S.T. turn off time = trr + tgr
122. How do you design gate pulse width?
123. What is snubber circuit? How do you design snubber?
124. What is heat sink? Its purpose is what?
125. What is circuit breaker & fuse? Why these are used in power circuit?
126. What is ac voltage controller? Mention different types? What are its applications?
Explain the working operation of
(a). on & off AC voltage controller
127. (b). uni directional or Half wave controller
(c) . Bidirectional or Full wave AC voltage controller
with R load & RL load with wave forms, with equations?
128.
Why continuous gate pulses are applied to full wave ac voltage controller with RL load
circuit?
129. Explain the working operation of static on load tap changer?
130. Why negative gate voltage should not be applied to gate of SCR?
131. Write symbols, static characteristics of all power devices concerned to syllabus?
132. Name different current controlled power devices?
133. Name different voltage controlled power devices?
134. What is I2t rating?
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DEPT. OF ECE,KSSEM