Power electronic lab manual

To prove that the half controlled converter works in only one quadrant. Prepared by R. The output wave forms are plotted on the graph sheet.

Similarly RL-load steps of the above are repeated. How many quadrants does a Half controlled rectifier works? What is meant by Line commutation? How the thyristors get commutated? Does a Half controlled rectifier work as inverter? To prove that the fully controlled converter works in only two quadrant. Thyristors-4 no. Rheostat ohms 4. CRO 6. Check the working condition of all the SCRs before connecting them in the circuit. Preferably work at low voltages V for every new connections after careful Verification raised to the max.

Wave forms across the load are observed in CRO values are noted down and tabulated for. How many quadrants does a Full controlled rectifier works? When a full controlled rectifier work as inverter? AIM: To study the performance of various turn-on methods of thrusters by its gate terminal. To prove that the firing angle range for R-triggering is 0 to 90 To prove that the firing angle range for RC-triggering is 0 to To prove that the firing angle range for UJT-triggering ramp triggering.

RC-Firing circuit study unit. UJT-Firing circuit study unit 3. Thyristor-TYN no 4. Rheostat ohms 5. The main supply is switched ON and triggering circuit is switched ON 3.

Preferably work at low voltages V for every new connection after careful Verification raised to the max. What is the range of firing angle in R-Triggering? What is the range of firing angle in RC-Triggering? What is meant by Ramp Triggering? What is the importance of pulse transformer? Thyristors-2 no or Ac voltage controller Power Module Kit 2. Ac Voltage controller firing kit 3. Viva Questions 1. What does ac voltage controller mean?

What are the applications of ac voltage controllers? What are the advantages of ac voltage controllers? What are the disadvantages of ac voltage controllers? What are the two methods of control in ac voltage controllers? What is meant by unidirectional or half-wave ac voltage controller? What are the disadvantages of unidirectional or half-wave ac voltage controller? What is meant by bidirectional or half-wave ac voltage controller? What is the control range of firing angle inac voltage controller with RL load?

What type of gating signal is used in single phase ac voltage controller with RL load? What are the disadvantages of continuous gating signal? What is meant by high frequency carrier gating? What is meant by sequence control of ac voltage regulators?

What are the advantages of sequence control of ac voltage regulators? To study the performance of single phase cycloconverter for R load. Thyristors-4 no or Cycloconverter Power Module Kit 2. Cycloconverter firing kit 3. What is meant by cyclo-converter? What are the two types of cyclo-converters? What is meant by step-up cyclo-converters? What is meant by step-down cyclo-converters? What are the applications of cyclo-converter? What is meant by positive converter group in a cycloconverter?

What is meant by negative converter group in a cycloconverter? What is a synchronous connection changer? Personal Computer 1 Nos 2. Run the simulation file 4.

Wave forms are observed in Scope. What is meant by inverter? What are the applications of inverter? What are the main classifications of inverter? Why thyristors are not preferred for inverters? How output frequency is varied in case of a thyristor? Give two advantages of CSI. Why diodes should be connected in anti parallel with the thyristors in inverter circuits? What is meant by series inverter? What is meant by parallel inverter? What are the applications of a series inverter? How is the inverter circuit classified based on commutation circuitry?

Why forced commutation if required in inverters? What are the conventional forced commutation techniques for thyristors based inverters? What is meant by McMurray inverter? What are the applications of a CSI? What is meant by PWM control? What are the advantages of PWM control?

What are the disadvantages of the harmonics present in the inverter system? What are the methods of reduction of harmonic content? What are the disadvantages of PWM control? What are the different types of PWM control? What is single pulse width modulation? What is the disadvantage of the single pulse width modulation? Define: amplitude modulation index What is the need for voltage control in an inverter? List different methods of controlling the output voltage of inverters?

Define the term inverter gain? Differentiate half bridge and full bridge inverter. What are the performance parameters of inverters? What are the reasons for adding a filter on the inverter output?

What is meant by Current source inverters? What are the arrangements for obtaining three-phase output voltages in inverter? What are the all the advantages and disadvantages of conduction mode in 3 inverter? What is the purpose of over modulation in inverter? What are the effects of eliminating lower order harmonics in inverter? Run the simulation file Prepared by R. Connections are given as per the circuit diagram 2.

Connections are given as per the circuit diagram. The input supply is given to the trainer. Firing pulses are given to the SCR. The output waveforms are verified from the respective terminals through the CRO. Open navigation menu. Close suggestions Search Search. User Settings. Skip carousel. Carousel Previous. Carousel Next. What is Scribd? Explore Ebooks. Bestsellers Editors' Picks All Ebooks.

Explore Audiobooks. Bestsellers Editors' Picks All audiobooks. Explore Magazines. Editors' Picks All magazines. Explore Podcasts All podcasts. Difficulty Beginner Intermediate Advanced. Explore Documents. Power Electronics Lab Manual. Uploaded by Raj Tilak. Triggering of S.

T triggering of S. Connections are mode as shown in the circuit diagram 2. C voltmeter. This value of R is set in the circuit, Step No S 3. Explain the working operation of U. Why U. What is the use of pulse transformer? Explain the design part of UJT? Why do we require turn-on circuits for thyristors? Why do we require turn-off circuits for thyristors?

Signature of the staff-in-charge - 26 - Variable Frequency Operation 1. The input D. The theoretical Ton and theoretical T are to be calculated by using a formula. All observations and calculations are tabulated in a tabular column. Power Electronics Lab manual SSIT For successful commutation, turn off time of the circuit should be greater than turn off time of the device.

Fixed Frequency Operation 1. Voltmeter 3. Explain the working operation of oscillation chopper circuit? What type of commutation circuit is employed in this circuit?

Why it is necessary? Why UJT triggering is preferred? Explain the working function of each component? Signature of the staff-in-charge - 32 - 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. Connections are mode as shown in the circuit diagram b 2.

Compare S. What is universal motor? Comment on the different graphs of this experiment? To study the performance and waveforms of full wave controlled rectifier with Resistance load and Inductive load 2. Connections are made as shown in the circuit diagram for resistive load.

By varying a variable resistor R in step-by-step gradually. Observe the waveforms at different points as shown and waveforms are traced on tracing paper.

For Inductance load repeat step no. Explain the performance and working operation of single-phase full controlled rectifier with relevant waveforms for Resistive load, Inductive load.

Compare H. R with F. In cyclo-converter, why H. R with Inductive load cannot be implemented ……………………………………………….. Signature of the staff with date Input DC voltage is set to convenient value 10v to 25v. Ton 4. Observe load and device voltage waveforms. Tabular Column: - Sl. Signature of the staff with date - 51 - Signature of the staff with date - 53 - Firing Angle Speed in Sl.

Firing Angle Speed in No. AC Motor: - 1. Above procedure is repeated for AC Motor. Signature of the staff with date - 55 - To begin with switch on the power supply to the firing circuit check that trigger pulses by varying the frequency. Now apply trigger pulses to SCRs and observe voltage waveform across the load. Signature of the staff with date - 57 - Signature of the staff with date - 58 - Connecting are made as shown in the circuit diagram 2.

Set input voltage to 5 volts 4. Apply trigger voltage, observe corresponding output voltage ac voltage and wave forms at load terminal 5. Signature of the staff with date - 59 - 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. Conduct a suitable experiment to obtain collector and transfer characteristics of IGBT.

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. Conduct an experiment to obtain synchronized triggering pulses to turn ON SCR in full wave rectifier with resistive and inductive load.

Conduct an experiment on controlled half wave rectifier to vary the DC power fed to load by using RC triggering. Conduct an experiment on controlled full wave rectifier to vary the DC power fed to load by using RC triggering.

Conduct a suitable experiment to control the speed of Induction motor. Conduct a suitable experiment to control the speed of Universal motor. 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 is power IGBT? What is turn of time? What is turn off time? What is static characteristics? What is dynamic Characteristics?

Explain gate characteristics of SCR? What is current controlled device? What is voltage controlled device? What is the intention of using power device in power control circuit? What is power control? 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 step up chopper? What is buck boost regulator? What is cuck regulator? Explain the working operation of single phase controlled half wave rectifier with a R load 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 Explain the working operation of single phase Half controlled bridge rectifier with a R load Explain the working operation of single phase full controlled bridge rectifier with a R load Define average output voltage, Rms Voltage, peak or maximum voltage?

Derive an expression of average output voltage, Rms out voltage of any wave form 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? 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 90 0 by using RC triggering What is Uni-junction transistor UJT? Write equivalent circuit of UJT?

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 Design of UJT triggering circuit. When UJT will conduct? How UJT exhibits negative resistance property?

Derive an expression of of frequency of UJT triggering pulse? What is the function of pulse Transformer? Explain each term Why do we require protection circuits for power devices? Explain What is over current? How do you project SCR against over current? What is over voltage? How do you lprotect SCR against over voltage? How device will be protected against heavy power dissipation? Why Triac has 4 modes of operations? Why mode 1 is most sensitive among all modes?

What is commutation? What is commutation circuit? Mention the different types of forced commutation circuit? What is Latching current? What is its significance? What is Holding current? What is dual converter? Why full wave bridge controlled bridge rectifier with RL load not with freewheeling Why dual converter is called as four quadrant operator?