Lab 3 Boost Experiment

B7

Q1. a) Figure Q1 is a single phase 2-level voltage source converter (VSC) with a total DC voltage V-1000V. A PWM scheme, by comparing a reference value with a 1kHz triangular waveform, is used to control the switches S₁ and S2, and output 340v at Vo. With the aid of graphs explain how pulse signals for the switches are generated, sketch the output voltage Vo, determine the duty cycle and the modulation index. Va + 2 it Va d + TS₁ V {1+5₂ = Figure Q1 A single phase VSC

The Figure 2 shows an electronic circuit designed for supplying power to a load (R1). The supply voltage 235V (RMS, AC) at frequency of 50HZ. The required DC voltage and power for the load are 24V and 3.6 W respectively. The Electrical Components of this AC to DC converter are: A full-wave rectifier to convert AC voltage to DC voltage. A regulator with transistor and Zener diode to ensure a constant voltage and power for the load. D1 Iide 91 Vaut VLoad D2 D3 Vde VI sine R1 RL Regulate Reetifier Figure 2. Complete Circuit Assume that the diodes are real diodes (NOT ideal diodes). The following information is available: The collector to base resistor of the regulator R1 = 5.0 k The transistor Q1 with B value of 24 is used for the regulator circuit. Determine the following quantities for this electronic device and fill the table below: Question Answer The voltage of Zener Diode (Vz) The current in R1 The DC current into the regulator | (Idc) Base current of transistor (IB) Collector…

Design of a DC-DC Converter. The Circuit Below shows a basic Buck-Boost Converter with a highly inductive Load. With a Deliberate mistake in the configuration of the Circuit Connection. The Value of L1 is 22mH, C1 is 10uF, R1 is 220 and L2 is 10mH. The circuit operates with a switching frequency of 20KHZ. The Duty cycle of the Clock signal V2 is given by the function below: ( 17 ) х0.2 Duty Cycle, k = 0. 55 + 100 Your Unique Duty Cycle = %3D Buck-Boost Converter Q1 IRG4BC10U D1 R1 222 1N4009 C1 LV1 12V L1 22mH 10µF L2 10mH a) Find the mistake in the configuration of the circuit and correct the connection error.

ii)Rhs= 1.325 ℃/w

consider the following specifications for buck converter : Vin= 80v, Ro = 9 ohms, Po = 100watts, frequency is 150khz. determine a. the inductor value at the boundary condition. b. the maximum inductor current value for L = 10 Lcrit. (c). the doide rms and average current values

A resistor Ra is in series with a voltage source Va. Draw the circuit. Label the voltage across the combination as v and the current as i. Draw and label the volt–ampere characteristic (i versus v).

1) AC power in a load can be controlled by using a. Two SCR's in parallel opposition b. Two SCR's in series c. Three SCR's in series d. Four SCR's in series 2) The advantage of using free - wheeling diode in half controlled bridge converter is that a. There is always a path for the ac current independent of the ac line b. There is always a path for the dc current independent of the ac line c. There is always a path for the dc current dependent of the ac line d. There is always a path for the ac current dependent of the ac line 3) Silicon controlled rectifier can be turned on a. By applying a gate pulse and turned off only when current becomes zero b. And turned off by applying gate pulse c. By applying a gate pulse and turned off by removing the gate pulse d. By making current non zero and turned off by making current zero

Q5. For the following center tapped transformer, show the waveform across each half of the secondary winding and across Ri, when a 100 V peak sine wave is applied to the primarywinding. What is the PIV rating must the diode have? (Use constant voltage drop model for the Silicon diode) IN4001 Ry OV 10k) D IN4001

3 A peak rectifier (peak tollower) Cir cuit is gian below. Vs is a GOH3 Sinuscidal Vollge with peak value Upz50V. 50V. The load resistance R= Sk . Find the Vallke of the capacitance C Such that the peak- to-peak ripple 2 volts. (idenl diede) Voltage Vr Vs

What are DC transients? What is the source of transient in electrical circuit / system? How to mitigate transient current? and Transient voltage ? Provide 3 sample calculations involving DC circuit under transient current condition on series R-L and Series R-C circuit? Need a simple explanation, can't quite understand the definitions I have currently.

A 20-V-rms 60-Hz ac source is in series with an ideal diode and a 100-Ω resistance. Determine the peak current and PIV for the diode.

QUESTION 1 Design a high efficiency 3.3 V, 5A d.c.to d.c. power converter from a 4 to 5.5 Vdc source. The maximum allowable inductor current ripple and output voltage ripple are 0.1A and 20 mV, respectively. Assume a switching frequency of 20 kHz. a) Design a suitable converter power circuit using a MOSFET switch, showing all calculation of inductor and capacitor values and drawing a circuit diagram of the final design including component values. Indicate the peak inverse voltage and forward current rating of any diode required, and the maximum drain- source voltage of the MOSFET. b) On the Schematic diagram, draw the path of the current flow during the ON time and the OFF time. c) Describe the effect of changing the values of the inductor and the capacitor in the circuit. d) What is the effect of switching frequency in the circuit? e) Draw the schematic diagram of a circuit with the output voltage higher than the input voltage.

a-Draw the cct Q1/(A) For the waveforms of s phase angle control Ac-Ac converter: - diagram and complete other waveforms. b- Derive the equation of V Mean and V Effective. c-If a л/6 compute the i/p P.F, average i/p current and o/p in this cct. (15M). Q1(B) Prove that the single phase half wave rectifier with load inductive that:- vdc= Vmax 2π [1+cos(+0)] (10M) Q2/(A) Design parallel inverter to generate square wave with frequency 400 Hz to supply resistive load 120 2,240 v, if the battery voltage 12. (15M) Q2/(B)What are the meaning of the following: - [choose five only] (10M) 1-PWM 2- Combined inverter 3-UPS 4- Triac. 5- Smart technology device 6-Switching mode regulator 7-Throsold v. Q3/(A) Three phase F.W.R is operated from a star connection 208v,60 Hz supply, RL=1002, this rectifier must supply a load of 40 2 at half its max. O/P v. Find: -1- Firing angle. 2-r.m. s and average o/p current 3- o/p frequency. 4- if the firing angle smaller than 60° 5-Draw the waveforms for all…

1) a) As depicted in the figure, input voltage is 120 Volts (RMS) and diode drops are 0.7 Volts. Design this circuit with given two ac outputs and calculate turns ratio of live transformer. voltage i) 10 V ii) 100 V 2) b) Consider a circuit using Si diodes and 10 k ohms resistors. Design this clipper circuit with output ranges below; i) -0.7 V and above ii) +2.1 V and above iii) +1.4 V c) As given in the figure a clamper circuit with the input +10V- signal Vi is proposed to design. Determine the output voltage with the exact solution step by step. Sketch transfer characteristic Vo versus V₁. V₂ Vo H 2RS -10V- -2√ 01 Vo Trims

Q2) A 3-phase, half-wave thyristor converter is connected through a voltage source 150 V as input voltage and used to supply resistive load of 10 N. Determine rsm voltage, rms current, ripple factor and dissipated power in the resistor R. If a = 45° and f = 50 Hz.

PROBLEM SET 1. Derive the formula for the RMS value for the following a) b) 3m 2. Design a rectifier fed from 220-V line through a step-down transformer. The load requires an average voltage of 9 V and average power of 2.5 W. Use each of the three circuits: half-wave, center-tapped full-wave and bridge type full-wave. 3. Following the analysis applied to the half-wave rectifier with capacitor filter, show how to arrive at the output waveform for a center-tapped full-wave with filter capacitor. See output waveform on page 90. 4. Given: Half-wave rectifier; transformer secondary voltage = 32 V; Capacitance 4700 µF; average load voltage 18 V. Determine ripple factor and average load current 5. Design a half-wave rectifier with a capacitor filter that will deliver to the load an average voltage is 15 V at 280 mA. Ripple should not be higher than 5%. 6. Given: The input to a voltage regulator circuit varies from 11.4 to 12.2 V. The load voltage is to be maintained at 9.1V with maximum…

Please written by computer Answer the following questions:a. Name a suitable topology that can be used in the above DC/DC converters to achieve the required regulation with the minimum provided efficiency.b. Calculate the efficiency of the linear regulator.c. Calculate the total input power and the input current.d. Calculate the overall efficiency of the system.e. If a 100uF capacitor is used at the input to minimize the ripple. Assume the rise time of the input source is 0.2ms. Estimate the maximum inrush current to charge the capacitor to 12V.

Three-phase half wave rectifier supply resistive load with DC power of 4 kW; the ammeter connected with D1 indicates 8 A r.m.s current, and the source frequency is 50 Hz Due to system inductance the average voltage drops to 96.2% of idealized value ( when the inductance is neglected). How much will the average and r.m.s voltage s be? The r.m.s phase current and average load current Is=? & Idc=? The secondary r.m.s voltage and transformer capacity Vs & KVA? The inductances causes the voltage drop Lc=? The diode forward current and maximum inverse voltage? Now, if the phase B is failed ( disconnected), how much with new dc voltage be in %..Vdc=….% ??

Part 2: In a step-up converter, consider all the components to be ideal, Let Va be 8-16 V, V. 24 V (regulated), fs-20 kHZ, Po ≥ 6 W. i). Calculate the minimum inductance L required to keep the converter operation in continuous-conduction mode under all conditions. ii). Specify the value of inductor for a maximum ripple of 3%. iii). Design a capacitor for part (i) and (ii) with a voltage ripple of less than 2%.

2. Given the circuit a. State how each switch can be realized using transistors and/or diodes, and whether the realization requires single-quadrant, current/voltage bi-directional two quadrant switch or four quadrant switches then redraw the circuit. b. Solve the converter to determine the inductor currents, capacitor voltages and conversion ratio. Ignore all losses.

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The average (DC) value of a half-wave rectified voltage with a peak value of 200 V is: a. 63.7 V b. 127.3 V c. d. OV 141 V 2. Voltage regulation is determined by: a. load current b. Zener current and load current c. changes in load resistance and output voltage d. changes in no-load voltage and full-load voltage When a 60-Hz sinusoidal voltage is applied to the input of a full-wave rectifier, the output frequency is: a. 120 Hz b. 60 Hz c. 240 Hz d. 0 Hz

ANSWER THE QUESTION

(b) A three-phase uncontrolled bridge rectifier is connected to an AC supply of 415V through a delta-star transformer as shown in the Figure. The load consists of large inductance to render a level load current of 60A at 300V. Assuming voltage drop across the power device to be 0.7V, compute the following: i) Rms value of secondary phase voltage and current; ii) Rms value of primary phase voltage and current3; iii) Transformer power rating in kVA and transformation ratio; iv) Device ratings. 本の。 本の 本の Load 本の。 本。 本の。 Figure