A six-pulse thyristor bridge rectifier is connected to a balanced three-phase, 50 Hz AC source. Assuming that the DC output current of the rectifier is constant, the lowest harmonic component in the AC input current is

A fully-controlled three-phase bridge converter is working from a 415 V, 50 Hz AC supply. It is supplying constant current of 100 A at 400 V to a DC load. Assume larger inductive smoothing and neglect overlap. The rms value of the AC line current in amperes (round off to two decimal places) is _________.        

A three-phase diode bridge rectifier is feeding a constant DC current of 100A to a highly inductive load. If three-phase, 415V, 50Hz AC source is supplying to this bridge rectifier then the rms value of the current in each diode,  in ampere, is________________.

A three-phase fully controlled bridge converter is fed through star-delta transformer as shown in the figure.

The converter is operated at a firing angle of , Assuming the load current  to be virtually constant at 1p.u. and transformer to be an ideal one, the input phase current waveform is

A solar energy installation utilizes a three-phase bidge converter to feed energy into power system through a transformer of 400V/400V, as shown below.

The energy is collected in a bank of 400V batteries and is connected to converter through a large filter choke of resistance.

The maximum current through the battery will be

A solar energy installation utilizes a three-phase bidge converter to feed energy into power system through a transformer of 400V/400V, as shown below.

The energy is collected in a bank of 400V batteries and is connected to converter through a large filter choke of resistance.

The kVA rating of the input transformer is

A three phase fully controlled bridge converter is feeding a load drawing a constant and ripple free load current of 10A at a firing angle of 30°. The approximate Total Harmonic Distortion (%THD) and the RMS value of fundamental component of the input current will respectively be

A three-phase, fully-controlled thyristor bridge converter is used as line commutated inverter to feed 50 kW power at 420 V dc to a three-phase, 415V (line), 50 Hz ac mains. Consider dc link current to be constant. The RMS Current of the thyristor is

A three-phase, 440 V, 50 Hz ac mains fed thyristor bridge is feeding a 440 V dc, 15 kW, 1500 rpm separately excited dc motor with a ripple free continuous current in the dc link under all operating conditions. Neglecting the losses, the power factor of the ac mains at half the rated speed, is

A 3-phase fully controlled bridge converter with freewheeling diode is fed from 400 V, 50 Hz AC source and is operating at a firing angle of 60°. The load current is assumed constant at 10A due to high load inductance. The input displacement factor (IDF) and the input power factor (IPF) of the converter will be

A solar cell of 350 V is feeding power to an ac supply of 440V, 50 Hz through a 3-phase fully controlled bridge converter. A large inductance is connected in the dc circuit to maintain the dc current at 20A. If the solar cell resistance is 0.5Ω, then each thyristor will be reverse biased for a period of

A three-phase diode bridge rectifier is fed from a 400V RMS, 50 Hz, three-phase AC source. If the load is purely resistive, the peak instantaneous output voltage is equal to

The circuit in figure shows a 3-phase half-wave rectifier. The source is a symmetrical, 3-phase four-wire system. The line-to-line voltage of the source is 100 V. The supply frequency is 400 Hz. The ripple frequency at the output is

A fully controlled natural commuted 3-phase bridge rectifier is operating with a firing angle α=30°. The peak to peak voltage ripple expressed as a ratio of the peak output dc voltage at the output of the converter bridge is  

A six pulse thyristor rectifier bridge is connected to a balanced 50 Hz three phase ac source. Assuming that the dc output current of the rectifier is constant, the lowest frequency harmonic component in the ac source line current is

A three phase thyristor bridge rectifier is used in a HVDC link. The firing angle α (as measured from the point of natural commutation) is constrained to lie between 5° and 30°. If the dc side current and ac side voltage magnitudes are constant, which of the following statements is true (neglect harmonics in the ac side currents and commutation overlap in your analysis)

A three phase semi-converter feeds the armature of a separately excited dc motor, supplying a non-zero torque. For steady state operation, the motor armature current is found to drop to zero at certain instances of time. At such instances, the voltage assumes a value that is

A thyristorised , three phase, fully controlled converter feeds a dc load that draws a constant current. Then the input ac line current to the converter has  

A three phase diode bridge is used to provide rectified output from a 400V, 50Hz, 3-phase supply to a R-L load with 10 Ω resistance and 300mH inductance.

A 3-phase, fully controlled, converter is feeding power into a d.c. load at a constant current of 150A. The rms current through each thyristor of the converter is:

A d.c. motor driven from a fully controlled 3 phase converter shown in figure, draws a d.c. current of 100A with negligible ripple.

(a) Sketch the a.c. line current  for one cycle

(b) Determine the 3rd and 5th harmonic components of the line current as a percentage of the fundamental current

In a 3-phase controlled bridge rectifier, with an increase of overlap angle, the output dc voltage

A three phase ac-to-dc diode bridge rectifier is supplied from a three-phase, 440V source. The rectifier supplies a purely resistive load. The average dc voltage across the load will be ________________V.

The output voltage of a six-pulse double star rectifier is the same as that of a three-phase half- wave rectifier. (True=1/False=0)

When a line commutated converter operates in the inverter mode