Question

QUESTION 3 (30 points) The following questions are related to the thyristor bridge topology shown in Figure 3.1 TA To Ta ioc VaN VAN R 3 T Ta TAL- Figure 3.1 a) By considering a highly inductive load current equivalent to a current source of value (inc), plot the current waveform of iA for an angle of 30 degrees (a-shown in Fig 3.2). Indicate on the waveform the length (in degrees) of the conduction and blocking parts of the waveform for a complete cycle. You must plot the waveform directly on Fig. 3.2. (10 pts) 2 Lba vhel 1.5 Van 05 Von -05 2 60 90 150 30 120 180 210 240 270 300 330 360 300 420 Angle (deg) Figure 3.2 b) By keeping the assumption of a highly inductive load, compute the voltage applied to the load by considering a firing angle (a) of 30 degrees. Use a line voltage of 575 Volts (line- line RMS) and a frequency of 60H2 to do your computation. (5 pts) c) Using the same conditions current? (10 pts) as in question b), determine the RMS value of the input d) By considering only the fundamental of the current (sine 60 Hz), what is the power factor of the bridge when it operates at the conditions used in question b)? (5 pts)

Answer 1

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