Question

A single-phase full bridge thyristor rectifier is supplied from a 200vrm 50HZ AC source, and supplies a series R-L load comprising a 202 resistance and a 36.8mH inductance 2.a. Sketch the circuit diagram for this rectifier Q2. [4 marks] [Refer to lecture notes] 2.b. Determine the maximum possible average DC voltage that can be achieved across the load resistor [4 marks] [VDC (avg) = 180V] 2.c. Determine the SCR firing angle at which the rectified output curent will just be continuous, and calculate the average DC output voltage under these conditions. [6 marks a30° If the bridge is now operated at a firing angle of a = 90°, sketch over two fundamental cycles, the waveforms of the DC output voltage that develops across the R-L load 2.d. [3 marks] the current flowing through the load resistor [3 marks [Refer to lecture notes] Total Marks for Question 2 = 20 marks

Answer 1

O2 20 3C.S mH 2av olvottage 2Vm Vo COSd wariuu possible voltage 2Vm Vo Vs 200 qiven ) Vm = \2V Vo 2x2X200

2 prt angle at which ont Continous Tan o Tan 2-0 30 Fom 2XJ21200 cos 3o Vo- Vo = 155:94 volt 2.8 wt 630 0 S40 4go 368 2-30 Fcasut 200x2 200x CUST T

200X Νι δ Τ Nο 10.0 Νο1t Α003 νο Υ- 20 ρ