MEEN 225 Lecture Notes - Lecture 4: Rectifier, Red, Thyristor

• School: Texas A&M University
• Department: Mechanical Engineering
• Course: MEEN 225
• Professor: John Steven Haglund

Document Summary

A 3-phase bridge rectifier has to supply power to a 360 kw, 240 v dc load. Hz feeder is available, calculate the following: voltage rating of the 3-phase transformer, dc current per diode, piv across each diode, peak-to-peak ripple in the output voltage and its frequency. E = ed / 1. 35 = 240 / 1. 35 = 177 v. Thus, a 3 transformer having a line voltage ratio of 600 v/177 v would be satisfactory. The primary & secondary windings may be connected in either wye or delta: dc load current id. From p = vi for the dc load dc current per diode. Therefore, for 1 cycle of 360 , only 3 diodes conduct. E min = 1. 225 x 177 = 216. 8 v. E max = 1. 414 x 177 = 250. 3 v. E peak-to-peak = 250 217 = 33. 5 v or epeak-to-peak = 0. 189 e = 0. 189 x 177. Fundamental ripple frequency = 6 x 60 hz = 360 hz.