CHAPTER XXV 



POLYPHASE REGULATORS 



Induction regulators of the polyphase type are used 

 principally with rotary converters, but are well adapted 

 to control polyphase transmission circuits. As in the 

 IRS type, they may be either air blast cooled, oil cooled 

 or oil and water cooled. The primary winding is con- 

 nected in shunt and the secondary in series with the 

 circuit. In the polyphase induction regulator, the 



Fig. 67 

 Regulator Diagram Three-Phase 



voltage induced in each phase of the secondary is con- 

 stant, but by varying the relative positions of the pri- 

 mary and secondary, the effective voltage of any phase 

 of the secondary is varied from maximum boost to zero, 

 and from zero to maximum lower. 



Referring to Fig. 67, which represents graphically 

 the voltage of the three phases of a three-phase or IRT 

 regulator, let AAA=the line voltage or the e.m.f. im- 

 pressed on the primary. This is shown by the large 

 circle. Let BA, BA and BA equal e.m.f. generated in 

 the secondary coils, which is constant with constant 

 impressed e.m.f. This is shown by the three small 

 circles on the circumference of the large circle. BBB 



[201] 



