: nil-: SYNCHRONOUS CONVERTER 357 



energy component or the component of current in phase with 

 the induced electromotive force produces cross magnetization 

 ;>age 132). When the converter is operating direct, any 

 current in quadrature with the induced electromotive force 

 merely st lengthens or weakens the field, depending upon whether 

 the current lags or leads. Consequently, there is magnetizing 

 action upon the fields when the current lags and demagnetizing 

 action when the current leads. (See Chap. X, Pars. 126 and 127, 

 pages 309 and 312.) As a result, the added quadrature current 

 merely strengthens or weakens the field but does not distort it. 

 Hence there is little or no sparking in a converter armature due 

 to field distortion. 



Armature of :i 4,(MM)-kw.. tiL'.Vvnl t . (i.-ncral Kln-tri-- >\ nrlmnmu- 



C(|J\ 



It will l.e remembered (see Vol. I, page 280), that in a direct- 

 current machine, an el.-ct nmmlive force of >ell'-induct ion exists in 

 rmature coils which are undergoing commutation. It is 

 :ble, therefore, that a counter electromotive force, opposite 

 and equal to this electromotive force of si-lf-imlnction. he m- 

 ; in these coils. Otherwise, sparking will msi even if 

 then- be no field distortion. In :i direct-current generator, this 

 counter i']ectrom..ti\. obtained cither by moving the 



brushes ahead of the neut ral plane or by I he u>r of commutat ing 



