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ELECTRIC POWER QUALITY E l e c t r i c - p o w e r q u a l i t y , i n c l u d i n g voltage and frequency e x c u r s i o n s , was studied under the heading of EMP and NEMP. The environment surrounding high voltage t r a n s m i s s i o n l i n e s may cr e a t e voltage spikes t h a t can be reduced to 2-1/2 times the average voltage. V a r i a t i o n i n u t i l i t y load demands causes frequency d e v i a t i o n ranging from a complete l o s s of power to slow swings i n frequency t h a t may exceed the G u i d e l i n e s . Power q u a l i t y d e v i a t i o n s may be brought about by l i g h t n i n g , n u c l e a r detonation i n the atmosphere, l a r g e step-load changes, l i n e f a u l t s , and switching surges. Power generated w i t h i n the b u i l d i n g and having no e x t e r n a l c i r c u i t s must, to a l e s s e r degree, be protected from the same d i s t u r b i n g f a c t o r s . P r i o r r e s e a r c h i n t o the nature of the electromagnetic e f f e c t s of n u c l e a r detonation i n the atmosphere revealed t h a t i t had much of the c h a r a c t e r of l i g h t n i n g . P r o t e c t i v e techniques used i n e x t e r n a l t r a n s m i s s i o n l i n e s did not giv e the q u a l i t y of power d e s i r e d s i n c e n u c l e a r detonation i n the atmosphere would generate voltage s p i k e s on c i r c u i t s w i t h i n the power s t r u c t u r e and, as a r e s u l t , s h i e l d i n g of i n t e r n a l c i r c u i t s was re q u i r e d . Some of the radar and computer components were found to be s u s c e p t i b l e to voltage or frequency d e v i a t i o n s i n excess of + 2 percent. S u s c e p t i b i l i t y to d e v i a t i o n i n e l e c t r i c power supply could not be reduced so methods were required to ensure th a t a ⢠-2-
p o r t i o n of the power was p r e c i s e . I t should be noted t h a t d i f f e r e n t p a r t s of the system were s u s c e p t i b l e to d i f f e r e n t types of d i s t u r b - ances . The radar i s s u s c e p t i b l e to surges while the computer i s s e n s i t i v e to s p i k e s . The o r i g i n a l premise was t h a t a source of i n t e r n a l power was required to prevent complete l o s s of power even f o r a sh o r t time. A s i n g l e power outage was found to d i s t u r b the ABM System performance f o r an extended time. These conditions suggested t h a t i n t e r n a l l y and e x t e r n a l l y developed power could probably be used to maximum advantage. E l e c t r i c u t i l i t y power from e x i s t i n g e l e c t r i c u t i l i t y systems was considered to be extremely d e s i r a b l e as i t tended to provide redundancy and perhaps a l s o reduce the ABM Power System c a p i t a l and operating c o s t s . U t i l i t y power seemed g e n e r a l l y a v a i l a b l e i n the areas s e l e c t e d f o r the ABM u n i t p l a n t s . The questions t h a t required extensive study were: 1. Could the voltage d e v i a t i o n s be c o n t r o l l e d w i t h i n an acceptable l e v e l ? 2. Could the frequency d e v i a t i o n from a s l i g h t dip to a complete power outage of sh o r t duration be accepted? Since some of the radar and computer subsystems could not t o l e r a t e voltage or frequency d e v i a t i o n s outside the G u i d e l i n e s , i t was obvious t h a t u t i l i t y power must always be supplemented by some i n t e r n a l power f o r the p r e c i s e e l e c t r i c power requirements, -3-
