Tham khảo tài liệu 'electric machinery fundamentals (solutions manual) part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CU 3 A AP I 2 2 R A kW f nv at rated conditions is Ị0ny IN D PP .8 kW D kW kW g If Ea is decreased by 10 the new value if Ea problem we will ignore RA . Then the quantity Ea sin 603 V 543 V. will be constant as Ea To simplify this part of the changes. Therefore sin 2 E 1 sin Ea2 sin 603-V sin Therefore I 0 V E 440 a D 543 V 43 0 _ _ . ---- ------- A o A jX j30 and the reactive power supplied by the motor to the power system will be q3 vI sin3 440 V A sin kVA R I 6-16. Answer the following questions about the machine of Problem 6-15. a If Ea 430 V and V 440 0 V is this machine consuming real power from or supplying real power to the power system Is it consuming reactive power from or supplying reactive power to the power system b Calculate the real power P and reactive power Q supplied or consumed by the machine under the conditions in part a . Is the machine operating within its ratings under these circumstances c If Ea 470 -12 V and V 440 0 V is this machine consuming real power from or supplying real power to the power system Is it consuming reactive power from or supplying reactive power to the power system d Calculate the real power P and reactive power Q supplied or consumed by the machine under the conditions in part c . Is the machine operating within its ratings under these circumstances Solution a This machine is a generator supplying real power to the power system because EA is ahead of V . It is consuming reactive power because A coE Ì . b This machine is acting as a generator and the current flow in these conditions is A n E V 430 135 440 0 V A 1 3 R JX . The real power supplied by this machine is P V cos 3 440 V A cos 43d 3 kW The reactive power supplied by this machine is 3 sin 3 440 V Q VI R A sin 10 .8 kV A 169 c This machine is a motor consuming real power from the power system because EA is behind V . It is supplying reactive power because A coE v .
