GE 889 Instruction Manual page 279

CHAPTER 4: SETPOINTS
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
Example 2: Operating quantities for a fault at a fraction k from the neutral grounding
point.
For analysis, consider the above figure and assume that E3 = 10 V, R = 5Ω, Xc = 5Ω, and k =
0.15.In this case, we have the magnitude of the neutral voltage at: VN = k x E3 = 0.15 x 10 =
1.5 and the magnitude of the neutral and zero-sequence voltages |VN + V0| as:V_0= ((1-
k)E_(3 Therefore, for faults at a fraction k = 0.15 from the neutral grounding point, we set
the operating quantities as follows:
PROTECTION
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