MGVCL Exam Paper (30-07-2021 Shift 1)
___ is the short time reduction in the rms voltage between 0.1 to 0.9 p.u for a duration of ___

Voltage sag, greater than 1 minute
Voltage sag, 0.5 cycle to 1 minute.
Voltage swell, greater than 1 minute
Voltage swell, 0.5 cycle to 1 minute.

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MGVCL Exam Paper (30-07-2021 Shift 1)
The necessary equation to be solved during the load flow analysis using Fast-Decoupled methid is given below:
where B' and B'' are formed using the imaginary part of the bus admittance matrix Ybus, n is the total number of buses in the system, m is the number of voltage regulated buses. The size of matrix B' is
∆P/|Vi|= -B' ∆δ
∆Q/|Vi| = -B'' ∆|Vi|

(n-m) x (n-m)
(n-m-1) x (n-m-1)
(n-1) x (n-1)
(m-1) x (m-1)

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MGVCL Exam Paper (30-07-2021 Shift 1)
Determine maximum permissible load which a 15 MVA, ONAN cooled transformer to IS : 2026 can take for 6 hr, if the initial load on it was 12 MVA. The weighted ambient temperature is 20˚C. Assume the permissible load kVA as a fraction of rated kVA is 1.25.

9.6 MVA
15 MVA
12 MVA
18.75 MVA

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