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What is the significance of sub-transient reactance and transient reactance in short circuit studies?
A 25 MVA, 11 kV generators with is connected through a transmission line and a transformer to a bus that supplies three identical motors as shown in Figure. Each motor has on a base of 5 MVA, 6.6 kV. The three-phase rating of the step up transformer is 25 MVA, 11/66 kV with a leakage reactance of 10% and that of the step-down transformer is 25 MVA, 66/6.6 kV with a leakage reactance of 10 %. The bus voltage at the motor is 6.6 kV when a three-phase fault occurs at the point 'P'.
For the specified fault, calculate- (i) The sub-transient current in the fault, (ii) The sub-transient current in the breaker-B
For the 2nd order system given Ts =7 sec and Tp= 3 sec find the value of % OS and location of poles.
Classify the following signal as energy signal or power signal. Find the
normalized energy or normalized power.
(i) sin 2t + 3 cos 4t
4.1 An interconnected 50 Hz power system consisting of one area has two
turbine-generator units, rated 600 and 800 MVA, with regulation constants
of 0.04 and 0.06 per unit, respectively, based on their respective ratings.
When each unit carries a 350 MVA steady-state load, let the area load
suddenly increase by 250 MVA. Determine:
4.1.1 The area frequency response characteristic on a 1000 MVA base. (5)
4.1.2 ∆
4.1 An interconnected 50 Hz power system consisting of one area has two
turbine-generator units, rated 600 and 800 MVA, with regulation constants
of 0.04 and 0.06 per unit, respectively, based on their respective ratings.
When each unit carries a 350 MVA steady-state load, let the area load
suddenly increase by 250 MVA. Determine:
4.1.1 The area frequency response characteristic on a 1000 MVA base. (5)
4.1.2 ∆
6. A three-phase, 50 Hz, 667 MVA, 22 kV, 4-pole steam driven turbine
generator has an
4.1 An interconnected 50 Hz power system consisting of one area has two
turbine-generator units, rated 600 and 800 MVA, with regulation constants
of 0.04 and 0.06 per unit, respectively, based on their respective ratings.
When each unit carries a 350 MVA steady-state load, let the area load
suddenly increase by 250 MVA. Determine:
4.1.1 The area frequency response characteristic on a 1000 MVA base. (5)
4.1.2 ∆
4.1 A 600 MVA, 50 Hz turbine-generator has a regulation constant R=0.06 per
unit based on its own rating. If the generator frequency increases by 0.02 Hz
in steady-state, what is the decrease in mechanical power output. Assume
a fixed reference power setting. (5)
4.2 A three-phase, 50 Hz, 100 MVA, 4-pole synchronous generator has an
inertia constant H of 3.5 s and is supplying 0.16 pu real power on a system
base of 500 MVA. The input to the generator is increased to 0.18 pu. Determine:
4.2.1 The kinetic energy stored in the moving parts of the generator
4.2.2 The acceleration of the generator
