Answer / kaami

advantages of DC generating station

1)since, V=IZ where Z=IR+reactance. As, f=0,
so Z=IR.
2)No skin effect in DC
3)natural capacitance in overhead transmission in AC cause the charging current to flow in overhead line thus causing the loss in transmission line. since in dc, charging current is absent so no natural capacitance.

advantages of AC generating station

1)output voltage due to DC machine are limited mainly due to restriction on rotor and carbon brushes. Output voltage from ac machines can be achieved very high upto 33kv because power is taken from the stationary part.
2)main advantage is stepping up or stepping down voltage to transmit to large distances.

A 100 kVA , 400 v/250 kv testing transformer has 8% leakage reactance and resistance on 100 KVA base . A cable has to be tested at 500 kv using the above transformer as a resonant transformer at 50 hz . if the charging current of the cable at 500 kv is 0.4 A find the series inductance required . Assume 2% resistance for the inductor to be used and the connecting leads . Neglect dielectric loss of hte cable . what will be the input voltage to the transformer ?

0 Answers   L&T,

---

Is current shock due to voltage or current? pls answer

2 Answers   ABB,

---

what is bausbar?

4 Answers   Essar,

---

what is cut out fuse?

1 Answers  

---

What is the effect on 3phase induction motor if current setting knob of DOL kept at minimum current?

0 Answers  

---

what is power ratio between star & delta connection of 3 phase induction motor

1 Answers  

---

how a flip flop can be used as a latch?

0 Answers  

---

what is the effect when the shunt field winding is opened in dc shunt motor (i) at the time of starting ? (ii) in running condition ?

4 Answers  

---

Hi My dear all Friends, There is a question regarding HVAC Engineering and widely used in Power Projects. Question- What is the diffrence Between REF, SEF and Differential Protection....???? Where REF - Restricted Earth Fault SEF - Senstive Earth Fault.

0 Answers  

---

when we should use Central Battery system and UPS system and why? in other words, what are the differences between the two systems?

1 Answers  

---

What is nyquist contour?

0 Answers  

---

Is there any capacitor in 3-phase IM?why,xplain.

2 Answers  

---