Answer / ravi

These terms appear in the calculation of fault currents.
Common sources of fault currents are rotating machines,
i.e., motors and generators. An important factor in
detrmining the magnitude of a fault current is a variable
reactance that changes rapidly after the initiation of the
fault until it reaches a steady state.

Subtransient Reactance:-usually denoted as X''d (X double
prime sub d), is the reactance used to determine the
current during the first cycle after the occurance of the
fault.
Transient Reactance:-In about 0.1 second this
reactance increases to the
level known as Transient Reactance usually denoted as X'd,
and after 0.5 to 2 seconds it increases to the leven known
as Synchronous Reactance and denoted as Xd, and this
determines the fault current after a steady condition is
reached.

Answer / chunkey pandey

These terms appear in the calculation of fault currents.
Common sources of fault currents are rotating machines,
i.e., motors and generators. An important factor in
detrmining the magnitude of a fault current is a variable
reactance that changes rapidly after the initiation of the
fault until it reaches a steady state.

Subtransient Reactance:-usually denoted as X''d (X double
prime sub d), is the reactance used to determine the
current during the first cycle after the occurance of the
fault.
Transient Reactance:-In about 0.1 second this
reactance increases to the
level known as Transient Reactance usually denoted as X'd,
and after 0.5 to 2 seconds it increases to the leven known
as Synchronous Reactance and denoted as Xd, and this
determines the fault current after a steady condition is
reached.

What is thef ormula to calculate the rating of a capacitor for a single phase motor

2 Answers  

---

We all have seen transmission and Distribution lines In transmission lines the voltage is high and current is low(to reduce I^2r loss) and in distribution lines voltage is low but current is high however the size of transmission wires is bigger than that of distribution wires even though the amount of current carried by the distribution lines is more than that of transmission lines why?

4 Answers  

---

What types of I/O have you designed? What were their size? Speed? Configuration? Voltage requirements? Process technology? What package was used and how did you model the package/system? What parasitic effects were considered?

0 Answers  

---

What should be the percentage increase in length of the dead end clamp for bus bar conductor (Hawthorn) after hydraulic pressing and what should be the applied pressure?

0 Answers  

---

check list of maintenance of transformer?

11 Answers   ABC, Cosmos, EPRON, Essar, Godrej, Hescom, Infosys, KPTCL, TCS,

---

what is MFD value in capacitor?I have 201 Kva load & reactive power is 150 Kvar. so how it is calculated?

2 Answers   IIT,

---

why ten delta testing is carried out on power transformer

0 Answers  

---

In CTs tan delta point should be earthed , what is the reason behind it?

0 Answers  

---

what is the difference between OD and VL

1 Answers   Bescom,

---

what is active power and rective power and power factor

1 Answers  

---

What are instrument transformers?

6 Answers  

---

In electrical cables what is U and U0 refers?

11 Answers  

---