Calculate the value of the reactance to limit

Assignment Help Electrical Engineering

Reference no: EM131631353

Assignment

1. FIGURE 1 shows four generators feeding into a sectionalised busbar with a fault limiting reactor.

FIG. 1

Each generator is rated at 11 kV and 30 MVA and has a reactance of 0.2 p.u.

Calculate the value of the reactance to limit the fault level on a feeder to 500 MVA.

2. FIGURE 2 shows the sectionalised busbar of a two generator power station connected to the national grid.

Calculate, using a 40 MVA base, the fault level for a 3-phase symmetrical short circuit on the 11 kV feeder.

FIG. 2

3. State:

(i) The function of a plug bridge on an IDMT electromagnetic protection relay.

(ii) Two ways in which the setting of an IDMT electromagnetic relay may be altered.

4. (a) An 11 kV, single phase system is protected by a scheme using 1000/5 CTs and an IDMT relay having a plug setting of 150% and time multiplier setting of 0.68 (FIGURE 3).

Using the standard PSM/time characteristic, find the relay operating time (TMS = 1) for a 236 MVA fault.

FIG. 3

(b) The circuit breakers CB1, CB2, CB3 and CB4 are part of a scheme which uses 1000/5 CTs and IDMT relays.

If the maximum fault current capability is 6700 amps, clearance of which must be initiated in 2.25 secs, select, using the standard characteristic:

(i) plug setting multipliers for CB1 at plug settings of 100% and 50%

(ii) the time multiplier setting of each IDMT relay to afford effective discrimination of 0.4 sec at a plug setting of 50%

Verified Expert

The work is related to power system which involves the solution for total 4 problems. calculation of reactance is done in problem 1. problem 2 is based on the calculation of the fault level for a 3-phase symmetrical short circuit on the 11 kV feeder. Problem 3 is about IDMT electromagnetic relay. This is theoretical. Finally we have problem 4 for scheme using 1000/5 CTs and an IDMT relay having a plug setting

Reference no: EM131631353

Questions Cloud

Explain institute policies to help prevent or mitigate : What are the factors (e.g., timely and appropriate clinical services) that determine whether patients at risk for pressure ulcers receive proper skin care

The difference between a welfare system and a safety net : Interestingly, most people don't know the difference between a welfare system and a safety net which is what the debate frequently encounters as a roadblock.

What would be some of the advantages to a business manager : At Etsy, new developers are expected to begin pushing code to production on day one. That expectation is one way Etsy encourages it employees to embrace.

Would american college health association be good candidate : Would the American College Health Association be a good candidate? Explain the reasoning you would use the select the one organization to join.

Calculate the value of the reactance to limit : Calculate the value of the reactance to limit the fault level on a feeder to 500 MVA - find the relay operating time

Evaluation of the industry strategic position : Use Porter's five forces to make a qualitative evaluation of the industry's strategic position. Be sure to explain each of the five forces.

How are global markets integrated and connected : How are global markets integrated and connected? How might issues in China impact domestic market performance in the United States?

What captures attitudes toward time and persistence : what captures attitudes toward time, persistence, ordering by status, protection of face, respect for tradition, and reciprocation of gifts and favors?

What do us welfare programs intend to accomplish : What do you think the impact will be on other countries around the world as China and Russia regard transitioning to market economics ?

User Account

All Pages