Answer / baswaraj

The power ratio between Star to Delta is 1:3

Here is the Explanation:

Let?s suppose Vs be the supply voltage per phase.

So the line voltage of the supply will be ?3Vs.

Now assume any type of load; for simplicity assume it a
only resistive load.

And let it be ?R? per phase.



For Delta connected load:



Calculation for per phase power; PD= I2R



Where I ? load current (per phase)

And,

I = ?3Vs/R {as line voltage of the supply is directly
applied to the phase of the delta load}

So,

Pd = (?3Vs/R )2R = 3Vs2/R watts per phase.

For 3 phases:

P3D = 3Pd = 3*3Vs2/R = 9Vs2/R watts.



Now for Star connected load:



PS = I2R = (Vs/R)2R = Vs2/R watts

For 3 phases: P3S = 3PS = 3 Vs2/R watts



Conclusion:

P3S / P3D = 3Vs2/R / 9Vs2/R = 1/.

If the Supply voltage is increased by n times, the cross section of conducter will [increase/decrease] by ________ times ?

4 Answers  

---

difrent between vcb acb sf6 and mccb breakers

1 Answers   DMRC,

---

We have a 12MW power plant & we inject 5-6MW power to Orissa GRID. For this we have a 33KV/11KV switch yard having 12.5MVA power transformer. Some times we draw power during emergency. It is observed that during Export or Import for load less than 500Kw the power factor is decreasing to 0.3 . This is happening only during export or import. During island condition TG power factor OK.Our capacitor bank is provided with our Power plant auxilliary load. Please suggest how I can we improve our power factor during low load (GRID).

3 Answers  

---

What is hipot test procedure?

0 Answers   CCC,

---

The inventer is a battery, but if lost current at home u will turn on the fan but the is AC and inventer battery is dc . Then how the fan was rotating. What device Or machine in fan converst the Dc power to Ac power

0 Answers  

---

---

a solar energy installation utilizes a three phase bridge converter to feed energy into power system through a transformer of 400v/400v.the energy is collected in a bank of 400v battery and is connected to converter through a large filter choke of resistance 10ohms.1.the maximum current through the battrey will be.2.the kva rating of the input transformer is.

1 Answers   GATE,

---

what do you mean by synchronous speed of a three phase induction motor?

5 Answers   FlexPoint,

---

why the efficiency of the dc machine is high ,when it is operated as a generator?

3 Answers  

---

Is there any relation between transformer capacity and its bdv?

1 Answers  

---

why we are discharging h.t supply during shutdown time

1 Answers  

---

What is correction factor in Tan delta test?

1 Answers  

---

what is the difference between potential transformer and capacitive voltage transformer?

1 Answers  

---