SLC/WK1: "Advanced Electrical Transformers and Power Factor"

Hello friends and welcome to my article in the SLC S22/WK1 in the dynamics as organised by @mahadisalim and i would be performing tasks as required.

^{A. Name the two transformers from the diagram and explain why?}

^{Tutors Lesson}

From the tutors lesson the transformers are divided into the left and right transformers from the lesson.

The left Transformer (220/415V); This transformer is a step up transformer with secondary voltage (VS) greater than the primary voltage (VP) indicated as 220/415V

Right Transformer (415/220V); A transformer known as step down transformer because it is a transformer with secondary voltage (VS) less than primary voltage (VP) indicated in diagram as 415/220V

^{"What is the turn ratio of the two transformers"}

To determine turn ratio of two transformers we use the special formula

RIGHT TRANSFORMERS

n = Np/Ns = Vp/Vs
Primary turns (Np)= 8
Secondary turns (Ns)= 4
This means turn ratio is 8÷4= 2:1

LEFT TRANSFORMER

Primary turns (Np)= 4
Secondary turns (Ns)= 8
Ratio turns to; 4÷8= 1:2

Therefore ratio of right transformer and left transformer are 2:1 and 1:2 respectively

^{B. Identify various parts of a power transformer with a picture and write the functions of each part}

Identifying various parts of a power transformer from the above image, comprises of key components which indeed are;

Radiator Fins:

This shows radiator fins which helps emitting heat generated from transformer, this transformer hast normally from inside to outside, but it gets cool from the special components aids in dispersing and diffusing heat from the transformers outside to keep it in good shape.

Transformer Tank:

Transformers tank houses windings, insulating oil and other special components providing mechanical protection and preventing external interference from entering inside

Conservator Tank:

This allows expansion, holding extra insulating oil, conserves the oil after cooling operation takes place, making sure oil remains in special positions in the tank.

Breather:

It is a silica gas which helps absorb moisture from air entering transformer tanks contained, keeping free and dry the transformer from contamination, a crucial part of insulation which aids thee transformers get preserved.

^{What type of transformers is used for your home's electricity, Describe your understanding with pictures}

^{My local Transformer}

A transformer shown is used in power distribution, the one used in my area steps down high voltage electricity to a lower voltage to be embraced by the area, being a perfect transformer for the zone. It's size in comparison to others look so small compared to its effectiveness, in performing its duties which is quite a relief as we get steady power supply due to its presence in our area.

^{Calculate how many kVA transformers will be required for a 5000 kw load}

Calculating how many kVA transformers required for a 5000 KW load we really apply this foula to convert KW to kVA below.

^{KVA= KW/power factor (PF)

KW= Real power in kilowatts

PF= Power Factor 0.8

The power factor is a constant in all regards thus;

KVA= 5000/0.8

KVA= 625kVA total load.}

^{NOTE📌; If transformer has more than 300kVA capacity, it can be calculated as 6250/300= 20.8 approximately about 13 transformers}

^{Look at the transformers name plate in pictures and find the following points}

Calculating the current in high voltage (HV) and low voltage (LV) sides of the 33/0.415kV, 2.5MVA transformer, we will have to present both formula work below.

I = Power(s)/√3 × Voltage(V)

Defining parameters;
I= current (A) S= Apparent power in Va (kVA × 1000) Voltage= in volts(V) 1.732 = √3 (3 phase system)

Provided Data:
Transformer rating
S=2.5mVA 2500, kVA= 2,500,000VA
HV voltage VHv = 33,000V LV=Voltage = 415V
High Voltage HV Current
HV = 5/ √3×VHV
Substituting
I HV = 2,500,000/1.732×33000
= 2,500,000/57.156
= 43.74A

Low Voltage (LV) Current
=5/√3×VLV
Substituting
2,500,000/1.732×415
=2,500,00/718.78
=3478.11A
Therefore, HV= 43.74A and LV= 3478.11A respectively

^{What do you mean by power factor? What is the power factor value given by electricity supply company in your country.}

Power Factor is measurement of how effective the voltage is, it could be the ratio of real power which does great work to apparent power supplied in varying circuit.

Actual power is consumed by equipment to perform important work, measured in kilowatts, spotted as real power. Apparent power is total power supplied whereas power oscillates between reactive components and source is reacting power.

Nigeria power supply is privatized having various power supply companies running power in major power supply companies such as EEDC, DISCO just to mention but a few which uses 0.8 to 1 power factor for commercial and industrial use.

^{Given template of two transformers shown in figure write 3 differences}

^{1st transformer}	^{2nd Transformer}

First Transformer	Second Transformer
200kVA power capacity	2500kVA power capacity
11,000 (HT) and 415 V (L.T)voltage rating	33,000 (HV) and 415 V (LV) voltage rating
Dyn 11 Vector group	∆/y-11 vector group.

• Name of oil used in transformer is pyranol FALSE
• Core loss of transformer is winding FALSE
• Efficiency of transformer is less than other electrical devices FALSE
• Transformer rating is in KW FALSE
• Transformer insulation test is done with megher meter TRUE

I have concluded article and invite @dove11 @ruthjoe @eliany @solaymann to join challenge