Transformer Design - How Is CT Size Calculated?

Sin=CT internal Secondary Burden (In^2*Rct=5.6 W) , In (rated CT Secondary Current 1A.) PL (The total Lead burden from CT to the relay can be calculated as In^2*RL) PL=1.121 W.

What is 42 in transformer winding rule?

According to Rule 42 for making the transformer, the area has to be divided by using the content. 5.38 * 220 = 1184.61 turns = 1190 turns needs for producing 220v output.

How do I convert kVA to kW?

kW or kilowatt is a unit of electric power. It is equal to 1,000 Joules per second and it measures how fast the energy is transferred. That means that in DC circuits, 1 kVA is equal to 1 kW. That means that 1 kVA is equal to 1,000 watts.

What is eddy current loss?

Definition of eddy-current loss : loss of energy (as in electrical machinery or transformers) due to eddy currents in cores or conductors — compare core loss.

What is the BDV value of transformer?

As per IEC, the minimum BDV of transformer oil should be 30 KV as per transformer oil BDV test standard. The transformer oil is used in the transformer for insulation as well as for cooling purpose.

What are the parameters to design a transformer?

Program Quickly Calculates Transformer Design Parameters

• Primary input voltage.
• Secondary output voltage.
• Operating frequency.
• Required output power.
• Efficiency.

What is CT ratio in transformer?

The CT ratio is the ratio of primary current input to secondary current output at full load. For example, a CT with a ratio of 300:5 is rated for 300 primary amps at full load and will produce 5 amps of secondary current when 300 amps flow through the primary.

Is standard for transformer design?

This Indian Standard (Part 8) which is identical with IEC 60076-8 : 1997 'Power transformers - Part 8: Application guide' issued by the International Electrotechnical Commission (IEC) was adopted by the Bureau of Indian Standards on the recommendation of the Transformer Sectional Committee and approval of the

What is rating factor of CT?

Typical rating factors of CT's are 1.0, 1.25, 1.33, 1.5, 2.0, 3.0, and 4.0. Many times the manufacturer will only list the CT rating factor at 30°C ambient (room temperature).

Which oil is used in transformer?

Mineral oils are still widely used in the industry. Mineral oil is generally effective as a transformer oil, but it has some disadvantages, one of which is its relatively low flashpoint versus some alternatives. If a transformer leaks mineral oil, it can potentially start a fire.

What is a 3 phase transformer used for?

Three-phase transformers are used for power generation and electrical distribution network applications. They can be found in high power industrial loads such as rectifiers, motor drives, and other equipment.

What are the 5 applications of transformer?

Uses of Transformers in Daily Life

• Alternating Current Regulation.
• Charging Batteries.
• Steel Manufacturing.
• Electrolysis.
• Controlling the flow of Electricity through a circuit.
• Audio Transformer.
• Coolant.
• Ammeters or Current Transformers.

What is is standard for CT & VT?

The main Standard references for the inductive type of CTs and VTs (with iron laminates) in medium voltage networks are: EN 60044-1 current transformers; EN 60044-2 voltage transformers.

What is kVA rating?

A kVA is 1,000 volt-amps. It's what you get when you multiply the voltage (the force that moves electrons around a circuit) by the amps (electrical current). Kilovolt-amps measure what's called the 'apparent power' of a generator. This is different from kilowatts (kW), which measure the 'true power'.

How do I choose a transformer size?

How to Size a Transformer

1. Transformer size is determined by the kVA of the load.
2. Load voltage, or secondary voltage, is the voltage needed to operate the load.
3. Line voltage, or primary voltage, is the voltage from the source.
4. Single-Phase has two lines of AC power.

Why Buchholz relay is used?

The Buchholz relay is used as a protective device sensitive to the effects of dielectric failure inside the equipment. A generic designation for this type of device is "gas detector relay".

Why CT secondary is 1A or 5a?

In this case, as the CT secondary has a current of 1A, to achieve ampere-turns balance, we need to have 100 turns of secondary winding. Moreover, the voltage output of a CT secondary, for a given primary current is constant.

Why kVA rating is used in transformer?

The first reason is the power loss in the transformer. Thus, the total losses in a transformer depend upon volt-ampere (VA) only and not on the power factor of the load. That is why the transformer rating is given in kVA and not in kW.

Which is better kW or kVA?

A measure of apparent power, kVA, or kilo-volt-amperes, reads the complete amount of power that is being used in a system, such as a generator. When such a system is 100% efficient, kW, or kilowatts, are equal to kVA.

What is the transformer principle?

The transformer works on the principle of Faraday's law of electromagnetic induction and mutual induction.