Admin Table of Contents
- 1 How do you increase the capacity of a transformer?
- 2 What is the necessity of cooling of transformer?
- 3 How the rating of a transformer is specified justify?
- 4 Why is cooling an important design considerations in large transformers?
- 5 What is transformer conservator tank?
- 6 How do I reduce the heat in my transformer?
- 7 How can we increase the rate of heat dissipation in transformer?
- 8 How does the temperature rise of a transformer depend on capacity?
How do you increase the capacity of a transformer?
The most common way to increase the available kVA rating of an existing transformer is to add additional fan cooling.
What is the necessity of cooling of transformer?
Cooling of a transformer is the process of dissipation of heat developed in the transformer to the surroundings. The losses occurring in the transformer are converted into heat which increases the temperature of the windings and the core. In order to dissipate the heat generated cooling should be done.
Which is not a valid cooling method for a transformer?
Air Blast. For transformers rated more than 3 MVA, cooling by natural air method is inadequate. In this method, air is forced on the core and windings with the help of fans or blowers.
What are the various methods of cooling of transformers?
Cooling of Dry type transformers The following two transformer cooling methods are adopted in dry-type transformers. Air Natural (AN) cooling – Cooled by surrounding air. Heat transfer by natural convection. Air Forced (AF) cooling – Forced sir circulation using fans and blowers.
How the rating of a transformer is specified justify?
Transformer ratings are measured in volt-amperes (VA) or kilovolt-amperes (WA). Engineers rate power transformers according to the maximum output voltage and current they deliver. The maximum voltage that can safely be applied to any winding is determined by the type and thickness of the insulation used.
Why is cooling an important design considerations in large transformers?
The design of the transformer relies on a specific heat transfer between the windings, oil and the radiator or cooler for heat extraction. Any increase in heat generation or any heat transfer reduction results in higher winding temperatures and shorter insulation life.
Why are the transformer placed in oil filled tank why are tanks provided with tubes fins?
Surface area exposed to air is increased with cooling tubes. Water would not be a good coolant. It is corrosive, it conducts electricity, and has lower boiling point than oil. The transformer oil serves the cooling purpose in the transformer.
What is the disadvantage of auto transformer?
The main disadvantage of an autotransformer is that it does not have the primary to secondary winding isolation of a conventional double wound transformer. Then an autotransformer can not safely be used for stepping down higher voltages to much lower voltages suitable for smaller loads.
What is transformer conservator tank?
Conservator Tank of a Transformer This is a cylindrical tank mounted on supporting structure on the roof the transformer main tank. The main function of conservator tank of transformer is to provide adequate space for expansion of oil inside the transformer.
How do I reduce the heat in my transformer?
Methods to reduce the energy loss in transformer:
- Use of low resistance wire for the winding of the coil.
- Heat loss due to eddy current can be reduced by the lamination of the iron core.
- The heat generated can be kept to a minimum by using a magnetic material which has a low hysteresis loss.
How transformer ratings are decided?
Why transformer rating is expressed in terms of kVA?
The copper and iron are the two types of losses that occur in the transformer. The copper loss depends on the current (ampere) flows through the windings of the transformer while the iron loss depends on the voltage (volts). i.e., the rating of the transformer is in kVA.
How can we increase the rate of heat dissipation in transformer?
The rate of heat dissipation can be increased by providing fins, tubes and radiator tanks. Here the oil takes the heat from inside the transformer and the surrounding air takes away the heat from the tank. Hence it can also be called as Oil Natural Air natural (ONAN) method.
How does the temperature rise of a transformer depend on capacity?
The losses and the heat dissipation increases with increase in the capacity of the transformer. The temperature rise of a transformer can be estimated by the following formula: ΔT = (PΣ/A T) 0.833 PΣ = total transformer losses (power lost and dissipated as heat) in mW; A T = surface area of transformer in cm 2.
Why does a transformer need to be cooled?
Whenever the transformer is loaded, the current in the windings inherently produces the heat. This heat, if not dissipated, will cause damage to the windings cores and other accessories in the tank. Sometimes nearly the tank surface is enough to dissipate the heat without extra provisions but it is only for small transformers.
Why is the oil and air method of transformer cooling so expensive?
Its cost is higher as compared to another process where the circulation of oil and air is done naturally because a fan and blowers are attached as extra cooling equipment, in this method. As the name itself says that both the oil and the air are applied by force for cooling of a transformer.