C57.120.1991 IEEE LOSS EVALUATION GUIDE FOR POWER TRANSFORMERS AND REACTORS

C57.120.1991 IEEE LOSS EVALUATION GUIDE FOR POWER TRANSFORMERS AND REACTORS

 

This IEEE loss evaluation guide was made to help electrical practitioners provide a method of establishing the economic value of the electric power intended to supply the losses of a transformer or reactor. With the use of this C57.120.1991 standard, decision-makers can have a guide for the proper weighing of alternatives when it comes to transformer selection that considers the cost-benefit relationship between these choices. Normally, it is a loss evaluation relative to economic benefit of a high-first-cost, low-loss unit against one with a lower-first-cost but with higher losses. Beside the users of transformers, transformer manufacturers can also benefit with this standard by using this as guide a mean to optimize their design and provide the most economical unit to bid and manufacture.
Also, evaluation of the cost of losses will help users compare the bids between different manufacturers thus they will be able to get the best purchase choice among competing transformers or reactors. Except, the purchasing stage, loss evaluation can also provide information to the transformer user when to retire or replace their purchased unit.

Ideally, before a transformer user purchases a unit, he should be able to determine, on a cost-per-kilowatt basis, the net present value of each of the transformer projected losses during its life span. This is to figure out whether the portion of this evaluated cost can be paid to the manufacturer to reduce losses.

Found in this IEEE standard are formulas and equations by which the cost of power, energy and money as well as the loading pattern of transformer can be converted to cost-per-kilowatt values of the transformer loss.

The basic concept of this C57.120.1991 standard is the evaluation of each of the known types of transformer losses; no-load, load, and auxiliary losses. Mostly found in this guide are a sum of the demand portion as well as the sum of the energy portion.

• Demand portion is the cost of installing system capacity in cost-per-kilowatt
• Energy portion is the present value of the energy that will be used by one kilowatt of loss during the booklife of the transformer, converted to cost-per-kilowatt.

Also, Loss Cost Rate formulas are found within this IEEE standard like the following;

• No-Load Power Loss Cost Rate (NLLCR)
• Load Power Loss Cost Rate (LLCR)
• Auxiliary Power Loss Cost Rate (ALCR1 & ALCR2)

>TO KNOW MORE ABOUT THIS STANDARD YOU CAN FOLLOW THIS LINK