Transformer Software


home Software software

Transformer Sizing Software


ETAP follows recommended procedures to determine the required transformer size based on the use of factors including altitude, temperature, insulation, number of phases, cooling stage, etc.


Transformer Sizing Analysis Software Key Features


  • Sizing based on actual connected or operating load
  • ANSI & IEC standard types, classes, & ratings
  • Considers ambient temperature, altitude, load growth, & load factors
  • MVA Sizing based on multiple cooling stages

ETAP has compiled the information contained on standards ANSI/IEEE C57, IEC 60076-2 & 60726 into a program that can easily determine the proper size of a power transformer. The method used by the program considers several factors like ambient temperature, altitude, cooling stage and type (dry or liquid fill). When sizing a transformer, it is also very important to consider the expected future growth of the required load. ETAP uses adjusting factors to take this into account. ETAP has built in functions that compare the calculated size and impedance against the minimum values recommended by the standards.


Transformer Sizing Analysis Software Standards


  • ANSI / IEEE - C57.116 – 1989
    Guide for transformers directly connected to generators
  • IEC - IEC 60076-2 – 1993
    Liquid-cooled power transformers
  • IEC - IEC 60726 – 1986
    Dry-type power transformers

In power systems, there are many devices whose proper size is critical to the design of a power delivery system. One of the most important is the power transformer. There are several factors involved in the process of sizing a power transformer. ANSI and IEC standards provide a set of guidelines that list these factors and how they can be used to determine if a transformer can handle its required operating load. Inadequately sized transformers may shorten the equipment operating life or cause overloading failures.

Transformer Sizing Analysis Software ETAP
ETAP has compiled the information contained on standards ANSI/IEEE C57.116, IEC 60076-2 & 60726 into a transformer sizing analysis program that can easily determine the proper size of a power transformer. This transformer sizing calculation method used by the program considers several factors like ambient temperature, altitude, cooling stage and type (dry or liquid fill). When sizing a transformer using ETAP transformer sizing analysis software, it is also very important to consider the expected future growth of the required load. The transformer MVA sizing module uses adjusting factors to take this into account. The power transformer short-circuit requirement “transformer impedance and basic impulse level (BIL)”, are also considered by the MVA transformer sizing module. The module has built in functions that compare the calculated transformer size and impedance against the minimum values recommended by the standards.

The ETAP Transformer Sizing module provides two sizing calculations. One calculation is to size the transformer MVA rating (both rated and maximum) and % Z for single-phase and 3-phase 2-winding transformers, based on ANSI and IEC standards. Another power transformer calculation is to optimize a generator unit transformer tap ratio based on ANSI standards. The first power transformer calculation is hereafter referred to as Transformer Sizing Analysis Software, whereas the second calculation is referred to hereafter as Transformer Tap Optimization Analysis Software.