Transformer Sizing Calculations Course

Course Description:

This course is intended to prepare the target persons with the ability to perform Transformer Sizing Calculations for all types and special cases of transformers.

The targeted Persons:

Design engineers, new graduate engineers, under graduate engineering students.


Skills Development:


On completion of this course the target person will be able to:

• Know selection factors for transformers,

• Know how to specify the important factors of transformers,

• How to calculate transformer ratios, efficiency and voltage regulation,

• How to perform the sizing calculations for normal power distribution transformers,

• Know the special cases of power transformers and how to size the transformer in each case.

Course Outline:

1	Glossary of Sizing Power and Distribution Transformers
2	Resources Used To Calculate Basic Ratings Of Power And Distribution Transformers
3	Selection Factors for Power and Distribution Transformers sizing calculations	Voltage class,
		Load type,
		Ambient Temperature,
		Standard Sizes,
		Cooling Classes,
		Temperature Rise,
		Altitude.
4	Applicable Calculations Procedures For Sizing Of Power  And Distribution Transformers
4.A	Summary Of Selection/Calculation Procedures	Select Power or Distribution Transformer,
		Select Liquid-Filled or Dry-Type Transformer,
		Select Primary Voltage,
		Select Secondary Voltage,
		Select BIL Ratings,
		Calculate Load kW and kVAR,
		Calculate Site kVA,
		Calculate Adjusted Site kVA,
		Select Transformer kVA Ratings from Standard Sizes,
		Select Transformer Cooling Class kVA Ratings.
5	Applicable procedures for calculating power and distribution transformer ratios
6	Applicable procedures for calculating power transformer efficiency
7	Applicable procedures for calculating power transformer voltage regulation.
8	Special Cases In Transformers Sizing Calculations
8.A	Secondary Unit Substations,	What is the Secondary Unit Substations?
		Components of Secondary Unit Substations
		Types of Secondary Unit Substations
		Procedures For Calculating Transformer Let-Through Current
8.B	Paralleled Transformers	Importance for using Paralleled Transformers
		Conditions for Parallel Operation of Transformer
		The factors that should be considered when paralleling transformers:
		1- Increased Fault Levels,
		2- Circulating Currents,
		3- Limiting kVA.
8.C	K-Factor Transformers, K-Factor/Factor K Calculators	Linear Vs. Nonlinear Loads
		The Effect of Nonlinear Loads on the Electrical Power Systems
		K-Factor
		Diversity of Harmonics
		K-Factor or Factor K?
		Sizing Methods of Transformers for Non-Linear Loads
		K-Factor/Factor K Calculator,
		Transformer Calculations Spreadsheet.
8.D	Transformers with Large Motor Loads.	Importance of Short Circuit and Motor Starting Calculations in Transformer Sizing
		Reviewing Some Motor basics
		General Rule For Sizing Transformers With Large Motor Loads
		Voltage Dip Calculation