Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
Transcript of Transformer
2.Why Transformers are Important?
Make electricity generation possible at the most economic generator voltage level
Make electric power transmission take place at the most economic transmission voltage
Supply electric power to users at a safe and suitable voltage
Mohd Fakhizan Romlie, PhD
1.What is a Power Transformer?
A device that changes AC electric power voltage level to AC electric power another voltage level at the same frequency through magnetic field action
Consist of two or more coils of wire wrapped around a common ferromagnetic core
Construction & How it works
Per Unit System
Three Phase Transformer
How does a Transformer Work ?
The permeability of the core, approaches infinity
No core losses
No resistance in the windings
No leakage flux
Understand the purpose of a transformer in a power system
Know the voltage, current and impedance relationships across the windings of an ideal transformer
Understand how real transformers approximate the operation of an ideal transformer
Be able to explain how copper losses, leakage flux, hysteresis and eddy current are modeled in a transformer equivalent circuit
Use the transformer equivalent circuit to find the voltage and current transformations across a transformer
Be able to calculate the losses and efficiency
Be able to derive the equivalent circuit of a transformer from measurement
Understand per unit system
Be able to calculate voltage regulation
Understand auto transformer
Understand three phase transformers
1. Copper Losses
2. Eddy Current Losses
4. Leakage Flux
3. Hysteresis Losses
OPEN CIRCUIT TEST
Referred to Primary Side
Referred to Secondary Side
Approximation - current excitation branch 2-3% only
HOW TO DETERMINE PARAMETERS?
SHORT CIRCUIT TEST
Resistive heating losses in the primary and secondary winding of transformer. Proportional to square of current.
Resistive heating losses in the core of transformer. Proportional to square of voltage applied to transformer.
Associated with magnetic domains in the core. It is a function of voltage applied to the transformer.
Flux escape from the core and pass through only one side of the transformer. Its produce leakage inductance in the primary and secondary winding.
1. Select 2 base quantities
- usually selected - voltage and power
2. Use electrical law
Eliminates the need for voltage-level conversions and impedance transformation at every transformer.
Machine and transformer impedances fall within a fairly narrow range according to voltage and power ratings of the device.
Text book page 93
Voltage and Current Relationship
Apparent Power Rating
The Internal Impedance