Contents
Why are there different equations for transformer design?
The transformer design equation only differs between the 3 due to what is known as a “voltage factor”. This equation can be found online in many places but what I’ve yet to see anywhere in the derivation of this voltage factor for these different types of applied voltage input waveforms.
How to calculate the differential protection of a transformer?
Let us examine the response of our transformer differential protection on through fault conditions. Consider a single line-to-ground through fault as shown on the figure below. The currents seen by the relay are affected by the CT ratio and connection hence the values of the secondary currents before compensation.
How to calculate the tap of a transformer?
The tap values can be calculated per the following equation: Case1: Consider a transformer differential protection scheme with a FULLY LOADED transformer. Let the winding currents on CT secondary be as follows for normal full load current draw from the transformer.
How to calculate differential protection for Delta wye transformer?
We will start the transformer differential protection calculation with the identification of the transformer vector group. For this example, we have a 25/33MVA 69/23kV Delta-Wye Transformer with vector group, Dyn1. We will apply wye connected CTs on both sides of the transformer.
How are the windings of a transformer connected?
A transformer transfers electric power from one circuit to another circuit without a change in frequency. It contains primary and secondary winding. The primary winding is connected to the main supply and secondary to the required circuit.
What do you need to know about a control transformer?
Control transformer: For sensing the output voltage and for power supply. Here we take the reference of winding data on enameled copper wire table and dimensions of transformer stampings table to select input and output windings SWG and core of the transformer for given specifications.
What kind of voltage forms are used in Transformers?
The usual voltage forms are sinusoids as seen in lower frequency silicon steel type transformers such as UL Class 2 recognized power transformers. It is also useful for higher frequency switching transformers such as push-pull transformers or flyback transformers.