No item in cart
Phasor Connection of Three Phase Transformers | Electrical Machine | GATE Preparation | EE
Real Life Application
The application of Phasor connection of Three Phase transformers is very important in the transmission and distribution of Power. It is the three phase system which has been adopted world over to generate, transmit and distribute electrical power. Therefore to change the level of voltages in the system three phase transformers should be used. Whenever a transformer is installed for transmission or distribution, the phase difference is one of the deciding factors for the type of transformer to be chosen.
To understand the concept with clarity it’s important to have basic idea of working of Transformers and Three Phase Circuits.
Three number of identical single phase transformers can be suitably connected for use in a three phase system and such a three phase transformer is called a bank of three phase transformer. Alternatively, a three phase transformer can be constructed as a single unit.
In a single phase transformer, we have only two coils namely primary and secondary. Primary is energized with single phase supply and load is connected across the secondary. However, in a 3- phase transformer there will be 3 numbers of primary coils and 3 numbers of secondary coils. So these 3 primary coils and the three secondary coils are to be properly connected so that the voltage level of a balanced 3-phase supply may be changed to another 3-phase balanced system of different voltage level.
The possible connections of three phase transformers are Star Star, Star Delta, Delta Star, Delta Delta. For example Star Delta means primary side has Star connection and secondary side has Delta.
The secondary voltages of a 3-phase transformer may undergo a phase shift of either +30° leading or -30° lagging or 0° i.e, no phase shift or 180° reversal with respective line or phase to neutral voltages. On the name plate of a three phase transformer, the vector group is mentioned. Typical representation of the Vector Group could be Yd1 or Dy11 etc. The first capital latter Y indicates that the primary is connected in star and the second lower case latter d indicates delta connection of the secondary side. The third numerical figure conveys the angle of phase shift based on clock convention. The minute hand is used to represent the primary phase to neutral voltage and always shown to occupy the position 12. The hour hand represents the secondary phase to neutral voltage and may, depending upon phase shift, occupy position other than 12 such as 6 or 1 or 11.
For any given three phase transformer the phase difference can be found out from the connection of the primary and secondary terminals, which is explained in this video lecture.
THE GATE Academy questions covered a wide variety of topics and were similar to GATE paper standard. The online platform replicated the actual GATE test environment and the detailed and video solutions were sufficient to clear all doubts regarding the question. Thanks to THE GATE Academy team to provide such wonderful tests & platform.
E Lectures helped me a lot in making a head start in the right direction. It helped whenever I got stuck in any topic. Mock Tests across 50 centers helped me judge my progress both on individual and comparative basis.
To begin with, it gives me immense pleasure to Thank,Thank the institute THE GATE ACADEMY for all their help and support.Its a place to learn, explore, grow and succeed.Well it helps you brush-up your engineering knowledge and learn new things and clears your concept in such great details
In one year’s time, I was able to prepare for GATE exam with the help of THE GATE ACADEMY and faculties. GATE Focused study materials and online mock tests helped me know my strengthen & weakness to prepare accordingly. I wish all the best to all GATE aspirants and suggest them to go through GATE coaching in case the basics are not clear.
I am Praveen. I got AIR 1 in Instrumentation stream. I want to dedicate this to my parents and to the Gate Academy faculty. Gate Academy coaching helped me tremendously to update myself continuously.I was very impressed with the way they taught each topic in different sessions with separate material for each session.
I took up mechanical coaching at THE GATE ACADEMY as there is no separate coaching for Engineering Sciences in India and Mechanical and Engineering sciences have more or less common topics.I feared that cracking GATE would be very difficult because I started my preparations very late but the counsellors and teachers guided me
GATE Success Story
- Our students get all India rank 1, 1, 1, 1, 4 and 4
- More than 142 students in top 100.