Unit 65
Utilisation of Electrical
Energy
Assignment 1b
Power Transformer Analysis
By Ian Greene
Contents
Assignment Brief: - 3
Single-Phase Transformer 4
PolyPhase Transformer 5
Star-Star (Y-Y) Connection Mode 6
Delta-Star (∆-Y) Connection Mode 8
Delta-ZigZag (∆-Z) Connection Mode 10
Sources/References …show more content…
Winders, Jr
In a Y-Y transformer the zero-sequence magnetizing currents produced by the odd harmonics all meet neutral point producing the current that goes through the neutral going back to the voltage supply. It also stops any distortion in the secondary phase voltages as the magnetic flux in the core of the transformer has a sinusoidal waveform and since the voltages are induced by the flux it will also give a sinusoidal waveform for the voltage stopping any distortion.
Star-Star (Y-Y) Transformer without grounded neutral
Power Transformers Principles and Applications by John J. Winders, Jr
With no grounded neutral it means there is no path for the zero-sequence magnetizing currents that causes a voltage distortion in the secondary phases that also results in a higher unwanted voltage in the windings.
Delta-Star (∆-Y) Connection mode
In a ∆-Y connected transformer the input primary side is delta that is three phases all connected phase to phase without a neutral and the output secondary side is wired in star that consists of three separate phases only connected by a common grounded neutral …show more content…
https://electricalnotes.wordpress.com/2012/05/04/zig-zag-connection-of-transformer/[24/10/17]
On the zigzag when three currents all equal and are in phase is applied on the zigzag transformer the ampere turns of each winding all cancel the ampere turns of each other which allows the in phase currents to flow to the neutral connected to all three phases. If the same is applied but the currents are 120° out of phase with each other then current isn’t allowed to flow since the windings haven’t canceled each other out.
A ∆-Z provides both third harmonic suppression and ground current isolation since it incorporates features from ∆-Y transformer but it also provides a bonus that the others don’t that is there is no phase angle displacement between the primary input and secondary
Utilisation of Electrical
Energy
Assignment 1b
Power Transformer Analysis
By Ian Greene
Contents
Assignment Brief: - 3
Single-Phase Transformer 4
PolyPhase Transformer 5
Star-Star (Y-Y) Connection Mode 6
Delta-Star (∆-Y) Connection Mode 8
Delta-ZigZag (∆-Z) Connection Mode 10
Sources/References …show more content…
Winders, Jr
In a Y-Y transformer the zero-sequence magnetizing currents produced by the odd harmonics all meet neutral point producing the current that goes through the neutral going back to the voltage supply. It also stops any distortion in the secondary phase voltages as the magnetic flux in the core of the transformer has a sinusoidal waveform and since the voltages are induced by the flux it will also give a sinusoidal waveform for the voltage stopping any distortion.
Star-Star (Y-Y) Transformer without grounded neutral
Power Transformers Principles and Applications by John J. Winders, Jr
With no grounded neutral it means there is no path for the zero-sequence magnetizing currents that causes a voltage distortion in the secondary phases that also results in a higher unwanted voltage in the windings.
Delta-Star (∆-Y) Connection mode
In a ∆-Y connected transformer the input primary side is delta that is three phases all connected phase to phase without a neutral and the output secondary side is wired in star that consists of three separate phases only connected by a common grounded neutral …show more content…
https://electricalnotes.wordpress.com/2012/05/04/zig-zag-connection-of-transformer/[24/10/17]
On the zigzag when three currents all equal and are in phase is applied on the zigzag transformer the ampere turns of each winding all cancel the ampere turns of each other which allows the in phase currents to flow to the neutral connected to all three phases. If the same is applied but the currents are 120° out of phase with each other then current isn’t allowed to flow since the windings haven’t canceled each other out.
A ∆-Z provides both third harmonic suppression and ground current isolation since it incorporates features from ∆-Y transformer but it also provides a bonus that the others don’t that is there is no phase angle displacement between the primary input and secondary