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Which type of transformer is used for distribution purpose?
Delta/delta
Star/star
Star/delta
Delta/star
Delta/star
Distribution transformers typically employ a Delta/Star (or ╬ФтИТY) configuration to provide both three-phase and single-phase supply to consumers. The primary winding is delta-connected to allow for three-wire input, while the secondary star connection provides a neutral wire for single-phase loads.
Distribution transformers typically employ a Delta/Star (or ╬ФтИТY) configuration to provide both three-phase and single-phase supply to consumers. The primary winding is delta-connected to allow for three-wire input, while the secondary star connection provides a neutral wire for single-phase loads.
VlineтАЛ=3тАЛ├ЧVphaseтАЛ тАФ Line to phase voltage relation in star secondary
IlineтАЛ=3тАЛ├ЧIphaseтАЛ тАФ Line to phase current relation in delta primary
The Delta connection on the high-voltage side reduces the number of turns required for the primary winding, resulting in economic insulation. The Star connection on the secondary side allows for a neutral point, which is crucial for balanced and unbalanced loading. This configuration allows for a line voltage of VLтАЛ and phase voltage of VphтАЛ, where VLтАЛ=3тАЛVphтАЛ, providing stability for residential and commercial distribution.
The neutral point in the Star connection enables the availability of two voltages (Phase voltage 230V and Line voltage 400V).
It allows the supply of single-phase loads between phase and neutral, and three-phase loads between phases.
This configuration is highly effective for unbalanced loads often found in distribution networks.
Provides both single-phase and three-phase power.
Neutral point can be grounded for safety.
Handles unbalanced loads efficiently.
Secondary side cannot be delta-connected to provide neutral.
Higher risk of circulating currents if harmonics are not managed.
Local area distribution networks.
Industrial power supply substations.
Commercial complexes requiring mixed-phase supply.
Delta/Delta transformers are often used for high-voltage transmission where no neutral is required.
Star/Star transformers are rarely used in distribution due to difficulty in handling unbalanced loads and issues with third-harmonic current.
D is correct тАФ The Delta/Star configuration provides a neutral point necessary for supplying single-phase distribution loads in a three-phase system.
Always remember: 'Delta-Delta' is for transmission/bulk power, while 'Delta-Star' is for distribution because it provides the mandatory neutral wire for single-phase appliances.