Three-Phase Transformer Overview

A device that transfers electrical energy between three-phase AC circuits.

A transformer that handles electrical energy between two single-phase circuits.

Core type and shell type.

Three cores, two yokes; windings are spirally wound around each core leg.

Central core with outer windings.

Delta or Wye configurations for primary and secondary coils, can be used in both types of constructions.

Generates, transmits, distributes power using three-phase AC.

Single-unit three-phase transformers are more economical than a bank of individual transformers (3 single-phase transformers).

Principle underlying transformer operation; changing magnetic field in one coil induces voltage in the other.

Thin layers of metal used to minimize eddy current losses.

A three-phase transformer constructed by stacking three single-phase transformers, where each phase has its own magnetic circuit.

Various ways windings of three-phase transformers are connected to the power source and loads.

A three-phase winding configuration where all the minus or all the plus points of the windings are connected together.

A three-phase winding configuration where the polarities are connected in a converse way in a closed loop.

A way to denote the connection types and phase displacement angle between primary and secondary windings of a transformer.

The winding connected to the input voltage source.

The winding connected to the output load.

Delta primary, Star secondary, 30-degree phase shift (secondary leads primary).

Star primary, Star secondary, no phase shift.

Connecting multiple transformers together, requiring careful consideration of vector groups.

A transformer connection using only two transformers in a delta configuration, offering reduced capacity (57.7% of full delta) but cost-effective for temporary or emergency use.

A three-transformer delta connection providing full rated power capacity and better voltage regulation for permanent installations.

A test to verify the transformer's temperature rise under load, ensuring safe operational limits.

Test to determine transformer performance (efficiency, voltage regulation) under operating load conditions

A test to check for imbalances in transformer magnetic circuit; core displacement or winding faults.

Test to determine phase displacement and polarity of transformer windings, crucial for parallel operation of multiple transformers.

Ensures transformer meets the overall power system design and operational requirements.

Transformer designed to operate with three phases of alternating current, common in power distribution.

Increase in temperature of transformer components (windings, oil) under load conditions

The ability of a transformer to maintain stable voltage output despite changes in load.

A transformer with three sets of windings: primary, secondary, and tertiary, each connected to different circuits.

Mechanism to adjust transformer voltage ratio while energized and under load.

Adjusts transformer voltage ratio only when de-energized.

Method for transforming three-phase to two-phase power, or vice versa.

Reduces high voltage to lower voltage for distribution to homes and businesses.

Used to step up or step down voltage in HVAC systems.

Connects different parts of a power system, crucial in electricity delivery.

Provides multiple voltage levels within a single transformer design.

Reduces the need for separate transformers, conserving space and cost.

Better voltage regulation owing to tertiary winding in three-winding transformers.

Loads that require two-phase power for specific industrial processes.

A load distribution across three phases that ensures equal current flow in each phase, improving efficiency in three-phase systems.

A transformer with three separate windings offering multiple voltage levels, increasing flexibility and saving space.

A mechanism that adjusts transformer voltage while the transformer is energized, vital for keeping consistent voltage.

A device that adjusts transformer taps only when the system is de-energized, suitable for less critical voltage control.

A connection that converts three-phase power to two-phase, often used in railway systems and other specialized applications.

Consists of a fundamental sine wave and harmonics from core non-linearity, mostly small compared to the fundamental component.

A high transient current that occurs in transformers during energization, typically short-duration high current.

Generally lower magnitude compared to power transformers due to reduced size and lower kVA rating.

Power transformers handle higher voltages and kVA ratings, while distribution transformers operate at lower voltage levels and lower kVA, serving different purposes within the power system.

A device using electromagnetic induction to transfer electrical energy between three-phase AC circuits.

A transformer with three windings (primary, secondary, tertiary) connected to different circuits.

Mechanism to adjust transformer voltage while energized and under load.

Adjusts transformer voltage ratio when de-energized.

Method to convert three-phase to two-phase power or vice versa.

Steps down high voltage for distribution to consumers.

Used for voltage stepping up or down in HVAC (Heating, Ventilation, and Air conditioning) systems.

Connects different parts of a power system, enabling electricity transport.

Offers improved voltage regulation and flexibility.

Often used in railway electrification for two-phase systems.

Loads requiring two-phase power for specific industrial processes.

Equal distribution of load across three phases in a three-phase system, promoting efficiency.

Fundamental sine wave with harmonics from core non-linearity.

High, transient current during transformer energization.

Transformers handling high voltage and kVA levels in power systems.

Steps down high voltage to lower voltage for distribution to consumers.

Transformer with three windings offering multiple voltage levels.

Adjusts transformer voltage ratio while energized.

Method converting three-phase to two-phase power.

Lower magnitude during energization compared to power transformers due to lower kVA rating.