English
RFQ

Download the app

What is Transformer Vector Groups?

Edwiin

06/02/2025

Transformer Vector Group Definition

The transformer vector group denotes the phase difference between the primary and secondary sides of a transformer, while also defining the arrangement of high-voltage and low-voltage windings in three-phase transformers. Vector groups are determined by the connection configurations of three-phase transformers, which can be categorized into four main groups based on the phase difference between corresponding line voltages of the high-voltage and low-voltage sides.

The phase difference—defined as the angle by which the low-voltage line voltage lags the high-voltage line voltage, measured in 30° increments clockwise—establishes the following groups:

Group 1: No phase displacement
Group 2: 180° phase displacement
Group 3: (-30°) phase displacement
Group 4: (+30°) phase displacement

For example, the connection Yd11 specifies:

"Y" = High-voltage windings in star configuration
"d" = Low-voltage windings in delta configuration
"11" = Low-voltage line voltage lags high-voltage line voltage by 11×30°=330°(clockwise from the high-voltage phasor).

Clock Method for Phasor Difference Measurement

The clock method visualizes phase differences as clock dial positions:

High-voltage windings = Minute hand
Low-voltage windings = Hour hand
30° (the angle between adjacent clock dial numbers) serves as the unit of phase shift.

Clock Method Phase Displacement Interpretation

When the hour hand points to 12, the phase displacement is 0°.
At hour position 1, the phase shift is -30°.
At hour position 6, the phase shift equals 6×30°=180°.
At hour position 11, the phase shift is 11×30°=330°.

The group reference numbers (0, 6, 1, 11) denote primary-to-secondary phase shifts corresponding to clock hours. For instance, a Dy11 connection (delta-star transformer) indicates the low-voltage line phasor at hour 11, which is +30° phase-advanced relative to the high-voltage line voltage.

Parallel Connection Requirement

Key Note: Only transformers within the same vector group can be connected in parallel.

Examples:
- Star-star (Y-Y) transformers can parallel with other Y-Y or delta-delta (∆-∆) transformers.
- A ∆-∆ transformer cannot be paralleled with a Y-∆ transformer due to incompatible phase shifts.

Topics

Machines Transformer

Edwiin

Hello，I'm Wdwiin. A decade of hands-on experience in electrical engineering, specializing in high-voltage systems, smart grids, and renewable energy technologies. Passionate about technical exchange and knowledge sharing, committed to interpreting industry trends with professional insights to empower peers. Connection creates value—let’s explore the boundless possibilities of the electrical world together!

Can a power transformer designed for 50Hz operate normally at a frequency of 60Hz?

Can a power transformer designed for 50Hz operate normally at a frequency of 60Hz?

Can a 50Hz-Designed Power Transformer Operate on 60Hz Grid?If a power transformer is designed and built for 50Hz, can it run on a 60Hz grid? If so, how do its key performance parameters change?Key Parameter ChangesShort-Circuit Impedance:For a given transformer (same voltage and capacity), short-circuit impedance is proportional to frequency. Thus, a 50Hz-designed unit operating at 60Hz sees a 20% increase—higher frequency intensifies alternating leakage field opposition to current.No-Load

What are the basic processes and key points in transformer simulation design?

What are the basic processes and key points in transformer simulation design?

1 IntroductionWhether using any finite element analysis software (such as COMSOL, Infolytica, or Ansys) for transformer simulation analysis—whether focusing on electric field, magnetic field, flow field, mechanical field, or acoustic field—the basic process is roughly the same. A true understanding of the key points in each process is the foundation for the success of the simulation analysis and the reliability of the final results.2 Basic Simulation ProcessA scientific and complete

Sharing of Transformer Concepts and Terminology

Sharing of Transformer Concepts and Terminology

Sharing of Transformer Concepts and TerminologyThe zero-mode impedance of a load is infinite, and its line-mode impedance is also extremely large, approximately 100 times that of the line-mode impedance of the line.The capacitance to ground of a cable is 25-50 times that of an overhead line.The free oscillation frequency of transient capacitive current: 300-1500Hz for overhead lines and 1500-3000Hz for cables.Performance requirements for an external grounding transformer: Under normal power supp

Example of Process Improvement for Enhancing Consistency of Small - Batch High - Temperature Special Transformers

Example of Process Improvement for Enhancing Consistency of Small - Batch High - Temperature Special Transformers

Given the lack of manufacturers for such transformers on the market, we design them in - house. We provide technical specs to partners, specifying materials like high - temp enameled wires.Electrical signals from downhole logging tools, transmitted via these transformers, impact formation - to - surface signal reliability. Thus, improving transformer consistency boosts signal uniformity, enhancing logging tool accuracy and our market competitiveness.Our common signal transformers are EI - type,

Source professional electrical partners, experts, and explore smart grid & energy solutions.