Yyn0 Vector Group
A vector group with both windings in star with in-phase displacement, used for small distribution transformers.
Yyn0: both HV/LV windings star-connected with neutrals, zero phase displacement.
Characteristics: both provide neutral points for grounding; no delta means no internal path for 3rd harmonics (must flow in supply); Zero-sequence impedance relatively high for three-limb cores.
Used for small distribution transformers (up to ~160 kVA), where both HV/LV grounding required.
Limitations: not suitable for large ratings with single-phase loads (unbalanced causes neutral shift). Dyn11 preferred for larger.
QDTB supplies Yyn0 with appropriate core design. See vector group guide for comparison.
Related Products
Related Terms
Vector Group
Standardized designation of transformer winding connections and phase displacement between HV and LV.
Vector Group Designations
The complete system of winding configuration codes for three-phase transformer system integration.
Three-Phase Transformer
A transformer for three-phase power systems with three winding sets on a common core.
Neutral Point
The common connection point of a star (wye) winding where the three-phase voltage vector sum equals zero.
More in “Design & Engineering”
Altitude Derating
The reduction in transformer capacity and insulation performance required at high altitudes where air density is lower.
Cooling Class (ONAN/ONAF/ODAF)
Standardized codes describing transformer cooling methods: O=Oil, N=Natural, A=Air, F=Forced, D=Directed flow.
Faraday Shield
An electrostatic shield between transformer windings blocking capacitive coupling of high-frequency noise.
Need help with transformer selection?
QDTB engineers can help you choose the right equipment based on your specific requirements