Shielded Winding
A transformer winding with shielding to reduce surge voltage stress and improve impulse distribution.
Shielded windings incorporate elements to improve impulse voltage distribution during transients and provide electrostatic isolation.
During steep impulse waves, capacitances to ground cause non-uniform distribution—first turns may see 50-80% of total voltage. Methods: electrostatic screens, interleaved disc windings, continuous tapes.
Essential for frequent switching, lightning-prone areas (high BIL), GSU transformers.
QDTB employs advanced shield designs in all power transformers for uniform impulse distribution. See Faraday shield for inter-winding shielding.
Related Products
Related Terms
BIL (Basic Impulse Level)
The ability of transformer insulation to withstand high-voltage surges from lightning or switching, measured in kV peak.
Lightning Impulse Test
A high-voltage test simulating lightning surges to verify transformer insulation withstands transient overvoltages.
Winding
Coils of insulated conductors in a transformer carrying current and linking magnetic flux for energy transfer.
Faraday Shield
An electrostatic shield between transformer windings blocking capacitive coupling of high-frequency noise.
More Terms Starting with “S”
Step-Up/Step-Down Transformer
Transformers increasing (step-up) or decreasing (step-down) voltage levels based on the turns ratio.
Short-Circuit Impedance (%Zsc)
Transformer impedance measured with one winding short-circuited, determining fault current and regulation.
Substation
A facility housing transformers, switchgear, and protection for voltage transformation and power routing.
Solar Transformer
A transformer optimized for solar PV plants handling inverter harmonics and variable loading.
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