The price is set per project. It follows the rating and winding arrangement first, then the tap changer, loss level, cooling and accessory makes. For a quotation, send the voltage ratio (with the MV voltage for a three-winding unit), the rating, the tap changer and range, the vector group and impedance, the loss level or the owner’s loss evaluation, the grid frequency, the site altitude and temperatures, and the document requirements.
220 kV Oil-Immersed Power Transformer
For substation contractors and utilities — 220 kV main transformers from 31.5 to 420 MVA, with the GIS, control and MV switchgear E-Houses to match.
Renewable Energy Collector Station SupportRenewable Grid-Connection Power DistributionSecondary Equipment E-HousePrimary Equipment E-House
Key Metrics
31500–420000kVA
Rated power
220 / 230 / 242kV
High voltage
±5 / ±10%
Tap range
S22 / S20 / S18
Loss levels
Product Features
Up to 420 MVA
Ratings span 31.5 MVA to 420 MVA across six series, and the two-winding off-circuit series continues past 300 MVA for the largest stations.
Up to 420 MVA
Ratings span 31.5 MVA to 420 MVA across six series, and the two-winding off-circuit series continues past 300 MVA for the largest stations.
On-load regulation
On-load units keep the secondary voltage on target as load and generation change, regulating ±10% in 1.25% steps without an outage.
Impedance by duty
Three-winding units come arranged for step-down substations or, in the off-circuit series, for step-up stations, so the impedance between windings matches the station’s role.
Autotransformer
Where 220 kV meets 110 kV, the autotransformer runs with markedly lower losses: 33 kW no-load and 311 kW load loss at 150 MVA, against 59 kW and 438 kW for an on-load three-winding unit.
Three loss levels
Every rating is listed at S22, S20 and S18, so the offer can follow the owner’s loss evaluation instead of one fixed design.
Product Details
S marks a three-phase unit. F and P are added when the transformer is fan-cooled or has forced-oil circulation, and Z when it has an on-load tap changer; off-circuit units leave Z out. The next figure is the loss level — 22, 20 or 18 — followed by the rated power in kVA and the voltage class in kV. SFPZ22-180000/220, for example, is a fan-cooled, forced-oil, on-load unit at loss level 22, rated 180 MVA at 220 kV.
Two-winding units serve one secondary voltage. The off-circuit series runs from 31.5 MVA to 420 MVA at 220 kV or 242 kV, with LV from 6.3 kV to 20 kV set by rating; a second off-circuit series has 63, 66 or 69 kV LV up to 240 MVA. On-load units reach 180 MVA with LV up to 38.5 kV, and 240 MVA with 66 or 69 kV LV. Three-winding units add a 69, 115 or 121 kV medium-voltage winding to a 6.3–38.5 kV LV winding, off-circuit up to 300 MVA or on-load up to 240 MVA. The on-load autotransformer links 220 kV with 115 or 121 kV and carries a 6.3–38.5 kV tertiary winding, also up to 240 MVA.
Off-circuit units have five HV tap positions at ±2×2.5%, selected with the transformer de-energised. On-load units carry an on-load tap changer with ±8×1.25% — 17 positions over ±10% — switched under load. The tap changer adds little to the losses: at 180 MVA and loss level S22, an on-load two-winding unit has 59 kW no-load loss against 56 kW off-circuit, with the same 413 kW load loss.
Two-winding units have 12–14% impedance. A three-winding unit has three pairs, set by the station’s duty: for a step-down substation HV–MV is 12–14%, HV–LV 22–24% and MV–LV 7–9%; the off-circuit series is also offered for step-up duty, with HV–MV at 22–24% and HV–LV at 12–14%. The autotransformer pairs a low 8–11% HV–MV impedance with 28–34% HV–LV and 18–24% MV–LV.
Each rating is listed at loss levels S22, S20 and S18. S22 and S20 share the same load loss and differ in no-load loss; S18 adds 5–6% load loss as well. At 180 MVA, two-winding off-circuit, the no-load losses are 56, 66 and 82 kW and the load losses 413, 413 and 436 kW. No-load current falls as ratings rise, from 0.71% at 31.5 MVA in the 66 kV-LV series to 0.24% at the top of the three-winding off-circuit and autotransformer ranges.
Delivery Scope Options
Scope 1
Single Unit or Complete Package Supply
Scope 1Single Unit or Complete Package Supply
Transformers are supplied as single units against the order schedule, or as a complete package together with the protective enclosure, the temperature controller and the cooling fans. The active part is wound, assembled and routine-tested at the works and shipped as a complete unit; the assembly interface for the accessories follows the transport conditions. Where the transformer is to arrive together with a prefabricated power module, the E-House line takes on the enclosure, the internal arrangement and the foundation fixing, and the transformer is delivered as equipment housed within it.
Scope Includes:
Single unit or complete package
Complete-unit shipment and assembly interface
Foundation and fixing interface
In-cabin delivery handled by the E-House line
Technical Specifications
Product form
Three-phase oil-immersed power transformer: two-winding, three-winding or autotransformer, with off-circuit or on-load tap changing
Type designation
S(F)(P)□-□/220 off-circuit; S(F)(P)Z□-□/220 on-load (loss level code, rated power in kVA, voltage class)
Rated power, two-winding off-circuit
31.5–420
MVA
Rated power, two-winding off-circuit, 66 kV LV
31.5–240
MVA
Rated power, three-winding off-circuit
31.5–300
MVA
Rated power, two-winding on-load
31.5–180 (LV up to 38.5 kV); 120–240 (LV 66 or 69 kV)
MVA
Rated power, three-winding on-load
31.5–240
MVA
Rated power, on-load autotransformer
31.5–240
MVA
High voltage
220 or 242 (two-winding off-circuit); 220, 230 or 242 (three-winding off-circuit); 220 or 230 (other series)
kV
Medium voltage
69, 115 or 121 (three-winding); 115 or 121 (autotransformer)
kV
Low voltage
By series and rating: 6.3–20 (two-winding off-circuit); 63, 66 or 69 (66 kV-LV series); 6.3–38.5, or 66 and 69 (two-winding on-load); 6.3–38.5 (three-winding and autotransformer)
kV
HV tapping
Off-circuit ±2×2.5%; on-load ±8×1.25%
Vector group
YNd11 two-winding; YNyn0d11 three-winding; YNa0d11 autotransformer
Impedance, two-winding
12–14
%
Impedance, three-winding (HV–MV / HV–LV / MV–LV)
Step-down 12–14 / 22–24 / 7–9; step-up (off-circuit) 22–24 / 12–14 / 7–9
%
Impedance, autotransformer (HV–MV / HV–LV / MV–LV)
8–11 / 28–34 / 18–24
%
Losses at 180 MVA, two-winding off-circuit (S22 / S20 / S18)
No-load 56 / 66 / 82; load 413 / 413 / 436
kW
No-load current
0.24–0.71, falling with rating
%
Construction
Three- or five-limb core, disc windings, moulded insulation parts, bell-type tank, expansion-type conservator
Frequency, insulation levels, cooling, sound level, dimensions, mass
Confirmed for the selected rating and project
| Parameter | Specification |
|---|---|
| Product form | Three-phase oil-immersed power transformer: two-winding, three-winding or autotransformer, with off-circuit or on-load tap changing |
| Type designation | S(F)(P)□-□/220 off-circuit; S(F)(P)Z□-□/220 on-load (loss level code, rated power in kVA, voltage class) |
| Rated power, two-winding off-circuit | 31.5–420 MVA |
| Rated power, two-winding off-circuit, 66 kV LV | 31.5–240 MVA |
| Rated power, three-winding off-circuit | 31.5–300 MVA |
| Rated power, two-winding on-load | 31.5–180 (LV up to 38.5 kV); 120–240 (LV 66 or 69 kV) MVA |
| Rated power, three-winding on-load | 31.5–240 MVA |
| Rated power, on-load autotransformer | 31.5–240 MVA |
| High voltage | 220 or 242 (two-winding off-circuit); 220, 230 or 242 (three-winding off-circuit); 220 or 230 (other series) kV |
| Medium voltage | 69, 115 or 121 (three-winding); 115 or 121 (autotransformer) kV |
| Low voltage | By series and rating: 6.3–20 (two-winding off-circuit); 63, 66 or 69 (66 kV-LV series); 6.3–38.5, or 66 and 69 (two-winding on-load); 6.3–38.5 (three-winding and autotransformer) kV |
| HV tapping | Off-circuit ±2×2.5%; on-load ±8×1.25% |
| Vector group | YNd11 two-winding; YNyn0d11 three-winding; YNa0d11 autotransformer |
| Impedance, two-winding | 12–14 % |
| Impedance, three-winding (HV–MV / HV–LV / MV–LV) | Step-down 12–14 / 22–24 / 7–9; step-up (off-circuit) 22–24 / 12–14 / 7–9 % |
| Impedance, autotransformer (HV–MV / HV–LV / MV–LV) | 8–11 / 28–34 / 18–24 % |
| Losses at 180 MVA, two-winding off-circuit (S22 / S20 / S18) | No-load 56 / 66 / 82; load 413 / 413 / 436 kW |
| No-load current | 0.24–0.71, falling with rating % |
| Construction | Three- or five-limb core, disc windings, moulded insulation parts, bell-type tank, expansion-type conservator |
| Frequency, insulation levels, cooling, sound level, dimensions, mass | Confirmed for the selected rating and project |
Product FAQs
Every series includes 31.5, 40, 50, 63, 90, 120, 150, 180 and 240 MVA. The two-winding off-circuit series adds 75 and 160 MVA and continues with 300, 360, 370, 400 and 420 MVA; the three-winding off-circuit series continues to 300 MVA. On-load two-winding units reach 180 MVA with LV up to 38.5 kV, and 120–240 MVA with 66 or 69 kV LV.
It follows the networks the station connects. A single secondary voltage calls for a two-winding unit. A station that feeds both a 110 kV or 66 kV network and a 35 kV or 10 kV bus takes a three-winding unit, arranged for step-down or step-up duty. Where 220 kV meets 110 kV, the on-load autotransformer links the two networks with lower losses and an 8–11% HV–MV impedance, plus a 6.3–38.5 kV tertiary winding.
Off-circuit taps (±2×2.5%) are set with the transformer switched off and suit a steady supply voltage. An on-load tap changer (±8×1.25%, 17 positions) regulates while the transformer carries load, for stations where voltage moves with load or renewable output. On-load units are listed up to 240 MVA; ratings above that are off-circuit.
Yes. The transformer is installed on its own foundation, and the rest of the substation can arrive prefabricated from the ETENZ E-House line: a GIS E-House for the 220 kV or 110 kV switchgear, a control E-House for protection, control and DC systems, and an MV switchgear E-House for the 35 kV or 10 kV side. Interfaces between the transformer and the E-Houses are settled at the same drawing review.
Yes. State the grid frequency, voltage ratio and tap range, vector group, impedance and document language with the order; frequency, insulation levels and cooling are confirmed for the project. Drawings, test records, the packing list and installation and maintenance instructions are prepared to the destination country’s requirements.
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