VPI Dry-Type Transformer: The new choice for eco-friendly, efficient, and safe power transmission!
01 General
1.1 Project Description
This 1000kVA vpi transformer is exported to South Africa in July, 2024. The vector group of this transformer is Dyn11. Dyn11 connection method, high voltage quality, neutral point does not drift. The primary voltage is 11 kV, the secondary voltage is 0.55 kV, the transformer is equipped with no load tap changer, the tapping range is ±2*2.5% at primary side, the cooling is ONAN/ONAF.
The dry type transformer has the characteristics of compact flame retardant structure, low running noise, light weight, small footprint, low loss, safety, stability, high heat resistance and strong overload capacity. With its excellent performance has been welcomed by the domestic market, products are exported to the European Union, North America, the Middle East and other global economic developed regions.
1.2 Technical Specification
1000 kVA vpi transformer specification and data sheet
| Delivered to | South Africa |
| Year | 2024 |
| Model | 1000KVA-11/0.55KV |
| Type | Opening winding dry type transformer |
| Standard | IEC60076 |
| Rated Power | 1000KVA |
| Frequency | 50HZ |
| Phase | 3 |
| Cooling Type | AN/AF |
| Primary Voltage | 11KV |
| Secondary Voltage | 0.55KV |
| Winding Material | Aluminum |
| Impedance | 6% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5%@primary side |
| No Load Loss | 1.8KW |
| On Load Loss | 9.1KW |
| Accessories | Standard Configuration |
| Insulation level | H |
| Basic impulse lighting withstand voltage-primary side (BIL) | 75KV |
| Power frequency withstand voltage-primary side | 35KV |
| Basic impulse lighting withstand voltage-secondary side (BIL) | / |
| Power frequency withstand voltage-secondary side | 3KV |
| Winding temperature rise @ rated service condition | 100K |
1.3 Drawings
1000 kVA vpi transformer diagram drawing and size.
02 Manufacturing
2.1 Core
| The iron core adopts high permeability magnetic grain orientation cold rolled silicon steel sheet (CRGO), full oblique non-hole binding, built-in pull plate structure, accurate geometric design, determine the material characteristics of the magnetic sheet to be used and many details, including vibration control, tilt position and other mechanical requirements and other design measures, so that the open dry transformer appearance is beautiful and clean, low no-load current, small no-load loss. Low noise. |  |
2.2 Winding
 | The high voltage coil adopts the continuous winding structure, the coil heat dissipation is good, so that the overload capacity of the transformer is stronger, and the high surge voltage is handled reliably. The low-voltage coil is foil, and the temperature distribution in the winding is balanced, which enhances the stability of the coil and improves the short-circuit resistance. The coil uses a unique vacuum pressure impregnated H-class flame retardant paint, and is cured at high temperature, and the surface can be dustproof, moisture-proof and stain-proof. |
2.3 Final Assembly
| Winding placement: the primary winding and secondary winding are installed on the iron core according to the design requirements. Winding connection: Connect the winding terminal according to the electrical drawing to ensure the connection is stable. Insulation materials: Place the insulation materials (such as insulating paper and insulating oil) according to the design requirements to ensure the integrity of the insulation system. Insulation test: insulation resistance test is performed to ensure that the insulation system complies with technical specifications. Fans or coolers: Install the transformer’s fans or coolers to ensure that the cooling system can effectively dissipate heat. Shell fixation: Install the shell or guard of the transformer in place to ensure that the shell is sealed with the main body of the transformer. Cable connection: Connect the high and low voltage cables of the transformer to ensure that the electrical connection is strong and meets safety standards. Grounding: Perform grounding treatment to ensure that the grounding system of the transformer is good. |  |
03 Testing
| No. | Test Item | Unit | Acceptance Values | Measured Values | Conclusion | |
| 1 | Measurement of winding resistance | / | Maximum resistance unbalance rate Line resistance: ≤2% | HV (line) | LV (line) | Pass |
| 0.20% | 0.98% | |||||
| 2 | Measurement of voltage ratio and check of phase displacement | / | The tolerance of voltage ratio on the principal tapping: ±1/10 Connection symbol: Dyn11 | -0.03% ~ 0.09% Dyn11 | Pass | |
| 3 | Measurement of Short-circuit Impedance and Load Loss | / kW kW | t: 120℃ Z%: measured value Pk: measured value Pt: measured value | 6.24% 6.28 7.909 | Pass | |
| 4 | Measurement of No-load Loss and Current at 90% and 110% of rated voltage | / kW | I0 : provide measured value P0: provide measured value | 90% Ur | 110% Ur | Pass |
| 0.378% | 0.462% | |||||
| 1.3734 | 1.6786 | |||||
| 5 | Applied Voltage Test | / | HV: 35kV 60s LV: 3kV 60s | No collapse of the test voltage occurs | Pass | |
| 6 | Induced Voltage Withstand Test | / | Applied voltage (kV): 2 Ur Induced voltage (kV): 1.1 Duration(s): 40 Frequency (HZ): 150 | No collapse of the test voltage occurs | Pass | |
| 7 | Partial Discharge Test | pC | The maximum level of partial discharges shall be 10 pC | ＜10 | Pass | |
04 Packing and Shipping
05 Site And Summary
Thank you for your interest in vpi transformer! Our products are widely recognized for their outstanding performance, superior reliability, and versatile designs tailored to diverse needs. Whether for industrial, commercial, or specialized applications, VPI dry-type transformers deliver efficient, safe, and long-lasting power solutions. We look forward to becoming your trusted partner in driving smart power solutions and a sustainable future. For more information or customized services, please feel free to contact us at any time!
