Mudico Energy Private Limited

Mudico Energy Company manufactures high-performance power transformers designed for reliability and efficiency. Our transformers, with ratings up to 20 MVA and primary voltage of 33 kV, are engineered to meet IEC 60076 and IS 2026 standards. Featuring a Dyn11 vector group, ONAN/ONAF cooling, and an efficiency of over 98% at full load, these transformers ensure optimal performance. With tap changers offering ±10% regulation in 1.25% steps and impedance range of 10-12%, our transformers provide unmatched reliability in power distribution systems.

A 1250 kVA transformer is a substantial piece of electrical equipment used for power distribution in commercial and industrial settings. The specifications can vary significantly based on the manufacturer, application (e.g., substation, pad-mounted, or dry-type), and regional standards (e.g., IEEE, IEC, IS).

Here is a general overview of typical specifications for a 1250 kVA transformer, which can serve as a guide. Always refer to the specific manufacturer's data sheet for precise details.

 

General Specifications

 

•  Rated Power: 1250 kVA

• Phases: 3-phase

   

• Frequency: 50 Hz or 60 Hz

• Cooling Type:

  • Oil-Immersed: ONAN (Oil Natural Air Natural) is common, meaning it's cooled by the natural circulation of the oil and air. Some may use ONAF (Oil Natural Air Forced) or KNAN (Kerosene Natural Air Natural).

  • Dry-Type: AN (Air Natural)

• Insulation Class:

  • Oil-Immersed: Typically Class A ( 105 ∘C) or Class N.

  • Dry-Type: Class F ( 155 ∘C) or Class H ( 180 ∘C).

•  Winding Material: Copper is common for its high efficiency and durability, but aluminum is also an option.

• Core Material: Cold-Rolled Grain-Oriented (CRGO) silicon steel.

• Vector Group: Dyn11 is a very common vector group for this type of transformer. Others include YNd1.

  Electrical Characteristics

• Voltage Ratings: These vary widely depending on the application.Primary (High Voltage - HV): Common voltages include 11 kV, 22 kV, 33 kV, 12.47 kV, or other values as required.Secondary (Low Voltage - LV): Common voltages include 400V, 415V, 433V, 480V, 600V, or 208V/120V.Impedance: The percentage impedance is crucial for fault current calculations and voltage regulation.typical values range from 4% to 6.15%. A common value for a 1250 kVA transformer is often around 5% to 6%.No-Load Loss (Core Loss): This is the power lost when the transformer is energized but not carrying a load. Typical values are in the range of 1.5 kW to 2.35 kW.Load Loss (Copper Loss): This is the power lost in the windings due to the flow of current. Typical values are in the range of 9.5 kW to 16.4 kW.Efficiency: A well-designed 1250 kVA transformer can have a maximum efficiency of over 99%.Temperature Rise:Oil-Immersed: Maximum temperature rise is typically specified as a rise in oil temperature and a rise in winding temperature, for example, 50$^\circ Cinoiland55^\circ$C in winding.Dry-Type: A common temperature rise for a Class F transformer would be 100$^\circCovera40^\circ$C ambient temperature.Basic Impulse Level (BIL): This indicates the transformer's ability to withstand voltage surges. Typical values for the HV side can be 75 kV or higher, and for the LV side, 30 kV or higherTapping Range: This allows for voltage regulation and can be either an off-circuit tap changer (OLTC) or an off-load tap changer (OCTC). A typical range might be ±8% in steps of 2%.

Solar Inverter Duty Transformer

A Solar Inverter Duty Transformer is a specially designed step-up transformer used in grid-connected solar power plants. It is placed between the solar inverter output and the utility grid. Unlike conventional distribution transformers, these transformers are engineered to withstand harmonics, frequent switching, and non-linear loads generated by solar inverters, while ensuring high energy efficiency and reliability.

Key FeaturesVoltage Ratio Options:LV side: 315 V / 400 V / 415 V / 690 V (as per inverter output)HV side: 11 kV / 22 kV / 33 kV (as per grid requirement)Capacity Range: 100 kVA to 10 MVA (customized up to 50 MVA, 220 kV for utility-scale projects)Vector Group: Dyn11 / YNd1 / YNyn0 (as per project requirement)Efficiency Level: BEE 5-Star / IEC 60076 Tier-2 / DOE 2016 compliant (>98.5% efficiency)Design: K-Factor rated to handle inverter harmonics, with enhanced thermal withstand capacityCooling Options: ONAN / ONAF (Oil-Immersed), Dry-Type (Cast Resin / VPI) for indoor or rooftop useConstruction: Copper/Aluminium windings, low-loss CRGO / Amorphous coreDuty Cycle: Continuous rated for renewable energy application.AdvantagesReduces energy losses, ensuring maximum solar plant outputHigh efficiency for better ROI (Return on Investment)Rugged design for 24×7 continuous operationHandles harmonics and voltage fluctuations from invertersAvailable in outdoor and indoor designsEnvironment-friendly with low noise & low losses.ApplicationsGrid-connected solar PV power plants (Rooftop / Ground mounted)Hybrid renewable energy projects (Solar + Wind + Storage)Captive solar plants for industries and commercial complexesMicrogrid and Smart-grid applications.Solar Inverter Duty Transformers ensure smooth integration of renewable solar energy into the power grid with high efficiency, reliability, and long service life.