MD – NIPP Lauds Skipper’s Leadership in Nigerian Power Sector


Setting Another Milestone: Successful Manufacturing and CPRI Type Testing of 60 MVA 145 kV class Transformer at Skipper’s Bhiwadi Plant

Skipper manufactures the entire range of products required in a HV substation namely: Transformers, Circuit breakers, CTs, PTs, Isolators and HT and LT Control and Relay Panels.
We also manufacture special duty products namely:
Rectifier Transformers, Furnace transformers, Earthing transformer and distribution transformer using CRGO steel or Amorphous steel.
All products are, at present, meant for LV and HV applications. A newly-built, modern plant is under construction at Bhiwadi India for manufacture of products in Extra High voltage classes, on a plot of Land measuring 40,000 sq. m.

Manufacture and Type Testing of Power Transformer
Skipper secured an order for a turnkey project at Gurada in Nigeria. Supply, erection and commissioning of 2 Nos. 60 MVA transformers as per specifications given hereunder was included in the awarded contract.

Rating : 40/50/60 MVA
Cooling : ONAN/ONAF/ONAF, Vector Group :
Voltage Ratio : 132/34.5 kV
Taps : on HV for Variation of HV Voltage

The Challenge

The application of the transformer is to evacuate power from a gas/hydro generating station for local distribution load at 33kV which calls for a very sturdy and reliable design of transformer. The client expectation was to supply the product duly type-tested for a high fault current capacity with a high operating reliability.

Important aspects of Design

Skipper 60 MVA Transformer
Skipper 60 MVA Transformer

The design has to provide for
• adequate dielectric strength,
• adequate SC strength, and
• adequate thermal ability,
• taking into consideration challenges imposed by local & climactic conditions (temperature, humidity etc.)

Most common arrangement and type of coils

The arrangement of coils most commonly employed for this specification of design is :

• LV (double disc type) as innermost coil concentric with limb
• HV (interleaved / partially interleaved type), 2 coils in parallel with main lead at the centre
• Regulating (discs type), 2 coils in parallel, placed outermost

Main lead take-out poses some threats to dielectric design. Also the SC strength suffers due to axial gap in regulating winding.

Skipper 60 MVA transformer
Winding process

Skipper’s Choice of Position of Regulating Winding

We chose the following coil positions :

LV : Double disc type as innermost coil concentric with limb
Regulating : Multi-start spiral concentrically placed between LV and HV
HV (interleaved), 2 coils in parallel with main lead in centre

No other factor influences the overall strength of transformer as much as the choice of position of the regulating winding viz. a viz. HV and LV windings.

The multi-start regulating winding placed concentrically between LV and HV offers the best dielectric and the highest SC strength. However, since this winding is placed in high leakage field, it results in high eddy losses. This was taken care of through the use of CTC.

Design Verification/Review of Design : This was carried out as per plan.

Emphasis on QC : This was carried out religiously at all stages of production right from selection
of Vendors.

Commitment to Set Goals

Executives staff and employees were fully committed to see by body during the all process of design and manufacture. There was no hesitation in stepping back to see if the process was carried out as planned.

Satisfaction of Achievement

When the unit passed all the Routine, Type and Special tests, the satisfaction of Skipperites surely surpassed any physical award. These transformers are successfully installed on site to the complete satisfaction of the client.

Skipper Commences Civil Construction of Unit-V at Kaharani Industrial Area, Bhiwadi

Bhoomi Pujan (Earth Breaking Ceremony) & commencement of civil construction for the project Transformer Factory and Associated Works at Kaharani Industrial Area, Bhiwadi, Rajasthan was done on Wednesday, 9 July 2014, at 10:30am. The function was conducted by Very Rev. M S Skariah Ramban, Diocesan Secretory- St. Basil Orthodox Church, assisted by Rev. Fr. Thomas Varghese.

Ground Breaking Ceremony of Unit V Bhiwadi India
Very Rev. M S Skariah Ramban conducting the Ground Breaking Ceremony

The products that will be manufactured at this new facility include EHV transformers upto 315MVA/400kV, Dry Type Distribution Transformers upto 5MVA 11/33kV, GIS & HGIS upto 220kV and Current and Voltage Transformers upto 220kV in the phase-1, whereas in phase-II, we shall have 765kV range of Power Transformers and Instrument Transformers.

The ceremony witnessed heavy participation from employees of Skipper Electricals (India) Ltd. The team was led by Mr. Deepak Kashyap, COO – Skipper Electricals (India) Ltd. Mr. Siddhant Sachdeva, Executive Manager – Skipper t&d. along with Mr. Bisht, DVP-EPC and Mr. Anil Kumar Choudhary, Assistant Manager – Civil, who conducted the formal meeting thereafter.

We heartily congratulate the project team:

1. Project Director – Mr. Winnie Thomas (M. Engg – Civil Engineering Design & MSc. Construction Project Management)
2. Project Manager – Mr. J K Gautam
3. Senior Manager – Mr. Sanjay Kant
4. Store Manager – Mr. Kunjumon
5. Senior Labour Supervisor – Mr. Kamlesh Sharma
6. Procurement and Local Coordinator – Mr. Sunder Singh