Kotsons Pvt. Ltd. Motia Khan, Delhi

KOTSONS manufactures a wide range of distribution and medium power transformers. These transformers can be free breathing or hermetically sealed. Conventional transformers are fitted with a conservator with breather for free breathing while hermetically sealed are without breathing with bolted cover. • Applicable standards : IEC / ANSI /BS / IS / SABS/ CENELEC / GOST Wide range of transformers in accordance to above standards with different combinations can be manufactured. The transformers are generally designed and manufactured to comply with the IEC publications 60076., Range : 25 kVA - 3150 kVA, Insulation level £ 12 KV £ 24 KV £ 36 KV • Indoor / Outdoor installation • Conductor : Copper or Aluminum as per customer requirement • Core : CRGO / Amorphous as per customer requirement • 3 D Core type can also be supplied • CSP ( Completely Self Protected ) feature can be provided up to 400 kVA • Maximum ambient temperature : as per customer’s specification • Top oil Temperature rise : as per customer’s specification • Average winding temperature rise : as per customer’s specification • Hermetically sealed type (with gas cushion / fully filled) / Conventional type   (with Conservator) • Color : as per customer’s requirement • Cooling : ONAN/ONAF as per customer’s requirement • Cooling arrangement : Corrugation or Pressed Steel Radiators • On Load Tap Changer with RTCC & AVR, can be provided above 500 kVA, if    required • Safety devices can also be provided upon request • Other optional fittings as required can be provided upon request

Special Purpose Transformers (SPMs) are explained by its name itself, these are made for a specific purpose / application. From designing to manufacturing everything is special and specific. Few types of SPMs are listed below : • Dual Ratio Transformers • Auto Transformers • Rectifier Transformers • Reactor Transformers • Earthing Transformers • LT – LT Transformers • Dual Secondary Transformer for Solar PV Application • Package Sub Station Transformer with RMU & LVDB KOTSONS designs and manufactures custom designed special transformers for industrial and power applications. We offer customized maintenance and service solutions for transformers with state-of-the-art machinery & equipment and testing facilities. In KOTSONS each transformer is designed as a new product and customized to comply with specific customer requirements. The KOTSONS engineering team covers the complete design of a transformer, from designing of core and coils to the tank and the supporting structures with proper cooling system and full protection. Transformer engineering begins from electromagnetic and thermal design of core and windings. This activity is performed by means of standardized calculation sheets developed by our Design Department over the years. 2D and 3D FEM software tools are used for particular studies, such as: short-circuit impedances of phase-shifted multi-winding transformers, eddy current and stray losses calculation due to harmonics, hot-spots calculation and localization on windings and carpentry, mechanical stresses due to short-circuit, insulation assessment. Transformer mechanical design is carried out using 3D software tools allowing dimensions optimization, mechanical stress evaluation and taking into account special external conditions (Seismic Zone, Low Noise Level). Each transformer is supplied with a set of basic documents describing its features and functionalities, such as fabrication drawings, HV/LV connection drawings, auxiliary circuit / schematic wiring diagrams, cooling system drawings, user's manual.

Applicable Standards : IEC / ANSI /BS / IS / SABS/ CENELEC /GOST KOTSONS manufactures wide range of power transformers upto 25 MVA with voltage class of 36 kV. These transformers are generally free breathing type. Oil filled in transformer is PCB free Mineral Oil / Midel 7131 / Silicon Oil / Nynas Nytro, etc. as per customer’s requirements. Wide range of transformers in accordance to above standards with different combinations can be manufactured. The transformers are generally designed and manufactured to comply with the IEC publications 60076. From 3150 kVA to 25000 kVA Insulation level £ 24 kV £ 36 kV • Indoor / Outdoor installation • Conductor : Copper or Aluminum as per customer’s requirement • Core : Generally CRGO type • Amorphous core type can be supplied up to 5000 kVA • 3 D Core type can be supplied up to 5000 kVA • Maximum ambient temperature : as per customer’s specification • Top Oil Temperature rise : as per customer’s specification • Average winding temperature rise : as per customer’s specification • Conventional Conservator Free Breathing type (with dehumidifier / with   air cell (Bladders)) • Color : as per customer’s requirement • Cooling : ONAN/ONAF as per customer’s requirement • Cooling arrangement : Corrugation or Pressed Steel Radiators • Altitude : as per customer’s requirement • On Load Tap Changer with RTCC & AVR, can be provided above 500 kVA, if   required • Safety devices can also be provided upon request • Other optional fittings as required can be provided upon request

Manufactures wide range of power transformers upto 25 MVA with voltage class of 36 kV. These transformers are generally free breathing type. Oil filled in transformer is PCB free Mineral Oil Midel 7131 Silicon Oil Nynas Nytro, etc. as per customer’s requirements. Wide range of transformers in accordance to above standards with different combinations can be manufactured. The transformers are generally designed and manufactured to comply with the IEC publications 60076.

Special Purpose Transformers (SPMs) are explained by its name itself, these are made for a specific purpose application. From designing to manufacturing everything is special and specific. Few types of SPMs are listed below : Transformer engineering begins from electromagnetic and thermal design of core and windings. This activity is performed by means of standardized calculation sheets developed by our Design Department over the years. 2D and 3D FEM software tools are used for particular studies, such as: short-circuit impedances of phase-shifted multi-winding transformers, eddy

A wide range of distribution and medium power transformers. These transformers can be free breathing or hermetically sealed. Conventional transformers are fitted with a conservator with breather for free breathing while hermetically sealed are without breathing with bolted cover. Wide range of transformers in accordance to above standards with different combinations can be manufactured. The transformers are generally designed and manufactured to comply with the IEC publications 60076.

Open Ventilated Dry Type (OVDT) Vacuum Pressure Impregnated (VPI) Eco Friendly Transformers KOTSONS was one of the first Indian manufacturer to use the DuPont ReliatraN® branded solution and develop Ventilated Dry Type Transformers in collaboration with E. I. du Pont de Nemours and Company, U.S.A. KOTSONS Eco Friendly VP transformer coils are vacuum pressure impregnated in high temperature varnish. The process includes complete submersion in varnish under vacuum and pressure and regulated curing using PLC controlled equipment to ensure consistency. The finished coils are effectively protected against moisture, dirt, and most industrial contaminants. A 220°C Class NOMEX® Listed insulation system is used on KOTSONS OVDT VPI transformers regardless of specified temperature rating. This system accommodates a standard temperature rise of 155°C. Optional temperature rises of 90°C and 115°C and fan cooling allow for unsurpassed overload capacity. Salient Features & Advantages of OVDT VPI Dry Transformers: 1. Excellent mechanical and short-circuit strength due to the VPI Process 2. No danger of fire or explosion. No liquids to leak hence no flammable liquid & no oil pollution 3. Less weight than comparable cast resin units 4. Low total ownership costs and low initial costs 5. Use of NOMEX® UL® Certified Insulation Materials, listed 220°C insulation system, regardless of temperature rating 6. VPI transformers are non-explosive with high resistance to flame and do not require vaults, containment dikes, or expensive fire suppression systems 7. Low Partial Discharge - VPI process ensures void free insulation system 8. Moisture Ingress Resistant & Immune to polluted atmosphere 9. Easy to repair (open coils) due to OVDT Design 10. Eco Friendly, No harm to environment at the end of Life

Wide range of CSP transformers in accordance to above standards with different combinations can be manufactured. The CSP transformers are generally designed and manufactured to comply with the IEC publications 60076. CSP feature can be provided in the following range of transformers.CSP technology is more known for high performance distribution transformers which mitigate the operation and maintenance problems associated with conventional transformers. CSP technology enables a transformer to protect itself from secondary faults, lightning protection, persistent severe overloads, and provides visual warning of the overload conditions. CSP technology also protects the distribution system to which it is connected, in case of its failure. This means, that in case of failure of the transformer, it gets isolated from the system.

Applicable Standards : IEC / ANSI /BS / IS / EN /GOST Wide range of CSP transformers in accordance to above standards with different combinations can be manufactured. The CSP transformers are generally designed and manufactured to comply with the IEC publications 60076. CSP feature can be provided in the following range of transformers. • Single Phase: 5kVA-167 kVA, • Three Phase: 10 kVA-400 kVA, Insulation level £ 12 KV £ 24 KV £ 36 KV • Indoor / Outdoor installation • Conductor : Copper or Aluminum as per customer requirement • CRGO / Amorphous as per customer requirement • Hermetically sealed type (with gas cushion / fully filled) / Conventional type  (with Conservator) • Color : as per customer requirement • Cooling arrangement : Corrugation or Pressed steel Radiators • Maximum ambient temperature : as per customer specification • Top oil Temperature rise : as per customer specification • Average winding temperature rise : as per customer specification Concept of CSP transformers CSP technology is more known for high performance distribution transformers which mitigate the operation and maintenance problems associated with conventional transformers. CSP technology enables a transformer to protect itself from secondary faults, lightning protection, persistent severe overloads, and provides visual warning of the overload conditions. CSP technology also protects the distribution system to which it is connected, in case of its failure. This means, that in case of failure of the transformer, it gets isolated from the system. Components and benefits of the CSP System CSP System has four essential components. They are: 1. Oil immersed Circuit Breaker for overload and secondary fault protection 2. Signal Light for indication during overload condition on transformer 3. HV Fuse for over-current, protection by isolating a failed transformer from the systemthe transformer by tripping and prevents any thermal damage occurring to the transformer. Besides protecting from secondary fault, the breaker also provides thermal protection to the transformer. It is an electro mechanical device with three major elements. These elements are: • Temperature sensing through the use of bimetallic strips which are built into the breaker such that the load current flows through them. The bimetallic strips responds thermally to the temperature of the transformer oil and also to the temperature changes created by the flow of the load current through them • Latching and tripping functions • The signal light latch • The emergency control assembly • The magnetic trip device • It works as Current interrupter Signal Light The signal circuit is mechanically connected to the circuit breaker latching and bimetal systems through an auxiliary contact. A signal light is mounted on the wall of the transformer tank. It gives a visual external indication when the transformer oil temperature reaches a specified preset value of temperature during overload condition. Once the signal light glows then it can be turned off only by manually operating the external handle of the circuit breaker. Primary (High Voltage Fuse) Expulsion Fuse for System Protection In a CSP transformer, the primary fuse is placed in oil and connected in series with the primary winding. This expulsion fuse is to protect that part of the electrical distribution system, which is ahead of the transformer from faults which occur inside of the distribution transformer. If a fault occurs in the windings or some other part of the transformer, it will cause abnormally large currents to flow, resulting in the fuse to melt open and clear the circuit. Thus, the fault is limited only to those customers who are served by this particular transformer and service is maintained on the rest of the system. Surge Arrester The surge arrester are mounted near to the high voltage bushings to shorten the ground lead connection between the arrester and the transformer reducing the lightning impulse voltage stress on the transformer winding. The surge arrester diverts the flow of surge to earth by changing its impedance characteristics from high resistance to low resistance.

KOTSONS has set up state of the art amorphous metal core transformer manufacturing facility by importing the latest amorphous metal cores manufacturing equipment. This plant has the latest equipment in India to produce energy efficient amorphous metal transformer cores that are annealed under absolute inert atmosphere to get at most lower losses thereby enhancing the energy savings in comparison with the similar manufacturing facilities in India. Amorphous metal exhibits a unique random molecular structure unlike the rigid grain structure of the silicon steel. This, in turn, enables easy magnetization & demagnetization, thereby reducing hysteresis loss. Further processing of amorphous metal in very thin lamination (approximately 1/10th of silicon steel lamination thickness) enables significant reduction in eddy current losses. Advantages of Amorphous Metal Transformers over Transformers with CRGO Silicon Steel : 1. The thickness of Amorphous Metal is 0.025 mm against CRGO silicon sheet steel thickness 0.23-0.3 mm. Lesser in thickness in sheet results in lower eddy current loss 2. Random molecular structure of amorphous metal causes less friction than CRGO when a magnetic field is applied. This allows easy magnetization and demagnetization significantly lowers hysteresis losses, thus amorphous core significantly reduces core losses which is about 65-75% 3. Saves energy and therefore reduces greenhouse gases and other pollution 4. Excellent option to reduce distribution losses and improve efficiency 5. Superior electrical performance under harmonic condition. Possible to improve power quality and mitigate harmonics 6. Lower temperature rise, slower deterioration of insulations and hence longer life 7. Increase in use of power electronics has resulted in considerable amount of higher harmonics distortion in electrical power system. Higher frequency harmonics lead to increase in transformer core losses whereas amorphous alloy provides lower loss under high frequency 8. Easy for repair and replacement of coils

KOTSONS Pvt. Ltd., as a part of their continuous efforts towards promotion of energy efficient and green technology environment has added a new product to their portfolio, the 3D Core transformers. 3D Core is a structure with 3 identical single frame continuously wound by several trapezoid tape; three pillars of the core shape a equilateral triangle and the 3 phases are symmetrical. 3-phase magnetic circuits of the core are completely balanced; the magnetization direction is identical with the direction of rolling of silicon steel, magnetic flux distribution is even with neither lap nor seam; there is neither obvious high resistance area nor distortion of density of magnetic flux at the seams.   Advantages of 3D Transformers over conventional stack core / wound core type transformers: 3D Core transformer is an energy-saving transformer with better structure and performance. It has the following outstanding benefits: • Reduced Material- Less Weight • Reduced Energy Loss-Energy Saver • 3-Phase Equilibrium- Equal Load • Low No-load Current • Low Noise - Installation anywhere • Overload Capacity-Natural Cooling • Strong Emergent Short-circuit Protection • Low Strength of Electromagnetic Field • Low Current Harmonic Spectrum • Anti-theft Applicable standards : IEC / ANSI / BS / IS / SABS / CENELEC / GOST Wide range of transformers in accordance to above standards with different combinations can be manufactured. The transformers are generally designed and manufactured to comply with the IEC publications 60076. Range : From 50 kVA to 5000 kVA Insulation level £ 12 kV £ 24 kV £ 36 kV • Indoor / Outdoor installation • Conductor : Copper or Aluminum as per customer’s requirement • CSP (Completely Self Protected) feature can be provided up to 400 kVA • Maximum ambient temperature : as per customer’s specification • Top Oil Temperature rise : as per customer’s specification • Average winding temperature rise : as per customer’s specification • Hermetically sealed type (with gas cushion / fully filled) / Conventional type   (with Conservator) • Color : as per customer’s requirement • Cooling : ONAN/ONAF as per customer’s requirement • Cooling arrangement : Corrugation or Pressed steel Radiators • On Load Tap Changer with RTCC & AVR, can be provided above 500 kVA if   required • Safety devices can also be provided upon request • Other optional fittings as required can be provided upon request