GTA commenced its operations in West Africa by setting up its Power Transformer Repair facility in Nigeria in 2002 and is now well known for its investments into power sector. Our existing customers motivated us to go further augmenting our capacity to add repair and reverse engineering of air, water cooled HT motors & Generators upto 600MW/22kV so as to cater to complete family within same client needs.
The plant capacity has been augmented and presently we are fully geared up to take complete rewinding with “F” class Insulated Stator Coils, “H” class Insulated Rotor Coils, Re-designing and Rewinding of High Voltage Generator and Motor for Hydro Power Plant, Gas Power Plant, Cement Industries, Sugar Industries, Steel Plants etc.
Our Services Include:
REFURBISH – Dismantling and removing of worn out damaged generator components (like bearings, shaft, brackets, stator core, stator winding, rotor pole, rotor winding, slip ring, etc.) and replacing with new one at par with the existing design, re-fixing, erection, aligning and commissioning.
RE-DESIGN – Dismantling and removing of worn out damaged generator components and re-designing the components by RET (Reverse Engineering Technology) to rule out the existing root cause of failure, re-fixing, erection, aligning and commissioning.
UP-GRADING – The existing stator coil bitumen mica/class `B’ insulations/rotor asbestos insulations can be up-graded to class ‘F/H’ insulation with resin rich/VPI coils/bars and the existing stator core electrical steel material will be replaced with low loss electrical steel material.
UP-RATING – Dismantling, removing the existing components, re-fixing the new components, re-assembling, aligning and commissioning. In case, the existing turbine has capability to deliver higher outputs then we can carry out the below works and up-rate the machine’s capacity without much disturbance.
Stator frame - For transport convenience, the OEMs make the stator frame in segments (2/3/4/6, etc) depending upon the sizes. These segmental type stator frames sometimes get deformed and lead to core vibration and frequent coil failures. These problems can be rectified by RET.
Stator core - For transport convenience, the OEMs make the stator frame in segments (2/3/4/6, etc) depending upon the sizes. In that case, the stator cores also to be stacked as per the frame design in segment form (2/3/4/6etc). This segmental design in due course of service gets deformed and leading to core vibrations. This core vibrations will deteriorate the core lamination insulations and develop the hot spots (Eddy-current) and simultaneously allow the coils for free movement and damage the stator coils very badly. To eliminate this issue by (RET) Re-design the core for spiral stacking technology instead of segmental stacking and reduce the iron losses with low loss electrical steel materials simultaneously.
Stator winding – The existing old stator coil insulations may get deteriorated due to aging and thermal cycling. Sometimes, the old insulations may be bitumen mica/class `B’ insulations. It will be re-designed (RET) and manufactured with low copper loss coils/bars with class `F’ resin rich/VPI coils/bars.
Rotor shaft/spider/Arm/Rim – Any of the existing rotor components like rotor shaft, Spider, Arm, Rim etc., get damaged/worn-out, then it will be repaired/replaced with new one to rule out the existing root cause problem by using RET.
Rotor Pole Winding – The existing rotor pole coils are insulated with asbestos/class `B’ insulation materials. These insulation materials get deteriorated due to aging and thermal cycling and lead to free movement of pole coils and with more inter-turn shorts. These can be eliminated by re-insulating the coils to class `F/H’ insulations. If required, we can supply new spare universal pole coil assembly also.
