Procurement of transformers and reactors - Best practices adopted to achieve highest availability & reliability goal Das Richik Manas, Agrawal Gunjan, Lahiri S J, Srivastava Rajil, Singal A K Power Grid Corporation of India Ltd. Online published on 16 May, 2023. Abstract Electricity Power is playing major role for economic growth and provide quality of life. Uninterrupted and quality Power become the primary requirement in present scenario. India is the third largest producer of electricity in the world. As a long-term perspective (for up to 2050-time horizon), there is a huge renewable potential of 300GW mainly through solar/wind utilizing waste land in India's desert regions. Power Grid Corporation of India Limited (POWERGRID) is playing major role in development of transmission infrastructure essential for long-term sustainable growth of India's Power sector since 1992. Being operating largest synchronised Grid in the world, POWERGRID is presently having more than 3300 nos. of Transformers & Reactors of rating ranging from 66kV to 1200kV including Power Transformer, Shunt Reactor, Coupling Transformers for STATCOM/SVC application, fault current limiting Series Reactors and HVDC Converter Transformers. POWERGRID is maintaining system availability of more than 99.5%. The failure rate of Transformers & Reactors is well below the international failure rate. This is achieved due to reliable, trouble-free performance and minimal maintenance of Transformers and other associated equipment. In this paper, experience has been shared in various stages of Transformer procurement process followed by POWERGRID to achieve such milestones. For procurement of such critical equipment, every process is very important like Qualifying requirement of Manufacturer, Technical specification, bidding process, bid evaluation, Technical review (Design review), drawing approval, Quality Plan (MQP), Testing & commissioning. Bidding process -For reliable and better Transformers it is desirable to allow participation of those manufacturers who are fulfilling the qualifying requirements, which includes the manufacturing capability and Operational-experience. Financial position of manufacturers is also considered. In addition, manufacturers also have to-comply the requirement of Technical Specification. Deviation to the technical specification and other commercial-requirement evaluated thoroughly during the evaluation process. Various other methods including loss standardization have been implemented to smoothen the bidding process. Detailed Engineering - This is the process which is being followed after the award of contract. In this stage-design review, drawing approval and other critical points are being discussed and finalised. Transformer-manufacturers to use items of sub-vendors/suppliers from POWERGRID approved source only. Type test of critical bought out items are also being reviewed during this stage. POWERGRID is having exhaustive inspection and quality checks from ordering of all raw materials, bought out items to testing & despatch of Transformer from manufacturer works. Erection and commissioning is also getting equally importance Technical specification is most important part based on which Transformer is being designed, manufactured and tested. POWERGRID always strive for continuous improvement of specification based on manufacturing & operational feedback and align with the latest trend of proven technology. During detailed engineering, design-review of Transformer & Reactor is being carried out complying the requirement of technical specification. Further, in today's scenario, project completion schedule is reduced significantly. Procurement of Transformer-within short span of time is one of the biggest challenges. To address the reduced delivery schedule, POWEGRID has standardized various parameters including General arrangement of Transformer, bushing dimensions, foundations, fixing of cooler bank position and other major accessories so that one can replace any make of Transformer & Reactor hassle free in least possible time. Standardization has significantly reduced the space-requirement, replacement time and inventory cost. Further, standardization is also made in various other processes including Quality checks, raw material procurement, test procedures etc. This all has been achieved without compromising the quality of the Transformer. POWERGRID faced many challenges during this process, which are also addressed in this paper. Capacity and capability assessment of Transformer manufactures and sub-suppliers are the part of procurement. To maintain the quality and to ensure trouble free performance, POWERGRID imposes penalty/extended warranty based on violation of many performance parameters of Transformer during operation. In this paper all the above stages have been presented elaborately and every stages POWERGRID experience for procurement of quality Transformers have been discussed. Top Keywords Technical specification, Specific requirement, Detailed engineering, Quality control, Manufacturing-check points, Testing, Performance warrantee, Standardization. Top |