Power Quality Improvement through Smart Control & Diagnostics of Power Transformer Load Tap Changer

Post Delhi reforms in 2002, Tata Power Delhi Distribution Limited (erstwhile NDPL) has been consistently able to meet and overachieve its performance target related to utility business in terms of operational excellence, consumer services and other key stakeholder expectation. This has been possible through unique design and deployment of strategy, process, and technology vis-à-vis consistent commitment of TPDDL workforce. Reliability and Quality of supply is critical component of consumer satisfaction and needs continuous engagement and innovation from Planning, Engineering, Execution, Operation & Maintenance functions within organization. Over the year, Sub-transmission system in TPDDL has seen phenomenal growth both in terms of network expansion and technological interventions. Sub Transmission grid substation have increased from 38 No's with 1635 MVA capacity to 68 No's with 3838 MVA as on date. Smart Grid technologies & Roof top PV solar integration in coming times will make existing power system more dynamic, interactive and complex. PV Solar Integration, Electronic Appliances and Dynamic loading scenario considering industrial and residential growth in Delhi, makes the system more complex to ensure Quality power to Consumers. It has been a common practice in most of transmission and distribution industries in India that Power Transformers are operated on fixed taps. Historical data clearly indicates that 40% of transformer failures are attributed to OLTC faults as OLTC is the only moving part of transformers. Requirement of frequent specialized periodic maintenance is also one of the major reason because of which OLTC's are kept out of service in most of transmission and distribution utilities. Same was the case in Delhi Vidyut Board till its unbundling in 2002. This paper illustrates broadly how TPDDL designed and adopt smart technological and process innovation and latest maintenance strategy to ensure Quality Power Supply to its valuable 1.4 million consumer base.