Technical Audit of TM Khan Road Hyderabad 220kV Grid Station

Commissioned on September 30, 2000, the station has a total transformation capacity of 320MVA and feeds a large portion of Hyderabad and its surrounding areas. The station is equipped with two 160MVA-220/132kV autotransformers and two 10/13MVA-132/11kV power transformers, owned and maintained by the National Transmission and Despatch Company (NTDC). The technical audit of the station, conducted by the USAID Energy Policy Program in November 2014, identified several critical issues that require immediate attention. The loading condition of the transformers is above the prescribed limits per NEPRA grid code, with both 220/132kV transformers loaded at 100% and 132/11kV transformers loaded at 70.44% and 91.88%. This excessive loading reduces the expected useful life of the transformers and poses a significant risk to the reliability of the grid. The audit also highlighted the need for a proper drainage system during heavy rains, as the switchyard is at a lower level than the surroundings and is prone to waterlogging. The salinity and waterlogging problem in the area also requires proper adhesive painting of equipment and structures to prevent rusting and corrosion. In addition, the audit identified several maintenance-related issues, including the delay in overhauling of two 220kV and five 132kV circuit breakers, the non-performance of required tests for grid system operation and maintenance, and the non-functionality of sequential event recorders, fault/disturbance recorders, and voltage and power recorders. The recommendations of the technical audit include the installation of a forced drainage system to cater for heavy rains, the proper adhesive painting of equipment and structures to prevent rusting and corrosion, the augmentation of at least one transformer to reduce the loading condition, and the procurement of spare parts for major maintenance of four 220kV and five 132kV circuit breakers. Furthermore, the audit recommended the installation of tie line protection on both 220kV circuits, the enabling of carrier-aided facility for tele-protection on all 220kV circuits, and the installation of missing relays and other defective equipment. The SCADA system installed at the station is incomplete and has not been made functional, and the audit recommended its completion and functionalization. Overall, the technical audit of the TM Khan Road Hyderabad 220kV Grid Station highlights the need for immediate attention to several critical issues that pose a significant risk to the reliability of the grid. The implementation of the recommended measures is essential to ensure the safe and reliable operation of the station and to prevent potential power outages and equipment failures.