Dissecting IEEE 1310: a critical examination and ideas for improvements

This work critically examines the underlying assumptions and practices in IEEE 1310, focusing on two primary aspects. Firstly, we scrutinize the fundamental assumption, according to which, a high-voltage insulation system tends to have a shorter lifespan in machines that operate under frequent start-stops as compared to those operating at base-load conditions. Secondly, we assessed IEEE 1310 from a practical perspective, investigating its ability to simulate the repetitive temperature variations found in real machines, especially those in air-cooled hydro motor-generators in pumped-storage power plants. Our investigations revealed that the foundational assumption that links frequent start-stops to a shortening in insulation lifetime encounters serious challenges when confronted with the available historical data spanning the last four or five decades of accumulated service experience with large hydrogenerators. In addition, when the temperature cycles prescribed by the "Recommended Practice" are compared to the conditions found in real service, significant discrepancies and potential sources of test artifacts are observed. In response to these drawbacks in both practical and conceptual aspects, an effort is made to explore ways to minimize the deviations between IEEE 1310 practices and the complexities of real-world service operations.