Empirical Techniques for Improving Reliability of High Voltage Mica-based Insulation Systems

Mica-based insulation systems are an essential part of high voltage (HV) electric motors and generators. Accordingly, the performance and reliability of the machine are directly impacted by the dependability of the insulation. This paper aims to assess the impact of different design factors on various dielectric indices. These indices include breakdown voltage, dissipation factor, and partial discharge measurements, collected from empirical tests to assess insulation system resilience and endurance. All these evaluation measurements are carried out for fresh samples and thermally aged samples. Thermal aging is performed with different temperatures and durations. After that all samples are tested for voltage endurance in accordance with IEC 60034-18-32 and IEEE 1553, to evaluate their lifetimes. Analyzing the test outcomes, a number of practical methods and techniques are identified that help engineers improve their design and ensure higher longevity of HV electrical machines.