<![CDATA[Permanent Magnet Synchronous Generators (PMSG) are widely used in wind turbine systems because they have high efficiency and good reliability. However, in long-term use, PMSG’s are prone to a decline in the quality of the stator winding insulation due to thermal stress, which is can reduce performance and trigger generator malfunctions. If this happens continuously, it can accelerate the degradation of the insulation, so a method is needed that can detect insulation deterioration early. This research focuses on evaluating the impact of accelerated aging on the insulation quality of PMSG’s stator windings. The research uses Insulation Resistance (IR) and Polarization Index (PI) testing methods with a measuring device that called a Megger Test. The approach was applied on a small scale, with accelerated thermal stress treatment at a constant temperature of 160°C for 6 hours in accordance with the IEC 60085 standard for insulation class of F. In each heating a cycle, IR and PI tests were conducted referring to IEEE Std 43 to evaluate changes in insulation characteristics. The test results showed that the IR values for all phases were in the Over Limit condition (>4000 MΩ) from the baseline up to the 3rd hour of aging, then decreased to 2000–2180 MΩ (PI 1.03–1.08) at the 4th hour, and 1164–1273 MΩ (PI 1.09–1.20) at the 5th hour, finally reaching 0 MΩ at the 6th hour, indicating total insulation failure. This decrease in IR and PI shows insulation material degradation due to repeated heating, one sign being the reduced dielectric polarization capability. Consequently, IR and PI tests using the Megger Test have proven effective as a method to detect early PMSG insulation degradation caused by thermal stress.]]>
