Increasing integration of inverter power sources into the electrical power system has raised concerns about a lack of system inertia, leading to potential disturbances in system frequency and speed during grid disruptions. Virtual synchronous generator (VSG) control is a promising solution for inertia support of the electrical power system. VSG’s inertia enhances system stability by eliminating small and occasional disturbances. However, the required system-wide inertia and the appropriate inertia characteristics supplied by individual VSG remain unclear. Also, the power variation in power electronic interface inverters caused by VSG control increases the stress on power semiconductor devices. In this paper, the focus is that VSG’s inertia ensures grid-side stability by removing disturbances and the influence of VSG on the lifetime of power semiconductors. First, temperatures of the IGBTs are obtained from the inverter model considering the thermal model and HILs simulations with small and occasional disturbances. Next, the lifetimes of the IGBTs are calculated from the results of the rainflow analysis of these temperatures, using the linear cumulative damage theory in lifetime prediction. As a result, a trade-off relationship between system stability and IGBT lifetime is confirmed.