固有振荡频率 meaning in English

natural mode shape
natural oscillation frequency

If the numerical value line resonance frequency plus some shaft connatural frequency of generator is equal to operation frequency , it brings about coupling resonance between generator and system , which maybe results in shaft rupture of synchronous generators
当线路电气谐振频率与同步电机的轴系某一固有振荡频率近似互补于电网工频时，将导致机电系统的耦合振荡，严重的会造成同步发电机大轴的扭断。