Power system subharmonics

Power system subharmonics are considered with reference to some of their most significant effects. In particular, four kinds of sensitive electrical components are considered: lightning systems, transformers, induction motors and turbogenerators. Light flicker, hysteresis loop asymmetrization and core saturation, thermal aging and perturbing subsynchronous torques, respectively, are the corresponding subharmonic voltage effects. With reference to the available specialistic literature, some modeling aspects are recalled together with experimental or numerical results aimed to give an idea of the component susceptibility thresholds.