Propagation and Distribution Characteristics of Subsynchronous Oscillation in Power Grid

The interaction between a large number of high proportion renewable energy and high proportion power electronic devices connected to AC power grid has caused a new type of subsynchronous oscillation (SSO), which puts forward severe requirements for the stable operation and control of power system. However, previous studies on the mechanism and suppression methods of SSO have ignored the propagation and distribution path of SSO. Therefore, this paper first proposes a new time-domain simulation method and verifies its accuracy in a single- machine infinite bus system. Secondly, the time domain simulation method is applied to the multi-machine system to monitor the key nodes to obtain the propagation and distribution path of SSO voltage in the power grid. And the effects of frequency and electrical distance on SSO are studied.