Staff of the Public Utility Commission of Texas filed a strawman rule in Project 42631 to address subsynchronous oscillation (SSO) issues in the Electric Reliability Council of Texas (ERCOT) region.
"SSO is a potentially harmful phenomenon involving coincident oscillation between two or more transmission elements or generation resources at frequencies lower than the normal operating frequency (60 Hz) of the ERCOT System," Staff said.
Staff filed a strawman rule that defines SSO, SSO Risk, and SSO Solutions, establishes a process for the study of SSO, proposes technical criteria, and assigns cost responsibility for solutions.