Analysis and control on Sub-synchronous oscillation(SSO) of HVDC transmission for large-scale permanent magnet synchronous generators(PMSG)-based wind farm integration

The high-voltage DC transmission (HVDC) technology has become more and more popular for grid integration of large and remote wind farms. There was the new form of SSO appeared in Xinjing Grid which was the PMSG integration through an HVDC system, so the SSO was studied. The detailed model of the wind power transmission system through the two-terminal HVDC system was established. With the small signal method in case of the SSO fed into the system, due to the characteristics of the PMSG and HVDC topology, the expressions of the output signal of SSO were derived. Based on the ideal model，a control scheme for SSO suppression was proposed from the perspective of the PMSG controller. Finally, verified the rationality and effectiveness of the method based on the simplified Xinjiang grid model