Analysis Of Subsynchronous Oscillation Caused By HVDC And The Damping Controller Design

With the extensive application of HVDC transmission technology, the problem of subsynchronous oscillation(SSO) caused by HVDC is increasingly prominent in China. Therefore, analysis of SSO and the damping controller design are of great importance. On the basis of the simulation model of a complex AC/DC systems, the impact of relevant operating parameters on SSO are systematically analyzed in this thesis. Countermeasures are proposed to avoid SSO. In the literature, the load model has not been considered in SSO analysis. In this thesis, the impact of load model on the rectifier side and inverter side of the DC system are studied respectively. The analysis results show that it must consider the impact of the rectifier side load in the analysis of SSO. For the multimodal subsynchronous oscillation problem, this thesis designs additional subsynchronous damping controller(SODC) based on the submodal and phase compensation principle, using genetic algorithm as optimization algorithm. Eigenvalue analysis results show that the additional subsynchronous damping controller is good and can adapt the system operation mode change.