混合型统一潮流控制器抑制风电次同步振荡控制策略

混合型统一潮流控制器(hybrid unified power flow controller,HUPFC)可以实现统一潮流控制器(unified power flow controller,UPFC)与移相变压器('Sen'transformer,ST)的优势互补,广泛应用于系统潮流控制之中.但是,尚未有文献开展HU...

Control Strategy of Hybrid Unified Power Flow Controller to Suppress Wind Power Sub-synchronous Oscillation

The hybrid unified power flow controller (HUPFC) combines the advantages of unified power flow controller (UPFC) and ‘Sen’ transformer (ST), so HUPFC is widely applied in power flow control of the power system. However, little literature has studied the application of HUPFC to suppress sub-synchronous oscillation (SSO). To solve the problem of SSO in double-fed induction generator (DFIG) based wind farm connected to series compensated transmission system, a suppression strategy is proposed in the paper on the basis of the supplementary active resistance control (SARC) of HUPFC. Firstly, the principle of HUPFC and the suppression mechanism for SSO are introduced. Then, the SARC strategy is designed. By tracking sub-synchronous current in the transmission line, the SARC strategy makes HUPFC inject a sub-synchronous voltage which has the same phase as the sub-synchronous current and variable amplitude to the grid. Thereby, the system equivalent resistance is increased to a positive value to suppress SSO. Finally, the parameters design method of SARC is introduced and a detailed simulation model is carried out in PSCAD/EMTDC using the data of an actual wind farm in North China. The results of the frequency scanning and the time domain simulation both show that the proposed SARC strategy of HUPFC can effectively suppress SSO in DFIG-based wind farm connected to series compensated transmission system.