Study on Safe Operating Area of Series VSC-LCC Hybrid Rectifier Connected with Weak Grid

Series VSC-LCC hybrid rectifier (SVLHR) is a more promising scheme for long-distance transmission of largescale renewable power comparing with pure LCC and VSC rectifier schemes, due to its operational flexibility and economic efficiency. Meanwhile, SVLHR synthesizes both the supporting grid voltage ability of VSC rectifier and the DC fault blocking ability of LCC rectifier, which is meaningful for high renewable power penetration sending grid. In this paper, SVLHR connecting with weak grid scenario is studied, and the control strategy of SVLHR is also proposed. Further, SVLHR operational characteristics are analysed for determining the safe power output area. Simulations in PSCAD/EMTDC with detailed switching model verified the effectiveness of proposed control strategy.