Autonomous grid-synchronising control of VSC-HVDC with real-time frequency mirroring capability for wind farm integration

作者：Yang, Renxin; Zhang, Chen; Cai, Xu^*; Shi, Gang

来源：IET Renewable Power Generation, 2018, 12(13): 1572-1580.

DOI：10.1049/iet-rpg.2017.0824

• wind turbines
• wind power plants
• power generation control
• voltage-source convertors
• HVDC power convertors
• synchronous generators
• frequency response
• power grids
• robust control
• autonomous grid-synchronising control
• VSC-HVDC systems
• wind farm integration
• voltage source converter high-voltage direct current system
• autonomous grid-synchronisation
• real-time grid frequency mirroring capability
• receiving end converter
• inertial synchronising control
• ISC
• REC
• DC capacitors

This study provides a novel control method for voltage source converter high-voltage direct current (VSC-HVDC) systems with two salient features: autonomous grid-synchronisation without phase-locked loop and real-time grid frequency mirroring capability. The first feature is realised using a newly proposed control method for receiving end converter (REC) called inertial synchronising control (ISC). This method innovatively adopts the physical inertia of DC capacitors to directly synchronise with the grid, without emulating the motional equation of a synchronous generator (SG) as virtual SG control. Hence, less control loops and easy parameter tuning are achieved. The control robustness to grid impedance variation is also improved. Moreover, the second feature is realised with the merit of ISC. Owing to the fast grid-synchronisation capability of ISC, grid frequency dynamic is bound with DC voltage dynamic intrinsically; hence, the instantaneous grid frequency information can be obtained by measuring the local DC voltage of sending end converter, whereby wind turbines can proceed with inertial and frequency response. Consequently, REC is similar to SG in terms of electromechanical characteristics. The effectiveness of the proposed method is evaluated by comparing it to an existing method in PSCAD/EMTDC, and its performance on the robustness to grid impedance variation is addressed.

• 出版日期2018-10-1
• 单位上海交通大学