Open AccessAutonomous grid‐synchronising control of VSC‐HVDC with real‐time frequency mirroring capability for wind farm integration
Author(s) -
Yang Renxin,
Zhang Chen,
Cai Xu,
Shi Gang
Publication year - 2018
Publication title -
iet renewable power generation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 76
ISSN - 1752-1424
DOI - 10.1049/iet-rpg.2017.0824
Subject(s) - mirroring , robustness (evolution) , grid , frequency grid , voltage source , control theory (sociology) , automatic frequency control , computer science , capacitor , engineering , voltage , electronic engineering , electrical engineering , control (management) , biochemistry , chemistry , geometry , mathematics , communication , artificial intelligence , sociology , gene
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.