Determination of droop control coefficient of multi‐terminal VSC‐HVDC with system stability consideration. Issue 13 (15th March 2018)

• Record Type: Journal Article
• Authors: Peng, Qiao; Liu, Tianqi; Wang, Shunliang; Qiu, Yufeng; Li, Xingyuan; Li, Baohong
• Is Part Of: IET renewable power generation. Volume 12:Issue 13(2018)
• Page Start: 1508
• Page End: 1515
• Publication Date: 2018-03-15
• Subjects: voltage‐source convertors -- HVDC power transmission -- power system stability -- HVDC power convertors -- control system synthesis -- voltage control -- state‐space methods -- feedback -- minimisation -- closed loop systems -- eigenvalues and eigenfunctions -- robust control -- power transmission control -- power transmission faults; multiterminal VSC‐HVDC droop control coefficient determination -- system stability consideration -- multiterminal voltage source converter based high‐voltage direct‐current system -- droop controller -- active power regulation -- voltage regulation -- droop control coefficient design -- state‐space model -- feedback controllers -- optimisation problem -- Frobenius‐Hankel norm minimisation -- system S/T mixed sensitivity -- closed‐loop system eigenvalue constraint -- steady‐state error constraint -- optimal system stability -- four‐terminal VSC‐HVDC system -- faulty conditions; Renewable energy sources -- Periodicals; 333.79405
• DOI: 10.1049/iet-rpg.2017.0621
• Languages: English
• ISSNs: 1752-1416

Abstract

Abstract : In multi‐terminal voltage source converter based high‐voltage direct‐current (VSC‐HVDC) systems, droop controllers are commonly adopted to regulate the active power and voltage. Thus, the droop controller coefficients inevitably affect the system stability. In this study, a method to design droop control coefficient is proposed considering the system stability. The state‐space model of the multi‐terminal VSC‐HVDC system with droop controllers is established in which the droop controllers are considered as feedback controllers to reflect the control characteristics. Based on the model, the determination of droop control coefficients can be equivalent to an optimisation problem. The objective is to minimise the Frobenius‐Hankel norm of the system S / T mixed sensitivity. The constraint conditions include closed‐loop system eigenvalues constraint and steady‐state errors constraint. By doing so, the optimal system stability and robustness are achieved. To verify the proposal, simulations on a four‐terminal VSC‐HVDC system are performed with two another sets of droop control coefficients for comparison. Simulation results show that the proposed droop controller can ensure system stability and robustness under various disturbances and faulty conditions.