A distributed DC voltage control method for VSC MTDC systems

• Published in: Electric power systems research Vol. 82; no. 1; pp. 54 - 58
• Main Authors: Dierckxsens, C., Srivastava, K., Reza, M., Cole, S., Beerten, J., Belmans, R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2012; Elsevier
• Subjects: Applied sciences; Convertors; Direct current networks; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Exact sciences and technology; Multi-terminal HVDC (MTDC); Power electronics, power supplies; Power networks and lines; Regulation and control; Voltage droop; Voltage Source Converter (VSC); Multi-terminal HVDC (MTDC); Voltage Source Converter (VSC); Voltage droop; Control system; Voltage regulation; Software package; Power system stability; Power electronics; Voltage control; Voltage source converter; Power control; Direct current; Distributed control; Voltage stability; Multiterminal networks; System simulation; Voltage dip; HVDC systems; Electric fault; Electrical characteristic
• ISSN: 0378-7796; 1873-2046
• DOI: 10.1016/j.epsr.2011.08.006

► The DC grid voltage can be controlled by a single converter or by a distributed control. ► A distributed voltage control can relieve the pressure of the otherwise centralized voltage controlling converter. ► We combined a PI-controller on the main voltage controlling converter with a voltage droop characteristic in other converters. ► The combined approach reduces DC voltage transients. With the development of VSC HVDC transmission, the realization of the first VSC MTDC grid is coming within reach. An outstanding issue is DC voltage control in MTDC systems. The easiest way to maintain stable operation is to assign the task of DC voltage regulation to one converter. This paper discusses a control strategy for an extended VSC MTDC grid using a typical DC voltage control on one DC bus, combined with a DC voltage droop characteristic on the other DC buses. The impact of the proposed control structure on the stability of the AC and DC grid is investigated by numeric simulations using the MatDyn software package.