Comparison of different frequency controllers for a VSC-HVDC supplied system
Artikel i vetenskaplig tidskrift, 2008

This paper studies three different frequency controllers and their effects on the voltage disturbance ride-through capability of a VSC-HVDC supplied industrial system. The idea of implementing frequency controller is to improve the power quality of industrial plants by slightly decreasing the VSC output voltage frequency since industrial processes are more sensitive to voltage drops than frequency deviations. The first two controllers, frequency controllers I and II, are fixed frequency controllers and the third one, frequency controller III, is a PI frequency controller. In order to compare three different controllers, a system with a simplified VSC-HVDC and different load types is simulated in PSCAD/EMTDC. Simulation results show that with frequency controller III, the VSC-HVDC supplied industrial plant can avoid a voltage collapse by decreasing frequency during or after disturbances. Furthermore, with an increase of the converter current limit, the possibility of mitigating voltage dips increases. For frequency controllers I and II, the extent of the disturbance ride-through capability depends on the current limit of the VSC-UVDC. A higher current limit results in a higher ride-through capability. The effect of the dc capacitor on improving the system voltage disturbance tolerance is also investigated during and after disturbances when the VSC-HVDC uses frequency controller I. The system voltage disturbance ride-through capability increases with an increase of the dc capacitance or the current limit.

current limit

voltage disturbance

voltage sags

voltage dips

frequency controllers

voltage source converters-high-voltage direct

power

current (VSC-HVDC)

ride-through capability

loads

link

Författare

C. Q. Du

ABB Corporate Research Center

Agneholm Evert

Gothia Power AB

Gustaf Olsson

Chalmers, Energi och miljö, Elkraftteknik

IEEE Transactions on Power Delivery

0885-8977 (ISSN)

Vol. 23 4 2224-2232

Ämneskategorier

Elektroteknik och elektronik

DOI

10.1109/tpwrd.2008.921130