ACLI Revue internationale avec comité de lecture
| MMC Stored Energy Participation to the DC Bus Voltage Control in an HVDC Link|
IEEE Transactions on Power Delivery, Vol. 31, N°. 4, pages. 1710-1718, 08/2016, Abstract
SAMIMI Shabab, GRUSON François, DELARUE Philippe, COLAS Frédéric, BELHAOUNE Moez, GUILLAUD Xavier
The modular multilevel converter (MMC) is be- coming a promising converter technology for HVDC transmission systems. Contrary to the conventional two- or three-level VSC-HVDC links, no capacitors are connected directly on the dc bus in an MMC-HVDC link. Therefore, in such an HVDC link, the dc bus voltage may be much more volatile than in a conventional VSC-HVDC link. In this paper, a connection between the dc bus voltage level and the stored energy inside the MMC is proposed in order to greatly improve the dynamic behavior in case of transients. EMT simulation results illustrate this interesting property on an HVDC link study case.
ACT Conférence internationale avec acte
| Optimal Control Design for Modular Multilevel
Converters Operating on Multi-Terminal DC Grid|
2016 Power Systems Computation Conference (PSCC), pages. 1-7, 06/2016, URL, Abstract
BELHAOUNE Moez, FREYTES Julian, AYARI Mohamed, COLAS Frédéric, GRUSON François, BENHADJ BRAIEK Naceur, GUILLAUD Xavier
This paper proposes an advanced control strategy for Modular Multilevel Converters (MMC) integrated in Multiterminal DC grid. In this present work, a three terminal MMC-MTDC system connecting onshore AC systems with an offshore wind farm is setup. Firstly, the voltage droop control associated to the conventional cascaded controllers for MMC stations is studied, the dynamic behavior of the DC voltage is analyzed and some drawbacks are outlined. In order to improve the dynamic behavior of the controlled DC bus voltage and the stability of MTDC system, an optimal multivariable control strategy of each MMC converter is proposed and integrated in a voltage droop controller strategy. The designed advanced controller allows to improve the overall DC grid stability and to reach the droop values designed on static considerations with acceptable dynamic behavior. By means of numerical simulations in EMTP-RV software, it is shown that the proposed control strategy performs well the stability of MTDC grid with 400- level model for MMC compared with the classic existing control methods.
| Impact of control algorithm solutions on Modular Multilevel Converters electrical waveforms and losses|
EPE ECCE Europe 2015, 09/2015, URL, Abstract
GRUSON François, FREYTES Julian, SAMIMI Shabab, DELARUE Philippe, GUILLAUD Xavier, COLAS Frédéric, BELHAOUNE Moez
Modular Multilevel Converters (MMC) are becoming increasingly popular with the development of HVDC connection and, in the future, Multi Terminal DC grid. A lot of publications have been published about this topology these last years since it was first proposed. Many of them deal with converter control methods, other address the method of estimating losses. Usually, the proposed losses estimation techniques are associated to simple control methods For VSC (Voltage Sources Converters) topology, the losses minimization is based on the limitation of the RMS currents values. This hypothesis is usually extended to the control of MMC, by limiting the differential currents to their DC component, without really being checked.