ACLI Revue internationale avec comité de lecture
| Modelling of a VSC-based multi-terminal HVDC network for dynamic stability analysis|
The International Journal for Computation and Mathematics in Electrical and Electronic Engineering (COMPEL), Vol. 36, N°. 1, pages. 240 - 257, 08/2016, Abstract
SHINODA Kosei, GUILLAUD Xavier, BACHA Seddik, BENCHAIB Abdelkrim, FRANCOIS Bruno
Purpose Self-commuted voltage source converter (VSC) can significantly extend the flexibility and operability of an HVDC system and be used to implement the concept of multi-terminal HVDC (MTDC) grid. To take full advantage of MTDC systems, its overall behaviour must be characterized in quasi static and dynamic states. Based on the numerous literatures, a dedicated two-level VSC model and its local controllers and DC grid voltage regulators are developed for this purpose. Furthermore, the requirement of the system to guarantee all the physical constrains must be well assessed and concrete demonstrations must be provided by numerical simulations. Design/methodology/approach First, a two-level VSC model and its local controllers and DC grid voltage regulators are developed. Then, DC cable models are investigated and their characteristics are assessed in the frequency domain. Those developed models are combined to form a three-terminal HVDC grid system on Matlab/Simulink platform. To analyze the stability of this electrical system, the dynamics of the system against variations of power dispatch are observed. Findings To analyze the stability of this electrical system, the dynamics of the system against variations of power dispatch are observed. The differences in the DC grid voltage dynamics and the power flow of the converter stations coming from the embedded primary controls are analysed, and the technical requirements for both cases are assessed. Originality/value In this paper, the dynamic stability of an MTDC system has been analysed and assessed through an adequate simulation model, including its control scheme and the cable models. The interest of the improved PI model for cables is highlighted.
ACT Conférence internationale avec acte
| Energy Difference Controllers for MMC without
DC Current Perturbations|
The 2nd International Conference on HVDC (HVDC2016), Sep 2016, Shanghai, China, 10/2016, Abstract
SHINODA Kosei, FREYTES Julian, BENCHAIB Abdelkrim, DAI Jing, SAAD Hani, GUILLAUD Xavier
The Modular Multilevel Converter (MMC) is a most promising converter technology for the High Voltage DC application. The complex topology of the MMC requires several additional controllers to balance the energy in the capacitors which are distributed all over the converter. Typically, there is a requirement of two controls; one is the regulation of the total energy in each leg, and the other is the distribution of the energy between the upper and the lower arms. This paper presents control strategies for the latter one being capable of distributing the energy only by internal power flow, so that undesired interference with the associated grids can be completely avoided. The proposed controls are achieved by forcing the common mode currents to be balanced while keeping the classic cascaded control structure as much as possible. The effectiveness and advantage of the proposed solutions are demonstrated by simulations.
| Energy control of modular multilevel converter with a novel analytic filter|
Power Electronics and Applications (EPE'16 ECCE Europe), 2016 18th European Conference on, 09/2016, Abstract
SHINODA Kosei, BENCHAIB Abdelkrim, DAI Jing, GUILLAUD Xavier
The complex topology of the Modular Multilevel Converter (MMC) requires some additional controllers to keep its functionalities. One of the important requirements on the MMC control is to balance the energy stored in the distributed capacitors in the arms on the three legs. However, due to the superimposed internal DC and AC power flows in the converter, the energy stored in the arms contains intrinsic oscillations. This paper provides a thorough analysis on those intrinsic oscillations on the internal energy of the MMC. Based on the analysis, a novel analytic filter is proposed, which enables to extract average value of the energy while keeping other internal dynamics stable. The proposed filter is implemented on an EMTP-RV platform. The simulation demonstrates its improved dynamic response and reduction of the internal losses compared to the existing solutions.