Blar i NTNU Open på forfatter "BergnaDiaz, Gilbert"

Analysis of MMC Dynamics in DQZ Coordinates for Vertical and Horizontal Energy Balancing Control
BergnaDiaz, Gilbert; Freytes, Julian; Guillaud, Xavier; D'Arco, Salvatore; Suul, Jon Are Wold (Chapter, 2018)This paper presents a control system implementation in dqzcoordinates for equalizing the average energies stored in each arm of a Modular Multilevel Converter (MMC); a control objective that is typically referred to as ... 
Avoiding AC/DC grid interaction in MMC based MTDC Systems
Endegnanew, Atsede Gualu; BergnaDiaz, Gilbert; Uhlen, Kjetil (Chapter, 2017)In this paper, the interaction between ac and dc grids is studied for two types of MMC control structures; conventional and nonconventional control structures. Linear analysis methods that are based mode shapes and ... 
Control of HVDC systems based on diode rectifier for offshore wind farm applications
ida, Flåten; BergnaDiaz, Gilbert; Sanchez Acevedo, Santiago; Tedeschi, Elisabetta (Journal article; Peer reviewed, 2017)The transfer of energy from offshore wind farms using HVDC technology is highly dependant on the converter technology used. The conversion through HVDC has conventionally been done by Line Commutated Converters (LCC) or ... 
Dynamics and Stability of Meshed Multiterminal HVDC Networks
Sanchez Acevedo, Santiago; BergnaDiaz, Gilbert; Tedeschi, Elisabetta; Garces Ruiz, Alejandro (Journal article; Peer reviewed, 2018)This paper investigates the existence of an equilibrium point in multiterminal HVDC grids, assesses its uniqueness and defines conditions to ensure its stability. An offshore multiterminal HVDC system including two wind ... 
EnergyBased StateSpace Representation of Modular Multilevel Converters with a Constant Equilibrium Point in SteadyState Operation
BergnaDiaz, Gilbert; Suul, Jon Are Wold; D'Arco, Salvatore (Journal article; Peer reviewed, 2017)The internal currents and voltages of Modular Multilevel Converters (MMCs) contain multiple frequency components in steady state operation and remain timeperiodic even when transformed into a synchronously rotating reference ... 
Generalized Voltagebased StateSpace Modelling of Modular Multilevel Converters with Constant Equilibrium in SteadyState
BergnaDiaz, Gilbert; Freytes, Julian; Guillaud, Xavier; D'Arco, Salvatore; Suul, Jon Are Wold (Journal article; Peer reviewed, 2018)Abstract: This paper demonstrates that the sum and difference of the upper and lower arm voltages are suitable variables for deriving a generalized statespace model of an MMC which settles at a constant equilibrium in ... 
HVDC meshed multiterminal networks for offshore wind farms: Dynamic model, load flow and equilibrium
Garces, Alejandro; Sanchez Acevedo, Santiago; BergnaDiaz, Gilbert; Tedeschi, Elisabetta (Chapter, 2017)This paper presents sufficient conditions for the existence of an equilibrium point of multiterminal HVDC (MTHVDC) network for offshore applications. Newton's method is used both as a computational tool and as the basis ... 
Impedance computation for power electronic converters with Hilbert transform
Sanchez Acevedo, Santiago; Tedeschi, Elisabetta; BergnaDiaz, Gilbert; D'Arco, Salvatore; Sanz, Marina (Chapter, 2017)The Hilbert transform (HT) is widely used in signal processing and it has been found as a good tool to understand some physical phenomena in electrical systems. This paper presents a methodology to derive the input impedance ... 
Interfacing MultiMegawatt Offshore Wind Turbines with Modular Multilvel Converters.
Morozovska, Kataryna (Master thesis, 2015)The aim of the master thesis was to investigate the effect of Modular Multilevel Converter (MMC) on wind energy electrical system. In different literature sources MMC is used at the grid side of the turbine. This thesis ... 
Modular Multilevel Converter Control for HVDC Operation: Optimal Shaping of the Circulating Current Signal for Internal Energy Regulation
BergnaDiaz, Gilbert (Doctoral thesis at NTNU;2015:143, Doctoral thesis, 2015)ELECTRICITY will most probably be the dominant form of energy in the upcoming future. Triggered by the decline of fossil fuels along with their elevated and volatile prices, the threat that they represent to national ... 
Optimal Shaping of the MMC Circulating Currents for Preventing ACside Power Oscillations from Propagating into HVDC Grids
BergnaDiaz, Gilbert; Suul, Jon Are Wold; Berne, Erik; Vannier, JeanClaude; Molinas Cabrera, Maria Marta (Journal article; Peer reviewed, 2019)A constrained optimization problem based on the Lagrange multipliers method is formulated to derive the circulating current references of Modular Multilevel Converters (MMC) directly in abc coordinates. The resulting ... 
Particle Swarm Optimization Tuning of Modular Multilevel Converters in a TimeInvariant Framework
BergnaDiaz, Gilbert; Formentini, Andrea; Zanchetta, Pericle; Tedeschi, Elisabetta (Chapter, 2019)This work investigates the Particle Swarm Optimization (PSO) algorithm as a tool to tune the control parameters of a Modular Multilevel Converter (MMC) in a singleterminal HVdc configuration. More precisely, due to its ... 
PI PassivityBased Control and Performance Analysis of MMC Multiterminal HVDC Systems
BergnaDiaz, Gilbert; Zonetti, Daniele; Sanchez Acevedo, Santiago; Ortega, Romeo; Tedeschi, Elisabetta (Journal article; Peer reviewed, 2019)In this paper, a decentralized PI passivitybased controller is applied to modular multilevel converters to ensure global stability of a multiterminal highvoltage direct current system. For the derivation of the controller, ... 
PI Passivitybased Control of Modular Multilevel Converters for MultiTerminal HVDC Systems
BergnaDiaz, Gilbert; Zonetti, Daniele; Sanchez Acevedo, Santiago; Tedeschi, Elisabetta; Ortega, Romeo (Chapter, 2017)In this work, a decentralized PI passivitybased controller (PIPBC) is applied to the Modular Multilevel Converters (MMCs) to ensure global asymptotic stability of a multiterminal MTHVDC system. Since continuous MMC ... 
Port Hamiltonian Modelling of Modular Multilevel Converters with Fixed Equilibrium Point
BergnaDiaz, Gilbert; Sanchez Acevedo, Santiago; Tedeschi, Elisabetta (Chapter, 2017)The paper presents the derivation of a portHamiltonian model of an averaged Modular Multilevel Converter (MMC) that reaches a fixed equilibrium point solution. This MMC model can not be expressed in a straightforward way ... 
Statespace modelling with steadystate time invariant representation of energy based controllers for modular multilevel converters
Freytes, Julian; BergnaDiaz, Gilbert; Suul, Jon Are Wold; D'Arco, Salvatore; Saad, Hani; Guillaud, Xavier (Chapter, 2017)The average value model of the Modular Multilevel Converter (MMC) is in general nonlinear with time periodic variables. Recent developments demonstrated how the MMC model can be transformed into a a SteadyState Time ... 
Sufficient Conditions for Robust Frequency Stability of AC Power Systems
Alves, Erick Fernando; BergnaDiaz, Gilbert; Brandao, Danilo; Tedeschi, Elisabetta (Peer reviewed; Journal article, 2020)This paper analyses the frequency stability of ac grids in the presence of nondispatchable generation and stochastic loads. Its main goal is to evaluate conditions in which the system is robust to large, persistent active ... 
Tuning of Control Loops for GridConnected Modular Multilevel Converters under a Simplified Port Representation for Large System Studies
Sanchez Acevedo, Santiago; Tedeschi, Elisabetta; BergnaDiaz, Gilbert (Chapter, 2017)One of the present barriers to the widespread use of Modular Multilevel Converters (MMC) is the complexity of its control with respect to its predecessors. This paper presents a simple procedure to tune the current and ...