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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Fri, 19 Apr 2024 21:54:45 GMT2024-04-19T21:54:45ZOn Comprehensive Description and Analysis of MMC Control Design: Simulation and Experimental Study
http://hdl.handle.net/10985/18482
On Comprehensive Description and Analysis of MMC Control Design: Simulation and Experimental Study
ZHANG, Haibo; BELHAOUANE, Mohamed Moez; COLAS, Frederic; KADRI RIAD; GUILLAUD, Xavier; GRUSON, Francois
This paper presents an evolution of control systems of Modular Multilevel Converters (MMCs) focusing on the internal voltages and currents dynamics. MMCs have passive components that create extra dynamics compared to conventional VSCs. Some control schemes that do not consider these internal dynamics may still stabilize the system asymptotically thanks to the linearisation in the modulation step. However these control schemes are less robust because they are prone to poor damped oscillations on the dc side of the converter. The MMC circuit and energy relationships are presented in this paper. Along with a gradual development of the energy based control, the important roles of each internal dynamics are clearly demonstrated. Experimental results are presented to show the impacts of the linearisation in the modulation step on the system behaviour.
Wed, 01 Jan 2020 00:00:00 GMThttp://hdl.handle.net/10985/184822020-01-01T00:00:00ZZHANG, HaiboBELHAOUANE, Mohamed MoezCOLAS, FredericKADRI RIADGUILLAUD, XavierGRUSON, FrancoisThis paper presents an evolution of control systems of Modular Multilevel Converters (MMCs) focusing on the internal voltages and currents dynamics. MMCs have passive components that create extra dynamics compared to conventional VSCs. Some control schemes that do not consider these internal dynamics may still stabilize the system asymptotically thanks to the linearisation in the modulation step. However these control schemes are less robust because they are prone to poor damped oscillations on the dc side of the converter. The MMC circuit and energy relationships are presented in this paper. Along with a gradual development of the energy based control, the important roles of each internal dynamics are clearly demonstrated. Experimental results are presented to show the impacts of the linearisation in the modulation step on the system behaviour.Improving Small-Signal Stability of an MMC With CCSC by Control of the Internally Stored Energy
http://hdl.handle.net/10985/12894
Improving Small-Signal Stability of an MMC With CCSC by Control of the Internally Stored Energy
FREYTES, Julian; BERGNA, Gilbert; JON ARE, SUUL; D'ARCO, Salvatore; COLAS, Frédéric; SAAD, Hani; GUILLAUD, Xavier; GRUSON, Francois
The DC-side dynamics of Modular Multilevel Converters (MMCs) can be prone to poorly damped oscillations or stability problems when the second harmonic components of the arm currents are mitigated by a Circulating Current Suppression Controller (CCSC). This paper demonstrates that the source of these oscillations is the uncontrolled interaction of the DC-side current and the internally stored energy of the MMC, as resulting from the CCSC. Stable operation and improved performance of the MMC control system can be ensured by introducing closed loop control of the energy and the DC-side current. The presented analysis relies on a detailed state-space model of the MMC which is formulated to obtain constant variables in steady state. The resulting state-space equations can be linearized to achieve a Linear Time Invariant (LTI) model, allowing for eigenvalue analysis of the small-signal dynamics of the MMC. Participation factor analysis is utilized to identify the source of the poorly damped DC-side oscillations, and indicates the suitability of introducing control of the internal capacitor voltage or the corresponding stored energy. An MMC connected to a DC power source with an equivalent capacitance, and operated with DC voltage droop in the active power flow control, is used as an example for the presented analysis. The developed small-signal models and the improvement in small-signal dynamics achieved by introducing control of the internally stored energy are verified by time-domain simulations in comparison to an EMT simulation model of an MMC with 400 sub-modules per arm.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/128942018-01-01T00:00:00ZFREYTES, JulianBERGNA, GilbertJON ARE, SUULD'ARCO, SalvatoreCOLAS, FrédéricSAAD, HaniGUILLAUD, XavierGRUSON, FrancoisThe DC-side dynamics of Modular Multilevel Converters (MMCs) can be prone to poorly damped oscillations or stability problems when the second harmonic components of the arm currents are mitigated by a Circulating Current Suppression Controller (CCSC). This paper demonstrates that the source of these oscillations is the uncontrolled interaction of the DC-side current and the internally stored energy of the MMC, as resulting from the CCSC. Stable operation and improved performance of the MMC control system can be ensured by introducing closed loop control of the energy and the DC-side current. The presented analysis relies on a detailed state-space model of the MMC which is formulated to obtain constant variables in steady state. The resulting state-space equations can be linearized to achieve a Linear Time Invariant (LTI) model, allowing for eigenvalue analysis of the small-signal dynamics of the MMC. Participation factor analysis is utilized to identify the source of the poorly damped DC-side oscillations, and indicates the suitability of introducing control of the internal capacitor voltage or the corresponding stored energy. An MMC connected to a DC power source with an equivalent capacitance, and operated with DC voltage droop in the active power flow control, is used as an example for the presented analysis. The developed small-signal models and the improvement in small-signal dynamics achieved by introducing control of the internally stored energy are verified by time-domain simulations in comparison to an EMT simulation model of an MMC with 400 sub-modules per arm.Coupling Influence on the dq Impedance Stability Analysis for the Three-Phase Grid-Connected Inverter
http://hdl.handle.net/10985/17101
Coupling Influence on the dq Impedance Stability Analysis for the Three-Phase Grid-Connected Inverter
LI, Chuanyue; QORIA, Taoufik; COLAS, Frédéric; JUN, Liang; WENLONG, Ming; GUILLAUD, X.; GRUSON, Francois
The dq impedance stability analysis for a grid-connected current-control inverter is based on the impedance ratio matrix. However, the coupled matrix brings difficulties in deriving its eigenvalues for the analysis based on the general Nyquist criterion. If the couplings are ignored for simplification, unacceptable errors will be present in the analysis. In this paper, the influence of the couplings on the dq impedance stability analysis is studied. To take the couplings into account simply, the determinant-based impedance stability analysis is used. The mechanism between the determinant of the impedance-ratio matrix and the inverter stability is unveiled. Compared to the eigenvalues-based analysis, only one determinant rather than two eigenvalue s-function is required for the stability analysis. One Nyquist plot or pole map can be applied to the determinant to check the right-half-plane poles. The accuracy of the determinant-based stability analysis is also checked by comparing with the state-space stability analysis method. For the stability analysis, the coupling influence on the current control, the phase-locked loop, and the grid impedance are studied. The errors can be 10% in the stability analysis if the couplings are ignored.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10985/171012019-01-01T00:00:00ZLI, ChuanyueQORIA, TaoufikCOLAS, FrédéricJUN, LiangWENLONG, MingGUILLAUD, X.GRUSON, FrancoisThe dq impedance stability analysis for a grid-connected current-control inverter is based on the impedance ratio matrix. However, the coupled matrix brings difficulties in deriving its eigenvalues for the analysis based on the general Nyquist criterion. If the couplings are ignored for simplification, unacceptable errors will be present in the analysis. In this paper, the influence of the couplings on the dq impedance stability analysis is studied. To take the couplings into account simply, the determinant-based impedance stability analysis is used. The mechanism between the determinant of the impedance-ratio matrix and the inverter stability is unveiled. Compared to the eigenvalues-based analysis, only one determinant rather than two eigenvalue s-function is required for the stability analysis. One Nyquist plot or pole map can be applied to the determinant to check the right-half-plane poles. The accuracy of the determinant-based stability analysis is also checked by comparing with the state-space stability analysis method. For the stability analysis, the coupling influence on the current control, the phase-locked loop, and the grid impedance are studied. The errors can be 10% in the stability analysis if the couplings are ignored.Design, implementation and testing of a Modular Multilevel Converter
http://hdl.handle.net/10985/12896
Design, implementation and testing of a Modular Multilevel Converter
KADRI, Riad; COLAS, Frédéric; GUILLAUD, Xavier; DELARUE, Philippe; BERGE, Marta; DENNETIERE, Sébastien; OULD BACHIR, Tarek; GRUSON, Francois
The Modular Multilevel Converter (MMC) is a power electronic structure used for high voltage adjustable speed drives applications as well as power transmission applications and high-voltage direct current. MMC structure presents many advantages such as modularity, the absence of a high voltage DC bus and very low switching frequency. It presents also some disadvantages such as modeling complexity and control due to the large number of semiconductors to control. The objectives of this paper are to present the methodology to design a laboratory MMC converter and its control system. This methodology is based on an intensive used of real-time simulation, to develop and test the control algorithm is proposed. This MMC prototype must be as realistic as possible to a full scale MMC, with a large number of sub-modules (i.e. 640 kV on the DC side, a rated power of 1 GW and 400 sub-modules). A control hardware integrating distributed processors (one for each arm) and a master control is presented. The protocols to validate sub-modules, arms and the converter are explained.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/10985/128962017-01-01T00:00:00ZKADRI, RiadCOLAS, FrédéricGUILLAUD, XavierDELARUE, PhilippeBERGE, MartaDENNETIERE, SébastienOULD BACHIR, TarekGRUSON, FrancoisThe Modular Multilevel Converter (MMC) is a power electronic structure used for high voltage adjustable speed drives applications as well as power transmission applications and high-voltage direct current. MMC structure presents many advantages such as modularity, the absence of a high voltage DC bus and very low switching frequency. It presents also some disadvantages such as modeling complexity and control due to the large number of semiconductors to control. The objectives of this paper are to present the methodology to design a laboratory MMC converter and its control system. This methodology is based on an intensive used of real-time simulation, to develop and test the control algorithm is proposed. This MMC prototype must be as realistic as possible to a full scale MMC, with a large number of sub-modules (i.e. 640 kV on the DC side, a rated power of 1 GW and 400 sub-modules). A control hardware integrating distributed processors (one for each arm) and a master control is presented. The protocols to validate sub-modules, arms and the converter are explained.Energy and director switches commutation controls for the alternate arm converter
http://hdl.handle.net/10985/14358
Energy and director switches commutation controls for the alternate arm converter
VERMEERSCH, Pierre; GUILLAUD, Xavier; MERLIN, Michael M.C.; EGROT, Philippe; GRUSON, Francois
The Alternate Arm Converter (AAC) is promising multilevel Voltage Source Converter (VSC) suitable for High Voltage Direct Current (HVDC) transmission systems. This converter exhibits interesting features such as a DC Fault Ride Through capability thanks to the use of Full-Bridge Sub-Modules (SM) and a smaller footprint than an equivalent Modular Multilevel Converter (MMC). After an analysis of the converter operating modes called Non-overlap and Overlap mode, a sequential representation of the AAC operation is proposed. The main originality of this paper is the use of the Petri Net to describe all the phases and to highlight their sequencing. According to the phases identified thanks to the sequential approach, models and control structures for the grid currents, the internal energy and the Zero Current Switching (ZCS) are detailed. Furthermore, the step-by-step approach proposed in this paper allows a clear and rigorous modelling of this complex converter.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/143582018-01-01T00:00:00ZVERMEERSCH, PierreGUILLAUD, XavierMERLIN, Michael M.C.EGROT, PhilippeGRUSON, FrancoisThe Alternate Arm Converter (AAC) is promising multilevel Voltage Source Converter (VSC) suitable for High Voltage Direct Current (HVDC) transmission systems. This converter exhibits interesting features such as a DC Fault Ride Through capability thanks to the use of Full-Bridge Sub-Modules (SM) and a smaller footprint than an equivalent Modular Multilevel Converter (MMC). After an analysis of the converter operating modes called Non-overlap and Overlap mode, a sequential representation of the AAC operation is proposed. The main originality of this paper is the use of the Petri Net to describe all the phases and to highlight their sequencing. According to the phases identified thanks to the sequential approach, models and control structures for the grid currents, the internal energy and the Zero Current Switching (ZCS) are detailed. Furthermore, the step-by-step approach proposed in this paper allows a clear and rigorous modelling of this complex converter.Direct AC Voltage Control for Grid-Forming Inverters
http://hdl.handle.net/10985/17961
Direct AC Voltage Control for Grid-Forming Inverters
QORAI, Taoufik; LI, Chuanyue; OUE, Ko; COLAS, Frédéric; GUILLAUD, Xavier; GRUSON, Francois
Grid-forming inverters usually use inner cascaded controllers to regulate output AC voltage and converter output current. However, at the power transmission system level where the power inverter bandwidth is limited, i.e., low switching frequency, it is difcult to tune controller parameters to achieve the desired performances because of control loop interactions. In this paper, a direct AC voltage control-based state-feedback control is applied. Its control gains are tuned using a linear quadratic regulator. In addition, a sensitivity analysis is proposed to choose the right cost factors that allow the system to achieve the imposed specifcations. Conventionally, a system based on direct AC voltage control has no restriction on the inverter current. Hence, in this paper, a threshold virtual impedance has been added to the state-feedback control in order to protect the inverter against overcurrent. The robustness of the proposed control is assessed for diferent short-circuit ratios using smallsignal stability analysis. Then, it is checked in diferent grid topologies using time domain simulations. An experimental test bench is developed in order to validate the proposed control.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10985/179612019-01-01T00:00:00ZQORAI, TaoufikLI, ChuanyueOUE, KoCOLAS, FrédéricGUILLAUD, XavierGRUSON, FrancoisGrid-forming inverters usually use inner cascaded controllers to regulate output AC voltage and converter output current. However, at the power transmission system level where the power inverter bandwidth is limited, i.e., low switching frequency, it is difcult to tune controller parameters to achieve the desired performances because of control loop interactions. In this paper, a direct AC voltage control-based state-feedback control is applied. Its control gains are tuned using a linear quadratic regulator. In addition, a sensitivity analysis is proposed to choose the right cost factors that allow the system to achieve the imposed specifcations. Conventionally, a system based on direct AC voltage control has no restriction on the inverter current. Hence, in this paper, a threshold virtual impedance has been added to the state-feedback control in order to protect the inverter against overcurrent. The robustness of the proposed control is assessed for diferent short-circuit ratios using smallsignal stability analysis. Then, it is checked in diferent grid topologies using time domain simulations. An experimental test bench is developed in order to validate the proposed control.Tuning of Cascaded Controllers for Robust Grid-Forming Voltage Source Converter
http://hdl.handle.net/10985/14835
Tuning of Cascaded Controllers for Robust Grid-Forming Voltage Source Converter
QORIA, Taoufik; COLAS, Frédéric; GUILLAUD, Xavier; DEBRY, Marie-Sophie; PREVOST, Thierry; GRUSON, Francois
From the origin of the grid, energy has been delivered to electrical loads mainly by synchronous machines. All the main rules to manage the grid have been based on the electromechanical behavior of these machines which have been extensively studied for many years. Due to the increase of HVDC link and renewable energy sources as wind turbine and PV, power converters are massively introduced in the grid with a fundamentally different dynamic behavior. Some years ago, they were connected as simple power injector. Then, they were asked to provide some ancillary services to the grid, in the future, grid forming capability will be required. Even if grid-forming converters had been extensively studied for microgrids and offshore grids, it has to be adapted to transmission grid where the topology may be largely modified. This paper presents an algorithm for calculating the controller parameters of a grid-forming converter which guarantee a stable behavior for many different configurations of the grid.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/148352018-01-01T00:00:00ZQORIA, TaoufikCOLAS, FrédéricGUILLAUD, XavierDEBRY, Marie-SophiePREVOST, ThierryGRUSON, FrancoisFrom the origin of the grid, energy has been delivered to electrical loads mainly by synchronous machines. All the main rules to manage the grid have been based on the electromechanical behavior of these machines which have been extensively studied for many years. Due to the increase of HVDC link and renewable energy sources as wind turbine and PV, power converters are massively introduced in the grid with a fundamentally different dynamic behavior. Some years ago, they were connected as simple power injector. Then, they were asked to provide some ancillary services to the grid, in the future, grid forming capability will be required. Even if grid-forming converters had been extensively studied for microgrids and offshore grids, it has to be adapted to transmission grid where the topology may be largely modified. This paper presents an algorithm for calculating the controller parameters of a grid-forming converter which guarantee a stable behavior for many different configurations of the grid.Modular Multilevel DC Converter : Impact of the Control on the Design and Efficiency
http://hdl.handle.net/10985/24282
Modular Multilevel DC Converter : Impact of the Control on the Design and Efficiency
BOUKHENFOUF, Johan; VERMEERSCH, Pierre; DELARUE, Philippe; LEMOIGNE, Philippe; COLAS, Frédéric; GUILLAUD, Xavier; GRUSON, Francois
The Modular Multilevel DC Converter is an attractive non-isolated topology to inter- connect High Voltage DC Links. This paper presents the interaction among control, component design and efficiency of this converter. The impact of the two degrees of freedom on the design and the efficiency is analyzed.
Fri, 01 Sep 2023 00:00:00 GMThttp://hdl.handle.net/10985/242822023-09-01T00:00:00ZBOUKHENFOUF, JohanVERMEERSCH, PierreDELARUE, PhilippeLEMOIGNE, PhilippeCOLAS, FrédéricGUILLAUD, XavierGRUSON, FrancoisThe Modular Multilevel DC Converter is an attractive non-isolated topology to inter- connect High Voltage DC Links. This paper presents the interaction among control, component design and efficiency of this converter. The impact of the two degrees of freedom on the design and the efficiency is analyzed.Energetic Macroscopic Representati on and Inversion Based Control of a Modular Multilevel Converter.
http://hdl.handle.net/10985/10045
Energetic Macroscopic Representati on and Inversion Based Control of a Modular Multilevel Converter.
DELARUE, Philippe; GRUSON, Francois; GUILLAUD, Xavier
This papers deals with the Modular Multilevel Converter (MMC). This structure is a real breakthrough which allows transmitting huge amount of power in DC link. In the last ten years, lots of papers have been written but most of them study some intuitive control algorithms. This paper proposes a formal analysis of MMC model which leads to the design of a control algorithm thanks to the inversion of the model. The Energetic Macroscopic Representation is used for achieving this goal. All the states variables are controlled to manage the energy of the system, avoid some instable operational points and determine clearly all the dynamics of the different loops of the system.
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10985/100452014-01-01T00:00:00ZDELARUE, PhilippeGRUSON, FrancoisGUILLAUD, XavierThis papers deals with the Modular Multilevel Converter (MMC). This structure is a real breakthrough which allows transmitting huge amount of power in DC link. In the last ten years, lots of papers have been written but most of them study some intuitive control algorithms. This paper proposes a formal analysis of MMC model which leads to the design of a control algorithm thanks to the inversion of the model. The Energetic Macroscopic Representation is used for achieving this goal. All the states variables are controlled to manage the energy of the system, avoid some instable operational points and determine clearly all the dynamics of the different loops of the system.Synthesis of different types of energy based controller for a Modular Multilevel Converter integrated in a HVDC link
http://hdl.handle.net/10985/10783
Synthesis of different types of energy based controller for a Modular Multilevel Converter integrated in a HVDC link
SAMIMI, Shabab; DELARUE, Philippe; GUILLAUD, Xavier; GRUSON, Francois
Modular Multilevel Converters 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. Few of them are addressing explicitly the 2 different roles that are held by this converter in a HVDC link: controlling the power or controlling the DC voltage level. Moreover, for a given function, different ways of controlling this converter may be considered. This paper proposes an overview of the different solutions for controlling the MMC and proposes a methodology to synthesize the control architecture.
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/10985/107832015-01-01T00:00:00ZSAMIMI, ShababDELARUE, PhilippeGUILLAUD, XavierGRUSON, FrancoisModular Multilevel Converters 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. Few of them are addressing explicitly the 2 different roles that are held by this converter in a HVDC link: controlling the power or controlling the DC voltage level. Moreover, for a given function, different ways of controlling this converter may be considered. This paper proposes an overview of the different solutions for controlling the MMC and proposes a methodology to synthesize the control architecture.