The increasing interest in integrating intermittent renewable energy sources into microgrids presents major challenges from the viewpoints of reliable operation and control. In this paper, issues microgrid control are discussed, a review state-of-the-art strategies trends is presented; general overview main principles (e.g., droop control, model predictive multi-agent systems) also included. paper classifies three levels: primary, secondary, tertiary, where primary secondary levels...

The modular multilevel converter (MMC) is a newly introduced switch-mode topology with the potential for high-voltage direct current (HVDC) transmission applications. This paper focuses on dynamic performance of an MMC-based, back-to-back HVDC system. A phase-disposition (PD) sinusoidal pulsewidth modulation (SPWM) strategy, including voltage balancing method, operation MMC presented in this paper. Based proposed PD-SPWM switching mathematical model MMC-HVDC system, under both balanced and...

This task force paper summarizes the state-of-the-art real-time digital simulation concepts and technologies that are used for analysis, design, testing of electric power system its apparatus. highlights main building blocks simulator, i.e., hardware, software, input-output systems, modeling, solution techniques, interfacing capabilities to external hardware various applications. It covers most commonly simulators in both industry academia. A comprehensive list is provided a tabular review....

The modular multilevel converter (MMC) is one of the most potential topologies for high-power/voltage systems, specifically high-voltage direct current (HVDC). One main technical challenges an MMC to eliminate/minimize circulating currents arms while capacitor voltages are maintained balanced. This paper proposes a model predictive control (MPC) strategy that takes advantage cost function minimization technique eliminate and carry out voltage balancing task MMC-based back-to-back HVDC...

Performance of a carrier-based pulsewidth modulation (CB-PWM) strategy can be improved by the inclusion zero-sequence voltage in modulation-reference signal. This paper proposes new CB-PWM for three-level neutral-point-clamped (NPC) converter, which is based on injection. By voltage, sinusoidal-modulation reference modified to 1) carry out voltage-balancing task dc-link capacitors, with no additional control effort, 2) reduce switching losses, and 3) low-frequency oscillations neutral point....

Voltage-source converter (VSC) technologies are rapidly evolving and increasing the range of applications in a variety fields within power industry. Existing two- three-level VSC being superseded by new modular multilevel (MMC) technology for HVDC applications. The computational burden caused detailed modeling MMC–HVDC systems electromagnetic transient-type (EMT-type) programs complicates simulation transients when such integrated into large networks. This paper develops compares different...

The modular multilevel converter (MMC) has become the most promising technology for high-voltage direct current (HVDC) transmission systems. However, similar to any other voltage-sourced converter-based HVDC system, MMC-HVDC systems with half-bridge submodules (SMs) lack capability of handling dc-side short-circuit faults, which are severe concern overhead lines. In this paper, two new SM circuit configurations as well a hybrid design methodology embed dc-fault-handling in proposed. By...

The modular multilevel converter (MMC) is a potential candidate for medium/high-power applications, specifically high-voltage direct current transmission systems. One of the main challenges in control an MMC to eliminate/minimize circulating currents while capacitor voltages are maintained balanced. This paper proposes strategy using finite set model predictive (FCS-MPC). A bilinear mathematical derived and discretized predict states one step ahead. Within each switching cycle, best state...

Solid-state transformer (SST) and hybrid (HT) are promising alternatives to the line-frequency (LFT) in smart grids. The SST features medium-frequency isolation, full controllability for voltage regulation, reactive power compensation, capability of battery energy storage system (BESS) integration with multiport configuration. HT has a partially rated converter fractional can integrate small BESS. Fast grid-edge fluctuations from increased solar photovoltaic (PV) electric vehicle (EV)...

This article presents a cost-effective dynamic wireless power transfer (DWPT) system for efficient and stable output charging of autonomous moving equipment. The proposed is realized based on low-cost segmented configuration flexible operating strategy. Specifically, the combination <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</i> -series/series topology extended transmitter (Tx) coils. eliminates cross-coupling impact adjacent Tx coils...

The phenomenon of dc-capacitor-voltage drift is the main technical drawback a passive front-end multilevel diode-clamped converter (DCC). This paper formulates and analyzes dc-capacitor-voltage-drift five-level DCC, which operates based on sinusoidal pulsewidth-modulation (SPWM) switching strategy. analysis shows dependence voltage modulation index ac-side power factor DCC. concludes that an SPWM strategy, without use auxiliary circuitry, not able to prevent voltage-drift also proposes...

The modular multilevel converter (MMC) is a potential candidate for medium/high-power applications, specifically high-voltage direct current (HVDC) transmission systems. One of the technical challenges associated with control an MMC to carry out submodule (SM) capacitor voltages balancing task without imposing any unnecessary switching transition among SMs. This paper develops general framework voltage MMC. Based on developed and objective reducing transitions SMs, three voltage-balancing...

This paper introduces a novel hybrid seven-level converter that is based on the upgrade of five-level active neutral-point-clamped concept and suitable for high-power applications. The provides comprehensive analysis operation converter. Based analysis, space vector modulation (SVM)-based switching strategy takes advantage redundant vectors SVM to counteract voltage drift phenomenon proposed proposed. limit range also presented. It shown ability stabilize dc-link capacitor voltages per-phase...

The modular multilevel converter (MMC) is increasingly becoming popular for multi-MW drive systems. One of the main technical challenges associated with operation MMC adjustable-speed drives large magnitude submodule (SM) capacitor voltage ripple under constant-torque low-speed operation. This paper proposes two new control strategies to reduce SM in MMC-based systems proposed are based on injecting a square-wave common-mode at ac-side and circulating current within phase-legs attenuate...

The ever increasing penetration depth of Distribution Energy Resources (DER) and the development power electronics devices have a significant impact on DC transmission distribution systems. This paper provides an overview recent advancement also envisioned research grids, with objective identification discussion corresponding issues. Brief descriptions grids at various voltage levels their benefits are presented discussed. Different layouts for associated technical issues highlighted.

The DC-capacitor voltage drift is the main technical drawback of a multilevel diode-clamped converter (DCC) system. This paper proposes space vector modulation (SVM)-based switching strategy that takes advantage redundant states SVM to counteract phenomenon five-level DCC-based back-to-back high-voltage direct-current (HVDC) proposed based on online minimization quadratic cost function, associated with deviations dc capacitors. salient feature it enables balancing DC capacitors no...

The trend towards multimegawatt (multi-MW) wind turbines and the increasing interest in direct-drive variable-speed energy systems have made multilevel converters a promising candidate for large conversion systems. This paper presents new hybrid modular converter interfacing full-scale, permanent magnet synchronous generator (PMSG)-based system (WECS). proposed converter, which is used on grid side of system, consists three-level (MMC) series connection with three H-bridge modules....

Proper operation of a multilevel flying capacitor converter (FCC) necessitates closed-loop voltage balancing strategy. This paper proposes space vector modulation (SVM)-based approach that benefits from the switching state redundancy an <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</i> -level FCC to implicitly carry out task within Based on deviations voltages, cost function is defined and minimized choose proper redundant states among...

Cross regulation is the main technical challenge of a single-inductor multiple-output (SIMO) dc-dc converter. This paper proposes multivariable digital controller to suppress cross dual-output (SIDO) buck converter in continuous conduction mode (CCM) operation. The design methodology originates from open-loop shaping multi-input multi-output (MIMO) systems. control procedure includes: 1) determination family nonparametric models SIDO at operating points interest, 2) class controller, and 3)...

The modular multilevel converter (MMC) has become one of the most promising topologies for medium/high-power applications. Since MMC is structured based upon stacking up a number series-connected identical submodules (SMs), to improve its fault tolerance and reliability, SM failure detection location significant importance. In this paper, impact open-circuit switch failures SMs on operation analyzed. Based analysis under conditions, two methods are proposed, that is, clustering algorithm...

The modular multilevel converter (MMC) has attracted significant interest for medium-/high-power energy conversion applications due to its modularity, scalability, and excellent harmonic performance. One of the technical challenges associated with operation MMC is circulation double-frequency currents within phase legs. This paper proposes a circulating current control strategy in rotating reference frame, which, contrary existing solutions that are based on approximate/inaccurate models,...

The modular multilevel converter (MMC) is one of the most potential topologies for medium/high power/voltage applications. One main technical challenges an MMC to eliminate/minimize circulating currents within legs. Circulating currents, if not properly controlled, increase amplitude capacitor voltage variations, rating values components and losses. This paper proposes a closed-loop current control strategy specifically minimize variations. proposed based on adding offset signal modulating...

This article proposes a magnetic integration design for EV wireless power transfer (WPT) systems, where the compensation and transmitting coils overlap one on top of other to share ferrite layer without any decoupling consideration. The field generated by both are exploited power. To this end, method is proposed enable enhancement reactive flow between coils, achieve input zero phase angle constant current output. In addition, an efficient finite element analysis-based coil optimization...

The dc-dc modular multilevel converter (MMC), which has originated from the ac-dc MMC circuit topology, is an attractive topology for interconnection of medium-/high-voltage dc grids. Proper operation necessitates injection ac circulating current to maintain its submodule (SM) capacitor voltages balanced. current, however, needs be minimized efficiency improvement. In addition, a unique type imbalance amongst SM that caused by power flow mitigated. This paper proposes closed-loop control...