A virtual synchronous generator (VSG) control based on adaptive inertia is proposed to improve dynamic frequency regulation of microgrid. When the system deviates from nominal steady-state value, can exhibit a large slow process and, thus, nadir. And when starts return, small shaped accelerate dynamics with quick transient process. As result, this flexible property combines merits and inertia, which contributes improvement response. The stability algorithm proved by Lyapunov theory,...

In this paper, a distributed hierarchical control is proposed for ac microgrid, which could apply to both grid-connected (GC) mode and islanded (IS) as well transitions. The includes three levels: 1) the basic droop adopted primary control; 2) secondary based on with leaderâĂ"follower consensus protocol; 3) tertiary level mode-supervisory control, manages different targets of four operation modes. Under framework, following are achieved: frequency/voltage recovery accurate power sharing in...

For several reasons, particularly due to the mismatch in feeder impedance, accurate power sharing islanded microgrids is a challenging task. To get around this problem, distributed event-triggered control strategy proposed article. The suggested technique adaptively regulates virtual impedances at both fundamental positive/negative sequence and harmonic frequencies and, therefore, accurately share reactive, unbalanced, harmonics powers among generation units. method requires no information...

In this paper, a voltage modulated direct power control for three-phase pulsewidth rectifier is proposed. With the suggested method, differential equations describing dynamics are changing from linear time-varying system into time-invariant one. way, conventional feedback and feedforward controllers applicable independent of active reactive powers. The proposed method has guaranteed that closed globally exponentially stable. A linearization also employed generating reference inner loops....

To regulate the dc-link voltage of three-phase ac/dc converters, an enhanced state observer-based controller is presented in this letter. The proposed controller, contrary to traditional ones, does not require current measurement and offers a "plug play" capability, rather high disturbance rejection ability robustness against capacitance parameter variation. design procedure suggested discussed, its effectiveness verified using experimental results.

This article presents a reduced-order generalized proportional-integral observer based resonant super-twisting sliding mode controller (RST-SMC) for the three-phase ac-dc converters. On contrary to utilizing in regulating dc-link voltage, which may cause large undershoot/overshoot under disturbance, proposed voltage control strategy has high disturbance rejection ability and settling time been greatly reduced. In addition, RST-SMC current loop not only preserve merits of but also achieve...

Due to the droop control applied in islanded DC microgrids, bus voltage recovery, and current sharing cannot be guaranteed simultaneously. To solve this problem, a distributed dynamic event-triggered method is proposed paper. The presented scheme can remove deviation while achieving among generation (DG) units. In addition, requires no global information, only from physical network needed. Moreover, data of neighboring DGs at times are involved, which greatly reduces communication burden...

Due to the attack signal injection on DC microgrid system, voltage regulation and current sharing cannot be guaranteed overall system may even destabilized. To solve this problem, a generalized extended state observer (GESO)-based distributed attack-resilient control method is proposed for microgrids in paper. The presented scheme can detect mitigate unknown dc/low-frequency/grid-frequency signals while achieving accurate among generation (DG) units. In addition, benefiting from employing...

Due to the unbalanced load connection in sensitive bus (SLB), ac microgrid may suffer from voltage unbalance system. To overcome this issue, article presents a new distributed control scheme achieve compensation for islanded with limited noncontinuous communication among generation (DG) units. In article, two-layer framework, including cyber layer and primary layer, is employed. The proposed strategy that applied implements an event-triggered effectively compensate SLB. contrast centralized...

In this paper, a dc-link voltage protection (DCVP) control method is proposed to address the overvoltage issue due power backfeeding in parallel uninterruptible supply (UPS) system. The able protect inverter against excessive voltage, which increases system reliability and robustness. Moreover, current sharing strategy by online regulating virtual resistance of each UPS module. circulating fundamental harmonic currents caused line impedance mismatching or addition, an improved...

In this paper, we analyze the existence and stability of equilibrium dc micro-grids under master-slave control (where some distributed generations (DGs) are droop with dual-loop (Droop-DGs) DGs MPPT (MPPT-DGs)). Firstly, power-flow equation CPLs is obtained. Then, transform solvability into a fixed point for contraction mapping. Based on Banach's theorem, sufficient condition to guarantee solution in derived. The derived paper not only useful but also control. Besides, calculate solution, an...

To enhance the robustness and disturbance rejection ability of an on-line uninterruptible power supply (UPS) system, internal model control-based dc-link voltage regulation method is proposed in this paper. Furthermore, multimode operations UPS system are investigated their corresponding control strategies proposed. The capable achieving seamless transition traditional normal mode, photovoltaic-aided enhanced eco-mode (EEM), burn-in test mode (BTM). Meanwhile, load promised during...

With the high penetration of renewable energy sources (RES), storage system (ESS) units have been employed as critical components to compensate for power fluctuation generated by RESs in an ac microgrid. However, it's a major challenge achieve state-of-charge (SoC) balance ESS due difference initial SoC values and varied capacities. To deal with this issue, distributed event-triggered control strategy has proposed realize among regulating virtual resistances. Compared existing methods, only...

This study proposes a decentralized coordination control scheme for series-connected H-bridge rectifiers. Each rectifier module is controlled as voltage-controlled source by local controller, which needs only individual information. The controller composed of an active power-frequency (P-ω) and fixed voltage amplitude control. Compared to the conventional methods based multi-level phase-shifting modulation where centralized needed, proposed strategy allows indefinite modular expansion...

Due to the proliferation of critical nonlinear loads in islanded AC microgrids, power quality improvement at sensitive load bus (SLB) is a challenging task. To deal with this issue, distributed event-triggered control strategy for voltage harmonic compensation proposed paper. By applying strategy, generator (DG) units can be employed way compensate SLB. As result, SLB greatly improved. In addition, suggested technique allows measured by one or several dedicated DG compensation, which...

A novel parameter identification method with dynamic impedance regulation is proposed to maintain constant output voltage of wireless power transfer (DWPT) system under varied loads and mutual inductance conditions. The resonant capacitor in the receiver side replaced a switched-controlled (SCC) structure, which enables work two operation modes. And then comprehensive mathematical model established according these modes achieve identification. To avoid deterioration accuracy caused by...

With the high level penetration of power electronics interfaced Distributed Generation (DG) systems, applying these systems to compensate grid voltage unbalance is becoming an important and interesting ancillary service for utility. However, compensating leads active oscillation from DG may cause adverse effects operation. This paper proposes two control strategies compensation with reduced on oscillation. In first strategy, fully cancelled at Point Common Coupling (PCC). cannot be...

This paper presents a reduced-order-enhanced state observer (RESO)-based control strategy for the PWM dc-dc buck converter. With proposed RESO strategy, output voltage regulation of converter is able to achieve robust characteristics against external disturbance and internal parameter variation even without current measurement. In addition, by incorporating in controller, can be easily achieved with only proportional gain realize zero steady-state error. Finally, design discussed...

In the dc microgrid, bus voltage recovery and proper current sharing may be a challenging task under denial of service (DoS) attacks. To get around this issue, distributed edge-based event-triggered control (ETC) strategy is proposed in article. It shown that technique could eliminate deviation achieve DoS attacks by designing new sampling triggered mechanism. As result, system can effectively resist attacks, communication burden greatly relieved. Besides, system's stability proved Lyapunov...

Due to the mismatched line resistance in modular online uninterruptible power supply (UPS) systems, accurate active and harmonic sharing is an arduous work. To tackle this issue, article proposes a distributed dynamic event-triggered control for accurately compensate effect of mismatch among resistances. Benefiting from proposed strategy, UPS modules adaptively regulate virtual at fundamental frequencies, hence, are achieved. In addition, suggested technique allows exchange information only...

This paper presents a linear active disturbance rejection control (LADRC) for grid-connected converter with LCL filter. The high performance external disturbance, internal decoupling, parameter variation is achieved by adopting extended state observer(ESO) and designing controller direct pole placement. Robustness of uncertainty sensitivity input are analyzed in frequency domain to demonstrate the superior characteristic rejection. theoretical analysis verified Matlab/Simulink. simulation...

In this paper, first, the existing frequency and voltage amplitude restoration control strategies are reviewed. Moreover, proposed second order washout filter strategy is to enhance dynamic response under load disturbance. The physical parameter of method derived, system stability for discussed. Finally, extensive simulation results provided verify effectiveness UPS system.

In this paper, a regeneration protection solution is proposed to address the dc-link overvoltage issue and unequal power sharing in parallel uninterruptible supply (UPS) systems. First, voltage control strategy protect inverter against excessive that may trigger mechanism of UPS system. addition, an active power-sharing by regulating virtual resistance solve circulating current caused issue. Finally, feasibility verified experimental results from system prototype.

In this article, a novel hybrid voltage/current control scheme with low-communication burden is proposed for series-type inverters in decentralized manner. All the inverter units are controlled by their individual local controllers without real-time central global-communication. Among them, few serve as current (CCIs) to regulate grid current, and rest work voltage (VCIs). Under architecture, five main targets achieved: 1) frequency self-synchronization of each VCI based on phase-angle...