In this paper, a small-signal model of voltage source converter (VSC) is developed to investigate the stability dc-link control. This contributes representing dynamics characteristics VSC integrated weak grid. Effects grid strength, operating point, and control loops' interactions on performance are taken into consideration. Based proposed model, eigenvalue analysis employed study with varying conditions. Analysis results show that introduce partial positive feedback in Furthermore, effect...

This paper analyzes DC-link voltage stability as affected by phase locked loop (PLL) in source converters (VSC) when connected to weak grid. PLL has an impact on power transferred the grid from VSC due active/reactive current regulation aligned reference frame. voltage, directly related flows, is then dynamics. Interactions between and control are more serious where terminal input of PLL, becomes susceptible flow variations VSC. In this paper, a system with infinite bus via impedance studied...

With increasing application of voltage source converters (VSCs), electromagnetic stability, characterized by fast dynamics and controls elements such as inductors capacitors, becomes challenging for power system stability. This paper investigates modeling stability analysis VSC internal in dc-link timescale. Concepts inertia, damping power, synchronizing are introduced to provide a physical insight into issue. Internal can be identified analyzing powers. Insufficient either or will result...

This paper investigates the impact of phase-locked loop (PLL) dynamic on stability DC-link voltage control (DVC) in source converter (VSC) attached to weak grid. To start with, a small signal model VSC grid DVC timescale is presented for analysis. On basis, characteristics are analyzed from perspective damping and restoring components which can determine stability. With considering PLL dynamic, it found that performs as phase-lag regulation generates additional negative component grid, thus...

This paper contributes to giving physical insights into stability of DC-link voltage control in multi-wind turbines integrated weak grid. Wind farm operation will suffer from integrating AC grid, due strong coupling between the wind and grid dynamics. Multi-VSCs model is presented for analysis with effect among VSCs strength. Based on model, self-impact components interaction-impact are study interactions VSCs. Impacts studied by investigating variations considering strength, operating point...

This paper investigates the effect of control-loops interactions on power stability limits voltage-source converter (VSC) as connected to an ac system. The focus is put physical mechanism in VSC, revealing that among control loops result production additional loop. open-loop gain loop employed quantify severity control-loop interactions. Furthermore, current sensitivity, closely related interactions, applied estimate maximum transferrable VSC grid. On basis, analysis results show between...

In this paper, effect of reactive power control (RPC) on the stability DC-link voltage (DVC) in source converter (VSC) when attached to weak grid is investigated. grid, disturbance DVC leads variations terminal and makes RPC respond. turn, contributes output variation influences DVC. behaves as a lagging regulator for results active output. Referencing analysis theory synchronous machine, damping restoring components are proposed. Stability affected by analyzed evaluating influence...

This paper presents an improved virtual synchronous control (VSynC) for the grid-connected voltage source converter (VSC) so as to continuously operate under grid with steady unbalance. The VSynC introduces negative sequence power controls on basis of conventional VSynC. is capable regulating internal reduce negative-sequence injected currents and oscillated powers VSC aroused by voltage. Three alternative local objectives itself state unbalanced conditions their corresponding references are...

Due to the power mismatches between residential load and rooftop photovoltaic (PV) generation, voltage profile of low-voltage distribution system (LVDN) may exceed allowable limit during daytime is well below lower at night. To solve this problem, an optimal configuration battery energy storage (BES) systems used for PV improve LVDN. Firstly, typical curves electric generation are analysed demonstrate principle integrated regulation method. Secondly, two-stage strategy proposed minimise...

In order to solve the problem of insufficient reliability diesel engine as emergency power supply pumped storage station, a grid-connected/islanded control strategy PV and battery systems station is proposed. To begin with, strategies different operation modes optical system are introduced. grid-connected mode, PQ used coordinate output meet load demand. When faults occur in grid, switch islanded mode. At this time, adopts V / F maintain stability voltage frequency. The still uses control,...

This study presents the results of hybrid energy storage system (HESS) and improved maximum power point tracking (MPPT) algorithm simulation analysis undertaken to improve smoothing performance solar photovoltaic (PV) plant installed in ship system. Frequency hierarchical control is used assign high-frequency oscillation part supercapacitor low-frequency battery. Meanwhile, MPPT also limit output PV plant, which can reduce necessary capacity HESS further. The effectiveness proposed method...

LEO satellite networks are becoming more and important because of their potential effectiveness in promoting simultaneous data transmission global coverage the future. However, dynamic changes network topology intermittency inter-satellite links (ISLs) inevitably bring severe challenges to multipath traffic scheduling. In response these challenges, we propose an adaptive scheduling algorithm for based on pheromone, which pheromone is used characterize state perform topological change...

This paper studies the coordinated reactive power control strategy of combined system new energy plant and storage station. Firstly, a multi time scale model voltage for station flexible connected to AC/DC hybrid grid is established. The divided into current scale, command dispatching scale. Then, proposed. Finally, domain simulation plants established, coordination connecting verified in simulation. results show that proposed has good dynamic characteristics stability.

This paper investigates the stability of photovoltaic(PV) and battery energy storage systems integrated to weak grid. In order analyze issue, a small-signal model PV inverter connected grid is established. The effects output power under condition constant generation strength on are analyzed. Analysis results show that, with decrease strength, declines, increase PV, too. Finally, time-domain built verify correctness analysis.

Distributed Denial-of-Service (DDoS) attack is a long-lived that hugely harmful to the Internet. In particular, emergence of new type DDoS called Link Flooding Attack (LFA) makes detection and defense more difficult. LFA, attacker cuts off specific area by controlling large numbers bots send low-rate traffic congest selected links. Since flows are similar legitimate ones, traditional schemes like anomaly intrusion no longer applicable. Blockchain provides solution address this issue. paper,...

Recent works have shown that phase-locked loop (PLL) synchronized wind turbines (WTs) suffer stability issues when integrated into weak grids. However, most of the current studies are limited to a single machine case, interactions among WTs usually overlooked. This paper multiple doubly-fed induction generators (DFIGs) connected in parallel AC grid. A state space model two-DFIG system is firstly presented. Subsequently, eigenvalue sensitivity analysis shows instability can occur at low...

The DC-link voltage control (DVC) timescale (i.e., the frequency dynamics covering converter outer controls) instabilities in wind generation have gained increased attention recently. This paper presents DVC modeling and stability analysis for multi doubly-fed induction generators (DFIGs) connected to weak AC grids. A reduced-order, small-signal model of a grid-tied multi-DFIG system, designed analysis, is firstly proposed. allows dynamic interactions among control, active power (APC),...

This study investigates design and analysis of direct current (DC)-link voltage stabiliser for source converter (VSC) as connected to weak grid. To begin with, stability mechanism VSC is investigated with integrated It found that phase-locked loop terminal control perform a lagging regulation DC-link control, decreasing system. According the mechanism, needs provide leading eliminate negative effects. Then, scheme, effect are studied. Design schemes stabiliser's inner loops presented by bode...

This study investigates modelling of multi-voltage source converters (VSCs) in DC voltage control timescale for small-signal stability analysis. Multi-VSCs a is impacted due to the coupling among their systems and grid dynamics. With considering loops interactions dynamics, multi-VSCs’ model proposed Control contain loop, terminal loop phase-locked loop. Furthermore, VSC dynamics are separated. Besides, eigenvalues analysis conducted multi-VSCs timescale. Impacts strength on verified.

In this paper, a coordinated planning method for reliability and economy of distribution network with PV energy integration is studied. order to establish the model, power loss different loads evaluated construct user's function. The supply users under safety risk assessment multiplied by function various types obtain cost. Then, improved particle swarm optimization algorithm used solve optimal scheme network. Compared traditional result based on economic coordination model increases lines...

Vanadium redox flow battery (VRB) is considered to be the most promising large-scale energy storage technology because of its high design flexibility and good reversibility. Operating characteristics VRB are affected by various parameters including temperature, electrolyte rate, current. Problems such as premature voltage cut-off low efficiency may caused improper settings operational parameters. Previous operation strategy only optimizes single variable, temperature or neglecting coupled...