With increasing penetration of the renewable energy, grid-tied PWM inverters need to take corresponding responsibilities for security and stability future grid, behaving like conventional rotational synchronous generator (RSG). Therefore, recognizing inherent relationship intrinsic differences between RSGs is essential such target. By modeling typical electromechanical transient inverters, this paper first proves that are similar in physical mechanism equivalent mathematical model, concept...

With the rapid development in wearable electronics, self-powered devices have recently attracted tremendous attention to overcome restriction of conventional power sources. In this regard, a simple, scalable, and one-pot electrospinning fabrication technique was utilized construct an all-fiber-structured triboelectric nanogenerator (TENG). Ethyl cellulose co-electrospun with polyamide 6 serve as positive material, kind strongly electronegative conductive material MXene sheet innovatively...

A renewable energy-based dc micro-grid with hybrid energy storage, consisting of battery and ultracapacitor, is investigated. To achieve high penetration depth sources into the utility grid, a novel system operation strategy corresponding management method proposed. In strategy, ultracapacitor unit works as sole voltage source to support link in both connected islanding mode. The controlled deliver/absorb predefined amount power to/from grid during mode zero This design will certainly...

This paper proposes a novel three-phase phase-locked loop (PLL) algorithm, which focuses on the reforming of primary signals before grid synchronization rather than improving phase estimation methodologies. The unbalanced are reformed to balanced ones without damage angle, through negative sequence voltages is removed. eliminates errors conventional synchronous reference frame PLL and enhances its response speed with higher bandwidth. process supposed be carried out at every zero-crossing...

The latest research has pointed out that the phase-locked loop (PLL) plays an important role in shaping impedance of grid-connected converters, yet most works so far merely focus on synchronous reference-frame PLL. Alternatively, this letter presents analysis second-order generalized integrator frequency-locked (SOGI-FLL), which been introduced for realizing grid synchronization stationary reference frame. influences voltage perturbation estimated phase and further output current are...

The capacitor-inductor-inductor-capacitor (CLLC) resonant converters are drawing more and attention for their superiority in soft switching, wide output range, symmetrically bidirectional operation. However, CLLC converter still suffers the problems of unsatisfactory voltage regulation low efficiency under light-load conditions. Therefore, this article proposes an optimization extended phase-shift (EPS) control full-bridge to improve efficiency. In order study relations between phase-shifts...

A shunt active power filter (APF) with current detection at the source side is considered as a closed-loop system from view of whole distribution system, which expected better harmonics filtering performance compared one load detection. The conventional control scheme can be mainly grouped into two types: 1) current-source-based (CS) and 2) power-balance-based (PB) scheme. As introduced in this paper, CS has good dc-voltage regulation, but it bears inevitable conflict between stability,...

With inhomogeneous irradiance on photovoltaic (PV) units significantly deteriorating the effectiveness of solar energy harvest, distributed maximum power point tracking (DMPPT) concept is considered as an effective solution against resultant mismatch. A comparative analysis full processing and differential structures, two main branches DMPPT solution, provided first. Advantages disadvantages widely used structures are analyzed compared from different aspects. To harvest more realize better...

Weather-dependent photovoltaic (PV) system power variation may become frequent and rapid, which could be regarded as perturbation for the microgrid (MG). This would lead to voltage frequency fluctuations dramatically degrade MG performances. Conventional secondary control strategy restore after a certain time delay, but it cannot satisfy speed demands when rapid perturbations appear. To overcome limitation, this paper proposes novel real-time compensation suppress fluctuations. The proposed...

Conventional control strategy of a shunt active power filter (SAPF) for harmonic and unbalance mitigation is to locally compensate the component load current, which may not be economical enough multinode system with distributed nonlinear loads (NLLs) unbalanced (UBLs). Actually SAPF will influence voltage at neighboring nodes, therefore it promising optimize method from perspective. For this purpose, first paper analyzes drawbacks local compensation proposes optimization problem system-wide...

Inertia emulation in inverter control strategies benefits improving dynamic frequency performance a microgrid. Therefore, some introduce virtual inertia, and the corresponding is investigated. These mainly focus on dynamics from perspective of an inverter, whereas their influence ac bus interaction among different inverters are still unclear. This paper aims to investigate multiple generation units both grid-connected islanded modes considering inertia interaction. A transfer function model...

With the employment of power electronic converters, renewable energy resources introduce noticeable diversity into different generation units and dramatically change characteristics supply side. Cooperation kinds in steady dynamic states hence becomes important issues for grid integration. This article studies transient active circulation caused by parameter difference among units, such as synchronous generator voltage-controlled inverters. Parameter differences brought inverters are...

The active power control of increasing renewable energy resources is a growing concern. For example, solar exploitation highly dependent on the central controller and other resources. Previous research has introduced some solutions for this problem, but performance usually unsatisfactory in allocation, communication dependence, mode switch, algorithm complexity. This article proposes straightforward effective strategy two-stage photovoltaic (PV) inverter, which uses voltage-control method to...

Abstract Flexible physical sensors have attracted increasing attention due to their wide applications in human motion monitoring, human–machine interfaces, smart robots, and personalized medicine recent years. As a natural biomass, bacterial cellulose (BC) plays an important role the development of new generation low cost, renewability biodegradability, 3D porous structure, mechanical flexibility, robustness, which acts as substrate, reinforcing agent, active material forms hydrogel,...

Microgrid (MG) is generally developed at utility terminal which contains lots of unbalanced loads and distributed generations (DGs). The interaction between MG the unbalance or DGs will degrades control performance interfaced inverter in dramatically leads to voltage unbalance. In this paper, a negative-sequence compensation based three-phase unified correction strategy proposed. While operates islanded mode, positive virtual impedance used eliminate negative resulted from current, then...

The structural and interfacial instability of Ni-rich layered cathodes LiNi0.9Co0.05Mn0.05O2 (NCM9055) severely hinders their commercial application. In this work, straightforward high-temperature solid-state methods are utilized to successfully synthesize Nb-doped Li3PO4-coated by combining two niobium sources, NbOPO4·3H2O Nb2O5, for the first time. Studies indicate that Nb doping enhanced integrity structure, Li3PO4 coating reduced water absorption on surface considerably boosted...

With the access of massive power electronic converters, multi-converter system has become a typical form modern system. The safe and stable operation ability such is closely related to voltage response performances under disturbances. concept support strength (referred as 'system strength') commonly used in industry describe performance composed grid converters. Some metrics, short-circuit ratio (SCR) are proposed characterize above Most existing metrics focus on from perspective stability...