Self-healing Protection Research Articles

Adaptive electronic relay for smart grid based on self-healing protection.

The protection system is crucial for grid stability and safeguarding essential components, including generators, transformers, transmission systems, and power connections. The smart grid system increases the flexibility and complexity of the power system, making fault detection and isolation the primary challenges for the protection system. This paper presents an optimal protection solution using an adaptive electronic relay to enhance reliability and enable self-healing. The proposed protection algorithm quickly detects faults and automatically isolates them from the rest of the healthy system in 25ms. The relay operation algorithm has been validated using MATLAB SIMULINK software. The results confirm the effectiveness of the proposed smart electronic relay in various sections of the smart grid system, including transformers, transmission and distribution.

In Situ Alloying Enabled by Active Liquid Metal Filler for Self-Healing Composite Polymer Electrolytes.

Solid inorganics, known for kinetically inhibiting polymer crystallization and enhancing ionic conductivity, have attracted significant attention in solid polymer electrolytes. However, current composite polymer electrolytes (CPEs) are still facing challenges in Li metal batteries, falling short of inhibiting severe dendritic growth and resulting in very limited cycling life. This study introduces Ga62.5In21.5Sn16 (Galinstan) liquid metal (LM) as an active liquid alternative to conventional passive solid fillers, aiming at realizing self-healing protection against dendrite problems. Compared to solid inorganics, for example silica, LM droplets could more significantly reduce polymer crystallinity and enhance Li-ion conductivity due to their liquid nature, especially at temperatures below the polymer melting point. More importantly, LMs are unraveled as dynamic chemical traps, which are capable of blocking and consuming lithium dendrites upon contact via in situ alloying during battery operation and further inhibiting dendritic growth due to the lower deposition energy barrier of the formed Li-LM alloy. As a proof of concept, by strategically designing an asymmetric CPE with the active LM filling, a solid-state Li/LiFePO4 battery achieves promising full-cell functionality with notable rate performance and stable cycle life. This active filler-mediated self-healing approach could bring new insights into the battery design in versatile solid-state systems.

Tailoring exfoliated 2D Mo-PDA nanopetals as sustainable intelligent anti-corrosion nanoreservoir for upgrading the self-healing/barrier function of epoxy coatings

The present study unfurled novel route to tailor cutting-edge molybdenum-polydopamine (AHPDA) and molybdenum-polydopamine-Ce3+/4+ nanocarriers (AHPDA@Ce) using in-situ self-nucleophilic polymerization techniques and scrutinized their intelligent anti-corrosion and physicomechanical properties in solution and coating phases. The manageable emancipation of Ce3+/4+,MoO42-, polydopamine (PDA) derivatives from exfoliated AHPDA and AHPDA@Ce nanocarriers at the extract solutions brilliantly reduced the icorr from 5.14 to 2.22 and 1.45 µA/cm2, respectively. Afterward, the derivatives assembled intricate barrier films at the electrochemical active sites, outstandingly restricting the severe corrosion on steel panels immersed in AHPDA@Ce and AHPDA extract solutions. Moreover, even after 48 h immersion, not only did the scratched EAHC (containing AHPDA@Ce nanocarriers) and EAHM (including AHPDA nanocarriers) coatings exhibit superior self-healing protection by 382 % and 327 % promotion in RTotal towards NE coatings (neat epoxy), but also intelligent EAHC and EAHM coatings tolerated the salt spray condition up to 1000 h exposure rather than 400 h of NE coating. Also, the intact EAHC and EAHM coatings after 24 weeks of submersion with noteworthy log|Z|0.01Hz of 10.51 and 9.98 Ω cm2 showcased boosted barrier-passive function lifetime with respect to the NE coatings (5.68 Ω cm2). Furthermore, smart EAHM and EAHC nanocomposites flaunted lower adhesion loss of 2.3 and 5.2 times, respectively, as well as, an incredible 76.11 % and 31.50 % improvement in the reduction of cathodic peel-off area regarding the NE coating. Ultimately, smart EAHC and EAHM coatings could be employed as eco-friendly effective anti-corrosion coatings with terrific self-healing/barrier function and durable service life in strategic knowledge edge applications.

PH-controlled release system based on the super-assembly of tannic acid and Cu2+ for metal protection

MOF-5 was employed to act as a nanocarrier to load the corrosion inhibitor of BTA molecules (MOF-5@BTA). A novel pH-responsive release system was also fabricated on the basis of the metal–phenolic network (MPN) coated on MOF-5@BTA via super-assembly (MOF-5@BTA@MPN). The chemical structure and surface morphologies of the prepared MOF-5@BTA@MPN were evaluated. Ultraviolet–vis measurements confirmed the pH-responsive release property of the prepared nanoparticles. Furthermore, the prepared nanoparticles were reinforced in epoxy resin to fabricate a composite coating. The results demonstrated that the composite coating exhibited excellent barrier and self-healing protection effects.

NIR-Triggered High-Efficiency Self-Healable Protective Optical Coating for Vision Systems

Recently, self-healing materials have evolved to recover specific functions such as electronic, magnetic, acoustic, structural or hierarchical, and biological properties. In particular, the development of self-healing protection coatings that can be applied to lens components in vision systems such as augmented reality glasses, actuators, and image and time-of-flight sensors has received intensive attention from the industry. In the present study, we designed polythiourethane dynamic networks containing a photothermal N-butyl-substituted diimmonium borate dye to demonstrate their potential applications in self-healing protection coatings for the optical components of vision systems. The optimized self-healing coating exhibited a high transmittance (∼95% in the visible-light region), tunable refractive index (up to 1.6), a moderate Abbe number (∼35), and high surface hardness (>200 MPa). When subjected to near-infrared (NIR) radiation (1064 nm), the surface temperature of the coating increased to 75 °C via the photothermal effect and self-healing of the scratched coatings occurred via a dynamic thiourethane exchange reaction. The coating was applied to a lens protector, and its self-healing performance was demonstrated. The light signal distorted by the scratched surface of the coating was perfectly restored after NIR-induced self-healing. The photoinduced self-healing process can also autonomously occur under sunlight with low energy consumption.

Benzotriazole corrosion inhibitor loaded nanocontainer based on g-C3N4 and hollow polyaniline spheres towards enhancing anticorrosion performance of waterborne epoxy coatings

Multi-dimensional composite nanocontainers provided an opportunity to prolong the service life of waterborne self-healing coatings through combining intelligent protection with physical barrier. Herein, we constructed a benzotriazole (BTA) corrosion inhibitor loaded nanocontainer with barrier/controlled release/corrosion inhibition properties by assembling graphitic (g)-C3N4 lamella, hollow polyaniline capsule and outer polydopamine wall. Hollow polyaniline and g-C3N4 lamella with adsorption properties provide effective space and sites for loading BTA corrosion inhibitor. Outer polydopamine wall can not only realize the controlled release of corrosion inhibitor, but also ensure the good compatibility between the composite container and the water-based epoxy resin. In addition, polydopamine (PDA) and polyaniline (PANI) as a container frame can also serve as active inhibitors after the release of corrosion inhibitor to enhance the self-healing protection effect of waterborne coatings. In comparative evaluation, the composite coatings containing BTA-loaded nanocontainers (0.5 wt.%) exhibit obviously physical barrier effect after soaking in 3.5 wt.% NaCl solution for 40 days, and maintains good protective performance after immersion for 80 days. Meanwhile, the artificial scratch experiment verified the effective self-repair protection of the composite container to the coating under the condition of damage. To be sure, it will provide an effective improvement idea for the long-term application of waterborne epoxy coating in marine environment.

An adaptive bidirectional protective relay algorithm for ferroresonance in renewable energy networks

Smart grid comprises utility system and renewable resources including wind farm and solar system. It causes bidirectional flowing of power especially in distribution level, and establishing communication facility amongst utility system, distributed generations (DG), and loads. In this study, influence of occurrence of ferroresonance in the utility system is investigated on technical quantities of DFIG and operation of directional overcurrent (DOC) relay installed in wind farm is assessed by means of PSCAD/EMTDC simulation software. Smart grid stand in need of a self-healing protection; therefore, an adaptive algorithm on the basis of neural network and signal analysis tools like, wavelet transform, moreover, analysis of ferroresonance in time domain is designated for overcurrent relay. The relay with new algorithm can conform to protection strategy of smart grid. It discriminates ferroresonance from other nonlinear and transient abnormalities, which affect deviation of electrical quantities. Protection strategy established in smart grid decides on behaviour of the relay through the algorithm. It takes an appropriate decision in ferroresonant states to modify setting quantities of the relay and changes direction of operation to enhance reliability and availability of power electricity in smart grid. The relay is capable of predicting ferroresonance in the network to fulfil smart grid requirements.

Active anticorrosion and self-healing coatings: A review with focus on multi-action smart coating strategies

• Recent trends in active anticorrosion protective coatings are summarized. • Self-healing coatings as defect closing routes for metal protection are reviewed. • Functionalities and multi-action mechanisms in multifunctional coatings are discussed. The development of smart coatings with potential for active anticorrosion and self-healing protection of metals is essential for long-term performance of metallic structures in aggressive chemical environments. Presently, emphasis has been placed on the development of advanced smart coatings for corrosion protection in different applications. Innovative multifunctional coatings with fascinating stimuli-responsive functionalities are considered “smart”. The stimuli-responsive functionalities of these smart coatings when properly harnessed result in a class of coatings with inherent autonomous control of corrosion. Fundamentally, when metals are exposed to aggressive environments, occurrences at the metal-solution interface cause environmental changes. These changes can be controlled when triggers from external environment set off active components of smart coating, thereby enhancing coating's life and functionality. Common triggers include the availability of moisture, concentration of chloride ion, pH gradient, mechanical damage, impact, fatigue, light, redox activity and temperature. In this review, recent technological trends in active anticorrosion and self-healing coatings as functional routes for metal protection are summarized, stimuli responsiveness and mechanisms of inhibition are discussed, and recent multi-action protective systems are particularly focused on.

Preparation and Self-Healing Application of Isocyanate Prepolymer Microcapsules

In this study, we successfully manufactured polyurethane microcapsules containing isocyanate prepolymer as a core material for self-healing protection coatings via interfacial polymerization of a commercial polyurethane curing agent (Bayer L-75) and 1,4-butanediol (BDO) as a chain extender in an emulsion solution. With an optical microscope (OM) and a scanning electron microscope (SEM), the resulting microcapsules showed a spherical shape and an ideal structure with a smooth surface. Fourier transform infrared spectra (FTIR) showed that the core material was successfully encapsulated. Thermal gravimetric analysis (TGA) showed that the initial evaporation temperature of the microcapsules was 270 °C. In addition, we examined the influence of the concentration of the emulsifier and chain extender on the structure and morphology of the microcapsules. The results indicate that the optimal parameters of the microcapsule are an emulsifier concentration of 7.5% and a chain extender concentration of 15.38%. Microcapsules were added to the epoxy resin coating to verify the coating’s self-healing performance by a surface scratch test, and the results showed that the cracks could heal in 24 h. Furthermore, the self-healing coating had excellent corrosion resistance.

An Intelligent Algorithm for Negative Sequence Directional Element of DFIG during Ferroresonance in Smart Grid

Smart grid comprises utility system and Distributed renewable power Generations such as wind and solar energy. The smart grid system represents bidirectional flowing of energy and communication facilities among utility system, Distributed Generations (DG) and consumers. Smart grid including wind farm is seriously exposed to high magnitudes of nonlinearities like ferroresonance. It causes mal operation of protective relays in wind farm. This paper investigates impact of ferroresonance in utility system on operation of DFIG (Doubly-Fed Induction Generator) and Negative Sequence Directional Element (NSDE) in Wind Park by means of PSCAD/EMTDC software. As smart grid insists on a self-healing protection, an intelligent algorithm based on wavelet transform, neural network and ferroresonance analysis in time domain is proposed for NSDE to discriminate ferroresonance. The algorithm appropriately conforms to smart grid protection strategy. It discriminates ferroresonance from other nonlinear abnormalities and is able to distinguish different types of ferroresonance. To accord with smart grid requirements, the algorithm is designed to forecast occurrence of ferroresonance in the grid.

Designing a high-performance waterborne epoxy coating with passive/active dual self-healing properties by synergistic effect of V2O5@polyaniline-tannic acid inhibitors

Inspirations from nature have led to extensive developments in metal passivation and smart self-healing technologies toward metal corrosion protection. Integration of both intriguing features helps to achieve high-efficiency corrosion inhibition protection. In this study, we designed a novel anticorrosion system composed of waterborne epoxy (WEP) and VPC nanofillers (V2O5 modified by polyaniline and tannic acid complexes) (V2O5@PANI@Fe-TA (3)). Among them, the PANI-modified V2O5 particles have dual roles as oxidation passivation protection and a passive barrier. The tannic acid corrosion inhibitor loaded onto the particles can be released under pH stimulation to provide appropriate activity inhibition function. This dual, synergistic self-healing protection coupled with a robust film barrier was the main reason for the strong anticorrosion properties of the coating system. In a specific experiment, the anticorrosion performance of the composite coatings was verified by electrochemical and salt spray tests. Results revealed that the value of |Z|10mHz for VPC/WEP composite coating was still higher than 108 Ω/cm2 after 80 d of immersion as compared to those of the pure WEP. Interestingly, the VPC/WEPs also exhibited a significant self-healing effect when the corrosive medium reached the metal/coating interface through defects or artificial scratches. This is due to the synergistic protective effect of metal passivation and activity inhibition, which enhanced the anticorrosion properties of the coating system.

Nanotribology of Ionic Liquids: Transition to Yielding Response in Nanometric Confinement with Metallic Surfaces

Room Temperature Ionic Liquids (RTILs) are molten salts which exhibit uniques physical and chemical properties, commonly harnessed for lubrication and energy applications. The pure ionic nature of RTIL leads to strong electrostatic interactions among the liquid, furthermore exalted in the presence of interfaces and confinement. In this work, we use a tuning-fork based dynamic Surface Force Tribometer (TF-SFT), which allows probing both the rheological and the tribological properties of RTILs films confined between a millimetric sphere and a surface, over a wide range of confinements. When the RTIL is confined between metallic surfaces, we evidence an abrupt change of its rheological properties below a threshold confinement. This is reminiscent of a recently reported confinement induced capillary freezing, here observed with a wide contact area. In parallel, we probe the tribological response of the film under imposed nanometric shear deformation and unveil a yielding behaviour of the interfacial solid phase below this threshold confinement. This is characterized by a transition from an elastic to a plastic regime, exhibiting striking similarities with the response of glassy materials. This transition to yielding of the RTIL in metallic confinement leads overall to a reduction in friction and offers a self-healing protection of the surfaces avoiding direct contact, with obvious applications in tribology.

Epoxy Self-Healing Coating by Encapsulated Epoxy Ester Resin in Poly (Urea-Formaldehyde-Melamine) Microcapsules

In this work, poly (urea-formaldehyde-melamine) (PUFM) microcapsules containing a commercial epoxy ester resin were synthetized by in-situ polymerization technique. The microcapsules size distribution was analyzed by laser diffraction and the obtained microcapsules were evaluated by the Fourier-transform infrared spectroscopy (FTIR), in order to prove the ester epoxy resin microencapsulation. The filled microcapsules were incorporated in an epoxy three layer coating system, varying the microcapsules concentration (10 % and 15 %) and the microcapsules incorporation on the different layers - first, second or both. The coatings electrochemical behaviors were evaluated by electrochemical impedance spectroscopy (EIS) technique and localized scanning vibrating electrode technique (SVET). Pull-off adhesion tests were performed in the coatings systems, in order to verify if the microcapsules presence did affect the adhesion and/or cohesion coating properties. The EIS results showed that microcapsules change the coating electrochemical response, but the samples visual aspect suggests that the microcapsules improve the barrier properties of the microcapsules systems. The coating system containing the microcapsules showed a significant self-healing effect when stressed by a mechanical defect and the higher concentration (15 wt. %) of microcapsules provided a better self-healing protection, with better anticorrosive performance. Additionally, the microcapsules did not disturb the adhesion/cohesion properties of the coating system.

Polyaniline/CeO2 nanocomposites as corrosion inhibitors for improving the corrosive performance of epoxy coating on carbon steel in 3.5% NaCl solution

Polyaniline/cerium dioxide (PANI/CeO2) nanocomposite (NPs) was synthesized by in situ polymerization of aniline in the presence of CeO2 NPs. Various analytical facilities, i.e., powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM), were utilized to characterize the synthesized CeO2 and PANI/CeO2 NPs. The coatings prepared from the synthesized PANI/CeO2 NPs exhibited excellent corrosion resistance that was superior to epoxy coatings added with PANI in NaCl solution. The exceptional improvement of corrosion protection performance of the PANI/CeO2 /epoxy coatings is associated with the synergetic protection of the enhancement of the protective barrier due to the role of CeO2 NPs and PANI against the diffusion of aggressive ions (e.g., Cl−) and the improvement of self-healing protection attributed to the redox behavior of PANI. Thus, the hybrid PANI/CeO2 NPs are considered as the best route to enhance the protection performance of the epoxy coatings on carbon steel.

A Novel Reactive Current Injection (RCI) Control for Microgrid Protection with Inverter Based Distributed Generation (IBDG)

As the development of renewable distributed generations (DGs) is growing rapidly, the autonomous self-healing microgrid had emerged as an effective solution for integrating renewable DGs in the distribution networks. However, before the autonomous self-healing microgrid can be realized, one of the main issues that needs to be resolved is the ability to utilize the most cost-effective protection system—overcurrent relays—to achieve the goal. However, the overcurrent relay is insensitive to the limited fault current contributed by the inverter-based distributed generation (IBDG). Therefore, this paper will propose a novel inverter fault current control with a reactive current injection (RCI) that injects the correct fault current vector, albeit with a limited magnitude, for detection by the cost-effective directional overcurrent relay. This paper will also evaluate the performances of the different RCI controls in delivering an efficient self-healing microgrid protection based on a directional overcurrent relay. The proposed self-healing protection scheme is tested with both a simple distribution test network and also the IEEE 16 bus test system, considering random system parameters like variations in IBDG location, fault location, load capacity and load power factor. Moreover, the performance of the proposed inverter RCI control is also tested under changing weather conditions.

Corrosion resistance of a self-healing rose-like MgAl-LDH coating intercalated with aspartic acid on AZ31 Mg alloy

Intercalating corrosion inhibitor into protective coating with lamellar structure is an effective approach to get high corrosion resistance or a self-healing protection for metallic substrates. In present work, aspartic acid (ASP), an environmental friendly corrosion inhibitor was explored to insert into the MgAl-layered double hydroxides (MgAl-LDHs) on AZ31 magnesium alloys by a simple one-step hydrothermal method. The effect of growth time on the structure, morphology, composition and corrosion resistance of MgAl-ASP-LDHs and the self-healing ability of the scratched MgAl-ASP-LDHs samples were systemically investigated. Owing to the corrosion inhibition of ASP ions and their larger specific surface area to entrap aggressive anionic species such as Cl−, the MgAl-ASP-LDHs were found to have better corrosion resistance than MgAl-NO3−-LDHs. Resulting from the largest ratio of pore coverage and the three-dimensional rose flaky nanostructure, the MgAl-ASP-LDHs hydrothermally grown for 12 h has the best corrosion resistance. Due to the synergistic effect between ASP and laminate structure of LDHs, the MgAl-ASP-LDH coatings exhibit a good self-healing ability.

Mussel-Inspired Self-Healing Coatings Based on Polydopamine-Coated Nanocontainers for Corrosion Protection.

The mussel-inspired properties of dopamine have attracted immense scientific interest for surface modification of nanoparticles due to the high potential of dopamine functional groups to increase the adhesion of nanoparticles to flat surfaces. Here, we report for the first time a novel type of inhibitor-loaded nanocontainer using polydopamine (PDA) as a pH-sensitive gatekeeper for mesoporous silica nanoparticles (MSNs). The encapsulated inhibitor (benzotriazole) was loaded into MSNs at neutral pH, demonstrating fast release in an acidic environment. The self-healing effect of water-borne alkyd coatings doped with nanocontainers was achieved by both on-demand release of benzotriazole during the corrosion process and formation of the complexes between the dopamine functional groups and iron oxides, thus providing dual self-healing protection for the mild steel substrate. The coatings were characterized by electrochemical impedance spectroscopy, visual observations, and confocal Raman microscopy. In all cases, the coatings with embedded benzotriazole-loaded MSNs with PDA-decorated outer surfaces demonstrated superior self-healing effects on the damaged areas. We anticipate that dopamine-based multifunctional gatekeepers can find application potential not only in intelligent self-healing anticorrosive coatings but also in drug delivery, antimicrobial protection, and other fields.

Neuron system shock superimposed response based on catastrophe dynamics

With the rapid development of computer science and artificial intelligence technology, the complexity and intelligence of the neural network models constructed by people have been greatly improved. When the complex neuron system is subjected to the impact of “catastrophic”, its original characteristics may be changed, and the consequences are difficult to predict. Catastrophe dynamics mainly studies the source of the sudden violent change of nature and human society and its evolution. The impact of the system can be divided into endogenous and exogenous shocks. In this article, catastrophe theory is used to study the neuron system. Based on the mean field model of Hurst and Sornette, introducing the weight parameters, mathematical models are constructed to study the response characteristics of the neuron system in face of exogenous shocks, endogenous shocks, and integrated shocks. The time characteristics of the shock response of the neuron system are discussed too, such as the instantaneous and long-term response of the system in face of shocks, the different response forms according to the weight or linear superposition, and the influence of adjusting parameters on the neuron system. The research result shows that the authoritarian coefficient and weight coefficient have a very important influence on the response of neuron system; By adjusting the two coefficients, the purpose of disaster prevention, self-healing protection and response reducing can be well achieved.

Inhibitor-Containing Composite Coatings on Mg Alloys: Corrosion Mechanism and Self-Healing Protection

The way of self-healing coating formation at the surface of magnesium alloys by means of plasma electrolytic oxidation method (PEO) with subsequent filling of the obtained layer with inhibitor has been suggested. The electrochemical properties of such coatings have been described in details. The obtained experimental results indicate that the protective properties of the samples with inhibitor-containing coating were increased (IC = 8.6×10–8 A/cm2) in comparison with the samples without coating (5.3×10–5 A/cm2) and the base coating obtained by plasma electrolytic oxidation method (PEO) (3.4×10–7 A/cm2). The local scanning electrochemical methods of surface investigation, notably Scanning Vibrating Electrode Technique (SVET) and Scanning Ion-Selective Electrode Technique (SIET) were used for determining the kinetics and mechanism of the self-healing process. The treatment by the solution containing 8-hydroxyquinoline, which inhibits the corrosion process, enables one to increase the protective properties of the composite coating in 30 times in the corrosion-active environment in comparison with the base PEO-coating and avert the intensive destruction of the material.

Self-Healing Hybrid Protection Architecture for Passive Optical Networks

Expanding size of passive optical networks (PONs) along with high availability expectation makes the reliability performance a crucial need. Most protection architectures utilize redundant network components to enhance network survivability, which is not economical. This paper proposes new self-healing protection architecture for passive optical networks (PONs), with a single ring topology and star-ring topology at feeder and distribution level respectively. The proposed architecture provides desirable protection to the network by avoiding fiber duplication at both feeder and distribution level. Moreover, medium access control (MAC) controlled switching is utilized to provide efficient detection, and restoration of faults or cuts throughout the network. Analytical analysis reveals that the proposed self-healing hybrid protection architecture ensures survivability of the affected traffic along with desirable connection availability of 99.9994 % at minimum deployment cost, through simple architecture and simultaneous protection against failures.