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Power-to-gas (P2G) and gas-fired generation units (GFGUs) enable the bidirectional energy flow of integrated energy systems (IESs). The static security of IES should be analysed considering the interdependence between energy systems. In this study, the static security of IES is analysed, and a novel static security control strategy to improve the security of IES after N−1 contingency is proposed considering P2G. First, electricity–gas IES model is presented, and the multi-energy flow of IES is solved by the Newton–Raphson method. Then, N − 1 static security analysis is carried out for the electricity system and natural gas system. Based on the obtained Jacobian matrix during the energy flow calculation process after N − 1 contingency, variable sensitivity matrixes of voltage, gas pressure, branch power flow and pipeline flow to control variables are derived. Furthermore, a static security control strategy for IES based on the sensitivity matrices is developed to regulate operation statuses of P2G and GFGU and compressor outlet pressure to mitigate the violation of security constraints. The performance of the proposed analysis method and control strategy is evaluated by IES 4-12 and IES 118-48 test systems. The results demonstrate that the proposed control strategy can mitigate security risks of IES after N − 1 contingencies.

The increasingly disturbing electromagnetic wave pollution has intensified research for high-performance shielding materials to protect humans and the environment. It remains a great challenge to combine high electromagnetic interference (EMI) shielding performance with mechanical robustness and stretchability. These crucial features have been simultaneously achieved in this work by using a facile method to prepare elastomer/MXene nanocomposites. An EMI shielding effectiveness of 49 dB was obtained from a 1-mm thick nanocomposite film at 19.6 vol% of MXene; the film has a density of 1.25 g/cm3. The outstanding electrical conductivity of MXene – 4350 ± 125 S·cm−1 – provided free charge carriers in the matrix to absorb electromagnetic signals, leading to the dominance of absorption mechanism over reflection mechanism. Owing to a nanofiller modification step, the nanocomposite films demonstrated not only outstanding EMI shielding but sufficient strength and stretchability. A nanocomposite at 14.0 vol% exhibited Young's modulus of 15.85 ± 0.75 MPa and tensile strength 25.94 ± 0.81 MPa with elongation at break of 170 ± 5.6%, which relates to high stretchability. These impressive properties make our nanocomposites suitable for use in harsh environments as well as applications in stretchable devices, protective clothing, aerospace, aircraft, and automotive industries. Refereed/Peer-reviewed

In this study, we developed a buckypaper (BP) composed of a mono-dispersion of multi-walled carbon nanotubes (MWCNTs) via a spray-vacuum filtration method. This highly flexible and sensitive carbon nanotube buckypaper (MWNCTs-BP) sensor can be integrated into complex curved surfaces and at critical stress areas to monitor the dynamic manufacturing process of fibre-reinforced composites in real time. A dynamic heating cure cycle and two revised cure cycles were designed to study the response of the resistance of the buckypaper to resin phase changes during the composite manufacturing process. Dynamic mechanical analysis (DMA) was performed to obtain the cure behaviour of a glass fibre/epoxy composite as a baseline to compare with the MWCNTs-BP sensor output. The experimental results show that the cure behaviour of epoxy/glass composites can be effectively monitored by the relative resistance change of the BP sensor embedded in the composite laminate. The MWCNTs-BP shows that the lowest viscosity point and gelation point of the composite resin were at 78 °C and 125 °C during the dynamic heating cure cycle, which is consistent with the DMA results. The lowest viscosity and gelation point can also be accurately obtained during the revised cure cycles. The MWCNTs-BP system has great potential as a sensor to establish and optimize manufacturing processes and to improve the cure quality of fibre-based resin composites. Refereed/Peer-reviewed