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Abstract The transient DC bias current will be generated when the input voltage or load of the dual active bridge (DAB) converter suddenly changes, resulting in the excessive peak value of the inductor current and saturation of the transformer core. An improved three‐phase‐shift (ITPS) strategy based on double integral sliding mode‐direct power control (DISM‐DPC) is proposed in this paper to suppress DC bias current without additional hardware. The proposed ITPS determines the steady‐state phase shift ratio through an inductor RMS current optimisation strategy. The transient phase shift strategy can be determined by the transient DC bias current model, which eliminates the DC bias within one switching cycle and effectively reduces the current impact. In addition, a dual‐loop compensation control method of power inner loop and output voltage outer loop is proposed. Compared with the steady‐state control method, the transient optimisation method of double‐loop compensation control can stabilise the output voltage quickly, effectively reduce the transient impact of the current and improve the dynamic performance of the circuit operation. The experimental results verify the theoretical analysis and prove the effectiveness of the scheme.

In order to effectively solve the influence of the magnetic sensor array error caused by axial inconsistency on the measurement accuracy, an array composed of four fluxgate sensors is built by using the Euler rotation matrix, and the consistency correction is carried out. Firstly, aiming at the non orthogonal, scale factor, zero bias and other error factors of the sensor itself, a 9-PARAMETER correction coefficient matrix is constructed to compensate the non orthogonal magnetic field measurement of the sensor, and the ideal orthogonal three component magnetic field measurement value is obtained. On the above-mentioned basis, the reference sensor in the magnetometry array is selected, and the roll, pitch and azimuth of the sensor to be calibrated are transformed to establish the Euler rotation matrix, and the model for 9-PARAMETER consistency correction is constructed. The reference sensor and the sensor to be calibrated are placed on the magnetic gradiometer for experimental verification. The experimental results show that the root mean square error of magnetic field measurement is within 10 nT after the sensor measurement error compensation correction, and the angle error of each axis measurement is within 0.01åfter the consistency correction (4.22 nT). It shows that the magnetic field measurement values of different measuring points in the sensor array can be well projected on the coordinate axis of the reference sensor after correction, and the magnetic field information of the measuring points can be correctly projected, which has high reliability.

Three‐dimensional graphene architecture (3DGA) as reinforcement with successive reinforcement effect has attracted intense attention in the field of polymer composites, while 3DGA also faces the disadvantages of weak interfacial adhesion with matrices. The surface decoration of 3DGA with molybdenum disulfide (3DGA@MoS2) further promoted the diffusion and penetration of epoxy molecular for 3DGA network with the aid of resin transfer molding (RTM) technic. The MoS2 transition nanolayer not only forms covalent bonding with 3DGA but mechanical interlocks with epoxy, which effectively improved the interface combination in composite. Compared with neat epoxy, the glass transition temperature (Tg) and tensile strength increased by 18°C and 58.6%, as well as the average friction coefficient and wear rate decreased by 84% and 89%, respectively, by low loading of only 2 wt% 3DGA@MoS2. Hence, the 3D graphene modified strategy by surface decoration provides a new insight for manufacturing high‐performance epoxy‐graphene composites with excellent tribological properties. Highlights: A highly ordered and interconnected 3DGA reinforcement was fabricated.MoS2 serves as interlayer, forming covalent bond and mechanical interlock.Incorporation of 3DGA@MoS2 enables rapid heat conduction and load transfer.Bi‐interpenetrating 3D structure/polymer network endows good wear resistance.Improved comprehensive properties ascribe to strong interface adhesion. [ABSTRACT FROM AUTHOR]

In this work, the structural and electronic properties of two-dimensional (2D) atomically thick (100) diamond nanofilms are investigated by first-principles calculations. The results of phonon dispersion curves and ab initio molecular dynamics simulations indicate that the nanofilms are dynamically and thermally stable with three types of reconstructed surfaces (named 5-MR, 5-7-MR, and 5/5-7-MR). The bandgaps (Eg) of the nanofilms with 5-MR and 5-7-MR patterns are in regions of 1.02–1.40 eV and 0.32–0.55 eV, respectively, and an oscillatory phenomenon of Eg appears related to parity of the layer number. The nanofilms with the 5/5-7-MR pattern show a metallic feature. The variations in Eg are determined by surface states with different configurations. These novel diamond-based structures may be useful for applications such as 2D semiconductors in diamond-based electronic devices. [ABSTRACT FROM AUTHOR]