A sliding mode controller based on SVPWM strategy (SMC-SVPWM) is proposed for three-phase voltage-source-converter-based shunt active power filter. Superconducting magnetic energy storage is used to improve the filtering performance. A sliding mode controller (SMC) is amended to determine the space region of the current error vector for improving dynamic response speed. SVPWM is utilized to select the optimal voltage vector to mitigate the chattering of the SMC and reduce switching frequency. The feasiblity of the proposed SMC-SVPWM method is verified by a series of simulation results and a comparative analysis between the SMC-SVPWM and conventional control methods under various loads.

This paper presents a superconducting magnetic energy storage (SMES)-based current-source active power filter (CS-APF). Characteristics of the SMES are elaborated, including physical quantity, coil structure, and priorities. A modified control is proposed and utilized in the SMES-CS-APF to simultaneously solve the harmonic issue produced by the nonlinear load, and mitigate the power oscillation under unbalanced voltage opera-tion. Finally, the effectiveness of the proposed SMES-based CS-APF is proved by simulation, and the superiority of using SMES is confirmed by comparison between SMES-CS-APF and bat-tery-based voltage source (VS)-APF. As compared, the pro-posed modified control is more suitable fitting with the SMES-CS-APF, due to its fast response and large power level.

The HTS Conductor on Round Core (CORC) Cables have been widely recognized as the proper candidate for superconducting applications such as the high-field magnets and power transmission cables. This article presents the modeling of HTS CORC cables using the FEM H formulation model merged into the package COMSOL Multi-physics. The 2D and 3D H formulation models of HTS CORC cables were compared and analyzed. There were two important parameters in our CORC design: (1) the gap angle between the HTS tapes in a single layer, and, (2) the degree of twist for each HTS tapes (normally identified as the pitch). The 2D CORC model has much faster solving speed over the 3D model and sometimes is able to model the AC loss in a reasonable range, while, the 3D CORC model has the advantages over 2D CORC model with respect to more information in each sector with the different conditions of two parameters above, and more realistic loss calculation.

This paper proposes to integrate power fluctuation suppression and active filtering control into the centralized photovoltaic (PV) inverter based on superconducting magnetic energy storage (SMES). The superconducting coil (SC) is interfaced to the DC-link of the PV inverter through a DC/DC converter. The PV-SMES-based system performs the dual demands of transferring maximum power from PV array apart from suppressing power fluctuations and harmonics existing in microgrid. An improved sliding mode controller (SMC) was developed for the DC/DC converter to stabilize the DC-link voltage of PV inverter. The stability of the proposed controller is demonstrated using Lyapunov stability theory. The comprehensive performance of the PV-SMES-based system is verified through a series of simulation comparisons based on a lead-acid battery scheme.

With the gradual complexity of the high temperature superconducting (HTS) applications, the calculation model of large-scale devices is time-consuming. A semi-homogeneous modeling method based on the T-A formulation is proposed to study the electromagnetic characteristic of HTS magnet. Compared to the homogeneous model, the proposed model can improve the calculation accuracy without compromising speed. The model in this paper is beneficial to the design, rapid optimization and evaluation of the HTS magnet.

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