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Developing active series compensation in transmission systems is challenging due to the large currents and voltage capabilities required. The main purpose of this paper is to show that the magnetic energy recovery switch (MERS) can be an attractive new series compensator by applying appropriate control. The MERS is similar to a single-phase full bridge, meaning that compared to the gate-commutated series capacitor, it has twice the number of active switches. However, advantages, such as the double voltage-current operating range, eliminating the need for reverse blocking switches, zero current turn-on, and a lower current conduction period of each switch can make the MERS an attractive alternative. The basic characteristics of the MERS have been found to be similar to a series connection of a voltage source anda capacitor in steady state. With this dual characteristic, a control method has been developed where the minimization of the harmonics in the series-injected voltage and stable operation during large setpoint changes have been achieved. The resulting subharmonic characteristic also indicates a low risk of subsynchronous resonance. Experimental results verify the proposed configuration and control. Index Terms--Capacitor-compensated transmission lines, load-flow control, power electronics, power system stability, power transmission control.

The research and development status of the superconducting magnetic energy storage (SMES) and the application of the SMES to the accelerator magnet power supply are discussed. The progress of power semiconductor has shown the availability of SMES for stabilizing the power system and maintaining power quality along with controlling the frequency fluctuation.

The superconducting model coil based on the force-balanced coil (FBC) design is developed. The improvement in the quench current has shown a primary capability of the FBC as a SMES coil.

The design of the one-tenth sized model coil based on the forced-balanced coil (FBC) design for 100-MJ class superconducting magnetic energy storage (SMES) is discussed. Findings reveal that the FBC based coil is capable of minimizing the mechanical stress and the required mass of the structure for induced electromagnetic forces.

The 7-T Force-Balanced Coil (FBC) which is a helically wound toroidal coil, is designed in order to demonstrate the validity of the FBC concept for high field superconducting magnets. The 7-T FBC is designed within an allowable radius whose maximum working stress within an allowable stress of the stabilizer of NbTi strand.

Force Balanced Coil (FBC) is a helically wound toroidal coil which can control the distribution of working stresses and minimize the structure requirements. The results indicate that by applying the Force Balanced Coil (FBC) concept, superconducting magnets will be realized in smaller size.

A power supply with magnetic energy recovery current switch is developed for pulsed magnets, such as the synchroton accelerator bending magnets, magnetizer. As an application of DC circuit, a semi-conductor Marx-generator, which generates the high voltage pulse, composed of a multistage magnetic energy recovery is described.

Superconducting magnetic energy storage (SMES) systems can be used to improve power supply quality and reliability. In addition, large amounts of power can be drawn from a small stored energy supply. Nevertheless, the strong electromagnetic force caused by high magnetic fields and coil current is a serious problem for SMES. To cope with this problem, we propose a new coil design, the tilted toroidal coil (TTC). The TTC, obtained from the toroidal field coil (TFC) system by varying two pitching angles, allows the balancing of the electromagnetic force in the major radius direction, maintaining the same manufacturing simplicity of the TFC system. After determining balanced configurations through computer simulation, we built an experimental device to confirm the feasibility of the balancing effect. Index Terms--Electromagnetic force balance, superconducting magnetic energy storage (SMES) systems, toroidal coil systems.

Background and purpose: Angioplasty of the dural sinus has rarely been performed for the treatment of cavernous sinus dural arteriovenous fistulas. We evaluated the efficacy of selective transvenous embolization (TVE) combined with balloon angioplasty of the occluded inferior petrosal sinus (IPS) for the treatment of cavernous sinus dural arteriovenous fistulas (CSDAVFs). Materials and methods: A total of 8 consecutive patients with CSDAVFs with occlusion of the IPS treated by selective TVE with balloon angioplasty of the IPS from July 2018 to January 2019 were retrospectively reviewed. There were 6 females and 2 males with an average age of 77.6 years. All patients showed ocular symptoms. Angiography showed cortical venous reflux in 7 cases and localized shunted pouches at the medial portion of the cavernous sinus, intercavernous sinus, or laterocavernous sinus. Selective TVE was performed via the occluded IPS with bilateral femoral venous approaches, and the occluded IPS was reconstructed by angioplasty with a 2- to 3-mm diameter balloon during or after selective TVE. Results: CSDAVFs disappeared immediately after treatment, and the occluded IPSs were successfully reconstructed with re-establishment of normal antegrade venous flow in all cases. No complications were observed, and symptoms resolved within 2 weeks after treatment. During the 7-month mean follow-up period (range 1-12 months), no cases showed recurrence of CSDAVFs. Conclusion: Selective TVE combined with balloon angioplasty of the occluded IPS is safe and effective for the treatment of CSDAVFs and re-establishes normal venous circulation in selected cases with localized shunted pouches. [ABSTRACT FROM AUTHOR]

Magneto-optic polarimeters have been developed that can function as magnetic-field sensors for long-pulsed fusion devices.

The current-sharing problem of superconducting triple strands is investigated and discussed.

The coil of a superconducting magnetic energy storage (SMES) system is optimized, using the virial theorem.

The relation between the toroidal magnetic field and stress is obtained, using the virial theorem. A new toroidal field (TF) coil for tokamaks is proposed.

Force-balanced coil applied to superconducting magnetic energy storage is investigated in terms of design considerations.

Research is presented describing how current distribution is very sensitive to the distribution of inductance in a multi-strand superconducting cable conductor. When this type of conductor has strands with higher magnetic coupling, frequency causes a dynamic change in current distribution.

The SiC-based power electronics device is developed, which has more advanced electrical characteristics than conventional si-based device. In order to study SiC-based device experimentally, SiC-based Schottky Barrier Diode (SBD), as an example of SiC-based power electronics device, is investigated on its temperature dependence of forward voltage in comparison with Si-based SBD.