• Proceedings of the KIEE Conference
• /
• 1998.07a
• /
• pp.140-142
• /
• 1998

The major part of SMES (Superconducting Magnetic Energy Storage) system consist of the superconducting coil, cryostat and current lead, power converter. The 0.7MJ SMES coil was a design and manufacture by using SMES device that we developed a design code. A SMES coil was wound with high winding tension in order to prevent wire motion from Lorentz force. This paper described optimum design for the SMES coil.

• Progress in Superconductivity and Cryogenics
• /
• v.9 no.1
• /
• pp.32-36
• /
• 2007

The 600 kJ calss high-temperature superconducting(HTS) SMES(superconducting magnetic energy storage) system is being developed by Korean Electrotechnology Research Institute(KERI). The system is operated in cryogenic temperature and high vacuum condition. The SMES magnet was cooled by conduction cooling method using a Gifford-McMahon cycle cryocooler. Thus the electric insulation design at cryogenic temperature and high vacuum is a key and an important element. Because it accomplish compact design that is a big advantage of HTS SMES. This paper describes the electric insulation design, fabrication and experimental results for a mini model of conduction cooled HTS SMES.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.5
• /
• pp.473-477
• /
• 2005

A Bi-2223 tape has been developed for power applications such as a fault current limiter, a power cable and a superconducting magnetic energy storage system. In such applications, the Bi-2223 tape carries time varying transport current and in addition experiences time varying external magnetic field. It is well known that the external magnetic field not only causes magnetization loss in the Bi-2223 tape, but also drastically increases transport loss due to a so-called 'dynamic resistance' We developed an evaluation setup, which can measure transport loss in external at magnetic fields. Using this equipment, we measured the dynamic resistances for various amplitudes and frequencies of an external at magnetic field perpendicular to the face in the tape. Simultaneously we investigated the effect of an external ac field on transport loss with different experimental conditions. This paper describes test results ana discussions on correlation between the dynamic resistance and the transport loss for the Bi-2223 tape.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.50 no.6
• /
• pp.293-299
• /
• 2001

This paper proposes a new power conditioning system for the SMES composed of a thyristor PWM converter with a resonant commutation circuit. The operation of the proposed system and the dynamic interaction between SMES and the power system is analyzed by a theoretical approach with equivalent circuits and verified by computer simulations with EMTP, considering a typical 154kV power system. The proposed system can provide a solution for the power factor regulation and harmonic level reduction in the ac terminal with low-cost system configuration.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2000.02a
• /
• pp.136-138
• /
• 2000

1.5kA HTS current leads for a superconducting magnetic energy storage(SMES) magnet, which are connected to a conventional vapor cooled copper leads, were designed. The HTS lead composed of cylindrically arranged Bi-2223/Ag-1 at5Au tapes and a stainless steel tube. The minimum operating current of the lead is 1.71 kA at 77.3K, self magnetic field, and the heat input to the liquid helium from the clod end of the 36 cm lead is 0.5 W/lead.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.04a
• /
• pp.88-95
• /
• 2002

Recent development in the field of RE-Ba-Cu-O (REBCO, RE: Y or rare earth elements) bulk high-Tc superconductors (HTS) is reviewed in the present paper. After the fatal weak link problem of sintered REBCO superconductors has been overcome by melt processing, this field has been greatly advanced during last ten years. The critical current density $J_c$ at 77 K has been enhanced by introducing effective flux pinning sites into the $REBa_2Cu_3O_y$ (RE123) superconducting matrix. Large melt-textured REBCO bulk crystals have been fabricated with the TSMG(top-seeded melt growth) technique. Mechanical properties of REBCO bulks have been improved by using the Ag additive or epoxy resin. Real bulk applications such as current lead, fault current limiter, flywheel energy storage system, magnetic field source, magnetic separation system, and etc., surely come true near future.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.807-809
• /
• 2000

We are developing a small-sized superconducting magnetic energy storage ($\mu$ SMES) magnet with the storage capacity of a few megajoules, which provides electric power with high quality to sensitive electric loads. As the earlier step of the fabrication of the $\mu$ SMES magnet, this paper describes recovery current experimental results of a kA class superconductor. Recovery current of a superconductor was tested in two points of copper ratio and cooling effect.

• Proceedings of the KIEE Conference
• /
• 1997.07c
• /
• pp.794-796
• /
• 1997

The superconducting magnetic energy storage (SMES) system is considered to be useful to charge or release an energy in power system because of the high efficiency and quick response. But we need much capital to construct and to operate a SMES. A site and capacity of SMES are important elements for effective operating and planning. In this paper, we proposed a performance function to determine an optimal site and capacity of SMES according to variety condition of power system such as fault point. In addition, to demonstrate the validity of a proposed method, the simulations were carried out on two-machine 5-bus system.

• Progress in Superconductivity and Cryogenics
• /
• v.9 no.3
• /
• pp.67-71
• /
• 2007

The electrical insulation design of 600 kJ conduction cooled high-Tc superconducting magnetic energy storage (SMES) have been studied in this paper. The high voltage is applied to both ends of magnet of high-Tc SMES by quench or energy discharge. Therefore. the insulation design of the high voltage needs for commercialization. stability. reliability and so on. In this study. we analyzed the insulation composition of a high-Tc SMES. and investigated about the insulation characteristics of the materials such as Kapton. AIN. $Al_2O_3$. GFRP and vacuum in cryogenic temperature. Base on these results. the insulation design for 600 kJ conduction cooled high-Tc SMES was performed.

• Journal of Electrical Engineering and Technology
• /
• v.5 no.4
• /
• pp.552-560
• /
• 2010

This paper presents an application of layered Artificial Neural Network controller to study load frequency control problem in power system. The objective of control scheme guarantees that steady state error of frequencies and inadvertent interchange of tie-lines are maintained in a given tolerance limitation. The proposed controller has been designed for a two-area interconnected power system. Only one artificial neural network controller (ANN), which controls the inputs of each area in the power system together, is considered. In this study, back propagation-through time algorithm is used as neural network learning rule. The performance of the power system is simulated by using conventional integral controller and ANN controller, separately. For the first time comparative study has been carried out between SMES and CES unit, all of the areas are included with SMES and CES unit separately. By comparing the results for both cases, the performance of ANN controller with CES unit is found to be better than conventional controllers with SMES, CES and ANN with SMES.