Vitzrotech Co.

Ansan, South Korea

Vitzrotech Co.

Ansan, South Korea
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Park S.-H.,National Fusion Research Institute | Kim H.-T.,National Fusion Research Institute | Vinyar I.,PELIN LLC | Lee J.,VITZROTECH Co. | And 4 more authors.
Fusion Engineering and Design | Year: 2016

KSTAR (Korea Superconducting Tokamak Advanced Research) has used a gas puffing system as a main fueling method since 2008. Up to date total fueling efficiency of the gas puff is less than 30%. A pellet injection is a more effective technique to control a plasma density than the gas puffing system and a supersonic molecular beam injection. Therefore, we have developed the pellet injection system for KSTAR. The pellet injection system for KSTAR consists of a pellet injector which injects pellets of a deuterium (diameter of 2. mm, length of 1.5-2. mm) at a velocity above 200. m/s with an injection frequency of 1-20. Hz, a 2-stage differential pumping system, a guide tube, a control system and so on. It is planned to inject pellets through a high field side and increase the plasma performance. © 2017 Elsevier B.V.

Lee H.-S.,Pohang Accelerator Laboratory | Park Y.J.,Pohang Accelerator Laboratory | Joo Y.-D.,Pohang Accelerator Laboratory | Heo H.,Pohang Accelerator Laboratory | And 11 more authors.
Journal of the Korean Physical Society | Year: 2015

One hundred seventy-two accelerating structures are required for the Pohang Accelerator Laboratory X-ray free-electron laser’s (PAL-XFEL’s) 10-GeV main linear accelerator. So far, we have purchased 80 structures from Mitsubishi Heavy Industry (MHI), which have quasi-symmetric couplers in the accelerating structure to reduce the quadruple and the sextuple components of the electric field in the coupling cavity. High-power tests have been conducted for the first structure of the MHI structure, and Research Instruments (RI) has developed a 3-m long accelerating structure that has an operating frequency of 2856 MHz and in/out couplers of quasi-symmetric racetrack shape for the PAL-XFEL linear accelerator. This structure also has been tested by PAL and RI in the Pohang accelerator laboratory (PAL) to check the maximum available electric field gradient. We will describe the test results of these structures and the current status for the fabrication of the other accelerating structures in this paper. © 2015, The Korean Physical Society.

Kim C.-H.,National Fusion Research Institute | Kong J.-D.,National Fusion Research Institute | Eom D.-Y.,National Fusion Research Institute | Joung N.-Y.,National Fusion Research Institute | And 8 more authors.
Fusion Engineering and Design | Year: 2012

The Korean Superconducting Tokamak Advanced Research (KSTAR) superconducting magnet power supply is composed of a Poloidal Field Magnet Power Supply (PF MPS) and a Toroidal Field Magnet Power Supply (TF MPS). When the PF MPS is operated, it requires a large amount of power instantaneously from the KSTAR electric power system. To achieve the KSTAR operational goal, with a long pulse scenario, a peak power of 200 MVA is required and the total power demand for the KSTAR system can exceed 200 MVA. The available grid power is only 100 MVA at the KSTAR site. Increasing the available grid power was uneconomical and inefficient which is why NFRI are installing a Motor Generator (MG). National Fusion Research Institute (NFRI) has made a contract with Vitzrotech and Converteam to design, manufacture and install the MG. Converteam has designed the electromagnetic and mechanical specification of the MG and Variable Voltage Variable Frequency (VVVF) converter. In this paper we discuss the conceptual design, including energy saving and electrical capacity of the MG system and the performance of the MG to satisfy the KSTAR 300 s operation scenario. In addition, the manufacturing and installation plan for the KSTAR MG is discussed. © 2012 Elsevier B.V.

Kim C.-H.,National Fusion Research Institute | Eom D.-Y.,National Fusion Research Institute | Lee W.-J.,National Fusion Research Institute | Kong J.-D.,National Fusion Research Institute | And 8 more authors.
Fusion Engineering and Design | Year: 2014

Peak power of 200 MVA is required in order to achieve the goal within a long pulse scenario for the final operation of the Korean Superconducting Tokamak Advanced Research (KSTAR). The available grid power is only 100 MVA at the National Fusion Research Institute (NFRI) site. Motor generator (MG) was considered as a method of resolving such problems. The design of the KSTAR MG system was completed in July 2010 and individual devices were produced by relevant manufacturers. The installation of individual devices was completed in December 2012. Specifically, the stator and rotor were assembled at the site due to their large size and weight. The bearings, variable voltage variable frequency (VVVF) and excitation systems were transported and installed on site after being manufactured externally. The building used for MG installation was built in 2011. With the building designed for ease of installation, an overhead crane was designed to allow access to the loading bay. In this paper, we discuss the installation of the MG system and the construction of the building suitable for installation of individual devices. In addition, performance on the test results of individual devices is also discussed. © 2014 Elsevier B.V.

Gu C.-W.,Hanyang University | Lee K.-A.,Hanyang University | Ju H.-J.,Hanyang University | Ko K.-C.,Hanyang University | Lee C.-K.,Vitzrotech Co.
Proceedings of the 2012 IEEE International Power Modulator and High Voltage Conference, IPMHVC 2012 | Year: 2012

Vacuum interrupter (VI) has been commercially available in medium voltage switching equipment. Recently, the development of the VIs is focused to reduce the size. Thus, it is necessary to a smaller size contact. In this paper, we investigated the interruption behavior in the real VI with two different contact size of the transverse magnetic field (TMF) type which is widely used for interrupting the arc current in vacuum. Additionally, we investigated the interrupting capability according to the change of opening speed by using contact with the lower interrupting performance obtained from earlier tests. In our experiment, CuCr25 contact was applied, Weil-Dobke voltage superposition circuit was used for a short circuit current test. Through the correlation between the contact size and opening speed, we could design a smaller VI, and it was applied to 17.5kV 25kA vacuum circuit breaker (VCB). © 2012 IEEE.

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