Conveners
Tue-Af-Po2.16 - Power Supplies and Flux Pumps II: Transformers
- Jun Ma (Cambridge University)
- Yujia Zhai (Hunan University)
Abstract—As a marvelous promotion of applications with HTS magnet in a variety of fields appears, it is of particular importance to compensate persistent current decay in HTS magnets. Therefore, a large quantity of means of contactless power supply (CPT) have emerged in endlessly. In general, CPT mainly consists of 5 parts, which include power, inverter circuit, electromagnetic inductive...
In High Temperature Superconductor (HTS) direct current (dc) magnet applications much of the cryocooler load required for continuous operation is imposed by the external current leads. Operation of HTS dc magnets at high currents requires large cross-section leads, but these leads provide a large thermal bridge between the ambient current supply and the cryogenic superconducting components....
In general, superconducting rotating machines have been widely deployed because they have advantages such as smaller volume, lighter weight, and higher efficiency than conventional rotating machines. However, superconducting rotating machines need a cryogenic system to keep field coils in a superconducting state. High temperature superconducting (HTS) flux pumps inject DC current into...
High temperature superconductor (HTS) magnet working in persistent current mode (PCM) shows great potential in improving the efficiency of electrical applications, since it can offer amazing merits in lowering the energy cost and realizing the compact and light weight design of electrical devices. Unfortunately, the lossless PCM HTS magnet is unavailable due to the non-ignorable joint...
High-temperature superconducting (HTS) coils wound without turn-to-turn insulation (NI coils) show excellent electrical and thermal performance compared to HTS coils wound with insulation material (INS coils). However, charging the NI coils using a direct current (DC) power supply have a slower charging time than the INS coils. To overcome this slow charging time, research is underway to...
Though an HTS jointless coil can conduct a persistent current without decay, it needs an external power source for the excitation. We have magnetized the HTS jointless coils by field cooling and also have excited by flux pumps with rotating permanent magnets. A stationary flux pump has several comparative advantages over the field cooling or the rotary flux pump.
In this paper, we designed...
Abstract
A facility capable of testing superconducting cables with current of tens of kA is essential for the development of large superconducting magnets. A superconducting transformer (SCT) is a suitable choice as a high DC current source for testing superconducting cables. In this work, we will present our experimental results of a SCT that was originally developed by Lawrence...
JT-60SA is the second largest tokamak device constructed in the world, which is being implemented aiming to start the first experiment in 2020. One of the most important features of JT-60SA is to have superconducting magnets for long-pulsed plasma discharge (100 s flattop). JT-60SA has ten of poloidal field (PF) coils for inductive current drive and shape control of a plasma. Their stored...
Water-cooled resistive high-field research magnets require a high power supply with an extremely high current stability, and a low current ripple and noise. The conventional resistive magnet power supply uses thyristor rectifiers, followed by a passive filter and an active filter in series to reduce the voltage ripple. This Paper describes a new circuit topology design of the resistive magnet...
The high stability flat-top pulsed magnetic field (FTPMF) is strongly needed for some scientific researches such as nuclear magnetic resonance (NMR) and specific heat measurement. The high stability FTPMF Facility based on the battery power supply with a linear bypass circuit had been built at Wuhan National High Magnetic Field Center the in 2018. The linear bypass circuit mainly consists of...
In the past years, the thyristor converter technology has been adopted in the Tokamak coil power supply, mainly because of current carrying capacity and overload capability of thyristor with high power level. However, thyristor converter technology also has inherent defects, including poor dynamic control, low power factor, and producing a large number of reactive power and harmonics that...
