Dada Wang

Development of a Leakage Flux-Controlled Reactor

In order to flexibly compensate reactive power, it is necessary to develop a controllable reactor in long distance and ultrahigh voltage system. A leakage flux-controlled reactor (LFCR) is developed in this paper. The operation principles of LFCR are discussed in detail, and a 380 V single-phase LFCR prototype is developed. Relevant experiments have been done to test its performance. The results of the experiments indicate that LFCR has no harmonic and the reactance of LFCR is stable. Also, LFCR with two control windings can realize four kinds of reactance adjustment rates: 1.94%, 75.99%, 90.53%, and 99.05%.

Feasibility Research on Improving the Pulsed Current Output of Superconducting Inductor by Using HTS Air-Core Transformer

This paper aims to study the feasibility of improving pulsed current output by using High temperature superconducting (HTS) air-core transformer. Based on the theoretical analysis, the simulations are done. Results of the simulations indicate that the HTS air-core pulse transformer can magnify the output current magnitude and accelerate the velocity of discharge. However, when a series of inductor modules use the same one HTS air-core transformer, the residual current may influence the discharging waveform. To eliminate residual current, self-coupling discharging model is proposed. The simulated and experimental results illustrate that a self-coupling model can eliminate the residual current effectively. The results of this analysis contribute to the research of superconducting inductor pulsed current output.

Research on the Inductance Variation of Bi2223/Ag Magnet

For the magnet used in power apparatus, the inductance is an important parameter which may change the input-output characteristic of the apparatus. In research of the high temperature superconducting (HTS) magnet in energy storage system and other electric apparatus, we found the difference of the magnets inductance between normal state and superconducting state. In this paper, the electromagnetic models of Bi2223/Ag tape and windings are established firstly. Based on the simulation analysis and measured results, the reason of inductance variation of HTS magnet has been clarified. The regularity of inductance variation of HTS pancake and magnet has been researched, and new requirement for the veracity in the process of superconducting magnets design has been claimed.

Numerical Simulation of Coupled Heat Transfer, Stress, and Electromagnetic Properties in an SMES Magnet

This paper describes the analysis procedure and FEM model considering the parallel effects of stress and thermal problem coupled with the electromagnetic field problem of a 10 MJ Superconducting Magnetic Energy Storage (SMES) magnet. Since the coupled processes in most analyses are very simplified or even not considered, the general aim of this paper was to create, solve, and validate a numerical model of the coupled stress and thermal phenomena that occur within an SMES magnet. A finite element model has been developed to solve the coupling of the magnetic field, stress, and thermal problems. Temperature and stress distribution of the SMES magnet in two operating conditions are simulated, taking into account the eddy current, ac loss, and heat conduction. This provides useful insight for optimized coil design and condition assessment of SMES.