Tadeusz Janowski

Design and testing of 230 V inductive type of Superconducting Fault Current Limiter with an open core

A single-phase, 230 V Superconducting Fault Current Limiter using two Bi2223 HTS tubes with the total critical current 2.5 kA situated in vacuum insulated cryostat has been described in this paper. We designed and manufactured the inductive SFCL with an open core as core shielded type acquired the optimal design parameters by using Finite Element Method. We tested the limiter performances at liquid nitrogen temperature 77 K. We proved that the performances of properly designed limiter with open core could be comparable to the limiter with closed core.

Properties comparison of superconducting fault current limiters with closed and open core

The high-T/sub c/ superconducting fault current limiter (SFCL) can be classified into resistive, inductive and hybrid types. The inductive type HTSFCL seems to show most prospect due to the simple design (construction) of the secondary superconducting winding in the form of ceramic type BSCCO and for the reduction of current leads. In an inductive type SFCL, ferromagnetic cores for magnetic flux are applied, however open cores are also taken into consideration in order to simplify the construction. The results of experimental and computational investigations of inductive SFCL parameters are presented in this paper.

Experimental and numerical analysis of energy losses in resistive SFCL

The resistive SFCL (superconducting fault current limiter) is a superconducting device which may operate both in superconducting state and in normal conducting (resistive) state. The paper presents FEM numerical model (in FLUX2D) of resistive SFCL made using Bi-2212 bifilar coil (NEXANS) cooled by pool boiling cooling technique (liquid nitrogen, 77 K). Real geometry of resistive SFCL is replaced by equivalent, due to energy and current density, geometry of numerical model. The electro-thermal numerical model of resistive SFCL can be used to estimate the energy and maximum temperature in limiter and the time to switch off the current to protect against damage.

Design and Performance Results of First Polish SMES

The magnet for superconducting magnetic energy storage system (SMES) cooled by SRDK-408 cryocooler has been described in this paper. The superconducting magnet consists of 7 double-pancake coils made of Bi-2223 HTS tape with the inner and outer diameters 210 mm, 315 mm respectively and height of 191 mm. The inductance of the magnet is about 1 H. In the paper we report the design and the first measurements results of the magnet.

Design and Numerical Analysis of the 15 kV Class Coreless Inductive Type SFCL

Superconducting fault current limiters (SFCLs) are the most attractive devices for the power network, because limiters can be used to limit the short current in electrical network. This paper presents the design, the numerical model, and the calculated electrical parameters of the new 15-kV class SFCL prototype. The coreless superconducting fault current limiter consists of three windings: a primary and secondary windings made of SF12050 tape and a parallel connected primary copper winding. All windings are inductively coupled and intended to work in liquid nitrogen. The transient magnetic FEM-circuit numerical models of SFCL were used to analyze the current, resistance, and temperature of SFCL in the limitation state.

The influence of superconducting fault current limiter structure on the V-I characteristic

Superconducting fault current limiters (SFCL) use the natural ability of rapid shifting from the normal to the resistive state of superconductor due to their critical current value exciding. This special feature of superconducting materials enables designing of electrical devices with parameters that cannot be achieved by using conventional materials. The voltage dependence on the structure of superconducting inductive fault current limiter in a superconducting state has been described in this paper. This dependence has enabled elaboration of computer software for parameters optimizations of SFCL primary winding. This dependence in a resistive state is also described. The analysis was carried out using FLUX2D software based on a finite element method.

Power Supply Systems of Ozone Generators with Magnetic Frequency Multipliers

Abstract Discharge plasma reactors are very complex technological systems. Power supply is not only inseparable part of this system but also one of the most important. Very often efficient and reliable power system decides about application of the plasma processes on industrial scale. Paper presents transformer type power system of ozone generator, its comparison with other systems from their efficiency point of view and designing directions on the example of 150 Hz supplier.