Further study of a novel inductive SFCL for multiterminal HVDC systems

Abstract

Multiterminal high voltage direct current (HVDC) systems are developing rapidly lately. However, the high rising rate of fault current and the lack of interrupting capacity of the available DC circuit breakers hinder the further development of multiterminal HVDC systems. Being aimed at the challenge, this paper proposes a novel inductive DC superconducting fault current limiter (SFCL) to cooperate with available DC circuit breakers to cope with the short-circuit fault current in a multiterminal HVDC system effectively. In the normal power transmission of a multiterminal HVDC system, the SFCL presents low impedance and enables a smooth reclosing operation after an interruption. It is able to make a maximum use of the permeability of the iron core to offer a large inductance to curb the rising rate of the fault current in the early few milliseconds as a fault takes place. In addition, it can have an adjustable current limiting threshold to match the different requirements of different grid protection schemes. In this paper, first the working principle of the proposed SFCL is introduced. Then the experimental results on a concept-proofing prototype are reported and analyzed. The experimental results have verified the principle and functional ability of the proposed SFCL.

Bulk MgB2 Superconducting Materials: Technology, Properties, and Applications

“…The MgB 2 superconductors with a bulk density of about 2.63 g/cm 3 are the lightest materials among practical superconductors. This makes MgB 2 attractive for portable applications [ 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 , 175 , 176 , 177 , 178 , 179 ], especially for aviation and space technology [ 26 , 146 , 171 ].…”

“…During a fault event, the current in the circuit increases, causing a phase transition in the secondary superconducting coil, accompanied by an increase in the device impedance and, following that, a fault current limitation [ 145 , 146 , 151 ]. An inductive SFCL can be also used for the protection of high-voltage direct-current (HVDC) systems [ 152 ]. The secondary coil can be formed using a superconducting ring or a set of rings (hollow cylinders) to increase the SFCL power [ 145 , 146 , 151 ].…”

Recent progress on CO2 separation membranes

“…21 In terms of CO 2 capture gas separation, zeolite membranes exhibit high selectivity for CO 2 adsorption due to their small pore structure, 22 potential high screening selectivity, and strong electrostatic eld. 23 Himeno et al 24 prepared a DDR (deca-dodecasil R) membrane for CO 2 separation based on a zeolite membrane. At 25 °C, the permeability of the membrane to the CO 2 single component reached 100 barrer, and the selectivity of CO 2 /CH 4 and CO 2 /N 2 mixed gas with a 50/50 feed ratio was 200.…”

“…21 In terms of CO 2 capture gas separation, zeolite membranes exhibit high selectivity for CO 2 adsorption due to their small pore structure, 22 potential high screening selectivity, and strong electrostatic field. 23 …”