R-Q curve based evaluation method for current-limiting performance of DC R-SFCL in high voltage DC system

Abstract

The current-limiting performance of the dc resistive-type superconducting fault current limiter (dc R-SFCL) is vital to the reliability in the high voltage dc current (HVDC) transmission system. It is expensive and difficult to utilize the discharging process of the precharged dc capacitor to evaluate the current-limiting performance. In this paper, a R-Q curve based evaluation method for current-limiting performance of dc R-SFCLs in dc system is proposed, which replaces the dc impulse experiment with ac impulse experiment. A ± 160kV dc SFCL prototype is designed by Guangdong Power Grid Co., Ltd., and tested to acquire the experimental heat accumulation Q and the experimental R-Q curve. Accordingly, the mathematical model consistent with the prototype is built in PSCAD. Finally, a fault condition is simulated in dc system to verify the feasibility of the R-Q curve based evaluation method. It is shown that the proposed method has superior properties in simplifying the testing platform, reducing the test requirements and costs, and providing reference for precise modeling of SFCLs.

Experimental Tests of DC SFCL Under Low Impedance and High Impedance Fault Conditions

“…A 160 kV/1 kA DC resistive SFCL based on rare earth barium copper oxide (REBCO) tape has been developed and installed at the Nan'ao ±160 kV HVDC power grid in China, which is the highest voltage level and the largest capacity in the world so far. This SFCL consists of 24 pancake coils with noninductive winding [15], [16]. In the European Union FAST-GRID project, a 50 kV/1.5 kA DC resistive SFCL module will be developed and tested.…”

Synthesis of Double Defects in g‐C3N4 to Enhance the H2O2 Production by Dual‐Electron O2 Reduction

“…Especially, the BCN, SCN‐4, N 2 −SCN‐4, and Air−SCN‐4 exhibited varying degrees of redshift, which might be due to the introduction of defects. According to the formula, [40] αhν = A ( hν ‐ E g ) n /2 ( ν is the frequency of light, E g is the bandgap width, h stands for the Planck constant, and for indirect bandgap semiconductors, the values of n is 4, α represents absorption coefficient), and the bandgap values of photocatalysts could be calculated by Tauc plots (Figure 6b) from the corresponding UV‐vis absorption spectra. To further explore the band structure of the samples, the XPS valence band spectra (VB‐XPS) were employed to estimate the VB potential.…”

Modelling of Resistive Type Superconducting Fault Current Limiter for HVDC Grids

“…Besides, with the R-SFCL a reduction of the fault current of is appreciated. Table 5 sums up the maximum current values of all converters and limiting factors, which is defined in Equation (18). grids.…”

“…Besides, with the R-SFCL a reduction of the fault current of is appreciated. Table 5 sums up the maximum current values of all converters and limiting factors, which is defined in Equation (18). With the integration of R-SFCLs, the peak currents, related to mechanical induced forces, and the final converter current, related to thermal stress, are drastically reduced.…”

“…Therefore, they are able to reduce fault currents but they do not exhibit the required period of time for heating and developing resistance. Non-linear look-up tables adjust this limitation and gradually state the resistance [18]. Some models represent the recovery time [19].…”