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Saturated core type superconducting fault current limiter (SFCL) can effectively limit the short-circuit current in power system. However, the high induced voltage will occur between the terminals of DC superconducting bias winding caused by the variation of magnetic flux linked by DC winding due to the increasing short-circuit current. The DC source may be damaged. Thus, the induced voltage should be considered in DC winding design. The paper aims to discuss these issues.

Three-dimensional finite element method coupled with electric circuit.

The short-circuit current flowing through AC windings and induced voltage of DC winding are analyzed by using three-dimensional finite element method coupled with electric circuit for a 220-kV three-phase SFCL. Several circuit elements, such as a capacitor connected with DC winding in parallel, an additional short-circuit winding wound around DC core column and an energy-released piezoresistor, are, respectively, used for induced voltage reduction. These methods aim to save magnetic coupled energy in DC winding, or oppose the variation of magnetic flux, or limit the voltage of DC winding by using a resistor with low resistance.

The different methods for reduction of induced voltage of superconducting DC winding are studied and discussed. The decreased induced voltage may benefit the safety of superconducting DC winding and the source.

A saturated iron core superconducting fault current limiter (SISFCL) has an important role to play in the present-day power system, providing effective protection against electrical faults and thus ensuring an uninterrupted supply of electricity to the consumers. Previous mathematical models developed to describe the SISFCL use a simple flux density-magnetic field intensity curve representing the ferromagnetic core. As the magnetic state of the core affects the efficient working of the device, this paper aims to present a novel approach in the mathematical modeling of the device with the inclusion of hysteresis.

The Jiles–Atherton’s hysteresis model is utilized to develop the mathematical model of the limiter. The model is numerically solved using MATLAB. To support the validity of model, finite element model (FEM) with similar specifications was simulated.

Response of the limiter based on the developed mathematical model is in close agreement with the FEM simulations. To illustrate the effect of the hysteresis, the responses are compared by using three different hysteresis characteristics. Harmonic analysis is performed and comparison is carried out utilizing fast Fourier transform and continuous wavelet transform. It is observed that the core with narrower hysteresis characteristic not only produces a better current suppression but also creates a higher voltage drop across the DC source. It also injects more harmonics in the system under fault condition.

Inclusion of hysteresis in the mathematical model presents a more realistic approach in the transient analysis of the device. The paper provides an essential insight into the effect of the core hysteresis characteristic on the device performance.

This article is aims to inform aircraft propulsion system designers of the implications which fundamental power distribution design assumptions have on the effectiveness and viability of turboelectric distributed propulsion (TeDP) systems. Improvements and challenges associated with selecting alternating or direct current for normal- and superconducting distribution systems are presented. Additionally, for superconducting systems, the benefits of bi-polar DC distribution are discussed, as well as the implications of operating voltage on the mass and efficiency of TeDP grid components.

The approach to this paper selects several high-level fundamental configuration decisions, which must be made, and it qualitatively discusses potential implications of these decisions.

Near term TeDP architectures which employ conventionally conducting systems may benefit from alternating current (AC) distribution concepts to eliminate the mass and losses associated with power conversion. Farther term TeDP concepts which employ superconducting technologies may benefit from direct current (DC) distribution to reduce the cryocooling requirements stemming from AC conduction losses. Selecting the operating voltage for superconducting concepts requires a divergence from the present day criteria employed with terrestrial superconducting transmission systems.

The criteria presented in the paper will assist in the early conceptual architecting of TeDP systems.

The governing principles behind the configuration of multi-MW airborne electrical microgrid systems are presently immature. This paper represents a unique look and the motivating principles behind fundamental electrical configuration decisions in the context of TeDP.

The purpose of this paper is to describe the necessity for the use of fully superconducting electrical power systems (SEPS) in future hybrid electric aircraft which facilitates the use of a distributed propulsion system.

The paper looks at the overall design of the electric power systems for these applications and compares the design process of a more conventional power network with a fully superconducting one. The design issues and solutions in each case are then described.

The paper concludes that SEPS will give many advantages to the aircraft design and operation.

Significant efforts needs to be oriented towards the development of fully SEPS and dedicated facilities are required for reliable experimental data that will allow the modelling of these systems.

The requirement for more experimental work has not yet been considered by the Industry, as it is a general belief that these networks will behave similar to the conventional ones.

This paper aims to clarify voltage sourced converter’s (VSC’s) influence rules on the alternating current (AC) short-circuit current and identify the key factors, so as to propose the short-circuit current suppression strategy.

This paper investigates the key factors which impact the short-circuit current supplied by the VSC based on the equivalent current source model. This study shows that the phase of the VSC equivalent current source is mainly affected by the type of fault, whereas the amplitude is mainly decided by the control mode, the amplitude limiter and the electrical distance. Based on the above influence mechanism, the dynamic limiter with short-circuit current limiting function is designed. The theoretical analysis is verified by simulations on PSCAD.

The short-circuit current feeding from VSC is closely related to the control mode and control parameters of the VSC, fault type at AC side and the electrical distance of the fault point. The proposed dynamic limiter can make VSC absorb more reactive power to suppress the short-circuit current.

The dynamic limiter proposed in this paper is limited to suppress three-phase short-circuit fault current. The future work will focus more on improving and extending the dynamic limiter to the fault current suppression application in other fault scenarios.

The research results provide a reference for the design of protection system.

The key influence factors are conducive to put forward the measures to suppress the fault current, eliminate the risk of short-circuit current exceeding the standard and reduce the difficulty of protection design.

This paper aims to present a novel energy-efficient saturated open-core fault current limiter (FCL) with special permanent magnet (PM) modules.

The special PM modules are used to drive the cores of FCL into a saturated state from different directions in the normal operation condition, reducing the DC current of the saturated open-core FCL. An equivalent magnetic circuit model of the saturated open-core FCL with PM modules is built to calculate the magnetic flux density in the cores of FCL. By applying the modified nodal approach on the circuit, the nonlinear equations of the magnetic circuit can be achieved. The Newton – Raphson method is used to solve the nonlinear equations. The model shows good accuracy verified by finite element simulation and a physical experiment.

Compared with the original saturated open-core FCL structure with PMs, the novel saturated open-core FCL structure can save 84% DC power. The physical experiment results show that the saturated open-core FCL has a good performance on limiting the fault current.

A novel saturated open-core FCL structure with PM modules is proposed in this paper. A physical model of the saturated open-core FCL structure with PM modules is manufactured and tested. About 84% DC power can be reduced by using the PM modules in this saturated open-core FCL, and it can save most of the cost of the saturated open-core FCL.

The purpose of this study is to propose a control scheme based on state estimation algorithm to improve zero or low-voltage ride-through capability of permanent magnet synchronous generator (PMSG) wind turbine.

Based on the updated grid codes, during and after faults, it is necessary to ensure wind energy generation in the network. PMSG is a type of wind energy technology that is growing rapidly in the network. The control scheme based on extended Kalman filter (EKF) is proposed to improve the low voltage ride-through (LVRT) capability of the PMSG. In the control scheme, because the state estimation algorithm is applied, the requirement of DC link voltage measurement device and generator speed sensor is removed. Furthermore, by applying this technique, the extent of possible noise on measurement tools is reduced.

In the proposed control scheme, zero or low-voltage ride-through capability of PMSG is enhanced. Furthermore, the requirement of DC link voltage measurement device and generator speed sensor is removed and the amount of possible noise on the measurement tools is minimized. To evaluate the ability of the proposed method, four different cases, including short and long duration short circuit fault close to PMSG in the presence and absence of measurement noise are studied. The results confirm the superiority of the proposed method.

This study introduces EKF to enhance LVRT capability of a PMSG wind turbine.

It has constantly been important to investigate the distribution of magnetic fields in high temperature superconducting (HTS) transformers because the high magnetic field applied to the HTS tapes reduces the critical current and increases the ac losses. The purpose of this study is investigation of the impact of the radius of double pancake windings on the electromagnetic behavior of HTS transformer. In this paper, by changing the radius of the windings in a step-by-step manner in two modes, the electromagnetic behaviors in double pancakes (DPs) of a single-phase HTS transformer have been investigated.

In this paper a 15.4 kVA single-phase HTS transformer has been designed and simulated using the finite element method, using COMSOL multiphysics software. The effect of changing the radius of the low-voltage (LV) and high-voltage (HV) windings on the electromagnetic parameters such as distribution of circulating currents and magnetic field in the LV DP windings has been investigated.

According to the results, by increasing the radius of the LV winding, the electromagnetic behavior of the highest and lowest DPs becomes highly undesirable, while in other DPs, it becomes desirable. The same thing happens by increasing the radius of the LV and HV windings, but with much less intensity. Therefore, according to Ce, the most optimal case is when the two windings (HV and LV) are close to each other and to the core, and if the radius needs to be increased, it is better to increase the radius of both windings.

For the first time, the impact of the radius of DP windings on the electromagnetic behavior of HTS transformer has been investigated.

A numerical analysis tool has been developed to study electromagnetic characteristics of high‐temperature superconducting thin film used for a resistive‐type fault current limiter (FCL) and coated conductor. It adopts the finite element method based on current vector potentials with thin‐plate approximation. Transport current, temperature dependence and strong non‐linearity of electromagnetic properties, and state transition of superconductor are taken into account by solving a three‐dimensional coupled problem of electromagnetic field, an electric circuit and thermal field. Then using this numerical analysis tool the current imbalance and current limiting characteristics of a FCL device, the influence of inhomogeneity of superconducting properties on them, and AC losses in YBCO coated conductor are studied.

This study aims to provide a scientific framework for the selection of suitable substation technology in an electrical power distribution network.

The present paper focuses on adopting an integrated multi-criteria decision-making approach using the Delphi method, analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS). The AHP is used to ascertain the criteria weights, and the TOPSIS is used for choosing the most fitting technology among choices of air-insulated substation, gas-insulated substation (GIS) and hybrid substation, to guarantee educated and supported choice.

The results reveal that the GIS is the most preferred technology by area experts, considering all the criteria and their relative preferences.

The current research has implications for public and private organizations responsible for the management of electricity in India, particularly the distribution system as the choice of substations is an essential component that has a strong impact on the smooth functioning and performance of the energy distribution in the country. The implementation of the chosen technology not only reduces economic losses but also contributes to the reduction of power outages, minimization of energy losses and improvement of the reliability, security, stability and quality of supply of the electrical networks.

The study explores the impact of substation technology installation in terms of its economic and environmental challenges. It emphasizes the need for proper installation checks to avoid long-term environmental hazards. Further, it reports that the economic benefits should not come at the cost of ecological degradation.

The present study is the first to provide a decision support framework for the selection of substation technologies using the hybrid AHP-TOPSIS approach. It also provides a cost–benefit analysis with short-term and long-term horizons. It further pinpoints the environmental issues with the installation of substation technology.