Fault Current Limiters Research Papers (original) (raw)

2025

SCFCL Model in Power System Analysis Software Rev

2024, Performance Assessment of Resistive Superconducting Fault Current Limiter for 33/11 kV Distribution System

This paper evaluates the performance of a Resistive-type Superconducting Fault Current Limiter (R-SFCL) within a 33/11 kV distribution network, focusing on protecting sensitive electrical components—such as distribution transformers and connected loads—from various short-circuit faults. Using MATLAB/Simulink, the study simulates fault conditions, including single-line-to-ground and three-phase faults, to assess the R-SFCL’s effectiveness in fault current mitigation and system stability enhancement. Key parameters like fault location, fault type, R-SFCL characteristics, and control strategies are systematically analyzed to optimize R-SFCL deployment within the network. Results indicate that incorporating the R-SFCL significantly improves system stability, fault current interruption capabilities, and overall reliability, supporting the robust operation of distribution systems. By highlighting the R-SFCL’s potential to reduce equipment damage and improve power quality, this paper advances the understanding of fault current mitigation technologies, offering valuable insights for optimizing distribution network performance in the context of renewable energy integration.

2024, Performance Analysis of Resistive Superconducting Fault Current Limiter (R-SFCL) for Distribution Network

This thesis presents the modeling and analysis of a resistive-type Superconducting Fault Current Limiter (R-SFCL) within a 33/11 kV distribution network to enhance reliability and protection under both normal and fault conditions. The R-SFCL’s rapid transition from a superconducting to a resistive state limits fault currents before reaching the first peak, significantly mitigating the impact of short-circuit faults. MATLAB/Simulink is used to simulate the network performance, focusing on common fault types like single-line-to-ground and three-phase faults across main and sub-feeders. The study identifies appropriate current ratings for the R-SFCL based on line currents under normal conditions and quantifies fault currents prior to SFCL integration. Results indicate the R-SFCL's effectiveness in reducing fault impacts, supporting efficient and safe network operations, and minimizing upgrade costs associated with renewable energy integration.

2024

Power system faults are a typical occurrence today. A striking electrical gadget called a superconducting fault current limiter was developed to address the issue of extremely high fault current in the power system. In this article, the performance of a superconducting fault current limiter with existing switchgear is investigated. Simulink is used to model a resistive type SFCL initially. An air-core superconducting transformer and a PWM converter make up the active SFCL. By modifying the converter's output current, the magnetic field in the air-core can be controlled. Next, the equivalent impedance of the active SFCL may be tuned for current restriction and potential overvoltage suppression. This paper uses MATLAB to construct and simulate a revolutionary fuel cell-based SFCL. The simulation results show that by limiting the fault current and overvoltage, the active PV-based SFCL can help to prevent damage to the power system.

2024, Applied sciences

The doubly-fed induction generator has significant features compared to the fixed speed wind turbine, which has popularised its application in power systems. Due to partial rated back-to-back converters in the doubly-fed induction generator, fault ride-through capability improvement is one of the important subjects in relation to new grid code requirements. To enhance the fault ride-through capability of the doubly-fed induction generator, many studies have been carried out. Fault current limiting devices are one of the techniques utilised to limit the current level and protect the switches, of the back-to-back converter, from over-current damage. In this paper, a review is carried out based on the fault current limiting characteristic of fault current limiting devices, utilised in the doubly-fed induction generator. Accordingly, fault current limiters and series dynamic braking resistors are mainly considered. Operation of all configurations, including their advantages and disadvantages, is explained. Impedance type and the location of the fault current limiting devices are two important factors, which significantly affect the behaviour of the doubly-fed induction generator in the fault condition. These two factors are studied by way of simulation, basically, and their effects on the key parameters of the doubly-fed induction generator are investigated. Finally, future works, in respect to the application of the fault current limiter for the improvement of the fault ride-through of the doubly-fed induction generator, have also been discussed in the conclusion section.

2024

The Doubly-Fed Induction Generator (DFIG) has significant features in comparison with Fixed Speed Wind Turbine (FSWT), which has popularized its application in power system. Due to partial rated back-to-back converters in the DFIG, Fault Ride-Through (FRT) capability improvement is one of the great subjects regarding new grid code requirements. To enhance the FRT capability of the DFIG, many studies have been carried out. Fault current limiting devices as one of the techniques are utilized to limit the current level and protect switches of the back-to-back converter from over-current damage. In this paper, a review is done based on fault current limiting characteristic of the proposed fault current limiting devices Therefore, Fault Current Limiters (FCLs) and Series Dynamic Braking Resistors (SDBRs) are mainly taken into account. Operation of all configurations including their advantages and disadvantages is explained. Impedance type and the fault current limiting devices’ location ...

2024

The demand for electricity is increasing at a very high rate and demand for power is running ahead of supply. Introduction of Distributed energy resources (DES) is the biggest change happening to the distribution network. There is an increased integration of DES with the distribution network using power electronics converters as to meet the continuously increasing demand of electricity. In future it is expected that the penetration level of distributed energy resources will further increase. The connection of distributed energy resources with the distribution network result in increase in the value of fault current which can causes the abnormal conditions in the entire power system network. The equipment installed at generating station and at substation is very expensive. Therefore it is necessary to protect these equipment from fault current. A Fault Current Limiter (FCL) is a revolutionary power system device that overcomes the problems due to increased fault current levels. It is a device that reduces prospective fault currents to a lower manageable level. In this paper principals of operation and structures of various fault current limiter is discussed. It gives short and up-to-date literature review of conventional fault current limiting devices as well as fault current limiting devices which are still in a research or development stage.

2024

This paper presents some techniques for reduction of transformer inrush current. The equation of inrush current is obtained and then by using these methods, transformer inrush current is reduced, then after comparing the result of each method, the best choice is determined. Results which have been obtained from EMTP simulation confirm these subjects.

2024

In this paper, power quality improvement by using a new structure of non superconducting fault current limiter (NSFCL) is discussed. This structure prevents voltage sags on Point of Common Coupling (PCC) just after fault occurrence, because of its fast operation. On the other hand, previously used structures produce harmonics on load voltage and have ac losses in normal operation. New structure has solved this problem by using dc voltage source. The proposed structure is simulated using PSCAD/EMTDC software and ...

2024, IEEE Transactions on Power Delivery

In this paper, voltage sag compensation of point of common coupling (PCC) using a new structure of fault current limiter (FCL) is proposed. The proposed structure prevents voltage sag and phase angle jump of substation PCC after fault occurrence. This structure has a simple control method. Using semiconductor switch (IGBT or GTO) at dc current rout leads to fast operation of the proposed FCL and consequently, dc reactor value is reduced. On the other hand, the proposed structure reduces total harmonic distortion (THD) on load voltage and it has low ac losses in the normal operation. As a result, other feeders which are connected to the substation PCC will have good power quality. Analytical analysis, simulation results using PSCAD/EMTDC software and experimental results are presented to validate effectiveness of this structure. Index Terms─Voltage sag, fault current limiter, power quality, point of common coupling (PCC), semiconductor switch, THD.

2024

This paper illustrates a generic Electrical Power Generation & Distribution System. The AC power frequency is variable and depends of the engine speed. The represents the generator mechanical drive and is modeled by a simple signal builder, which provides the mechanical speed of the engine shaft.The represents the power AC generator. It is composed of a modified version of the simplified synchronous machine. The mechanical input of the modified machine of 50 kW is the engine speed. The Generator Control Unit regulates the voltage of the generator to 200 volts line to line.The represents the Primary Distribution system. It is composed of three current and voltage sensors. There is also a 3-phase contactor controlled by the Generator Control Unit. Finally, a parasitic resistive load is required to avoid numerical oscillations. The section represents the secondary Power Distribution system. It is represented by 4 circuit breakers with adjustable current trip. The section represents the...

2024, Journal of emerging technologies and innovative research

The demand for electricity is increasing at a very high rate and demand for power is running ahead of supply. Introduction of Distributed energy resources (DES) is the biggest change happening to the distribution network. There is an increased integration of DES with the distribution network using power electronics converters as to meet the continuously increasing demand of electricity. In future it is expected that the penetration level of distributed energy resources will further increase. The connection of distributed energy resources with the distribution network result in increase in the value of fault current which can causes the abnormal conditions in the entire power system network . The equipment installed at generating station and at substation is very expensive. Therefore it is necessary to protect these equipment from fault current. A Fault Current Limiter (FCL) is a revolutionary power system device that overcomes the problems due to increased fault current levels. It i...

2024, International Journal of Research Publication and Reviews

Installation of parallel feeder increases reliability and uninterrupted power failure in distribution system and continuity of power supply maintained for consumers. Parallel feeder increases flexibility and scalability of power system. In this project, deals with examine of fault impact on parallel feeder based distribution system. The work presented in this project consist of simulation of parallel feeder in PSCAD/EMTDC software. Observing both sources current and load current is done in the simulation. The impact of fault current on different four busses under the influence of L-G, LL-G, LLL-G and LL with and without protection is studied. The severity of fault is much more in LLL-G fault as compared to other faults.

2024, IEEE Transactions on Applied Superconductivity

2024, IEEJ Transactions on Power and Energy

2024

The design process of a superconducting fault current limiter (SFCL) requires simulation and definition of its electrical, magnetic and thermal properties in form of equivalent circuits and mathematical models. However, any change in SFCL parameters: dimension, resistance, and operating temperature can affect the limiting mode, quench time, and restore time. In this paper, following the simulation of electrical and thermal behavior of resistive and inductive SFCLs and investigation on their performance variation responded to change parameters, the best design cases will be selected by using multiple criteria decision making (MCDM) techniques. As a case study, to evaluate proposed MCDM approaches in design of superconducting fault current limiter, a model in which a SFCL is located at an outgoing feeder in a 20 kV distribution substation will be considered and best designs will be presented for both resistive and inductive type.

2024, 2009 Brazilian Power Electronics Conference

This paper presents a new control strategy that allows the photovoltaic system operation under grid faults without overcurrent and assuring grid sinusoidal currents. The current limiter is made indirectly by using an active power limiter that is calculated dynamically based on the grid positive-sequence voltage. The paper also shows that the classic control strategies used in the PV systems cause harmonic current injections on the electrical grid and dangerous overcurrents when voltage sags occur. The strategy presented here overcomes these drawbacks and allows the inverter operation under any unbalanced condition. The control is made on stationary reference frame using Proportional-Resonant current control. This new control strategy is compared to the classic strategy through simulations in PSCAD/EMTDC and the experimental results prove its effectiveness.

2024, MATEC Web of Conferences

In this study, the most vital characteristic properties of induction motor, motor starting, maximum and nominal torque are analyzed for what are affected. For the analysis of torque, L type, T type and IEEE 112 equivalent circuit model is employed. Torque change is investigated with the help of codes developed in MATLAB to be used in electrical machines course. First, the slip-moment characteristic curve of the induction motor is divided into three working zones and it was determined which equivalent circuit model gave the best results in these study zones. Later, such parameters as stator and rotor resistance, stator and rotor reactance, magnetization reactance, core resistance and slip are researched for how torque values are affected from. The obtained values for each of the three equivalent circuit models are given and compared with experimental results. 50 HP squirrel cage induction motor parameters are used in analysis. In the analysis, the most influential parameters on the starting torque are found as rotor resistance and stator and rotor reactance. Change of other parameters' impact ratio depending upon right proportion and inverse proportion is observed. When nominal torque variations are investigated, again rotor resistance is the most influential parameter and by selecting proper factor effecting rotor resistance during design, the result of acquiring desired rotor resistance is obtained. When the maximum torque variations are examined, it appears that the stator and rotor reactance values are effective. Starting, maximum and nominal torque expressions change with square of voltage alters the effect on them a lot. Therefore, triangle or star connection importance arises during machine design.

2024, Energies

Designs of saturated-cores fault current limiters (FCLs) usually implement conducting or superconducting DC coils serving to saturate the magnetic cores during nominal grid performance. The use of coils adds significantly to the operational cost of the system, consuming energy, and requiring maintenance. A derivative of the saturated-cores FCL is a design implementing permanent magnets as an alternative to the DC coils, eliminating practically all maintenance due to its entirely passive components. There are, however, various challenges such as the need to reach deep saturation with the currently available permanent magnets as well as the complications involved in the assembly process due to very powerful magnetic forces between the magnets and the cores. This paper presents several concepts, achieved by extensive magnetic simulations and verified experimentally, that help in maximizing the core saturation of the PMFCL (Permanent Magnet FCL), including optimization of the permanent magnet to core surface ratios and asymmetrical placement of the permanent magnets, both creating an increase in the cores' magnetic flux at crucial points. In addition, we point to the importance of splitting the AC coils to leave the center core point exposed to best utilize their variable inductance parameters. This paper also describes the stages of design and assembly of a laboratory-scale single phase prototype model with the proposed PMFCL design recommendations, as well as an analysis of real-time results obtained while connecting this prototype to a 220 V grid during nominal and fault states.

2024, IEEE Transactions on Applied Superconductivity

Effect of the winding density in the AC coils on the performance of a saturated cores fault current limiter (SCFCL) has been studied, exploiting Finite Element Analysis. For a given design, a fixed number of turns was concentrated at the center of the AC coils limb, resulting in high windings density. The coil length was then increased gradually along the limb, decreasing the winding density and therefore decreasing the coil impedance. However, we found that the ratio between the fault to nominal state impedances increases with decreasing winding density. The results are discussed and explained as originating from the change in the flux linkage of windings in the coil for various core states. In the nominal-state of the SCFCL, the core is saturated and the coupling between the windings is lower, given the lower winding density. However, when the core is desaturated during a fault, the magnetic interaction of the windings with the core strengthens, the coupling between the windings increases and contributes to higher fault-state impedance. Thus, reducing the winding density may serve in increasing the impedance ratio of the device and improving the performance of SCFCLs. The results suggest that the windings density in SCFCLs should be used as a significant design parameter.

2023

The main aim of this work is to design and test a permanent magnet fault current limiter (PMFCL) to limit the fault current in electrical power system network. The (fit and forget) device presented in this thesis is based on two important aspects; the best selection of the state of the art soft and hard magnetic materials and the design topology of PMFCL. Rare I would like to express my sincere thanks and greatest gratitude to my thesis supervisor Dr Faris Alnaem for all his help, advice, comments and guidance in the completion of this thesis. In addition, I would like to give my thanks to my second supervisor, Dr Walid Issa for his help, suggestions and advice. My thanks to the Electrical and Electronic Engineering Department's staff members for their assistance in obtaining the different parts I needed for the experimental work of the PMFCL. My thanks to my friends. My special thanks to my family especially my sons (Mahmud and Yousef) for their support.

2023, Energy Procedia

With several significant advantages such as compactness, reliability, zero reset time, safe operation and fail safe, the permanent magnet fault current limiter (PMFCL) is a preferable solution to mitigate the fault current in power grids these years. In this paper, the substation voltage level PMFCL device, aims to extend the capacity of the power grid, is presented. The dry type PMFCL that does not require DC excitation coils is designed and simulated by 3D FEM. The 3D FEM magneto static solver has been used as time saving approach to predict the device fault current limitation in case of a fault. The peak transient currents simulation results were in agreement with the RMS values obtained using the magneto static inductance-current profile. The effect of the PMFCL on the fault current mitigation has been compared with an air-cored of similar specifications and a useful reduction in the fault current has been achieved.

2023

2023, SN Applied Sciences

Induction motors (IMs) are the most widely employed electrical motors due to their robust construction and adaptability. Due to their versatility and wide range of applications, it is crucial to examine the performance of these motors using a simple but thorough simulation model. In this study, we present the simulation models to conduct the DC test, the no-load test, and the locked rotor test on a three-phase induction motor using MATLAB/Simulink. These three tests are fundamental to determining the characteristics of a three-phase induction motor equivalent circuit. Furthermore, the authors extend the model to determine the starting current, starting torque, and breakdown torque of the motors under inquiry. The research further employs the right code in the MATLAB environment to ascertain the motors' torque-speed and current-speed properties. The results of the simulations are found to closely match the values achieved in real trials. Hence, this model can be employed to enhan...

2023, Zenodo (CERN European Organization for Nuclear Research)

In this study, a simple, but effective method is presented for the limitation of the Y-yg transformers transient current. One of the main privileges of this method is its simple topology. It does not need any control circuit or measurement unit. The method is based on a three-phase thyristor bridge with a low resistance reactor. Since the number of thyristors is minimized, the voltage ripple, electrical losses and the malfunction probability owing to device failure are decreased considerably. The proposed method is simulated and validated by MATLAB simulation and conventional methods test results. It is shown that the proposed configuration is effective for the transient current limitation of Y-yg transformers

2023, Engineering, Technology & Applied Science Research

This paper deals with the performance evaluation of a three-phase transient current limiter in distribution systems. A simulation model based on mathematical model of a three-phase, transient current limiter has been developed. The problem is formulated to justify the stable and harmonic free twelve-pulse and six-pulse converter based transient current limiter. Firstly, conventional methods like Bode Plot, Nyquist Plot and Nichols Chart are used to investigate the stability of twelve-pulse and six-pulse converter based transient current limiter. Next, a comparative analysis using fast Fourier transform is used to check the system harmonics using MATLAB simulation. The proposed design is found to be more efficient in making the system stable and harmonic free.

2023, Research Square (Research Square)

The increase in distribution power demand and distributed generation may lead to a rise in power substation fault current levels. One possible solution to this problem is the use of a Solid-State Fault Current Limiter (SS-FCL). In this context, this paper proposes the concept of a bridge-type solid-state device switching an air-core reactor as an SS-FCL topology. The overvoltage protection system details are presented, along with an explanation of the fault detection algorithm control's principle. An experimental setup is designed to evaluate various events in addition to the short circuit, such as load-steps, harmonic loads, motor startups and transformer's inrush. Fault current is detected within one millisecond, with a total reduction of 42%. The overvoltage protection system clamped the peak voltage across the semiconductor switch and kept the dv/dt below the maximum stipulated. The load input tests showed a proper limiting operation, provided the device is within the parameterization range.

2023, Frontiers of Informaion Technology & Electronic Engineering

2023, Transformers Magazine

How can a controllable superconducting series reactor suppress transient recovery voltage of a circuit breaker? Due to the development of modern grids and the extensive implementation of distributed generators, the fault current level... more

2023, IEEE Transactions on Power Delivery

Expansion of high-voltage dc (HVdc) systems to multi-terminal HVDC (MT-HVDC) systems/grids considerably increases the short circuit levels. In order to protect the emerging MT-HVDC systems/grids against fault currents, proper DC fault current limiters (FCLs) must be developed. This paper proposes an innovative high inductance solid-state DC-reactor based fault current limiter (HISS-DCRFCL) to be used in HVDC applications. In fact, during the HISS-DCRFCL normal operation, its inductance value is extremely low, and its value becomes considerably high during the fault period, which decreases the fault current amplitude. The proposed HISS-DCRFCL performance is analyzed by MATLAB/Simulink and the simulation results are verified and confirmed by laboratory experimental results using a scaled-down laboratory prototype setup.

2023, Journal of Iranian Association of Electrical and Electronics Engineers

This paper proposes a novel Fault Current Limiter (FCL) for the application on distribution networks to control voltage sags at the Point of Common Coupling (PCC) during faults. This new FCL is based on series resonance including resonance transformer and series capacitor. So, by proper design of the series resonance LC tank, the fault current is limited to an acceptable level. The FCL operation is simulated using MATLAB software. In order to confirm the simulation results, a prototype structure is built and its measurement results are in agreement with the simulation results. The simulated and experimental results show that it is feasible to develop the FCL with low cost and high reliability.

2023, Research Journal of Applied Sciences, Engineering and Technology

This study investigates influence of Fault Current Limiter (FCL) on short-circuits current level of substation bus bar splitter circuit breaker and its TRV. An approach for TRV evaluation is developed and applied for proposed power system as shown in this study. FCL circuit is connected to the power system in order to limit TRV. The limiter circuit consists of two equal windings which are turned around unique magnetic core. One of the windings is connected in series with the power system network and the other is connected to the network via series capacitor and power electronic switches. During normal operating condition, both tyristors are in on state and current of the primary and secondary windings are equal. This causes zero impedance of the limiter. During fault, faults current cause the power electronic switch to turn off which increases the limiter impedance. By increasing the limiter impedance, amplitude of TRV decreases substantially. The novel method presented in this study is a cheap and successful scheme.

2023, IET energy systems integration

Power systems are subjected to various types of faults as well as ferroresonance overvoltages. These result in the interruption of the normal operation of the power grid, failure of equipment, electrical fires, etc. To tackle these issues, this paper proposes a dual function limiter to control the fault current and ferroresonance phenomenon in power systems. This compound device is a solid-state series transformer-based limiter that includes IGBT switches, capacitor, rectifiers, and a DC reactor. During the grid normal operation, the proposed limiter is not active and therefore is invisible and it operates in the instant of fault inception or ferroresonance overvoltage occurrences. Analytical studies in all operation modes are presented and assessments on the performance of the proposed ferroresonance and fault current limiter (FFCL) are conducted in Matlab. Simulation results confirm the reported analytical studies and FFCL´s performance.

2023

Pattern Recognition techniques provide a variety of techniques, in mathematics and computer science, that is individually useful in many different applications. The primary goal of pattern recognition is supervised or unsupervised classification. Statistical approach is most commonly used in practice. More recently, neural network techniques from statistical learning theory have been receiving increasing attention. The pattern recognition process consists of the three stages: segmentation, feature selection and classification. Pattern recognition techniques can be categorized into four parts. These include Statistical Techniques, Structural Techniques, Template Matching, and Neural Network Approach. The aim of this review paper is to summarize and compare some of the well-known techniques of a pattern recognition system and identify research topics and applications which are at the forefront of this exciting and challenging field.

2023

A fault protection and location method for a dc bus micro grid system is presented in this paper. If a fault causes the dc bus to de-energize completely, it makes locating faults very difficult. The proposed algorithm can be implemented and executed by an intelligent electrical device for an individual node. The bus was segmented into overlapping nodes and links with circuit breakers (CBs) to isolate the segment in the event of a fault. Backup protection is implemented for circuit breaker failures to improve system reliability. This power can also be used for a pilot test before main CB reclosing to avoid system issues that can be expected when the reclosing fails due to a permanent fault in this paper, we investigate an event-based protection scheme for a multiterminal dc power system, which includes hybrid energy resources and various loading schemes. The proposed protection scheme transfers less data when compared with commonly used data based protection methods, and do not requi...

2023, Imam Hossein Comprehensive University

Considering the high importance of the electricity industry as the infrastructure of other infrastructures of the country, increasing the reliability of the correct operation of the protection programs in the electricity transmission network is considered as one of the measures that can be mentioned in the direction of passive defense. One of these methods is the use of fault current limiters (FCL) in the transmission network. In power systems, the technical and economic benefits of using FCL depend on the type, number, installation locations and optimal parameters of limiters. In the present study, the number, location and impedance of FCLs in the network are determined to achieve various goals such as reducing the short circuit level, then, the minimum number of limiters along with the installation locations and the optimal parameter of each limiter are calculated in two steps using a meta-heuristic algorithm, called the Hybrid Optimization algorithm (PSOGSA) (Combination of the Particle Swarm Optimization Algorithm (PSO) and Gravitational Search Algorithm (GSA)). In the following, the proposed meta-heuristic algorithm is compared with genetic algorithms, PSO and GSA. According to the results of the numerical studies conducted to compare the proposed algorithm with GA, PSO and GSA algorithms, the proposed hybrid algorithm instead of installing more fault current limiters, by increasing its impedance optimally while reducing the total cost of installing this equipment; has better performance in terms of reducing the short circuit level of buses and it converges to the optimal point faster.

2023, Journal of the Japanese Society of Computational Statistics

2023

Increase in power generation capacity of electrical power systems has lead to increase in the fault current level which can exceed the maximum designed short-circuit ratings of the switchgear. Many conventional protective devices installed for protection of excessive fault current in electric power systems, especially at the power stations are the circuit breakers, tripped by over-current protection relay. They have the response-time delay that allows initial of two or three fault current cycles to pass through before getting activated. Superconducting Fault Current Limiter (SFCL) is innovative electric equipment which has the capability to reduce fault current level within the first cycle of fault current. The application of the fault current limiter (FCL) would not only decrease the stress on network devices, but also can offer a connection to improve the reliability of the power system. There are various types of FCLs, which are made of different superconducting materials and hav...

2023, 2009 Brazilian Power Electronics Conference

2023, Energies

Switching models possess discontinuous and nonlinear behavior, rendering difficulties in simulations in terms of time consumption and computational complexity, leading to mathematical instability and an increase in its vulnerability to errors. This issue can be countered by averaging detailed models over the entire switching period. An attempt is made for deriving improved dynamic average models of three phase (six-pulse) and nine phase (18-pulse) diode rectifiers by approximating load current through first order Taylor series. Small signal AC/DC impedances transfer functions of the average models are obtained using a small signal current injection technique in Simulink, while transfer functions are obtained through identification of the frequency response into the second order system. For the switch models in Simulink and the experimental setup, a small signal line to line shunt current injection technique is used and the obtained frequency response is then identified into second order systems. Sufficient matching among these results proves the validity of the modelling procedure. Exact impedances of the integral parts, in interconnected AC/DC/AC systems, are required for determining the stability through input-output impedances.

2023, International Journal of Engineering and Technology Innovation

In this paper, a new method for both fault current limiting and voltage compensating using Active Superconducting Current Controller (ASCC) is proposed. The main objective of this paper is to present an appropriate control strategy for ASCC to achieve both the fault current limiting and voltage compensation purposes. Three different operating modes are defined for ASCC including normal mode, fault current limiting mode, and voltage compensation mode and a proper control strategy is designed for each mode. For the fault current limiting, the model of a typical three-phase system with ASCC is simulated and different states for current limiting in different levels are defined. Also, for the voltage compensating mode, the PI model for the line is considered and the line transmission matrix is obtained when the ASCC is connected at the sending end and middle of the line. Finally, proper settings for ASCC are determined such that the magnitude of the receiving end and the sending end volt...

2023, Majlesi Journal of Electrical Engineering

In this paper, the influence on the voltage compensation type, active superconducting fault current limiter (ASFCL) is investigated under symmetrical and asymmetrical fault conditions. ASFCL is consisting of three air-core superconducting transformers and a three-phase voltage source converter. In the normal (no fault) state, the flux in air core is compensated to zero, so the ASFCL has no influence on the main circuit. In the case of short circuit, by controlling the amplitude and phase angle of the second winding’s current, the limiting impedance which is in series with the AC main circuit can be regulated, and the fault current will be limited to a certain level. Control strategies consist of fault detection and PWM converter operation is designed. To simplify the design of controllers the mathematical equations can be expressed in synchronous rotating d-q frame. Furthermore, under the condition that the active SFCL is placed behind the relay element, its current-limiting impedan...

2023, Simulation of Transformer Inrush Currents and their Impact on the Grid

This MSc Thesis’s main objective is to determine the impact of transformer inrush currents in the grid and develop a tool that helps E.ON evaluate transformer sizing. The motivation of E.ON is to have a more precise way to estimate the... more

2023, ArXiv

Inrush current problems of the industrial transformers are occasionally more serious than the utility transformers. A new Solid-State Inrush Current Limiter (SSICL) is proposed for medium voltage power transformers. The SSICL consists of three similar sets. Each set includes a bidirectional semiconductor switch and an inrush current limiter resistor. Using a control strategy based on Kalman filtering, transformer inrush current is suppressed during magnetization process. In fact, built up profile of the inrush current is dictated in accordance with the estimated current by a slow dynamic Kalman filter. A single-phase prototype SSICL is developed and tested. The proposed control scheme is simulated in MATLAB-SIMULINK. By using Real Time (RT) toolbox of the MATLAB software and a PCI_1711U, interrelationship between the SSICL and its controlling system is realized. Some experiments are carried out to evaluate the performance of the SSICL. The results show that the proposed SSICL can co...

2023

702 M. Ganji et al. / IJE TRANSACTIONS B: Applications Vol. 32, No. 5, (May 2019) 701-709 Another approach to limit the inrush current include controlling the switching angle and the sequence of energizing each phase of the transformer. Both solutios require an additional detection and control energizing angle precise system. Lack of precision can result in large inrush currents at energizing instant. Moreover, independent operation of the circuit breaker poles is necessary to succeed in this approach [7–12]. Several types of current limiters (CLs) have been proposed for limting the transformer inrush and fault currents [13–22]. The application of the superconducting fault current limiter (SFCL) was recognized as an effective solution for limiting the transformer inrush current. Howevere, the high cost of superconducting material and cooling system are main drawbacks of SFCLs [14, 15]. The DC reactor-type inrush current limiter (DR-ICL) has been used for suppressing the inrush curre...

2023, International Journal of Engineering

This study presents a modified transient current limiter (MTCL) for mitigation the inrush current of transformers. The MTCL is based on conventional transient current limiter (TCL), which, its configuration is modified to overcome the TCL drawbacks of operation. The proposed MTCL offers lower power losses and voltage/current THD during normal operation mode. It needs only one limiting reactor instead of two limiting reactors, which results in cost saving. The theoretical analysis of the MTCL for suppressing the inrush current has been presented and the performance was tested by PSCAD/EMTDC simulation anda experimental prototype. Both simulation and experimental results showed that the MTCL is effective for suppressing the transformer inrush current. Also, the capability of the MTCL for suppressing the transformer inrush current was compared with the conventional TCL.

2023, 2009 Brazilian Power Electronics Conference

2023

A smart grid delivers electricity from suppliers to consumers using two-way digital technology to control appliances at consumers' homes to save energy, reduce cost and increase reliability and transparency. It improves the power quality of the grid. A fault current limiter is used to superconductors to instantaneously limit or reduce unanticipated electrical surges that may occur on utility distribution and transmission networks. One of the most important application of superconducting fault current limiters (SFCL) for upcoming smart grid is related to its possible effect on the reduction of abnormal fault current and the suitable location in the micro grids. Due to the grid connection of the micro grids with the current power grids, excessive fault current is a serious problem to be solved for successful implementation of micro grids. Superconducting fault current limiter (SFCL) is innovative electric equipment which has the capability to reduce fault current level within the first cycle of fault current. The first-cycle suppression of fault current by a SFCL results in an increased transient stability of the power system carrying higher power with greater stability. Four scenarios of SFCL's possible locations were analyzed for three different fault occurring points in the power system has been discussed. Here 10 MVA wind farm was considered for the simulation. In this proposed scheme we are considering 30 MVA wind-farms and it is comparing with the 10 MVA Wind farm. Three phase faults have been simulated at different locations in smart grid and the effect of the SFCL and its location on the wind farm fault current and voltage is evaluated.