A fault current limiter (FCL) is an effective means of limiting fault currents that is a promisin... more A fault current limiter (FCL) is an effective means of limiting fault currents that is a promising power system protection solution. This paper presents a comparative survey of research activities and emerging technologies of FCL and discusses in detail the features of an inductive FCL. Inductive FCLs possess superior performance and higher speed of operation in comparison with other FCLs. The magnetic structure of an inductive FCL is instrumental to superior performance. The review study discusses the feasibility and effectiveness of the magnetic flux based FCLs. In addition, the magnetic behavior of FCLs is discussed considering the analytical study of their equivalent circuits. Moreover, a comprehensive comparative study of inductive FCLs is presented based on their technical operational characteristics. tures • Analysis of imposed inductance of inductive FCLs during the normal and fault conditions
In this paper, a novel solid-state fault current-limiting circuit breaker (SSFCLCB) based on a se... more In this paper, a novel solid-state fault current-limiting circuit breaker (SSFCLCB) based on a series resonance LC tank is proposed. Since the series configuration of the resonance structure (a capacitor and a reactor) of the SSFCLCB is invisible during normal operation mode, it shows negligible impedance in the line. In fault conditions, the SSFCLCB topology changes to a rectifier bridge and feeds the resonance structure with rectified ac voltage. With the rectified voltage, the series capacitor is charged and, as a result, the faulty line is opened and the fault current is seized. Hence, the suggested SSFCLCB cannot only limit the fault current but can also open the faulty line and acts as a circuit breaker. For confirmation of these aspects, simulations are performed using MATLAB software. Also, a prototype structure is designed and built for results confirmation. This experimental setup is established to prove that SSFCLCB has excellent performance in its startup, normal operation, and current-limiting/breaking conditions. The results show that the SSFCLCB has the ability to improve distribution network reliability and it can decrease the network fault current level successfully.
The material cannot be used for any other purpose without further permission of the publisher and... more The material cannot be used for any other purpose without further permission of the publisher and is for private use only. There may be differences between this version and the published version. You are advised to consult the publisher's version if you wish to cite from it.
This paper presents a type of solar thermal power plant and also studies the efficiency of the co... more This paper presents a type of solar thermal power plant and also studies the efficiency of the common type of this distributed generation resource. In order to improve the efficiency of the power station, several techniques are studied such as the combined cycle plant, the thermoelectric generator and the intelligent control application. The thermodynamic analysis of the power plant and the performance of the equipment with an intelligent control system are validated by the developed experimental prototype.
Current power systems will suffer from increasing pressure as a result of an upsurge in demand an... more Current power systems will suffer from increasing pressure as a result of an upsurge in demand and will experience an ever-growing penetration of distributed power generation, which are factors that will contribute to a higher of incidence fault current levels. Fault current limiters (FCLs) are key power electronic devices. They are able to limit the prospective fault current without completely disconnecting in cases in which a fault occurs, for instance, in a power transmission grid. This paper proposes a new type of FCL capable of fault current limiting in two steps. In this way, the FCLs' power electronic switches experience significantly less stress and their overall performance will significantly increase. The proposed device is essentially a controllable H bridge type fault current limiter (HBFCL) that is comprised of two variable inductances, which operate to reduce current of main switch in the first stage of current limiting. In the next step, the main switch can limit the fault current while it becomes open. Simulation studies are carried out using MATLAB and its prototype setup is built and tested. The comparison of experimental and simulation results indicates that the proposed HBFCL is a promising solution to address protection issues.
Short circuit fault occurrence in high-voltage DC (HVDC) systems causes extremely high currents i... more Short circuit fault occurrence in high-voltage DC (HVDC) systems causes extremely high currents in a fast raising time that does not experience current zero-crossing. To protect HVDC systems/grids against fault current, fast HVDC breaker is an essential equipment. This study presents the design procedure of a novel HVDC breaker based on solid-state controllable reactor which is able to reduce the fault current's rate of rise and fault current amplitude to less than grid nominal current in the breaking process. The main achievement of the proposed HVDC breaker is that not only breaker does not encounter fault current, but also none of the series HVDC equipment is influenced by the fault. The designed breaker performance is studied by PSCAD/EMTPS, and then the simulation results are validated by the developed laboratory experimental setup.
The protection of sensitive loads against voltage drop is a concern for the power system. A fast ... more The protection of sensitive loads against voltage drop is a concern for the power system. A fast fault current limiter and circuit breaker can be a solution for rapid voltage recovery of sensitive loads. This paper proposes a compound type of current limiter and circuit breaker (CLCB) which can limit fault current and fast break to adjust voltage sags at the protected buses. In addition, it can act as a circuit breaker to open the faulty line. The proposed CLCB is based on a series L-C resonance, which contains a resonant transformer and a series capacitor bank. Moreover, the CLCB includes two anti-parallel power electronic switches (a diode and an IGBT) connected in series with bus couplers. In order to perform an analysis of CLCB performance, the proposed structure was simulated using MATLAB. In addition, an experimental prototype was built, tested, and the experimental results were reported. Comparisons show that experimental results were in fair agreement with the simulation results and confirm CLCB's ability to act as a fault current limiter and a circuit breaker.
How can a controllable superconducting series reactor suppress transient recovery voltage of a ci... more 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 increases, which affects the operation of circuit breakers
Wind energy has always been developed as one of the vital parts of modern power systems. However,... more Wind energy has always been developed as one of the vital parts of modern power systems. However, by integration of wind-based generation, the level of fault current is likely to be increased which can damage the wind generators, microgrid components, and upstream grids. Consequently, utilizing viable protecting structures might preserve wind generator structures and other sections of the electric system as well. In this paper, first, the issue of the fault current of wind generators is discussed, and then well-known solution for protecting wind generators against fault current will be classified based on the comprehensive review. Next, various power electronic-based structures which are proper for protection of systems against the fault current, will be debated and ultimately the features of reviewed structures will be compared and summarized in a table for the case of wind energy generator protection.
Expansion of high-voltage dc (HVdc) systems to multi-terminal HVDC (MT-HVDC) systems/grids consid... more 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.
Due to the extension of the power grid with many complex and compact pieces of power equipment, t... more Due to the extension of the power grid with many complex and compact pieces of power equipment, transformers will be more exposed to fast transient, resulting from various resonance conditions. Transformer resonance can result in severe overvoltage on internal parts of the winding, leading to insulation failure and, consequently, transformer outage. The main reasons for resonance occurrence, the practical method to measure the resonance of transformers, and the solution for preventing transformer resonances have been discussed in the scientific reports over the past few decades; however, a comprehensive review of these studies is not present in the literature. Hence this paper aims to provide a comprehensive review to categorize the main reasons for transformer resonance, modeling methods, and appropriate solutions to suppress this phenomenon and suggest some prospective protection for future works.
The main propose of this paper is to protect medium voltage smart grid applications from damages ... more The main propose of this paper is to protect medium voltage smart grid applications from damages of the destructive fault current based on resonant type fault current limiter. Because of the series connection of a capacitor and a reactor, the Series Resonance Fault Current Limiter (SRFCL) is invisible during normal operation and shows negligible impedance in the line. During the fault, a control circuit connects a rectifier bridge to the series reactor and induces a DC voltage on it. In this instant, the series reactor is short circuited, and the series capacitor remains in the line. Thus, the impedance of the series capacitor reduces the amplitude of the fault current.
Journal of Iranian Association of Electrical and Electronics Engineers, Mar 10, 2018
This paper proposes a novel Fault Current Limiter (FCL) for the application on distribution netwo... more 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.
This paper studies effect of power electronic load and its current harmonics in increasing curren... more This paper studies effect of power electronic load and its current harmonics in increasing current of shunt capacitance in the distribution network. Analytical method is done to show the effect of power electronic load on the current harmonic In order to show the proposed method effectiveness, a simple power electronic load is used including a rectifier bridge, a smoothing capacitor filter and a resistance. It has been shown that by increasing power electronic load, the shunt capacitance current is increased where the rate of current variation is related to the structure of power electronic load. MATLAB and PSCAD software's are used to simulate the proposed distribution network.
Research Journal of Applied Sciences, Engineering and Technology, Dec 1, 2012
This study investigates influence of Fault Current Limiter (FCL) on short-circuits current level ... more 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.
In this paper, voltage sag and voltage Total Harmonic Distortion (THD) in the distribution networ... more In this paper, voltage sag and voltage Total Harmonic Distortion (THD) in the distribution network are studied. The proposed electrical network is modeled by electrical source, Line and source impedances. It is assumed that the electrical load of this network is a sample electronic load. This load is a rectifier bridge where its output terminal is connected to a capacitor bank and a linear resistance. The distribution network power quality is analyzed by changing the load impedance, the capacitor bank and number of load in the network. The Voltage sag and THD in the distribution network are studied using PSCAD and MATLAB software.
Power systems are subjected to various types of faults as well as ferroresonance overvoltages. Th... more 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.
This study employs a novel smart solid state ferroresonance limiter (SSFL) for stabilising the ch... more This study employs a novel smart solid state ferroresonance limiter (SSFL) for stabilising the chaotic behaviour of a voltage transformer (VT). It is shownthat the ferroresonance overvoltage in VTs includes some resonance modes that can be classified as a fundamental, sub-harmonic and chaotic oscillations. The effects of the suggested SSFL on decreasing the amplitude of the ferroresonance over-voltages are examined. To confirm the simulation results, a laboratory prototype is implemented and tested. The performance of the suggested SSFL is simulated using MATLAB software and experimental results are compared with the simulation results. The measurement and experimental results are in agreement and clearly show the ability of the suggested SSFL on ferroresonance cancellation and VT protection against the occurred overvoltage.
A fault current limiter (FCL) is an effective means of limiting fault currents that is a promisin... more A fault current limiter (FCL) is an effective means of limiting fault currents that is a promising power system protection solution. This paper presents a comparative survey of research activities and emerging technologies of FCL and discusses in detail the features of an inductive FCL. Inductive FCLs possess superior performance and higher speed of operation in comparison with other FCLs. The magnetic structure of an inductive FCL is instrumental to superior performance. The review study discusses the feasibility and effectiveness of the magnetic flux based FCLs. In addition, the magnetic behavior of FCLs is discussed considering the analytical study of their equivalent circuits. Moreover, a comprehensive comparative study of inductive FCLs is presented based on their technical operational characteristics. tures • Analysis of imposed inductance of inductive FCLs during the normal and fault conditions
In this paper, a novel solid-state fault current-limiting circuit breaker (SSFCLCB) based on a se... more In this paper, a novel solid-state fault current-limiting circuit breaker (SSFCLCB) based on a series resonance LC tank is proposed. Since the series configuration of the resonance structure (a capacitor and a reactor) of the SSFCLCB is invisible during normal operation mode, it shows negligible impedance in the line. In fault conditions, the SSFCLCB topology changes to a rectifier bridge and feeds the resonance structure with rectified ac voltage. With the rectified voltage, the series capacitor is charged and, as a result, the faulty line is opened and the fault current is seized. Hence, the suggested SSFCLCB cannot only limit the fault current but can also open the faulty line and acts as a circuit breaker. For confirmation of these aspects, simulations are performed using MATLAB software. Also, a prototype structure is designed and built for results confirmation. This experimental setup is established to prove that SSFCLCB has excellent performance in its startup, normal operation, and current-limiting/breaking conditions. The results show that the SSFCLCB has the ability to improve distribution network reliability and it can decrease the network fault current level successfully.
The material cannot be used for any other purpose without further permission of the publisher and... more The material cannot be used for any other purpose without further permission of the publisher and is for private use only. There may be differences between this version and the published version. You are advised to consult the publisher's version if you wish to cite from it.
This paper presents a type of solar thermal power plant and also studies the efficiency of the co... more This paper presents a type of solar thermal power plant and also studies the efficiency of the common type of this distributed generation resource. In order to improve the efficiency of the power station, several techniques are studied such as the combined cycle plant, the thermoelectric generator and the intelligent control application. The thermodynamic analysis of the power plant and the performance of the equipment with an intelligent control system are validated by the developed experimental prototype.
Current power systems will suffer from increasing pressure as a result of an upsurge in demand an... more Current power systems will suffer from increasing pressure as a result of an upsurge in demand and will experience an ever-growing penetration of distributed power generation, which are factors that will contribute to a higher of incidence fault current levels. Fault current limiters (FCLs) are key power electronic devices. They are able to limit the prospective fault current without completely disconnecting in cases in which a fault occurs, for instance, in a power transmission grid. This paper proposes a new type of FCL capable of fault current limiting in two steps. In this way, the FCLs' power electronic switches experience significantly less stress and their overall performance will significantly increase. The proposed device is essentially a controllable H bridge type fault current limiter (HBFCL) that is comprised of two variable inductances, which operate to reduce current of main switch in the first stage of current limiting. In the next step, the main switch can limit the fault current while it becomes open. Simulation studies are carried out using MATLAB and its prototype setup is built and tested. The comparison of experimental and simulation results indicates that the proposed HBFCL is a promising solution to address protection issues.
Short circuit fault occurrence in high-voltage DC (HVDC) systems causes extremely high currents i... more Short circuit fault occurrence in high-voltage DC (HVDC) systems causes extremely high currents in a fast raising time that does not experience current zero-crossing. To protect HVDC systems/grids against fault current, fast HVDC breaker is an essential equipment. This study presents the design procedure of a novel HVDC breaker based on solid-state controllable reactor which is able to reduce the fault current's rate of rise and fault current amplitude to less than grid nominal current in the breaking process. The main achievement of the proposed HVDC breaker is that not only breaker does not encounter fault current, but also none of the series HVDC equipment is influenced by the fault. The designed breaker performance is studied by PSCAD/EMTPS, and then the simulation results are validated by the developed laboratory experimental setup.
The protection of sensitive loads against voltage drop is a concern for the power system. A fast ... more The protection of sensitive loads against voltage drop is a concern for the power system. A fast fault current limiter and circuit breaker can be a solution for rapid voltage recovery of sensitive loads. This paper proposes a compound type of current limiter and circuit breaker (CLCB) which can limit fault current and fast break to adjust voltage sags at the protected buses. In addition, it can act as a circuit breaker to open the faulty line. The proposed CLCB is based on a series L-C resonance, which contains a resonant transformer and a series capacitor bank. Moreover, the CLCB includes two anti-parallel power electronic switches (a diode and an IGBT) connected in series with bus couplers. In order to perform an analysis of CLCB performance, the proposed structure was simulated using MATLAB. In addition, an experimental prototype was built, tested, and the experimental results were reported. Comparisons show that experimental results were in fair agreement with the simulation results and confirm CLCB's ability to act as a fault current limiter and a circuit breaker.
How can a controllable superconducting series reactor suppress transient recovery voltage of a ci... more 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 increases, which affects the operation of circuit breakers
Wind energy has always been developed as one of the vital parts of modern power systems. However,... more Wind energy has always been developed as one of the vital parts of modern power systems. However, by integration of wind-based generation, the level of fault current is likely to be increased which can damage the wind generators, microgrid components, and upstream grids. Consequently, utilizing viable protecting structures might preserve wind generator structures and other sections of the electric system as well. In this paper, first, the issue of the fault current of wind generators is discussed, and then well-known solution for protecting wind generators against fault current will be classified based on the comprehensive review. Next, various power electronic-based structures which are proper for protection of systems against the fault current, will be debated and ultimately the features of reviewed structures will be compared and summarized in a table for the case of wind energy generator protection.
Expansion of high-voltage dc (HVdc) systems to multi-terminal HVDC (MT-HVDC) systems/grids consid... more 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.
Due to the extension of the power grid with many complex and compact pieces of power equipment, t... more Due to the extension of the power grid with many complex and compact pieces of power equipment, transformers will be more exposed to fast transient, resulting from various resonance conditions. Transformer resonance can result in severe overvoltage on internal parts of the winding, leading to insulation failure and, consequently, transformer outage. The main reasons for resonance occurrence, the practical method to measure the resonance of transformers, and the solution for preventing transformer resonances have been discussed in the scientific reports over the past few decades; however, a comprehensive review of these studies is not present in the literature. Hence this paper aims to provide a comprehensive review to categorize the main reasons for transformer resonance, modeling methods, and appropriate solutions to suppress this phenomenon and suggest some prospective protection for future works.
The main propose of this paper is to protect medium voltage smart grid applications from damages ... more The main propose of this paper is to protect medium voltage smart grid applications from damages of the destructive fault current based on resonant type fault current limiter. Because of the series connection of a capacitor and a reactor, the Series Resonance Fault Current Limiter (SRFCL) is invisible during normal operation and shows negligible impedance in the line. During the fault, a control circuit connects a rectifier bridge to the series reactor and induces a DC voltage on it. In this instant, the series reactor is short circuited, and the series capacitor remains in the line. Thus, the impedance of the series capacitor reduces the amplitude of the fault current.
Journal of Iranian Association of Electrical and Electronics Engineers, Mar 10, 2018
This paper proposes a novel Fault Current Limiter (FCL) for the application on distribution netwo... more 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.
This paper studies effect of power electronic load and its current harmonics in increasing curren... more This paper studies effect of power electronic load and its current harmonics in increasing current of shunt capacitance in the distribution network. Analytical method is done to show the effect of power electronic load on the current harmonic In order to show the proposed method effectiveness, a simple power electronic load is used including a rectifier bridge, a smoothing capacitor filter and a resistance. It has been shown that by increasing power electronic load, the shunt capacitance current is increased where the rate of current variation is related to the structure of power electronic load. MATLAB and PSCAD software's are used to simulate the proposed distribution network.
Research Journal of Applied Sciences, Engineering and Technology, Dec 1, 2012
This study investigates influence of Fault Current Limiter (FCL) on short-circuits current level ... more 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.
In this paper, voltage sag and voltage Total Harmonic Distortion (THD) in the distribution networ... more In this paper, voltage sag and voltage Total Harmonic Distortion (THD) in the distribution network are studied. The proposed electrical network is modeled by electrical source, Line and source impedances. It is assumed that the electrical load of this network is a sample electronic load. This load is a rectifier bridge where its output terminal is connected to a capacitor bank and a linear resistance. The distribution network power quality is analyzed by changing the load impedance, the capacitor bank and number of load in the network. The Voltage sag and THD in the distribution network are studied using PSCAD and MATLAB software.
Power systems are subjected to various types of faults as well as ferroresonance overvoltages. Th... more 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.
This study employs a novel smart solid state ferroresonance limiter (SSFL) for stabilising the ch... more This study employs a novel smart solid state ferroresonance limiter (SSFL) for stabilising the chaotic behaviour of a voltage transformer (VT). It is shownthat the ferroresonance overvoltage in VTs includes some resonance modes that can be classified as a fundamental, sub-harmonic and chaotic oscillations. The effects of the suggested SSFL on decreasing the amplitude of the ferroresonance over-voltages are examined. To confirm the simulation results, a laboratory prototype is implemented and tested. The performance of the suggested SSFL is simulated using MATLAB software and experimental results are compared with the simulation results. The measurement and experimental results are in agreement and clearly show the ability of the suggested SSFL on ferroresonance cancellation and VT protection against the occurred overvoltage.
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