Chaotic Ferroresonance Research Articles

Diagnosis of Chaotic Ferroresonance Phenomena Using Deep Learning

Ferroresonance is a non-linear and dangerous resonance phenomenon that can affect power networks and damage electrical equipment. The ferroresonance phenomenon is examined by dividing it into classes, with chaotic ferroresonance being the most dangerous type that causes overvoltage’s. Detecting chaotic ferroresonance in a short period of time is of great importance in terms of taking measures and reducing equipment damage. In this study, we explored the application of deep convolutional neural networks (DCNNs) for the identification and classification of chaotic ferroresonance phenomena. Two pre-trained AlexNet models were adapted using transfer learning to perform these tasks. The first model was utilized to identify chaotic ferroresonance, while the second was employed to distinguish between different subtypes of chaotic ferroresonance by dividing voltage curve graphs into different periods and shapes. The training and testing of both DCNN models were conducted using snapshot images extracted from the voltage curves of all phase voltages. The results of the experiments showed high accuracy in both the identification and classification of chaotic ferroresonance phenomena.

Chaotic Modeling of Ferroresonance with Single-Phase Open in a Three-Phase System and Its Fractional-Order Control

In this study, a chaos-theoretic method is proposed to model the case of ferroresonance that can occur under nominal conditions in power systems, and the factors that determine the types of ferroresonance to occur are examined. In the ferroresonance chaotic system modeled in Matlab environment, the length of the transmission line and the breaker capacities in the circuit are fixed and its relationship with the transformer efficiency is investigated. In the proposed chaotic modeling, considering the situations that may occur in practical applications, the ferroresonance situations that occur when the single-phase remains open in the three-phase system are examined. In the study, ferroresonance, which occurs when one phase is open in a three-phase system, is analyzed by considering the situations that may happen during practical implementations. The similarity between the mathematical expressions obtained from the systems that create ferroresonance and Duffing oscillator is evaluated. In the chaotic system, fundamental ferroresonance, subharmonic ferroresonance, and chaotic ferroresonance situations are created depending on the transformer loss. Additionally, ferroresonance that occurs when the chaotic system is of fractional-order is analyzed, and it is observed that results of ferroresonance with different fractional-order values are not different. The results show that transformer loss is a significant element to determine the type of ferroresonance in power transformers. Also, when the chaotic system is operated in the fractional-order setting, the ferroresonance cases that occur are re-examined, and it is observed that the system can exit from the chaotic situation and prevent the formation of ferroresonance when fractional-order control is applied. According to the results, the fractional-order method can be used to control ferroresonance.

Modeling and Suppression of Chaotic Ferroresonance in a Power System by Using Memristor-based System

Power systems contain capacitances and inductances that can initiate chaotic ferroresonance due to the non-linear operating characteristics of ferromagnetic materials, such as power transformer cores. Chaotic ferroresonance is a highly disturbing complex, non-linear phenomenon that may cause over-voltages and over-currents; hence, it can compromise regular system operation. The memristor is a non-linear passive two-terminal electricalcomponent, foreseen and introduced as the fourth ideal circuit element. In this study's novel approach, a memristive system is proposed for modeling chaotic ferroresonance in power systems. Employing the memristive circuit as the source of ferroresonance, flexible and adjustable solutions of the dynamic system can be obtained easily. The chaotic characteristic of the proposed system is verified by using a bifurcation diagram and Lyapunov exponent analysis. To reduce the effects of chaotic ferroresonance, a memristor-based system is proposed for damping chaotic oscillations of the system as a protection element. simulation program with integrated circuit emphasis (SPICE) simulations have been carried out for the performance analysis of the proposed system during ferroresonance, and suppression modes are presented.

Elimination of chaotic ferroresonance in power transformer by ISFCL

Abstract Ferroresonance occurrences as one of the complex phenomena in power system not only lead to unwanted thermal and insulation problems, but also can cause chaotic oscillations. In this paper, a new method is proposed to eliminate and damp ferroresonant oscillations. Hence, a kind of inductive superconducting fault current limiters (ISFCL) is applied to eliminate chaotic ferroresonance oscillations alongside utilizing the current limiting ability of ISFCL. With regard to that ferroresonance is classified as nonlinear dynamics, chaos theory is applied. By using this theory, changes in system parameters which occur chaotic ferroresonant oscillations, can be better investigate and analyze. Behavior of the system, with and without ISFCL, is shown in bifurcation and phase plane diagrams. Behavioral changes of the system can be easily seen in these diagrams. Obtained results strongly show effectiveness of using this method for eliminating and damping ferroresonant oscillations.

A new approach to eliminating of chaotic ferroresonant oscillations in power transformer

Abstract Ferroresonance is a complex phenomenon, which can result in thermal and electrical stresses on power system equipments. It can also cause chaotic oscillations in power system. In this paper, a new method is proposed to restrict and damp ferroresonant oscillations, which is based on a new of fault current limiter (FCL). In this method in order to restrict chaotic ferroresonance oscillations, a kind of fault current limiters (FCL) is used which has been used to restrict unwanted high current flow in power system before. To study the ferroresonance nonlinear dynamics, in this paper, the chaos theory is used. By using this theory, the changes in system parameters which can cause chaotic ferroresonant oscillations, can be reviewed and analyzed in details. The behavior of the system during ferroresonance occurrence, with and without using proposed FCL, is discussed in bifurcation and phase plane diagrams. By using these diagrams, the behavioral changes of the system can be easily seen in two cases. The simulation results strongly show the effectiveness of using the proposed FCL for restricting the ferroresonant oscillations.

Spectral analysis of voltages and currents during different modes of ferroresonance in switchgear

This paper presents a spectral analysis of three different modes of ferroresonance. Voltage and current signals of the fundamental, subharmonic and chaotic ferroresonance modes are processed. The signals are obtained by modeling a ferroresonance circuit in alternative transient program-electro magnetic transient program (ATP-EMTP). The magnitude spectrum and total harmonic distortion are calculated for each case. The results show that voltages and currents of different modes of ferroresonance produce different features, which may be used for ferroresonance identification, classification and mitigation in the future.

RECONSTRUCTION AND IDENTIFICATION AND CONTROL METHOD OF FERRORESONANCE OVERVOLTAGE BASED ON VOLTAGE TIME SERIES

Ferroresonance overvoltage and over-current can be restrained using nonlinear dynamics. However, the ferroresonance simplified model, which cannot reflect the huge ferroresonance circuit in the grid precisely and cannot satisfy real-time analysis, is adopted in the traditional nonlinear control method. Owing to these shortcomings, the strategy of controlling ferroresonance overvoltage based on voltage time series is proposed. Based on the voltage time series analysis methods, the ferroresonance system is identified using the best embedding dimension and the best time delay obtained from the phase space reconstruction. Afterward, the feedback controller is designed based on the platform of the identified model. Results show that fundamental, subharmonic and chaotic ferroresonance overvoltage can all be controlled using the method presented in this paper even without the system parameters and the accurate system model. Therefore, the control strategy is generally more applicable.

Adaptive detection of chaotic oscillations in ferroresonance using modified extended Kalman filter

Power quality and power disturbances have become an important factor for power systems. Chaotic ferroresonance is one of the disturbances that may cause overvoltages and overcurrents; hence, it can endanger the system reliability and continuous safe operating. A power system that generates chaotic oscillations is a dynamic system, which can be modeled with a Duffing equation. This paper introduces the application of a modified extended Kalman filter for improving the detection of chaotic behavior of power system signals. A modification algorithm is used to increase the estimation performance of the former casual extended Kalman filter. The proposed method is employed to distinguish the abnormalities from a signal contaminated with chaotic ferroresonance for promoting efficiency in power system characteristics detection.

Resistive Ferroresonance Limiter for Potential Transformers

The ferroresonance or nonlinear resonance is a complex phenomenon, which may cause overvoltage in the electrical power system and endangers the system reliability and operation. The ability to predict the ferroresonance in the transformer depends on the accuracy of the transformer model used. In this paper, the effect of the new suggested ferroresonance limiter on the control of the chaotic ferroresonance and duration of chaotic transients in a potential transformer including nonlinear core losses is studied. To study the proposed ferroresonance limiter, a single phase 100 VA, 275 kV potential transformer is simulated. The magnetization characteristic of the potential transformer is modeled by a single-value two-term polynomial. The core losses are modeled by third order power series in terms of voltage and include core nonlinearities. The simulation results show that the ferroresonance limiter has a considerable effect on the ferroresonance overvoltage.

Ferroresonance suppression in power transformers using chaos theory

The main goal of this paper is the determination of the effect of the metal oxide varistor (MOV) on various ferroresonance modes including fundamental resonance, subharmonic and chaos mode which are generated in electrical power systems. Chaos theory is used for analyzing this effect. Also, the bifurcation, phase plan diagram and time domain simulation are used for this purpose. The proposed power system contains a no-load or lightly loaded power transformer. The magnetization curve of the transformer core is modeled by a single-value two-term polynomial. The core loss is modeled based on the flux of the transformer. The MOV modeled as a nonlinear voltage dependent resistance. The suppression effect of MOV on chaotic ferroresonance in power transformer is studied in this paper. The simulation results confirm that connecting the MOV to the transformer has a considerable suppression effect on ferroresonance phenomena.

Ferroresonance of Power Transformers Considering Non-linear Core Losses and Metal Oxide Surge Arrester Effects

In this article, a simple case of ferroresonance in a three-phase transformer is used to study the effect of a metal oxide surge arrester on the control of chaotic ferroresonance and duration of chaotic transient in a power transformer including non-linear core losses. The time-domain simulations are derived using MATLAB (The MathWorks, Natick, Massachusetts, USA) for a three-phase 50-MVA, 635.1-kV power transformers while one of its phases is opened. The magnetization characteristic of the power transformer is modeled by a single-value two-term polynomial. The non-linear core losses are modeled by a third-order power series in terms of voltage, and the core losses non-linearities are considered as well. The simulation results show that connecting the metal oxide surge arrester to the transformer exhibits a great suppressing effect on occurred ferroresonance over-voltage.

Ferroresonance in Voltage Transformer ConsideringLinear and Nonlinear Core Losses Effect

Ferroresonance is a complex electrical phenomenon, which can cause overvoltages in the electrical power system and endangers the system reliability and continuous safe operating. This paper studies the effect of linear and nonlinear core losses on the chaotic ferroresonance in a voltage transformer. For confirmation this aspect simulation has been done on a one phase voltage transformer rated 100VA, 275kV. The magnetization characteristic of the transformer is modeled by a single-value two-term polynomial with q=7. The simulation results reveal that considering the nonlinear core losses on the voltage transformer, exhibits a great effect on ferroresonance overvoltages. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos along with ferroresonance voltages has been obtained and presented.

Damping Nonlinear Oscillations in Potential Transformers Including Hysteresis Effect

In this work, an overview of available papers are provided, at first ferroresonance phenomenon is introduced and then various type of ferroresonance in a potential transformer is simulated, then effect of neutral earth resistance on the onset of chaotic ferroresonance and duration of chaotic transient in a potential transformer including nonlinear core losses has been studied. It is expected that this resistance generally cause controlling ferroresonance overvoltages. The proposed approach was implemented using MATLAB, and results are presented. For confirmation this aspect simulation has been done on a one phase potential transformer rated 100VA, 275kV. Core losses is modelled in terms of voltage and includes nonlinearities in core losses .The simulation results show that connecting the neutral earth resistance on the system configuration, shows a great controlling effect on ferroresonance overvoltages.

Controlling Chaotic Ferroresonance in Autotransformer connecting Metal Oxide Surge Arrester and Neutral Earth Resistance

This paper investigates the effect of linear core losses, metal oxide surge arrester (MOSA) and neutral earth resistance on the onset of chaotic ferroresonance and controlling these overvoltages in an autotransformer. The transformer is chosen for study has a rating of 50 MVA, 635.1 kV. The magnetization characteristic of the autotransformer is modeled by a nonlinear polynomial. The core loss is modeled by linear core losses and is shown as a linear resistance. Three state of ferroresonance are studied: (i) onset of chaos due to interrupt in switching action including linear core losses of the transformer, (ii) effect of MOSA on the limiting these oscillation, and (iii) completely controlling effect of neutral earth resistance on the ferroresonance overvoltages. Results of simulation have been derived and shown by nonlinear dynamics method such as bifurcation diagrams, phase plan and time domain simulations.

Effect of New Suggested Ferroresonance Limiter on the Stability Domain of Chaotic Ferroresonance in the Power Transformer with Linear Core Model

This Paper studies the effect of new suggested ferroresonance limiter on controlling ferroresonance oscillations in the power transformer. It is expected that this limiter generally can control the ferroresonance. For studying these phenomena, at first ferroresonance is introduced and a general modeling approach is given. A simple case of ferroresonance in a three phase transformer is used to illustrate these phenomena. Then, effect of new suggested ferroresonance limiter on the onset of chaotic ferroresonance and control of these oscillations in a power transformer including linear core losses is studied. Simulation is done on a three phase power transformer while one of its phases is opened, and effect of varying input voltage on occurring ferroresonance overvoltage is studied. Results show that connecting the ferroresonance limiter to the transformer exhibits a great controlling effect on the ferroresonance overvoltage. Phase plane diagram, FFT analysis along with bifurcation diagrams are also presented. Significant effect on occurring chaotic ferroresonance, the range of parameter values that may lead to overvoltage and magnitude of ferroresonance overvoltage is obtained, showed and tabulated.

Studying Effect of Magnetizing Curve Nonlinearity Index on the Occurring Chaotic Ferroresonance Oscillation in Autotransformers

This paper investigates the effect of iron core saturation characteristic degree on the onset of chaotic ferrore-sonance and duration of transient chaos in an autotransformer. The transformer chosen for study has a rating of 50 MVA, 635.1 kV, the magnetization characteristic of the autotransformer is modeled by a single-value two-term polynomial with q = 5, 7, 11. The core loss is modeled by a linear resistance and is considered a fix value for it. Simulation results are derived by using MATLAB software and nonlinear dynamics tool such as bifurcation and phase plan diagrams. It is shown settling down to the chaotic region is increased when degree of core nonlinearity is gone from 5 to 11.

Analysis of Chaotic Ferroresonance Phenomena in Unloaded Transformers Including MOV

We study the effect of a parallel metal oxide surge arrester on the ferroresonance oscillations of transformers. It is expected that the arresters generally cause ferroresonance drop out. Simulation has been done on a three phase power transformer with one open phase. Effect of varying input voltage is studied. The simulation results reveal that connecting the arrester to transformers poles, exhibits a great mitigating effect on ferroresonant over voltages. Phase plane along with bifurcation diagrams are also presented. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos and magnitude of ferroresonant voltages is obtained, shown and tabulated.

Effect of Circuit Breaker Shunt Resistance on Chaotic Ferroresonance in Voltage Transformer

Ferroresonance or nonlinear resonance is a complex electrical phenomenon, which may cause over voltages and over currents in the electrical power system which endangers the system reli ...

Effect of Metal Oxide Arrester on Chaotic Behavior of Power Transformers

This paper investigates the Effect of Metal Oxide Arrester (MOV) on the Chaotic Behaviour of power transformers considering nonlinear model for core loss of transformer. The paper contains two parts. In part (1): effect of nonlinear core on the onset of chaotic ferroresonance in a power transformer is evaluated. The core loss is modeled by a third order power series in voltage. in part (2): Effect of Metal Oxide Arrester(MOV) on results in part (1) will be studied. The results reveal that the presence of the arrester has a mitigating effect on ferroresonant chaotic overvoltages. resulted bifurcation diagrams and phase plane diagrams have also been delivered.

Chaotic ferroresonance in a non-autonomous circuit

Accurate description of magnetization curve has important effect on ferroresonance. In most of earlier ferroresonance studies the magnetization curve is modelled as a 3rd or 5th order polynomial. However, it is not comprehensive. This paper investigates the chaotic ferroresonance behaviour exhibited by a non-autonomous circuit which contains a nonlinear flux-controlled inductance. The ferromagnetic characteristic of this nonlinear inductance represented by a magnetization curve could be expressed as an n th order two-term polynomial. By varying the value of exponent n, the circuit can assume a diverse range of steady-state regimes including fundamental and subharmonic ferroresonance, quasi-periodic oscillations, and chaos. A detailed analysis of some simulations demonstrates that the probability of chaos increases as the exponent of the magnetization curve rises. The effect of varying the magnitude of the source voltage on the chaotic behaviour of the circuit is also studied.