Arc Suppression Coil Research Articles

The Study of Fault Location Method Based on FTU Feeder Automation Technology

With the development of power distribution automation system, feeder automation technology in the small current grounding system single-phase grounding fault location plays an important role. In the neutral arc suppression coil grounding system, because of the compensation effect of arc suppression coil, the system fault feature is not obvious. This paper puts forward a method of RL series branch parallel in arc suppression coil, when system single-phase grounding fault occurs, the series branch switch gets closed and acts on the neutral, that changes the compensation degree of arc suppression coil to zero sequence current in fault line, the change of zero sequence residual current being the biggest in the fault section from neutral to fault point. FTU is used to monitor the change in each fault line for fault regional location.

Ground Fault Line Selection with Improved Residual Flow Incremental Method

According to the shortcoming of single-phase ground fault line selection method in the resonant grounded system such as the uncertainty of its device by fast compensation with the automatic compensation equipment, an arc suppression and residual flow incremental method is proposed to effectively choose the earth fault line. Firstly, when the single-phase ground fault occurs, the arc suppression coil parameters are adjusted to realize compensation and arc suppression. Then the arc suppression coil inductance values are modulated to make the zero-sequence current of fault line changed, at the same time, the zero-sequence current value is detected and its change will be captured to select the fault line. The simulation experiments prove that the arc grounding over voltage damage can be effectively reduced by arc suppression coil full compensation and fault line can be effectively selected by arc suppression and residual flow increment method. DOI: http://dx.doi.org/10.11591/telkomnika.v11i8.3106

Analysis of Choice on the Time of Paralleling the Resistance with Arc-suppression Coil

Analysis of Choice on the Time of Paralleling the Resistance with Arc-suppression Coil

Locating Method of Single-Phase Grounding Fault in Small Current Grounding System Based on Distribution Automation

In case of the arc suppression coil for neutral point grounding of small current grounding system, when single-phase grounding fault occurs, due to the arc suppression coil for fault line of the compensation effect of the zero sequence current, the fault features is not obvious, it can't implement the fault line selection and fault point location. This paper puts forward a method of change fault lines zero sequence current shortly, namely a resistance inductance (RL) series branch parallel in arc suppression coil, the series branch acts on the system shortly and changes arc suppression coil compensation degree temporarily in single-phase grounding fault. The change of zero sequence residual current only appears the loop from the neutral point to the fault point via the fault line, using FTU (feeder terminal units) on lines monitor the change of zero sequence current on each nodes for fault regional location. And prove this theory the feasibility of the by using MATLAB software of system modeling simulation method.

Application of DC component to select fault branch in arc suppression coil grounding system

When single phase earth fault occurs in the arc suppression coil grounding system, the amplitude of the transient capacitance current is high and decays fast, but the attenuation of the transient inductance current is much slower. This paper analyses the DC component of fault branch, and has found it is much bigger than that of the normal branches in transient state. All the simulation results obtained from three compensation types, different fault time and different wave cycles show that the DC component of fault branch is much higher than that of those normal branches. These results verify the effectiveness of taking the DC component as the method of fault line selection in the arc suppression coil grounding system.

Influence of the Arc Suppression Coil with Parallel Resistance on Single-Phase Arc Grounding Overvoltage

Neutral point grounding method with an arc suppression coil and a parallel resistance is a method that can inhibit arc overvoltage effectively. Through the simulation of arc suppression coil with parallel resistance in the situation of different resistance value, we can obtain if the parallel resistance is too big, it will produce overvoltage in the later of voltage recovery; if the parallel resistance is too small, it is easy to produce larger grounding residual flow, going against quenching of arc; Whether over compensation or owe compensation, oversized out-of-resonance degree will cause the fault phase voltage recovery oscillation overvoltage, small out-of-resonance degree is beneficial to the fault phase voltage rise slowly.

Analysis on the equivalent circuit of a kind of zero-residual-current arc suppression coil and distribution network

The existent arc suppression coil (ASC) can only realise the compensation for the reactive component of the fundamental capacitive current. But for the active and harmonic ones, they are powerless. Therefore, it is necessary to study on the so-called 'zero-residual-current ASC'. In this paper, the authors first introduce the structure of a kind of zero-residual-current ASC, namely, three phases and five columns ASC with double secondary windings. Then the authors analyse in detail its equivalent circuit and the equivalent circuit of the distribution network in which this kind of zero-residual-current ASC is used during the normal operation and the single-phase-to-ground fault respectively. Based on SABER and MATLAB, the simulation models of distribution network and TPFCASC with double secondary windings are given. From the waveforms of simulation experiments, we can see clearly that the so-called zero residual current is realised, which proves the theoretical analysis. It should be noted that the equivalent circuit of this zero-residual-current ASC is different from that of common power transformer. Owing to the air gaps in the iron cores, the exciting reactance of this zero-residual-current ASC is much smaller than that of common power transformer. Thus, only the exciting reactance is used as equivalent reactance in its equivalent circuit but without considering the leakage reactance of each winding.

Analysis on the Equivalent Circuit of a Kind of Zero-Residual-Current Arc Suppression Coil and Distribution Network

The existent arc suppression coil (ASC) can only realise the compensation for the reactive component of the fundamental capacitive current. But for the active and harmonic ones, they are powerless. Therefore, it is necessary to study on the so-called zero-residual-current ASC". In this paper, the authors first introduce the structure of a kind of zero-residual-current ASC, namely, three phases and five columns ASC with double secondary windings. Then the authors analyse in detail its equivalent circuit and the equivalent circuit of the distribution network in which this kind of zero-residual-current ASC is used during the normal operation and the single-phase-to-ground fault respectively. Based on SABER and MATLAB, the simulation models of distribution network and TPFCASC with double secondary windings are given. From the waveforms of simulation experiments, we can see clearly that the so-called zero residual current is realised, which proves the theoretical analysis. It should be noted that the equivalent circuit of this zero-residual-current ASC is different from that of common power transformer. Owing to the air gaps in the iron cores, the exciting reactance of this zero-residual-current ASC is much smaller than that of common power transformer. Thus, only the exciting reactance is used as equivalent reactance in its equivalent circuit but without considering the leakage reactance of each winding.

Single-Line-to-Ground Fault Location in the Compensated Distribution Network

One of the most difficult problems in compensated distribution networks is the grounded fault location. This paper proposes a new method for locating single-line-to-ground (SLG) faults in compensated distribution networks. The grounded fault location system is made up of the host, the controller, the signal generator and the grounded fault indicator (GFI). When a SLG fault occurs, the fault phase is identified firstly, and then a signal generator paralleled with the arc suppression coil injects a special current into the system. Subsequently, GFIs along the fault phase are activated to sample the fault phase current and send it back. The fault phase current is computed by the host with a fast Fourier transform algorithm. By comparing these frequency components of the fault phase current, the fault section is identified based on the significant difference of the second harmonic of two adjacent GFIs. Due to the short length of feeders, the distance between two adjacent GFIs is short enough for line patrol personnel to find and repair the fault easily. Finally, a modified IEEE 13-node feeder test is constructed in PSCAD/EMTDC to evaluate this method. The simulations results confirm the validity of the proposed approach.

Evaluation of neutral voltages in arc suppression coil systems

Evaluation of neutral voltages in arc suppression coil systems

Evaluation of Neutral Voltages in Arc Suppression Coil Systems

Although arc suppression coil systems are able to detected high impedance ground faults by monitoring the neutral voltage, there are other system abnormalities which can also cause a change in the neutral voltage. The causes of abnormal neutral voltages in arc suppression coil systems are analysed and criteria are developed to differentiate between them based on the phase angle and magnitude of the neutral voltage. Using the criteria developed in this paper, modern computerised protection systems will be able to automatically take appropriate action based on the type of system abnormality, immediately, when a system abnormality occurs.

Fault Location for Resonant Grounded System Based on Zero-Sequence Current Increment Method

In order to deal with the problem of single-phase earthing fault in resonant grounded system, a new method of fault line and segment selection was proposed using zero-sequence current increment through analyzing the line fault on substation outlet and the change of the fault component of zero-sequence current. The zero-sequence current in the line will change when the inductance of arc-suppression coil is changed. The method determines the fault location based on the characteristic of the change in the line. The effects of resistance grounding can be eliminated by converting zero-sequence currents to the same voltage. Matlab simulation experiments verify the correctness and validity of the method.

Capacitive Current Measurement Methods for Arc-Suppression Coil with Automatic Tuning

Accurately measuring capacitive current for the automatic tuning arc-suppression coil is the premise and basis of its compensating and arc-extinguishing functions. Several principles of capacitive current measurement applied widely are analyzed and compared. The resonance method to measure the capacitive current has high precision, but has complex tuning. The displacement voltage method has simple tuning, but has poor accuracy of measuring capacitive current. The measurement accuracy of the impedance triangle method and the E0 measurement method lies between the resonance method and the displacement voltage method. And its tuning is also relatively simple, but its measurement and control system is more complex. At last, how to choose appropriate capacitive current measurement method according to the arc-suppression coil tuning principle and the distribution network operation is pointed out.

The Research Based on Zero Sequence Energy to the Line Selection in Distribution Network

When single phase-to-ground fault happened in power network with arc suppression coil grounded, capacitor current through fault point is compensated and reduced by installing arc suppression coil. Zero-sequence current’s amplitude and phase of fault lines and sound lines are so similar that it increases the difficulty of selecting the fault line. But the resistance component of zero sequence current has no relationship with the arc extinguishing coil compensation, absolute value of resistance component to the fault lines show the maximum, and zero sequence current’s polarity of fault lines is contrary to sound lines. In this paper, because of the characteristic of resistance component, a method is put forward based on zero sequence energy to the line selection in distribution network, it import auto-reclosing techniques into the line selection. The principle is verified by MATLAB simulator. It has high accuracy to select the fault line with this method.

Survey on Capacitive Current Measurement Principles for Automatic Tuning Arc-Suppression Coil

Accurately measuring capacitive current for the automatic tuning arc-suppression coil is the premise and basis of realizing its compensating and arc-extinguishing functions. Several principles measuring capacitive current applied widely are theoretically analyzed and compared. The resonance method to measure the capacitive current has high precision, but has complex tuning. The displacement voltage method has simple tuning, but has poor accuracy of measuring capacitive current. The measurement accuracy of the impedance triangle method and the E0 measurement method lies between the resonance method and displacement voltage method. And its tuning is also relatively simple, but its measurement and control system is more complex. At last, to choose appropriate capacitive current measurement method according to the arc-suppression coil tuning principle and the distribution network operation is pointed out.

A Fault Line Detection Method Based on Wavelet Packet Analysis in Distribution Network

With the rapid development of power network automation, the detection of the default single-phase grounding fault line in small current neutral grounding system has became a hot spot in research of power network system. Generally, power network neutral point is not grounded or grounded through arc-suppression coil grounding. When single phase grounding fault occurs, the power network system is named as small current grounding system since the grounding short-circuit is small due to a low-impedance short circuit.

Research on Capacitance Current Treatment Methods in Mine High-Voltage Power Grid

In view of the coal mine neutral point ungrounded system when single-phase ground fault occurs, the grounding capacitance current is too big affect the security of coal mine powe supply.The paper analyzed testing data of capacitance current of coal mine network, established a treating scheme of capacitance current according to evaluating results, namely automatic tracking compensation arc suppression coil devices. The running results show that the scheme limits the size of the ground current and decreases rate of accidents of arc grounding over-voltage, which is good for improving the power supply safety.

Leakage Failure and Principle of Underground Low Voltage Grid

To describe the leakage protection of underground low voltage grid are based on zero-sequence voltage and zero sequence power direction of the current leakage protection and earth leakage protection based on the additional DC power supply two kinds. The paper gives the theoretical analysis of these two kinds of leakage, and unified the three-phase neutral point grounding system and by arc suppression coil grounding the under compensation leakage detection program, that provides a new approach for underground leakage detection.

Modeling and Harmonic Optimization of a Two-Stage Saturable Magnetically Controlled Reactor for an Arc Suppression Coil

Magnetically controlled reactors (MCRs) are usually used as three-phase shunt reactors. They have low harmonic distortion independent of the third harmonic current because most three-phase MCRs are delta connected. However, as arc suppression coils, MCRs are operated in the single-phase mode, and the harmonics can be much higher than those of three-phase MCRs. In this paper, the structure and the mathematical model of a two-stage saturable MCR (TSMCR) are proposed. There are two stages with different lengths and areas in the iron cores. The stages saturate at different times when the TSMCR outputs reactive current. The current harmonics of the first saturated stage can be compensated for when the second stage begins to saturate, to reduce the total harmonics of the output current. The mathematical model that reveals the distribution characteristics of the current harmonics for the TSMCR is also presented. A study of the mathematical model indicates that there are two key factors that affect the total current harmonics of the TSMCR. One is the parameter <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> , which represents the area ratio of the second stage to the first stage. The other one is the parameter <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> , which represents the ratio of the length of the first stage to the total length of the magnetic valve in the iron core. The simulations and experiments show that the maximum current harmonics of the novel MCR can be limited to 3.61% of the rated output current when <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> and <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> are chosen according to the theoretical mathematical model.

MATLAB Power System Simulation of Resonant Grounding Fault

In order to handle the situation of power system grounding fault better, this paper built the mathematical model of power system resonance grounding fault based on the resonance grounding principle. And simulated the resonance processes by using MATLAB/SIMULINK/ SIMPOWERSYSTEM (SPS) software. The obtained results show that there will appear zero sequence current at each point of power system when the grounding faults occurrs. And if the circuit has the point of biggest amplitude of zero sequence current, then it is just the fault phases. The simulation data further verified that arc suppression coil grounding could directly decreases the grounding current when the single-phase grounding fault occurred. Moreover, it effectively eliminates the arc from the process and becomes the more reasonable grounding mode.