Phase Grounding Fault Research Articles

Cascade model predictive control strategy for medium voltage flexible interconnected systems with arc suppression capability under single phase grounding fault

The distribution network faces problems such as diversified electricity demand and difficulty in ensuring power quality. At the same time, complex working environments often lead to brief single-phase ground faults, resulting in zero sequence currents in the distribution network. The flexible interconnection system of medium voltage distribution network plays an important role in balancing loads and providing electrical reliability. This article uses a three-phase four-wire converter as a flexible interconnection device, injecting zero sequence current into the neutral point through the fourth bridge arm. Simultaneously, a novel control strategy for medium voltage flexible interconnected systems based on cascaded model predictive control is proposed. The simulation and experimental results demonstrate the effectiveness of the proposed control strategy, which comprehensively achieves power mutual benefit, neutral point displacement voltage suppression, and active arc suppression during single-phase grounding faults in flexible interconnected systems.

A Non-neutral alternate arc suppression method for single phase grounding fault in active distribution network

To fully compensate reactive and active components of the single line-to-ground (SLG) fault current, additional DC power supply devices are usually used for arc suppression devices. Therefore, the alternate arc suppression method is proposed for the non-neutral multi-function arc suppression device (MF-ASD) in this paper, which can achieve energy self-balance in the MF-ASD during the SLG fault without additional DC power supply devices. Firstly, the DC-link charge–discharge characteristic of the MF-ASD is analyzed under different SLG fault conditions. Then, the alternate arc suppression principle and energy flow law between two non-faulty phases of the MF-ASD are described in detail. Further, the relationship between the alternate period, switching time, and the DC-link voltage are deduced as well. Then, the control parameters are reasonably designed for the DC-link voltage stability of two non-faulty phases of the MF-ASD. Finally, the correctness and feasibility of the proposed method are verified by simulation and experiment results.

Frequency Stability Enhancement Using ANFIS Based Inverter Power Control in Low Inertia Power System

Electricity generation is the process of generating electrical power from sources of primary energy. There are various methods of electricity generation on different types of energies. Among the source such as thermal power, nuclear power, or the renewable energies the cost of Generator electricity is relatively low. world wide ,about 20% of all electricity is generated by Generator power. Modern Generator turbines can convert as much as 90% of the available energy into electricity. In Tamil Nadu, there are 29 Generator power schemes having individual station capacity over 25MW aggregating to an installed capacity of 2,212.2 MW . At present there are 16 small /mini / micro Generator electric schemes with an installed capacity of 71.35 MW in operation in Tamil Nadu. In 2021, global installed Generator power electrical capacity reached almost 1400GW, the highest among all the renewable energy technologies. Generator electric power plant is usually built on a mountainous area and is isolated from the main power distribution system. It requires very efficient control strategy to control the speed of the Turbine in sudden variation and disturbance in the system. The main objective of this project is to develop mathematical model and design a ANFIS Logic Control (FLC) for Generator power plant during different fault schemes. In this project the ANFIS Logic Control (FLC) is used to control the frequency of the non- linear Generator power plant. The different types of fault models such as single phase ground fault and phase to phase fault are applied to the ANFIS Logic Control (FLC) Key Word: Solar panel, Wind Mill, Inverter, Frequency stability

The Test Bench for Simulation Phase Fault and Ground Fault Analysis Protection Concept Using Symmetrical Components

Various laboratory experiment platforms have been developed to provide students with theoretical knowledge and practical experience. Understanding concepts related to the process for determining the design of protection settings requires practical experience, which can be achieved by repeated trials. In this paper, the mechanism of a ground fault in a medium voltage feeder is done using a simulator substation as a case study. This process must be carried out twice, once for the ground-fault relays protection based on residual currents and then repeated based on residual voltage. For further understanding of the electrical distribution network, the system will be operated at 20 kV on the primary and 380 V on the secondary. The model uses smaller nominal voltages consisting of 380 V on the primary and the secondary. The result of one phase fault protection mechanism works well at each point of interference, and voltage transformers are protected from overheating and damage. The lowest value of the single-phase to ground short circuit that occurs at the fault location at the farthest point of interference from the protection relay location is used for the threshold setting on the voltage relay. The one phase fault protection mechanism works well at each point of interference, and the voltage transformer is protected from overheating and damage. For residual current ground fault protection effective, the threshold setting of phase fault inverse time delay with threshold setting I> is 1.5 ampere, and instantaneous I>> is 7.5 ampere. The effective threshold setting for residual ground fault protection wasUo> = 22% dan UO>> = 33,2%.

A Synchrophasor-Based Line Protection for Single Phase-Ground Faults

A Synchrophasor-Based Line Protection for Single Phase-Ground Faults

Single phase grounding fault location algorithm of wind farm collector lines based on multi-terminal information

Single phase grounding fault location algorithm of wind farm collector lines based on multi-terminal information

Analysis and simulation of the whole failure process of 35kV metal oxide varistor at outlet of main transformer

Equipment failure occurs frequently at the low-voltage side of main transformer, and the most common faults is metal oxide arrestors (MOV) explosion and potential transformers (PT) damage under different ground fault. However, because of the lack for simulation model, it is quite difficult to conduct accurate analysis of the whole fault process, and the fault cannot be effectively prevented. To solve this problem, research on analysis and simulation of the whole fault process of 35kV MOV configured at the outlet of main transformer is carried out in this paper. Basic information and recording waveforms about the field fault in 110kV/35kV/10kV substation and relative theoretical analysis are presented first. Simulation model is established in PSCAD/ETMDC, and the simulation results are consistent with theoretical analysis and recording results. The whole fault process is: C-phase ground fault occurred first. Then, A-phase and B-phase voltage increased to line-line voltage from phase-phase voltage, and this overvoltage caused breakdown of A-phase MOV. As a result, the C-phase ground fault transferred to A-C phase ground fault. After the arc in MOV extinguished, the A-C phase ground fault changed back to Cphase ground fault.

Distributed relay protection for distribution network based on hybrid power method and current method

The distributed power supply is gradually connected to the distribution network, the original single power source radiant network pattern of the distribution network no longer exists. The topology of the distribution network is characterized by variable topology and multi-power supply, and the traditional fault detection and protection actions cannot adapt to the new distribution network topology. Based on failure probability of the highest single phase ground fault in distribution network by the power differential method and differential current method to deal with failure, installed the reclosing device, and through the simulink simulation, verify the effectiveness of the proposed scheme, can effectively deal with the distribution network fault, to deal with instant fault and permanent fault, effectively reduce misoperation. In this paper, the scheme of setting the setting value independently is adopted, which can quickly restore the power supply in non-fault area and improve the continuity of power supply. It has very broad engineering application scenarios.

A Non-Neutral Rotating Arc Suppression Method for Single Phase Grounding Fault in Active Distribution Network

A Non-Neutral Rotating Arc Suppression Method for Single Phase Grounding Fault in Active Distribution Network

Performance test of small-current grounding line selection device based on the real-time digital simulation system

Single phase grounding fault is the most common fault type in small-current grounding distribution network, but the small-current grounding line selection device put into operation on site is often difficult to meet the application requirements, affecting the rapid and accurate treatment of grounding fault. Considering that there are many small-current grounding line selection manufacturers and various device forms, it is difficult to intuitively evaluate the line selection performance of different devices and make horizontal comparison, and there is no supporting basis for the selection and application of on-site line selection devices. Therefore, based on the real-time digital simulation system (RTDS), this paper establishes a test platform for small-current grounding line selection device. Based on the constructed test platform, four line selection devices form different manufacturers are tested in parallel, the performance of the devices is compared, and the influencing factors affecting the accuracy of line selection results are analyzed. The conclusions of this paper can provide strong support for the pilot application of small-current line selection devices.

Analysis of single phase ground fault characteristics of low resistance ground active distribution network

A large number of distributed generators access to low resistance grounding system may have great influence on the fault characteristics of single phase ground. In view of low resistance ground active distribution network, the connection mode of Inverter-interfaced Distributed Generators (IIDG) is discussed comprehensively based on operation safety and protection requirements. The equivalent model of IIDG and simplified zero sequence network model of low resistance grounding system contain multi-IIDG for single phase ground fault are established. The amplitude and phase characteristics of zero sequence current in single phase grounding fault of the system and the characteristics of high-resistance ground fault are analyzed. Simulative results by MATLAB/Simulink verifies the correctness of the analysis results of fault characteristics. The conclusions could be provided as reference for solving the grounding protection of system with high penetration of distributed generator.

Fault line selection in\xa0cooperation with multi-mode grounding control for the\xa0floating nuclear power plant grid

The Floating nuclear power plant grid is composed of power generation, in-station power supply and external power delivery. To ensure the safety of the nuclear island, the in-station system adopts a special power supply mode, while the external power supply needs to be adapted to different types of external systems. Because of frequent single phase-ground faults and various fault forms, the fault line selection protection should be accurate, sensitive and adaptive. This paper presents a fault line selection method in cooperation with multi-mode grounding control. Based on the maximum united energy entropy ratio (MUEER), the optimal wavelet basis function and decomposition scale are adaptively chosen, while the fault line is selected by wavelet transform modulus maxima (WTMM). For high-impedance faults (HIFs), to enlarge the fault feature, the system grounding mode can be switched by the multi-mode grounding control. Based on the characteristic of HIFs, the fault line can be selected by comparing phase differences of zero-sequence current mutation and fault phase voltage mutation before and after the fault. Simulation results using MATLAB/Simulink show the effectiveness of the proposed method in solving the protection problems.

Phase-Ground Fault Current Analysis and Protection of a High-Resistance Grounded Power System

This article provides a closer look at a high resistance grounded (HRG) power system using symmetrical components. It addresses the industry confusion, “how system charging current direction reverses during phase-ground fault condition without reversal of system voltage that causes fault current flow.” It presents fault current phasor diagram that caused industry confusion which lead IEEE Std P3003.1 published without the phasor diagram with the consensus of working group members including the author of this article. In this article, the theory of symmetrical components has been used for analysis of phase-ground fault to illustrate ground fault current flow directions and its phasor diagram. The industry concept, “phase-ground fault current flows from the faulted location to ground before it returns to the power source” has been used in the analysis. This concept has not been used in the IEEE Std. 142 -2007, causing ground fault protection confusion for HRG power systems. The fault current flow direction clarification will help in the application of a sensitive voltage polarized ground fault protection relay for HRG. During phase-ground faults with very low arcing fault currents which pose a sensitivity issue on ground fault protection relays, some relevant technical papers providing techniques of fault detection are referenced in this article. Clarification on the limitation of HRG grounding contained in IEEE Std. 142-2007 for phase-ground fault current not to exceed 10 A and power system voltage not to exceed 4.16 kV (for delayed clearing of first phase-ground fault) is also included in this article.

Insulation resistance and breakdown voltage analysis for insulator cover type YSL-70AP

Electrical energy has become a primary necessity, for every human around the world in globalization era. Electrical energy very important in every human activity to supporting the economy. Currently requires reliable of electrical distribution energy. Reliability of electrical energy supply is measured by the low value of SAIDI and SAIFI. Most of the PLN APJ has not able to fulfil SAIDI and SAIFI targeted by SPLN. There are 54 percent medium voltage disorder due to temporary interference. These disorders are caused by trees, animals and birds. insulator cover applied to reduce temporary interference. The problem is no research explaining the isolation quality and voltage breakdown capacity. This research conducted by quantitative testing and analysis. It was finding that the insulator cover type YSL-70-AP is reliable to reduce temporary disorder and environmentally with consideration: (a) The insulation value is 278.80 Mega Ohm, so that the electrical current of phase-ground fault is only 41.61 micro Ampere, just 0.36 percent of maximum limitation of PLN standard; (b) The voltage breakdown capacity is 49.63 Volt, more than 207 percent of minimum limitation of PLN standard. The voltage breakdown capacity can be increase by wings extension.

Novel active–passive compensator–supercapacitor modeling for low-voltage ride-through capability in DFIG-based wind turbines

Low-voltage ride-through is important for the operation stability of the system in balanced- and unbalanced-grid-fault-connected doubly fed induction generator-based wind turbines. In this study, a new LVRT capability approach was developed using positive–negative sequences and natural and forcing components in DFIG. Besides, supercapacitor modeling is enhanced depending on the voltage–capacity relation. Rotor electro-motor force is developed to improve low-voltage ride-through capability against not only symmetrical but also asymmetrical faults of DFIG. The performances of the DFIG with and without the novel active–passive compensator–supercapacitor were compared. Novel active–passive compensator–supercapacitor modeling in DFIG was carried out in MATLAB/SIMULINK environment. A comparison of the system behaviors was made between three-phase faults, two-phase faults and a phase–ground fault with and without a novel active–passive compensator–supercapacitor modeling. Parameters for the DFIG including terminal voltage, angular speed, electrical torque variations and d–q axis rotor–stator current variations, in addition to a 34.5 kV bus voltage, were investigated. It was found that the system became stable in a short time and oscillations were damped using novel active–passive compensator–supercapacitor modeling and rotor EMF.

Simulation Analysis of Overvoltage of Single Phase Grounding Fault in Paralleled 12-Pulse Rectifier System

In order to solve the problem of overvoltage of single phase grounding fault of paralleled 12-pulse rectifier system, firstly the common mode wave problem of monopole in DC side at fault is analyzed. Secondly, the transient overvoltage of the system at the AC side single phase fault is analyzed by simplifying the charging and discharging circuit of capacitances on DC side. Finally, the theory of frequency extinguishing arc is used to simulate the intermittent arc grounding overvoltage. It is proved that the capacitance on DC side also affects the AC overvoltage in the system that provides a basis for the better suppression of overvoltage in the project. The correctness of the conclusion is verified by PSCAD/EMTDC simulation software in the analysis process.

Device for limiting single phase ground fault of mining machines

The paper shows the reasons and consequences of the single-phase ground fault. With all the variety of devices for limiting the current single-phase ground fault, it was found that the most effective are Peterson coils having different switching circuits. Measuring of the capacity of the network is of great importance in this case, a number of options capacitance measurement are presented. A closer look is taken at the device for limiting the current of single-phase short circuit, developed in the Far Eastern Federal University under the direction of Dr. G.E. Kuvshinov. The calculation of single-phase short-circuit currents in the electrical network, without compensation and with compensation of capacitive current is carried out. Simulation of a single-phase circuit in a network with the proposed device is conducted.

A novel single phase grounding fault protection scheme without threshold setting for neutral ineffectively earthed power systems

The setting values of thresholds for fault feature parameters are critical in all kinds of protection schemes. When the detected feature parameter value exceeds the setting value, the protection will trip. However, the setting value based conventional protection schemes sometimes cannot satisfy the protection requirements of neutral ineffectively earthed power systems (NIEPS) due to wide variations in operating conditions and the complexities of fault cases. In this paper, a novel single phase grounding fault protection scheme without threshold setting is proposed. The fault detection is achieved based on operating states rather than setting values. A fuzzy c-means algorithm is used to divide the operating state of the protected feeder into non-fault states and fault states. The cluster center of each state is then obtained by classifying the historical feature samples of the protected feeder extracted under various operating conditions into their corresponding states in a constructed multi-dimensional fault feature space. The distances between the detected feature samples and the cluster centers of the non-fault and the fault states are calculated. If the distance to the fault state is shorter than that to the non-fault state, a fault is detected. Otherwise, the feeder is considered normal. A PSCAD/EMTDC simulator is used to simulate a 35 kV NIEPS under various operating conditions, non-linear loads, and complex fault cases. Results show that the proposed single phase grounding fault protection scheme without threshold setting can protect the system correctly under all kinds of faults.

Protection against single phase ground fault of the stator winding synchronous generator

Protection against single phase ground fault of the stator winding synchronous generator

Evaluation of Variation Ranges of Phase Voltages and Ground Currents in Three-Phase Unearthed Networks With Diode Rectifiers

Operating parameters of electrical networks such as phase voltages, leakage and ground fault currents are decisive for safe operation of low-voltage unearthed networks with diode rectifiers. The knowledge of maximum possible values of network operating parameters is necessary for correct assessment of numerous hazards. So far no simple methods of determination of the highest levels of these parameters in AC/DC IT 3-phase networks have been available. The present paper reports a new approach to the evaluation of the variation ranges of the operating parameters of these systems using Mathcad.