Short Circuit Fault Analysis Research Articles

Simulation and analysis of short circuit fault in ship power system based on simulink

Abstract In this paper, a short-circuit fault simulation of a ship’s electrical power system is carried out based on Simulink. According to the power system sketch of the ship, a simulation model is built, initial conditions are set, two-phase short-circuit faults and three-phase short-circuit faults are simulated, and the simulation results are analyzed. The results show that the short-circuit fault has a large impact on both the generator side and the load side, in which the impact on the load side is more serious. At the generator side, the voltage of the corresponding phase drops by about 1/3-1/2, and the current increases by about 1.5 times. At the load side, when a two-phase short circuit occurs, the voltage drops to half of the original one, and when a three-phase short circuit occurs, the voltage drops to 0. The short-circuit current has the largest value at the beginning of the short circuit, then oscillates and decays, and finally stabilizes at about 15 times the normal working current.

Performance and Short-Circuit Fault Analysis in Hybrid Excited and Interior PM Motors

Performance and Short-Circuit Fault Analysis in Hybrid Excited and Interior PM Motors

Analysis of Inter-Turn Short-Circuit Faults in Brushless DC Motors Based on Magnetic Leakage Flux and Back Propagation Neural Network

Inter-turn short-circuit (ITSC) faults are the most common fault types of brushless DC (BLDC) motors used in industry. Fault diagnosis of BLDC motors is of critical importance due to their wide spread applications. Existing diagnosis methods are based on voltage and current analysis which is useful but difficult to identify early faults and fault locations, as these suffer from external disturbances. This paper proposes a new offline method for fault detection based on magnetic leakage flux (MLF) and backpropagation neural network (BPNN) for improving the level of fault diagnosis. The ITSC and MLF are modeled and analyzed theoretically. Then they are verified by finite element analysis (FEM) and experimental tests. Hall sensors are used to form an array to collect MLF signals at different positions outside the test motor. The frequency-domain characteristic matrix of MLF signals is analyzed by BPNN models. The experimental results show that the proposed method can effectively detect ITSCs, and estimate the fault degree and the location of the fault. The method is a promising technology as it is non-intrusive and accurate.

A New Short-Circuit Current Calculation and Fault Analysis Method Suitable for Doubly Fed Wind Farm Groups.

The transient characteristics of wind farms in groups are quite different; in addition, there is a strong coupling between the wind farms and the grid, and these factors make the fault analysis of the grid with wind farm groups complicated. In order to solve this problem, a mathematical model of the converter is established based on the input-output external characteristics of the converter, and a transient model of a doubly fed wind turbine (DFIG) is presented considering the influence of the low-voltage ride-through control (LVRT) of the converter, and the effect mechanism of the LVRT strategy on the short-circuit current is analyzed. Finally, a short-circuit current calculation model of a doubly fed wind turbine with low-voltage crossing control is established. The interaction mechanism between wind farms during the fault is analyzed, and a short-circuit current calculation method of doubly fed wind farm groups is proposed. RTDS is used to verify the accuracy of the proposed short-circuit current calculation method for doubly fed field groups. On this basis, a method of power grid fault analysis after doubly fed field group access is discussed and analyzed.

Analysis on Rotor Vibration Characteristics under Dynamic Rotor Interturn Short Circuit Fault in Synchronous Generators

A dynamic rotor interturn short circuit fault may occur during synchronous generator operation. However, there is no method to analyze the generator’s characteristics under the dynamic rotor interturn short circuit fault and identify the fault. In order to solve this problem, a new dynamic rotor interturn short circuit fault analysis model is creatively proposed through mathematical derivation. Firstly, the rotor vibration characteristics and the mechanical response under magnetic pull excitation are theoretically analyzed. In addition, a finite element modeling method for the dynamic rotor interturn short circuit fault is proposed, and an experimental device is designed. The model of a synchronous generator under the dynamic rotor interturn short circuit fault is established to obtain the rotor’s unbalanced magnetic pulls and mechanical responses by finite element calculation. Finally, the rotor vibrations are tested on a CS-5 prototype generator. The validity of the model is verified by finite element calculation and an experiment. This paper provides theoretical support for the diagnosis of a synchronous generator’s dynamic rotor interturn short circuit fault.

SHORT CIRCUIT FAULT ANALYSIS IN THE ELECTRIC POWER DISTRIBUTION SYSTEM AT PT PLN (Persero) UP3 SOUTH MAKASSAR ULP KALEBAJENG USING ETAP

Short circuit fault analysis is needed to determine the amount of short circuit current flowing in a system. This study discusses the single-phase short-circuit current to the ground at the point where the disturbance occurs from the base of the network to the end of the Malewang feeder network. The purpose of this study was to determine the amount of short circuit fault current in the Electric Power Distribution System at PT PLN (Persero) UP3 South Makassar ULP Kalebajeng. This study used the ETAP program and manual calculations. The results of the study found that the contribution of the largest single-phase short-circuit fault current to the ground in the Malewang feeder occurred on Buses located at the base of the network close to the Substation, namely Bus 1 (Exim-Rec Kalaserena) of 0.311 kA, while thesmallest Buscontribution occurred on Buses located at the end of the network far from the Substation, namely Buses 14 (Bilonga) of 0.292 kA. From the results of the study, it can be concluded that the farther the interference bus is from the Substation, the greater the channel impedance. The greater the impedance, the smaller the short-circuit current.

Short-Circuit Fault Detection and Quantitative Analysis Based on Mean-Difference Model With Variational Modal Decomposition

Abstract Short-circuit failure is one of the triggers for thermal runaway of lithium-ion batteries, which can lead to serious safety issues. This paper attempts to estimate the short-circuit resistance of the cell using the mean difference model and relies on the estimated results to make a quantitative analysis of short-circuit fault. To achieve this goal, a combination of forgetting factor recursive least squares and extended Kalman filter is used to estimate the average open-circuit voltage within the battery pack. Subsequently, since both the open-circuit voltage (OCV) and intrinsic mode function (IMF0) components reflect the low-frequency characteristics of the battery voltage, we propose a new method based on the variational modal decomposition to extract the differential open-circuit voltage of the battery and finally make an estimate of the short-circuit resistance after obtaining OCV of the battery using the idea of the mean difference model (MDM). In addition, the effectiveness of the proposed method is verified under different degrees of short-circuit faults by connecting different resistors to the series battery pack.

Modelling and Analysis of Inter-Turn Short-Circuit Fault of PM Machines With Parallel-Connected Coils

This paper presents a general analytical fault model in a compact matrix form for surface-mounted permanent magnet (SPM) machines with parallel-connected coils, which is useful to study the machine performance under the inter-turn short circuit (ITSC) fault. To simplify the fault model, the multiphase Clarke transformation has been proposed. In the model, the branch currents rather than the phase currents are employed as state variables to describe machine behaviours under fault. Additionally, self- and mutual-inductances are obtained by winding function approach (WFA) plus slot permeance method. The proposed analytical fault model is applied to a 3 kW 96-slot 32-pole SPM machine and validated by time-stepping FE simulations. A small scale 12-slot 4-pole SPM machine prototype has also been built to further validate the accuracy of the proposed fault model.

Reliability Assessment of Power Semiconductor Devices for a 13-Level Boost Inverter Topology

Since the last few decades, research on multilevel inverters (MLIs) has been growing in the power electronics field. The MLI is preferred over conventional two-level converters due to its improved performance. In recent years, different types of MLI architectures have been proposed, each employing a unique combination of power semiconductor devices to produce a multilevel output voltage waveform. The reliability of a multilevel inverter is a crucial performance indicator that must be taken into account at every stage from design to commercialization. MLI is vulnerable to a variety of failure modes and processes due to a large number of interdependent components. In this paper, a 13-level boost inverter topology has been analyzed and test results are presented and discussed. The analysis has been carried out in terms of open-circuit fault (OCF), short-circuit fault (SCF), power loss, and thermal analysis. The results have been discussed and recommendations have been made for the better design of the inverter topology to improve reliability.

Analysis and Test of Short-Circuit Fault Between Strands of Stator Bar Based on the Characteristic of End Leakage Magnetic Field

As the demand for high efficiency and power density in AC motors grows, stator windings are increasingly using transposition bars to reduce winding losses. The bar is typically designed as a tight compact construction with several strands transposed in various ways. When a short-circuit fault occurs between the strands, establishing fault location and timely warning are key issues to ensure the safe operation of the motor. If the fault is not discovered and corrected promptly, it will deteriorate the winding faults and have more serious effects. This paper presented a method for detecting short-circuit faults based on the end leakage magnetic field of the stator bar. The relationship between strand currents and the leakage magnetic field is derived. By comparing the differences of the end leakage field between the health bar and the fault bar under different short-circuit fault degrees, the functional relationship between the leakage magnetic field signal and the fault currents is established. This detection method is proposed by working on the principle of the Hall-effect sensor. This paper also built a local sample test platform to verify the correctness of the detection method by comparing the experimental results with the simulation results.

Characteristics Analysis of Field Winding Inter-Turn Short-Circuit Fault for Large-Capacity Synchronous Condenser Based on Stator Winding Asymmetric Branch Current

Characteristics Analysis of Field Winding Inter-Turn Short-Circuit Fault for Large-Capacity Synchronous Condenser Based on Stator Winding Asymmetric Branch Current

Protection of the Future Harbor Area AC Microgrids Containing Renewable Energy Sources and Batteries

A significant share of global carbon emissions is related to marine vessels running solely on fossil fuels. The hybrid or fully electrified marine vessels using battery energy storage systems (BESS) both for onboard propulsion system and for cold-ironing during docking at harbor areas will significantly reduce marine related carbon emissions. However, the transformation of marine vessels’ operations from diesel engines to BESS will necessarily require charging stations and other electric power infrastructure at harbor areas. The sustainable and cheap energy of renewable energy sources like wind turbine generators (WTGs), photovoltaic (PV) systems and related BESS could be used at harbor areas for charging depleted vessel-BESS and supplying power to cold-ironing loads. For this purpose, two new harbor area smart grid or AC microgrid models have been developed by our research group. This paper presents a comprehensive analysis of three-phase short-circuit faults for one of the proposed AC microgrid models using PSCAD/EMTDC simulations. The fault study of harbor area AC microgrid-1 is done for both grid-connected and islanded modes. The main purpose of the fault study is to check if grid-connected mode overcurrent settings of intelligent electronic devices (IEDs) will also be valid for different islanded mode fault cases with different fault current contributions from converter-based distributed energy resources (DERs) including WTG, PV and BESS. The extent of fault current contribution from DERs and BESS to avoid adaptive protection settings and to ensure definite-time protection coordination and fast fuse operations during different islanded modes is investigated.

Modality analysis and algorithm design of stator short-circuit fault set for large compressed air energy storage generators

Using salt caverns and caves to build compressed air energy storage power stations is an important development direction in the field of large-scale energy storage. With the continuous maturity of technology, compressed air energy storage generators have gradually developed into large-scale units with a single-unit capacity of 300 MW. Due to the increase of single-unit capacity, the internal short-circuit fault of the stator will cause very serious losses. In addition, the compressed air energy storage generator has complex operating conditions and is more prone to various internal short-circuit faults. In order to effectively ensure its safe and reliable operation, it is particularly necessary to study the effective main protection configuration scheme. The optimal design of the main protection configuration scheme is based on the analysis of the possible internal short-circuit faults of the generator. At present, the stator windings of large-scale compressed air energy storage generators generally adopt double-layer wave winding or double-layer tap winding structures. For these two winding structures, this paper analyzes in detail the characteristics of all fault modalities that may occur inside the large-capacity compressed air energy storage generator and designs a general algorithm that can form their respective fault sets. Finally, the application of the algorithm in the analysis of the stator fault modality in a compressed air energy storage power station is introduced.

Characteristic analysis and diagnosis of short-circuit fault in armature winding of four-phase variable flux reluctance machine

Characteristic analysis and diagnosis of short-circuit fault in armature winding of four-phase variable flux reluctance machine

Analysis of Urban Rail DC Short Circuit Fault and Vehicle-Network Protection Coordination Based on Transient Characteristics

Analysis of Urban Rail DC Short Circuit Fault and Vehicle-Network Protection Coordination Based on Transient Characteristics

A Novel Universal Model Considering SAGE for MFD-Based Faulty Property Analysis Under RISC in Synchronous Generators

This article proposes a new rotor interturn short circuit (RISC) fault analysis model for the electromechanical property study in synchronous generators. The specific novelty of this model lies in two aspects: First, It considers that most generators exist static air-gap eccentricity (SAGE), so it analyzes the RISC fault under normal and SAGE, making the model more versatile, and second, it takes into account not only the short circuit degree, but also the short circuit position, consequently it is more universal. By feeding the number of short circuit turns (denotes the short circuit degree), the angle between the two slots, where the short circuit takes place (denotes the short circuit position) and the detailed parameters of the generator into the model, the developing tendency of the key magnetic flux density (MFD)-based parameters can be conveniently predicted. The advantages of the proposed model primarily lie in the universality and the calculation speed. It can quickly evaluate the generator operating conditions. The phase current and the electromagnetic torque are selected in this article as the representatives of the electrical parameter and the mechanical parameter, respectively. Two-dimensional finite element analysis and experimental studies validate the proposed model.

Investigation analysis of open circuit and short circuit fault on cascaded H-bridged multilevel inverter using artificial neural network approach

Cascaded H-bridge multilevel inverters are becoming increasingly used in applications such as distribution systems, electrical traction systems, high voltage direct conversion systems, and many others. Despite the fact that multilevel inverters contain a large number of control switches, detecting a malfunction takes a significant amount of time. In the fault switch configurations diode included for freewheeling operation during open-fault condition. During short circuit fault conditions are carried out by the fuse, which can reveal the freewheeling current direction. The fault category can be identified independently and also failure of power switches harmed by the functioning and reliability of cascaded H-bridge multilevel inverters. This paper investigates the effects and performance of open and short switching faults of multilevel inverters. Output voltage characteristics of five level MLI are frequently determined from distinctive switch faults with modulation index value of 0.85 is used during simulation analysis. In the simulation study, with the modulation index value of 0.85, one second open and short circuit faults are generated for the location of the defective switch. Fault is identified automatically by means of artificial neural network technique using sinusoidal pulse width modulation based on distorted total harmonic distortion and managed by its own. The proposed topology is to be design and evaluate using MATLAB/Simulink platform.

Simulation and Analysis of Internal Short Circuit Fault, Electromagnetic Forces and Thermal Analysis of Single Phase Transformer

Simulation and Analysis of Internal Short Circuit Fault, Electromagnetic Forces and Thermal Analysis of Single Phase Transformer

Frequency Analysis of Partial Short-Circuit Fault in BLDC Motors with Combined Star-Delta Winding

This paper analyses the condition of a partial short-circuit in a brushless permanent magnet motor. Additionally, the problem was analysed for three stator winding configurations: star, delta and star-delta connection. The paper presents an original mathematical model allowing a winding configurations to be analysed. What is more, the said mathematical model allows taking account of the partial short-circuit condition. Frequency analysis (Fast Fourier Transform—FFT) of the artificial neutral point voltage was proposed for the purpose of detecting the partial short-circuit condition. It was demonstrated that a partial short-circuit causes a marked increase in the diagnostic frequencies of the voltage signal. The proposed brushless permanent magnet motor diagnostic method is able to detect the fault regardless of the stator winding configuration type.

Theoretical Analysis and Experimental Validation of Flying-Capacitor Multilevel Converters Under Short-Circuit Fault Conditions

Addressing the increasing demand for high-efficiency and high-power-density converters, the flying-capacitor multilevel converter has shown itself as a promising topology. A key advantage of this topology is the reduced voltage rating of the switches, though also makes it vulnerable to device failure during short-circuit conditions. Despite large interest in fault-tolerant operation of these converters, alongside detailed descriptions of flying-capacitor balancing, little research has focused on the converter short-circuit fault analysis, which may cause a switch failure if not properly designed for. Therefore, this article presents a comprehensive model describing the large-signal short-circuit switching behavior of a general N-level flying-capacitor multilevel converter. Highly simplified models used to predict the evolution of the switch current and voltage stress during the fault are proposed, targeted at practicing engineers for conservative design guidelines. These models are used to determine the critical time for remedial action of the converter before reaching some predefined maximum conditions. A 2-to-10-level fully configurable flying-capacitor multilevel converter and a fault circuit hardware prototype are used to experimentally perform different short-circuit tests that show a good match to the measured behavior.