Differential positive sequence power angle-based microgrid feeder protection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Salauddin Ansari ◽  
Om Hari Gupta
Keyword(s):  
Operating Conditions ◽  
Positive Sequence ◽  
Current Signal ◽  
Capacitor Switching ◽  
Protection Scheme ◽  
Internal Fault ◽  
Distribution Generation ◽  
Operational Modes ◽  
Linear Loading ◽  
External Faults

Abstract Integration of distribution generation (DG) makes the growth of the microgrid protection scheme very challenging issues. Researchers from all over the world continuously are doing hard work for developing the microgrid protection schemes. A differential positive sequence power angle (DPSPA) based microgrid protection scheme is proposed in this paper using positive sequence (PS) components of voltages and currents. The DPSPA for the feeder is calculated considering both ends of voltage and current signal information, when it is more than threshold, internal fault is reported otherwise, it is an external fault. Taking into consideration the varying operational modes of the microgrid, variations in DG penetration, and variations in fault variables namely fault types, and fault locations, the proposed protection scheme is verified on a modified IEEE-13 bus feeder. Moreover, to test the robustness and efficacy of the suggested scheme, various non-faulty events including induction motor starting, non-linear loading, load switching, capacitor switching, and section cutoff have been conducted. The proposed scheme is also verified for external faults and it is found that it continues to be stable for the external faults. The findings exhibit this proposed scheme, which is based on DPSPA, can successfully protect the microgrid under changing operating conditions.

scholarly journals Fault Detection in DC Microgrids Using Short-Time Fourier Transform

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 277
Author(s):  
Ivan Grcić ◽  
Hrvoje Pandžić ◽  
Damir Novosel
Keyword(s):  
Fourier Transform ◽  
Fault Detection ◽  
Operating Conditions ◽  
Time Signal ◽  
Short Time Fourier Transform ◽  
Dc Microgrid ◽  
Protection Scheme ◽  
Simulink Model ◽  
Battery Energy ◽  
Short Time

Fault detection in microgrids presents a strong technical challenge due to the dynamic operating conditions. Changing the power generation and load impacts the current magnitude and direction, which has an adverse effect on the microgrid protection scheme. To address this problem, this paper addresses a field-transform-based fault detection method immune to the microgrid conditions. The faults are simulated via a Matlab/Simulink model of the grid-connected photovoltaics-based DC microgrid with battery energy storage. Short-time Fourier transform is applied to the fault time signal to obtain a frequency spectrum. Selected spectrum features are then provided to a number of intelligent classifiers. The classifiers’ scores were evaluated using the F1-score metric. Most classifiers proved to be reliable as their performance score was above 90%.

A Wavelet Based Directional Algorithm for UHVDC Line Protection

2015 ◽  
Vol 713-715 ◽  
pp. 950-953
Author(s):  
Ya Jie Li ◽  
Jian Cheng Tan ◽  
Shu Xian Zhang
Keyword(s):  
High Frequency ◽  
High Voltage Direct Current ◽  
Protection Scheme ◽  
High Impedance ◽  
Internal Fault ◽  
Current Transmission ◽  
Dc Line ◽  
Simulation Results ◽  
High Impedance Faults ◽  
Transmission Line Protection

When fault distance is greater than a certain value, attenuation of high frequency fault signal over the line is greater than what the DC line boundary is subject to. To sensitively detect a fault and improve the reliability of UHVDC (Ultra High Voltage Direct Current) transmission line protection, a new protection scheme based on wavelet based direction element is proposed, where directional element and attenuation of high frequency energy are used to identify an internal fault. Extensive simulation results show that the proposed protection scheme is able to sensitively detect high impedance faults, identify the faulty pole.

Function-Based Design of a Spacecraft Power System Diagnostics Testbed

2005 ◽  
Author(s):  
Ryan S. Hutcheson ◽  
Irem Y. Tumer
Keyword(s):  
Power System ◽  
Conceptual Design ◽  
Failure Modes ◽  
Fault Injection ◽  
Design Stage ◽  
Design Phase ◽  
Internal Fault ◽  
Conceptual Design Phase ◽  
Potential Failure ◽  
External Faults

NASA’s Ames Research center is currently designing a testbed to validate and compare potential Integrated System Health Management (ISHM) technologies. The proposed testbed represents a typical power system for a spacecraft and includes components such as a fuel cell, solar cells and redundant batteries. To fulfill design requirements, the testbed must be capable of hosting a wide variety of ISHM technologies including those developed by NASA as well as those developed in the aerospace industry abroad. An internal fault injection subsystem must be built into the system to provide a common interface for evaluating these different ISHM technologies. Additionally, to ensure robust operation of the testbed, the capability to detect and manage external faults must also be present. In order to develop a set of requirements for the internal fault injection subsystems as well as predict external faults, a comprehensive set of potential failures must be identified for all of the components of the testbed. To best aid the development of the testbed, these failures needed to be identified as early as the conceptual design phase, where little is known about the actual components that would comprise the finished system. This paper demonstrates the use a function-based failure mode identification method to identify the potential failures of the testbed during the conceptual design phase. Using this approach, designers can explore the potential failure modes at the functional design stage, before a form or solution has been determined. A function-failure database is used to associate the failures of components from previous design efforts to the testbed based on common functionality. The result is a list of potential failure modes and associated failure rates, which are used to improve the design of the testbed as well as provide a framework for the fault injection subsystem.

scholarly journals Principles and methods of non-contact DC contactors calculation for alternative power systems

2020 ◽  
Vol 1 (57) ◽  
pp. 9-15
Author(s):  
A. Soskov ◽  
Ya. Forkun ◽  
O. Iegorov ◽  
M. Glebova
Keyword(s):  
Power Systems ◽  
Alternative Energy ◽  
Operating Conditions ◽  
Heating Process ◽  
Line Voltage ◽  
Power Semiconductor ◽  
Capacitor Switching ◽  
Semiconductor Switch ◽  
Alternative Power ◽  
Short Time

It is shown that the principle of control and power supply of a non-contact bi-directional DC contactor by the electrical line voltage is implemented by connecting the electronic control circuit by one output between two opposite powered gate-controlled thyristors of the bilateral switch to the first pole of the contactor and the second one – to the output clamp. As a result, the electrical line voltage is fed to the electronic circuit only for a short time (up to ms), that is determined by the charge time of the switching capacitor to the breakdown voltage of the threshold zener diode. The peculiarities of the heating process of the power semiconductor contactor in different operating conditions were determined, that allowed to develop a methodology that with sufficient accuracy determines such important parameters as rated and operational current of the contactor. In addition, it was found that in order to reduce significantly the capacity of the switching capacitor, and consequently the size and cost, it is necessary while turning on of the switching thyristor the discharging current of the switching capacitor was equal to the current of its charging circuit, and their values should not be less than the maximum allowable current of turning off the gate-controlled thyristor. It is allows to define justified the parameters of the elements that provide a secure turning off the bilateral switch. The researches have also shown that the non-contact contactors due to the introduction of the network voltage control as compared with existing ones have peculiarities which rise competitive abilities. In particular, they are more reliable, they do not need to supply an additional power source, they exclude standard drivers, and minimize energy consumption. Thus, an exemplary aspect of using the obtained scientific result is the ability to create competitive reliable non-contact DC contactors for voltage up to 1000 V and currents of 100-600 A for alternative energy. Key words – non-contact bi-directional DC contactor, switching capacitor, switching thyristor, power semiconductor switch, alternative energy.

scholarly journals Adaptive Scheme for Detecting Induction Motor Incipient Broken Bar Faults at Various Load and Inertia Conditions

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 365
Author(s):  
Mohamed Esam El-Dine Atta ◽  
Doaa Khalil Ibrahim ◽  
Mahmoud Gilany ◽  
Ahmed F. Zobaa
Keyword(s):  
Main Idea ◽  
Threshold Value ◽  
Operating Conditions ◽  
Noisy Environment ◽  
Noisy Environments ◽  
Variable Loading ◽  
Protection Scheme ◽  
Stator Current ◽  
Fault Severity ◽  
Frequency Components

This paper introduces a novel online adaptive protection scheme to detect and diagnose broken bar faults (BBFs) in induction motors during steady-state conditions based on an analytical approach. The proposed scheme can detect precisely adjacent and non-adjacent BBFs in their incipient phases under different inertia, variable loading conditions, and noisy environments. The main idea of the proposed scheme is monitoring the variation in the phase angle of the main sideband frequency components by applying Fast Fourier Transform to only one phase of the stator current. The scheme does not need any predetermined settings but only one of the stator current signals during the commissioning phase. The threshold value is calculated adaptively to discriminate between healthy and faulty cases. Besides, an index is proposed to designate the fault severity. The performance of this scheme is verified using two simulated motors with different designs by applying the finite element method in addition to a real experimental dataset. The results show that the proposed scheme can effectively detect half, one, two, or three broken bars in adjacent/non-adjacent versions and also estimate their severity under different operating conditions and in a noisy environment, with accuracy reaching 100% independently from motor parameters.

scholarly journals A Harmonic Based Pilot Protection Scheme for VSC-MTDC Grids with PWM Converters

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1010 ◽  
Author(s):  
Mani Ashouri ◽  
Filipe Faria da Silva ◽  
Claus Leth Bak
Keyword(s):  
Pulse Width Modulation ◽  
Voltage Source ◽  
Multiple Faults ◽  
Hilbert Huang Transform ◽  
Pwm Converters ◽  
Protection Scheme ◽  
Selective Protection ◽  
Different Characteristics ◽  
External Faults ◽  
Pilot Protection

This paper presents a selective harmonic-based pilot protection scheme for detecting faults happened in the DC transmission section of VSC-MTDC grids with pulse width modulation (PWM) voltage source converters (VSCs). When a DC fault occurs in VSC-MTDC grids with PWM converters, first carrier frequency harmonic (FCFH) currents will be generated by all VSCs through the grid. FCFH currents have different flowing directions depending on the characteristics and the location of the fault. According to the characteristics of the existing FCFH in the fault currents, a selective pilot protection algorithm is designed for VSC-MTDC grids. Considering the internal and external DC transmission faults for specific zones, and the circulating flow of FCFH current in the DC link capacitors, the relays cannot detect FCFH currents for external faults, while for the internal faults, FCFH currents are clearly detected. To design the selective protection algorithm, Hilbert-Huang transform (HHT) is used to detect the instantaneous frequency and the instantaneous amplitude of the high frequency intrinsic mode function (IMF)s, which are extracted from the fault current waves. Multiple faults with different characteristics are applied to CIGRE DCS-2 VSC-MTDC grid with two-level and three-level VSCs modeled in PSCAD, and the HHT-based selective protection scheme is designed in MATLAB. According to the results, the proposed algorithm can truly discriminate between internal and external faults.

Identification of Transformer Sympathetic Inrush Based on W-DHNN

2013 ◽  
Vol 441 ◽  
pp. 200-203
Author(s):  
Lan Bing Li ◽  
Mao Fa Gong ◽  
Lei Li ◽  
Jian Yu Zhang ◽  
Hui Ting Ge
Keyword(s):  
Neural Network ◽  
Wavelet Analysis ◽  
Abrupt Change ◽  
Hopfield Neural Network ◽  
New Method ◽  
Fault Current ◽  
Current Signal ◽  
Feature Vectors ◽  
Internal Fault ◽  
Characteristic Values

A new method to identify sympathetic inrush and internal fault current of transformer based on W-DHNN is put forward. Wavelet analysis can detect the abrupt change of the current signal. And extract the feature vectors of the signal. The characteristic values as the input value of discrete Hopfield neural network. Then using discrete Hopfield neural network to discriminate sympathetic inrush and internal fault current. This paper uses PSCAD/EMTDC software to model and emulates different parameters of transformer and fault types. The results show that the method is feasible.

Sign in / Sign up

Export Citation Format

Share Document