scholarly journals Protection Scheme using RPI Concept in STATCOM Compensated EHV System

2019 ◽  
Vol 8 (9) ◽  
pp. 2730-2733
Keyword(s):  
Reactive Power ◽  
Phase 1 ◽  
Research Work ◽  
Fault Classification ◽  
Fault Identification ◽  
Test Cases ◽  
Static Synchronous Compensator ◽  
Protection Scheme ◽  
Fault Resistance ◽  
Parameter Scheme

This research work present a protection scheme for fault detection and fault classification in EHV with static synchronous compensator (STATCOM) using Regulated Power index (RPI) concept. RPI per phase is defined as the ratio of the sum of sending end apparent power and receiving end apparent power to the apparent power at receiving end for that phase [1]. STATCOM is used for reactive power compensation and regulates the system voltage by absorbing and generating reactive power. As per the requirement of system parameter scheme is developed for the detection of fault, identification of faulty phase and tripping the faulty phase. This scheme will be validated by considering various fault test cases considering severe fault conditions with very low resistance, high fault resistance conditions and internal faults with static synchronous compensator (STATCOM) at sending end on the MATLAB model of transmission system at 220 KV level.

scholarly journals Combined DFT and Fuzzy Based Faulty Phase Selection and Classification in a Series Compensated Transmission Line

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Praveen Kumar Mishra ◽  
Anamika Yadav
Keyword(s):  
Transmission Line ◽  
Fault Location ◽  
Fault Classification ◽  
Testing Time ◽  
Heavy Load ◽  
Phase Selection ◽  
Protection Scheme ◽  
Fault Resistance ◽  
Zero Sequence ◽  
Series Capacitor

The conventional distance protection scheme malfunctions sometimes in case of a fixed series capacitor compensated transmission line due to the change in relaying impedance of the protected line during faulty conditions. In order to mitigate this problem, a combined discrete Fourier transform and fuzzy (CDFTF) based algorithm has been proposed in this paper. This method has been tested on a 400 km, 735 kV series compensated transmission line network and WSCC 3-machine 9-bus system for all fault types using MATLAB/Simulink and PSCAD platforms, respectively. A fixed series capacitor is located at the middle of the protected line. The fundamental components of phase currents, phase voltages, and zero-sequence current are fed as inputs to the proposed scheme. The fault detection, faulty phase selection, and fault classification are achieved within 1/2–1 cycle of power frequency. The proposed CDFTF-based scheme is less complex and is better than other data mining techniques which require huge training and testing time. Test results corroborate the proposed scheme reliability with wide variations in fault location, fault resistance, fault inception angle, evolving faults, compensation level, and heavy load interconnection. The results discussed in this work indicate that the proposed technique is resilient to wide variations in fault and system conditions.

ANN-Based Relaying Algorithm for Protection of SVC- Compensated AC Transmission Line and Criticality Analysis of a Digital Relay

2020 ◽  
Vol 13 (3) ◽  
pp. 381-393
Author(s):  
Farhana Fayaz ◽  
Gobind Lal Pahuja
Keyword(s):  
Transmission Line ◽  
Failure Modes ◽  
Reactive Power ◽  
Circuit Breaker ◽  
Research Work ◽  
Back Propagation ◽  
Static Var Compensator ◽  
Data Set ◽  
Ac Transmission ◽  
Criticality Analysis

Background:The Static VAR Compensator (SVC) has the capability of improving reliability, operation and control of the transmission system thereby improving the dynamic performance of power system. SVC is a widely used shunt FACTS device, which is an important tool for the reactive power compensation in high voltage AC transmission systems. The transmission lines compensated with the SVC may experience faults and hence need a protection system against the damage caused by these faults as well as provide the uninterrupted supply of power.Methods:The research work reported in the paper is a successful attempt to reduce the time to detect faults on a SVC-compensated transmission line to less than quarter of a cycle. The relay algorithm involves two ANNs, one for detection and the other for classification of faults, including the identification of the faulted phase/phases. RMS (Root Mean Square) values of line voltages and ratios of sequence components of line currents are used as inputs to the ANNs. Extensive training and testing of the two ANNs have been carried out using the data generated by simulating an SVC-compensated transmission line in PSCAD at a signal sampling frequency of 1 kHz. Back-propagation method has been used for the training and testing. Also the criticality analysis of the existing relay and the modified relay has been done using three fault tree importance measures i.e., Fussell-Vesely (FV) Importance, Risk Achievement Worth (RAW) and Risk Reduction Worth (RRW).Results:It is found that the relay detects any type of fault occurring anywhere on the line with 100% accuracy within a short time of 4 ms. It also classifies the type of the fault and indicates the faulted phase or phases, as the case may be, with 100% accuracy within 15 ms, that is well before a circuit breaker can clear the fault. As demonstrated, fault detection and classification by the use of ANNs is reliable and accurate when a large data set is available for training. The results from the criticality analysis show that the criticality ranking varies in both the designs (existing relay and the existing modified relay) and the ranking of the improved measurement system in the modified relay changes from 2 to 4.Conclusion:A relaying algorithm is proposed for the protection of transmission line compensated with Static Var Compensator (SVC) and criticality ranking of different failure modes of a digital relay is carried out. The proposed scheme has significant advantages over more traditional relaying algorithms. It is suitable for high resistance faults and is not affected by the inception angle nor by the location of fault.

scholarly journals Automated power management strategy for wind power generation system using pitch angle controller

2019 ◽  
Vol 52 (3-4) ◽  
pp. 169-182 ◽  
Author(s):  
R Sitharthan ◽  
CK Sundarabalan ◽  
KR Devabalaji ◽  
T Yuvaraj ◽  
A Mohamed Imran
Keyword(s):  
Power Generation ◽  
Wind Power ◽  
Power Management ◽  
Control Strategy ◽  
Pitch Angle ◽  
Reactive Power ◽  
Research Work ◽  
Wind Power Generation ◽  
Generation System ◽  
Power Generation System

In this literature, a new automated control strategy has been developed to manage the power supply from the wind power generation system to the load. The main objective of this research work is to develop a fuzzy logic–based pitch angle control and to develop a static transfer switch to make power balance between the wind power generation system and the loads. The power management control system is a progression of logic expressions, designed based on generating power and load power requirement. The outcome of this work targets at an improved power production, active and reactive power compensation and ensures system load constraints. To validate the proposed control strategy, a detailed simulation study is carried out on a 9-MW wind farm simulation simulated in MATLAB/Simulink environment.

scholarly journals A Fast Protection Scheme for TCSC Compensated Transmission Line Using Wavelet-Alienation-Neural Technique

2021 ◽  
Author(s):  
Bhuvnesh Rathore ◽  
Amit Gangwar ◽  
Om Prakash Mahela ◽  
baseem khan ◽  
Sanjeevikumar *Padmanaban
Keyword(s):  
Cycle Time ◽  
Power Flow ◽  
Fault Location ◽  
Fault Current ◽  
Protection Scheme ◽  
Fault Resistance ◽  
Security Algorithm ◽  
Artificial Neural Network Ann ◽  
Thyristor Controlled Series Compensator ◽  
Frequency Power

This paper proposes a security algorithm based on thewavelet-alienation-neural technique for detecting, classifying, and locating faults on Thyristor-Controlled Series compensator (TCSC) compensated lines. A fault index has been calculated using wavelet transform and alienation coefficients with post-fault current signals measured/ sampled for quarter cycle time at both near and far end buses for fault detection and classification. The location of the fault is predicted using an Artificial Neural Network (ANN) after the fault has been diagnosed. Approximate coefficients (quarter cycle time) of both voltage and current signals, from both buses, were provided as input to ANN. Various case studies, such as variations in TCSC position, fault location, sampling frequency, power flow path, incipient angle of fault, TCSC control strategy, fault resistance, and load switching conditions, have verified the robustness of the proposed safety system.

Remaining Local Buckling Resistance of Corroded Pipelines

2010 ◽  
Author(s):  
Qishi Chen ◽  
Heng Aik Khoo ◽  
Roger Cheng ◽  
Joe Zhou
Keyword(s):  
Finite Element ◽  
Wall Thickness ◽  
Phase 1 ◽  
Compressive Strain ◽  
Research Work ◽  
Local Buckling ◽  
Model Verification ◽  
Metal Loss ◽  
General Corrosion ◽  
Buckling Resistance

This paper describes a multi-year PRCI research program that investigated the local buckling (or wrinkling) of onshore pipelines with metal-loss corrosion. The dependence of local buckling resistance on wall thickness suggests that metal-loss defects will considerably reduce such resistance. Due to the lack of experimental data, overly conservative assumptions such as a uniform wall thickness reduction over the entire pipe circumference based on the defect depth have been used in practice. The objective of this research work was to develop local buckling criteria for pipelines with corrosion defects. The work related to local buckling was carried out in three phases by C-FER and the University of Alberta. The first phase included a comprehensive finite element analysis to evaluate the influence of various corrosion defect features and to rank key parameters. Based on the outcome of Phase 1 work, a test matrix was developed and ten full-scale tests were carried out in Phase 2 to collect data for model verification. In Phase 3, over 150 parametric cases were analyzed using finite element models to develop assessment criteria for maximum moment and compressive strain limit. Each criterion includes a set of partial safety factors that were calibrated to meet target reliabilities selected based on recent research related to pipeline code development. The proposed criteria were applied to in-service pipeline examples with general corrosion features to estimate the remaining load-carrying capacity and to assess the conservatism of current practice.

Density Observations from a Full-Scale, Untrafficked Test Section with Guidance for Dryback Methods

2017 ◽  
Vol 2630 (1) ◽  
pp. 134-146 ◽  
Author(s):  
Braden T. Smith ◽  
Robert A. Moore ◽  
Isaac L. Howard
Keyword(s):  
Test Section ◽  
Construction Projects ◽  
Phase 1 ◽  
Research Work ◽  
Density Measurement ◽  
Performance Testing ◽  
Extended Period ◽  
Average Error ◽  
New Construction ◽  
Two Phases

This paper presents a discussion with data on factors related to the in-place density measurement of asphalt pavements. A review of the literature traces changes to asphalt density measurement technologies over the past 60 years. Two phases of investigation then are presented in which in-place density was evaluated for an ongoing study of environmental effects at a test section in Columbus, Mississippi. A series of laboratory and field activities was performed in Phase 1. In Phase 2, studies were made of laboratory drying practices of specimens that were cored after an extended period of field aging. The key conclusion from these efforts was that ASTM D7227 might not remove sufficient moisture from some specimens to achieve accurate density measurement when pavements have been exposed to moisture for extended periods of time. This paper presents a case with an average error in air void measurement of 0.9% (measured 9.1% when 10% was correct) for specimens that were cored, dried according to ASTM D7227, and then measured for mass in air 1 day later. This finding is of most concern to rehabilitation and research work in areas in which aggregates have high potential for absorption but is of no concern to new construction projects. Furthermore, the work presented here validated the use of ASTM D7227 in circumstances in which mixtures were exposed to moisture for short periods of time. The work also suggested three options to take to accurately measure in-place density for performance testing of aged pavements that contain high-absorption aggregates (i.e., dry in oven, develop correlation equations, or dry for several weeks).

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