Gap Analysis on MEES Execution

2021 ◽  
Author(s):  
Kamaljit Singh ◽  
Raju Paul ◽  
Faris Kamal ◽  
Ousama Takeiddine

Abstract Main Electrical Equipment Supplier (MEES) concept has been adopted on mega projects to facilitate overall electrical power system integration and standardization of items/systems within an EPC package as well as across multiple EPC packages and to avoid interface issues. A gap analysis has been performed in this paper based on experience on recent projects and recommendations are proposed as mitigation measures which will benefit Clients, Suppliers as well as FEED/EPC CONTRACTORs. Challenges faced during execution are categorized based on type as well as execution stages. Paper focusses on the major items to be defined as part of the frame agreement during MEES selection to minimize conflicts and issues later on. MEES package pricing (including material, non-material items and services) is done based on agreed Price Book. Gaps are identified as part of this paper including the methodology for change management. Scope limitation is also discussed in detail with clear objective of minimal risk to all stakeholders. Timing and responsibility of MEES selection, that is critical on mega projects with multiple packages, has also been analyzed. Concept of MEES is highly recommended on projects that have complex electrical power system, projects involving multiple EPC CONTRACTORs and also on the projects that are fast track in nature. It has been observed that most projects these days fall into one of these two categories which makes this paper even more relevant. However, execution of MEES package has vast scope for improvement. As part of MEES selection, the following shall be agreed and established, as a minimum: Selected make & model list of all the components along with the unit rates as part of MEES frame agreement that acceptable on project. Price book including all the main equipment envisaged on the project fully complying with project requirements. Comprehensive technical deviations acceptance list as part of MEES frame agreement. Technical compliance certificate indicating Vendor's compliance on the latest revision of Specifications/Data Sheets/ drawings associated with MEES Material Requisition (MR). Price Book should be sufficiently comprehensive without gaps to avoid variations after award. Most common gaps are identified and discussed in detail in the paper. It is highly recommended to select MEES during FEED stage (prior to bidding stage) in order to take advantages in terms of project schedule, change management and overall cost optimization. MEES concept, if managed with recommendations in this paper, can benefit all stakeholders.

1986 ◽  
Author(s):  
R. HINNRICHS ◽  
J. WHITSETT ◽  
R. PHILLIPS ◽  
W. ALLEN ◽  
J. CECKA

Author(s):  
Iyappan Murugesan ◽  
Karpagam Sathish

: This paper presents electrical power system comprises many complex and interrelating elements that are susceptible to the disturbance or electrical fault. The faults in electrical power system transmission line (TL) are detected and classified. But, the existing techniques like artificial neural network (ANN) failed to improve the Fault Detection (FD) performance during transmission and distribution. In order to reduce the power loss rate (PLR), Daubechies Wavelet Transform based Gradient Ascent Deep Neural Learning (DWT-GADNL) Technique is introduced for FDin electrical power sub-station. DWT-GADNL Technique comprises three step, normalization, feature extraction and FD through optimization. Initially sample power TL signal is taken. After that in first step, min-max normalization process is carried out to estimate the various rated values of transmission lines. Then in second step, Daubechies Wavelet Transform (DWT) is employed for decomposition of normalized TLsignal to different components for feature extraction with higher accuracy. Finally in third step, Gradient Ascent Deep Neural Learning is an optimization process for detecting the local maximum (i.e., fault) from the extracted values with help of error function and weight value. When maximum error with low weight value is identified, the fault is detected with lesser time consumption. DWT-GADNL Technique is measured with PLR, feature extraction accuracy (FEA), and fault detection time (FDT). The simulation result shows that DWT-GADNL Technique is able to improve the performance of FEA and reduces FDT and PLR during the transmission and distribution when compared to state-of-the-art works.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2699
Author(s):  
Marceli N. Gonçalves ◽  
Marcelo M. Werneck

Optical Current Transformers (OCTs) and Optical Voltage Transformers (OVTs) are an alternative to the conventional transformers for protection and metering purposes with a much smaller footprint and weight. Their advantages were widely discussed in scientific and technical literature and commercial applications based on the well-known Faraday and Pockels effect. However, the literature is still scarce in studies evaluating the use of optical transformers for power quality purposes, an important issue of power system designed to analyze the various phenomena that cause power quality disturbances. In this paper, we constructed a temperature-independent prototype of an optical voltage transformer based on fiber Bragg grating (FBG) and piezoelectric ceramics (PZT), adequate to be used in field surveys at 13.8 kV distribution lines. The OVT was tested under several disturbances defined in IEEE standards that can occur in the electrical power system, especially short-duration voltage variations such as SAG, SWELL, and INTERRUPTION. The results demonstrated that the proposed OVT presents a dynamic response capable of satisfactorily measuring such disturbances and that it can be used as a power quality monitor for a 13.8 kV distribution system. Test on the proposed system concluded that it was capable to reproduce up to the 41st harmonic without significative distortion and impulsive surges up to 2.5 kHz. As an advantage, when compared with conventional systems to monitor power quality, the prototype can be remote-monitored, and therefore, be installed at strategic locations on distribution lines to be monitored kilometers away, without the need to be electrically powered.


Author(s):  
Diego A. Monroy-Ortiz ◽  
Sergio A. Dorado-Rojas ◽  
Eduardo Mojica-Nava ◽  
Sergio Rivera

Abstract This article presents a comparison between two different methods to perform model reduction of an Electrical Power System (EPS). The first is the well-known Kron Reduction Method (KRM) that is used to remove the interior nodes (also known as internal, passive, or load nodes) of an EPS. This method computes the Schur complement of the primitive admittance matrix of an EPS to obtain a reduced model that preserves the information of the system as seen from to the generation nodes. Since the primitive admittance matrix is equivalent to the Laplacian of a graph that represents the interconnections between the nodes of an EPS, this procedure is also significant from the perspective of graph theory. On the other hand, the second procedure based on Power Transfer Distribution Factors (PTDF) uses approximations of DC power flows to define regions to be reduced within the system. In this study, both techniques were applied to obtain reduced-order models of two test beds: a 14-node IEEE system and the Colombian power system (1116 buses), in order to test scalability. In analyzing the reduction of the test beds, the characteristics of each method were classified and compiled in order to know its advantages depending on the type of application. Finally, it was found that the PTDF technique is more robust in terms of the definition of power transfer in congestion zones, while the KRM method may be more accurate.


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