scholarly journals A Performance Comparison of Aero-Derivative Gas Turbines and Electric Variable Speed Drives in Pipeline Compressor Duty on TransCanada’s Canadian Mainline

2000 ◽  
Author(s):  
Robert Betts ◽  
Guenther Duchon ◽  
David L. Williams
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
High Speed ◽  
Performance Comparison ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Natural Gas Transmission ◽  
Industrial Gas Turbines ◽  
Power Utilities ◽  
Drive Systems

Since the early 1960’s, the use of aero-derivative and industrial gas turbines on TransCanada’s natural gas transmission system has been the norm, with a total of 245 units installed to date. In 1996 and 1997 the company installed six high-speed, 30.6 MW, variable speed, electric drive systems. In the same time period eight aero-derivative gas turbines of similar power, with Dry Low Emissions, were installed. After an elapse of three years running time we now have enough data to compare the performance of the two different compressor drivers. A comparison of the performance of the two prime movers is made in a number of different ways. Operation and maintenance costs of the two different systems are considered, including the fuel costs of the natural gas and electricity, from three different Canadian electric power utilities.

scholarly journals Gas Turbine Driving Reciprocating Compressors Experience in Natural Gas Applications

1992 ◽  
Author(s):  
E. Giacomelli ◽  
P. Petrini ◽  
A. Montelatici ◽  
M. Desolati
Keyword(s):  
Natural Gas ◽  
Pollution Control ◽  
Gas Turbines ◽  
Capital Investment ◽  
Load Test ◽  
Monitoring Systems ◽  
Variable Speed ◽  
Special Design ◽  
Variable Speed Drives ◽  
Design Procedures

The flexibility of reciprocating compressors combined with the utilization of variable speed drives like gas turbines optimizes operating and capital investment costs in natural gas services. Reliability and respect for limits specified in pollution control regulations are the most significant requirements related to modern compression stations. Equipped with monitoring systems, the trains must benefit by special design procedures and modern full-load test facilities to ensure the complete confidence of users. The above features, together with energy saving advantages, make it possible to forecast the increasing application of compressor - turbine arrangements.

The Respective Merit of Gas Turbine vs Electric Drive for Pipeline Turbocompressors

2004 ◽  
Author(s):  
Klaus Jordan ◽  
Peter Walter ◽  
Axel Emde ◽  
Christoph Comberg
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Electric Drive ◽  
Gas Turbines ◽  
High Speed ◽  
Gas Pipeline ◽  
Natural Gas Pipeline ◽  
Emission Regulations ◽  
Drive Systems ◽  
And Storage

The paper briefly reviews the technology, gas turbine versus high speed electric drive, which represents two very different solutions for natural gas pipeline or storage compressor drive applications. The technical and economic merits of the competing drive systems have to be considered for each individual project. Traditionally, gas turbines have been the prime drivers for compressor trains, especially in Europe whereas in North America gas engine driven reciprocating compressors are also very common. With the liberalization of the electric power market and tighter environmental restrictions regarding local emissions, high frequency electric motor drivers became a competitive alternative profiting by decreased costs for the electricity infrastructure and the power supply, thus lowering the investment and operational costs. Gas turbines in compliance with the latest emission regulations will maintain their predominant role in natural gas pipeline and storage applications, especially in non-residential and remote areas.

Fundamentals of Solid-State AC Variable-Speed Drives

1969 ◽  
Vol 6 (01) ◽  
pp. 76-82
Author(s):  
Donald L. Schoen
Keyword(s):  
Solid State ◽  
High Performance ◽  
Practical Implementation ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Ac Drive ◽  
Ac Motor ◽  
Economic Trends ◽  
History Of ◽  
Drive Systems

Solid-state ac variable-frequency drives offer a new generation of high-performance, maintenance-free drive systems. The desire to use the rugged ac motor as a high-performance, variable-speed device goes back many years; however, its practical implementation had to wait three-quarters of a century for development of the silicon controlled rectifier. This paper opens with a brief review of the history of variable-speed dc and ac drive systems. Then the fundamentals of solid-state ac variable-speed drives are presented with emphasis on future technical and economic trends. The ac system is evaluated as an economic solution to providing basic functional drive requirements. The characteristics are compared with traditional high-performance dc systems. Finally, an attempt is made to describe the solid-state ac variable-speed drive of the future.

Investigation of Hydrogen Enriched Natural Gas Flames in a SGT-700/800 Burner Using OH PLIF and Chemiluminescence Imaging

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Andreas Lantz ◽  
Robert Collin ◽  
Marcus Aldén ◽  
Annika Lindholm ◽  
Jenny Larfeldt ◽  
...  
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Flame Front ◽  
Gas Turbines ◽  
Dynamic Pressure ◽  
Pressure Fluctuations ◽  
Burner Exit ◽  
Planar Laser ◽  
Industrial Gas Turbines ◽  
Dynamic Pressure Measurements

The effect of hydrogen enrichment to natural gas flames was experimentally investigated at atmospheric pressure conditions using flame chemiluminescence imaging, planar laser-induced fluorescence of hydroxyl radicals (OH PLIF), and dynamic pressure monitoring. The experiments were performed using a third generation dry low emission (DLE) burner used in both SGT-700 and SGT-800 industrial gas turbines from Siemens. The burner was mounted in an atmospheric combustion test rig at Siemens with optical access in the flame region. Four different hydrogen enriched natural gas flames were investigated; 0 vol. %, 30 vol. %, 60 vol. %, and 80 vol. % of hydrogen. The results from flame chemiluminescence imaging and OH PLIF show that the size and shape of the flame was clearly affected by hydrogen addition. The flame becomes shorter and narrower when the amount of hydrogen is increased. For the 60 vol. % and 80 vol. % hydrogen flames the flame has moved upstream and the central recirculation zone that anchors the flame has moved upstream the burner exit. Furthermore, the position of the flame front fluctuated more for the full premixed flame with only natural gas as fuel than for the hydrogen enriched flames. Measurements of pressure drop over the burner show an increase with increased hydrogen in the natural gas despite same air flow thus confirming the observation that the flame front moves upstream toward the burner exit and thereby increasing the blockage of the exit. Dynamic pressure measurements in the combustion chamber wall confirms that small amounts of hydrogen in natural gas changes the amplitude of the dynamic pressure fluctuations and initially dampens the axial mode but at higher levels of hydrogen an enhancement of a transversal mode in the combustion chamber at higher frequencies could occur.

High-Speed Spectrally Resolved Imaging Studies of Spherically Expanding Natural Gas Flames Under Gas Turbine Operating Conditions

2019 ◽  
Author(s):  
Pradeep Parajuli ◽  
Tyler Paschal ◽  
Mattias A. Turner ◽  
Eric L. Petersen ◽  
Waruna D. Kulatilaka
Keyword(s):  
Natural Gas ◽  
Flame Front ◽  
Gas Turbines ◽  
High Speed ◽  
Laminar Flame ◽  
Turbulent Flame ◽  
Initial Pressure ◽  
Flame Speed ◽  
Operating Conditions ◽  
Important Species

Abstract Natural gas is a major fuel source for many industrial and power-generation applications. The primary constituent of natural gas is methane (CH4), while smaller quantities of higher order hydrocarbons such as ethane (C2H6) and propane (C3H8) can also be present. Detailed understanding of natural gas combustion is important to obtain the highest possible combustion efficiency with minimal environmental impact in devices such as gas turbines and industrial furnaces. For a better understanding the combustion performance of natural gas, several important parameters to study are the flame temperature, heat release zone, flame front evolution, and laminar flame speed as a function of flame equivalence ratio. Spectrally and temporally resolved, high-speed chemiluminescence imaging can provide direct measurements of some of these parameters under controlled laboratory conditions. A series of experiments were performed on premixed methane/ethane-air flames at different equivalence ratios inside a closed flame speed vessel that allows the direct observation of the spherically expanding flame front. The vessel was filled with the mixtures of CH4 and C2H6 along with respective partial pressures of O2 and N2, to obtain the desired equivalence ratios at 1 atm initial pressure. A high-speed camera coupled with an image intensifier system was used to capture the chemiluminescence emitted by the excited hydroxyl (OH*) and methylidyne (CH*) radicals, which are two of the most important species present in the natural gas flames. The calculated laminar flame speeds for an 80/20 methane/ethane blend based on high-speed chemiluminescence images agreed well with the previously conducted Z-type schlieren imaging-based measurements. A high-pressure test, conducted at 5 atm initial pressure, produced wrinkles in the flame and decreased flame propagation rate. In comparison to the spherically expanding laminar flames, subsequent turbulent flame studies showed the sporadic nature of the flame resulting from multiple flame fronts that were evolved discontinuously and independently with the time. This paper documents some of the first results of quantitative spherical flame speed experiments using high-speed chemiluminescence imaging.

scholarly journals Analysis and performance evaluation of a three-phase sparse neutral point clamped converter for industrial variable speed drives

2021 ◽  
Author(s):  
Davide Cittanti ◽  
Mattia Guacci ◽  
Spasoje Mirić ◽  
Radu Bojoi ◽  
Johann Walter Kolar
Keyword(s):  
Degrees Of Freedom ◽  
Performance Comparison ◽  
Neutral Point ◽  
Modulation Scheme ◽  
Phase System ◽  
Variable Speed ◽  
Variable Speed Drives ◽  
Chip Area ◽  
Three Phase ◽  
Clamped Converter

Abstract This paper analyzes the operation and characterizes the performance of a three-phase three-level (3-L) Sparse Neutral Point Clamped converter (SNPCC) for industrial variable speed drives (VSDs). The operating principle of the SNPCC, which advantageously employs a lower number of power transistors than a conventional 3-L inverter, is described in detail, focusing on the AC-side differential-mode and common-mode voltage formation and on the DC-side mid-point current generation processes. The degrees of freedom in the SNPCC modulation scheme are defined and several switching sequences are investigated. Afterwards, the stresses on the active and passive components (e.g. semiconductor losses, machine phase current ripple, DC-link capacitor RMS current, etc.) are calculated by analytical and/or numerical means, enabling a straightforward performance comparison among the identified switching sequences. The most suited modulation strategy for VSD applications is then selected and a chip area sizing procedure, aimed at minimizing the total semiconductor chip size, is applied to a 800V 7.5kW three-phase system. The performance limits of the designed SNPCC are evaluated and finally compared to the ones of conventional 2-L and 3-L solutions, highlighting the promising cost/performance trade-off of the analyzed topology.

scholarly journals MODELING THYRISTOR TRANSDUCERS IN MATLAB ENVIRONMENT TAKING INTO ACCOUNT THE PECULIARITIES OF THEIR IMPLEMENTATION

2020 ◽  
pp. 150-165
Author(s):  
Andrey P. Chervonenko ◽  
Denis A. Kotin
Keyword(s):  
Electric Drive ◽  
Simulation Models ◽  
Power Converter ◽  
Synthesis Methods ◽  
Variable Speed ◽  
Digital Models ◽  
Variable Speed Drives ◽  
Electric Drives ◽  
Semiconductor Converters ◽  
Drive Systems

The authors present the study of synthesis methods for simulating the models of semiconductor rectifiers. Simulation of semiconductor rectifiers is quite studied today, but many authors carry out synthesis in their own unique way. The need to apply high technologies in variable speed drives with the development of mechanisms and working machines is growing, the automated variable speed drive is being introduced increasingly, making the energy substrate for aggregates and working machines. The relevance of this work is explained by the fact that currently developing technologies make it possible to manufacture more advanced semiconductor elements. The more relevant and significant is the study of refined digital models of electric drives containing semiconductor converters. This paper will summarize known approaches to the development of rectifiers’ digital models, as well as it will offer the authors’ own vision of this issue – taking into account as many individual features of semiconductor elements and the entire electric drive system as a whole as possible. The option proposed for consideration differs in that when developing in Matlab environment the parameters of real existing power elements and their digital analogues are consistent. The article also examines the issue of creating a digital model of the electric drive reverse system including a thyristor transducer and an engine; the transition characteristics of the refined model are illustrated. The result of this study is the analysis of different approaches to modeling semiconductor converters in electric drive systems. In this regard, a refined approach to modeling semiconductor rectifiers was considered, consisting of maximizing approximation of the model structure to real implementation, taking into account all elements, included in the structure of the ventilated electric drive. The study suggests that the developed simulation models can be used for the design of a real power converter in the conditions of a production enterprise.

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