Magnetic Bearing Design for Reduced Power Consumption

1996 ◽  
Vol 118 (4) ◽  
pp. 839-846 ◽  
Author(s):  
E. H. Maslen ◽  
P. E. Allaire ◽  
M. D. Noh ◽  
C. K. Sortore
Keyword(s):  
Power Consumption ◽  
Permanent Magnet ◽  
Gas Turbines ◽  
Load Capacity ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Fluid Film ◽  
Total Power ◽  
Total Power Consumption ◽  
Bearing Design

Magnetic bearings have relatively low power consumption compared to fluid film and rolling element bearings. They are now candidates for supporting gas turbines and aeropropulsion engines. This paper describes the design and construction of permanent magnet biased, actively controlled magnetic bearings for a flexible rotor. The rotor was originally supported in fluid film bearings consuming as much as 3000 watts of power. For the magnetic bearing, both permanent magnets and electromagnets are used in a configuration which effectively provides the necessary fluxes in the appropriate air gaps to support the rotor. The theoretical development related to the bearing design is presented along with some experimental performance results. The results include measurements of power consumption, load capacity, bearing linearized coefficients, and the dynamic response of the rotor. The measured total power consumption, excluding shaft losses, was 210 watts in the permanent magnet biased bearing.

scholarly journals Efficient Operation Method of Aquifer Thermal Energy Storage System Using Demand Response

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3129
Author(s):  
Jewon Oh ◽  
Daisuke Sumiyoshi ◽  
Masatoshi Nishioka ◽  
Hyunbae Kim
Keyword(s):  
Energy Storage ◽  
Power Consumption ◽  
Thermal Energy ◽  
Demand Response ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Storage System ◽  
Total Power ◽  
Operation Method ◽  
Total Power Consumption

The mass introduction of renewable energy is essential to reduce carbon dioxide emissions. We examined an operation method that combines the surplus energy of photovoltaic power generation using demand response (DR), which recognizes the balance between power supply and demand, with an aquifer heat storage system. In the case that predicts the occurrence of DR and performs DR storage and heat dissipation operation, the result was an operation that can suppress daytime power consumption without increasing total power consumption. Case 1-2, which performs nighttime heat storage operation for about 6 h, has become an operation that suppresses daytime power consumption by more than 60%. Furthermore, the increase in total power consumption was suppressed by combining DR heat storage operation. The long night heat storage operation did not use up the heat storage amount. Therefore, it is recommended to the heat storage operation at night as much as possible before DR occurs. In the target area of this study, the underground temperature was 19.1 °C, the room temperature during cooling was about 25 °C and groundwater could be used as the heat source. The aquifer thermal energy storage (ATES) system in this study uses three wells, and consists of a well that pumps groundwater, a heat storage well that stores heat and a well that used heat and then returns it. Care must be taken using such an operation method depending on the layer configuration.

scholarly journals A Novel Differential Log-Companding Amplifier for Biosignal Sensing

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zigang Dong ◽  
Xiaolin Zhou ◽  
Yuanting Zhang
Keyword(s):  
Power Consumption ◽  
Supply Voltage ◽  
Nonlinear Function ◽  
New Method ◽  
Total Power ◽  
Maximum Output ◽  
Output Current ◽  
Current Range ◽  
Symmetrical Configuration ◽  
Total Power Consumption

We proposed a new method for designing the CMOS differential log-companding amplifier which achieves significant improvements in linearity, common-mode rejection ratio (CMRR), and output range. With the new nonlinear function used in the log-companding technology, this proposed amplifier has a very small total harmonic distortion (THD) and simultaneously a wide output current range. Furthermore, a differential structure with conventionally symmetrical configuration has been adopted in this novel method in order to obtain a high CMRR. Because all transistors in this amplifier operate in the weak inversion, the supply voltage and the total power consumption are significantly reduced. The novel log-companding amplifier was designed using a 0.18 μm CMOS technology. Improvements in THD, output current range, noise, and CMRR are verified using simulation data. The proposed amplifier operates from a 0.8 V supply voltage, shows a 6.3 μA maximum output current range, and has a 6 μW power consumption. The THD is less than 0.03%, the CMRR of this circuit is 74 dB, and the input referred current noise density is166.1 fA/Hz. This new method is suitable for biomedical applications such as electrocardiogram (ECG) signal acquisition.

Exergy Analysis of a Novel Cryogenic Concept for the Liquefaction of Natural Gas Integrated Into an Air Separation Process

2016 ◽  
Author(s):  
S. Tesch ◽  
T. Morosuk ◽  
G. Tsatsaronis
Keyword(s):  
Natural Gas ◽  
Power Consumption ◽  
Exergy Analysis ◽  
Primary Energy ◽  
Separation Process ◽  
Air Separation ◽  
Total Power ◽  
Separation Unit ◽  
Total Power Consumption ◽  
Liquefaction Temperature

The increasing demand for primary energy leads to a growing market of natural gas and the associated market for liquefied natural gas (LNG) increases, too. The liquefaction of natural gas is an energy- and cost-intensive process. After exploration, natural gas, is pretreated and cooled to the liquefaction temperature of around −160°C. In this paper, a novel concept for the integration of the liquefaction of natural gas into an air separation process is introduced. The system is evaluated from the energetic and exergetic points of view. Additionally, an advanced exergy analysis is conducted. The analysis of the concepts shows the effect of important parameters regarding the maximum amount of liquefiable of natural gas and the total power consumption. Comparing the different cases, the amount of LNG production could be increased by two thirds, while the power consumption is doubled. The results of the exergy analysis show, that the introduction of the liquefaction of natural gas has a positive effect on the exergetic efficiency of a convetional air separation unit, which increases from 38% to 49%.

scholarly journals Optimization of Power Consumption for the Design of 802.11n MIMO_OFDM System

2018 ◽  
Vol 26 (4) ◽  
pp. 172-184
Author(s):  
Muthna Jasim Fadhil
Keyword(s):  
Power Consumption ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Mimo Systems ◽  
Total Power ◽  
Wireless System ◽  
Generator System ◽  
Total Power Consumption ◽  
Consumption Energy ◽  
High Reduction

In modern systems communication, different methods have been improved to change the prior imitative techniques that process communication data with high speed. It is necessary to improve (OFDM) Orthogonal Frequency Division Multiplexing technique because the development in the guideline communication of wireless system which include security data and transmission data reliability. The applications communications of wireless is important to develop in order to optimize the process of communication leads to reduce the level consumption energy of the output level signal. The architecture of VLSI is used to optimize the performance transceiver in 802.11 n OFDM-MIMO systems, this idea concentrate on the design of 6x6 MIMO_OFDM system in software simulink of MATLAB then using generator system for transfer to code of VHDL and applying in FPGA Xilinx Spartan 3 XC3S200 . The modelsim used to get the simulation while Xilinx power estimator is used to calculate power. The results registered total power consumption about 94mW while compared with previous work  was 136mW which means a high reduction of about 30.8% .

scholarly journals Development and Experimental Validation of Auxiliary Rolling Bearing Models for Active Magnetic Bearings (AMBs) Applications

2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Anna Tangredi ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Alessandro Ridolfi ◽  
Pierluca D’Adamio ◽  
...  
Keyword(s):  
Load Capacity ◽  
Critical Phenomenon ◽  
Magnetic Bearing ◽  
Design Tool ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Active Magnetic Bearings ◽  
Short Period ◽  
Auxiliary Bearing ◽  
Bearing System

Nowadays, the search for increasing performances in turbomachinery applications has led to a growing utilization of active magnetic bearings (AMBs), which can bring a series of advantages thanks to their features: AMBs allow the machine components to reach higher peripheral speeds; in fact there are no wear and lubrication problems as the contact between bearing surfaces is absent. Furthermore, AMBs characteristic parameters can be controlled via software, optimizing machine dynamics performances. However, active magnetic bearings present some peculiarities, as they have lower load capacity than the most commonly used rolling and hydrodynamic bearings, and they need an energy source; for these reasons, in case of AMBs overload or breakdown, an auxiliary bearing system is required to support the rotor during such landing events. During the turbomachine design process, it is fundamental to appropriately choose the auxiliary bearing type and characteristics, because such components have to resist to the rotor impact; so, a supporting design tool based on accurate and efficient models of auxiliary bearings is very useful for the design integration of the Active Magnetic Bearing System into the machine. This paper presents an innovative model to accurately describe the mechanical behavior of a complete rotor-dynamic system composed of a rotor equipped with two auxiliary rolling bearings. The model, developed and experimentally validated in collaboration with Baker Hughes a GE company (providing the test case and the experimental data), is able to reproduce the key physical phenomena experimentally observed; in particular, the most critical phenomenon noted during repeated experimental combined landing tests is the rotor forward whirl, which occurs in case of high friction conditions and greatly influences the whole system behavior. In order to carefully study some special phenomena like rotor coast down on landing bearings (which requires long period of time to evolve and involves many bodies and degrees of freedom) or other particular events like impacts (which occur in a short period of time), a compromise between accuracy of the results and numerical efficiency has been pursued. Some of the elements of the proposed model have been previously introduced in literature; however the present work proposes some new features of interest. For example, the lateral and the axial models have been properly coupled in order to correctly reproduce the effects observed during the experimental tests and a very important system element, the landing bearing compliant suspension, has been properly modelled to more accurately describe its elastic and damping effects on the system. Furthermore, the model is also useful to characterize the frequencies related to the rotor forward whirl motion.

Forecasting Electricity Demand of Shanghai Based on Power Consumption Intensity Decomposition

2011 ◽  
Vol 347-353 ◽  
pp. 2796-2800
Author(s):  
Ying Ling Shi ◽  
Mei Peng
Keyword(s):  
Power Consumption ◽  
Industrial Structure ◽  
Electricity Demand ◽  
Total Power ◽  
Decomposition Model ◽  
Total Power Consumption ◽  
Consumption Intensity

The paper describes the development of economy and electricity in Shanghai, builds a decomposition model of power consumption intensity, and analyzes the impacts of industrial power consumption intensity and industrial structure for the total power consumption intensity of Shanghai. Finally, the paper uses sub-scenarios to forecast electricity demand of Shanghai during Twelfth Five-Year period. The results show that the decrease of total power consumption intensity is mainly due to the decrease of industrial power consumption intensity, and the optimization of industrial structure has some contributions to the decrease of total power consumption as well.

Construction of a Carbon Fiber Reinforced Weft Guide Bar for a Crochet Knitting Machine

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Mathias Beer ◽  
Yves-Simon Gloy ◽  
Mohit Raina ◽  
Thomas Gries
Keyword(s):  
Carbon Fiber ◽  
Power Consumption ◽  
Total Power ◽  
Fiber Reinforced ◽  
Reduce Power Consumption ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Total Power Consumption ◽  
Fiber Reinforced Plastics ◽  
Carbon Fiber Reinforced

The crochet knitting machine is a warp knitting machine with a weft insertion system placed on a weft guide bar. On standard machines, the weft guide bar is made from aluminum and weighs about 570 g. The single-drive motors, which power the bar, account for 15–20% of the machines total power consumption. The aim of this research was to reduce power consumption by decreasing the mass of the weft guide bar. This was done by constructing the bar from carbon fiber reinforced plastics rather than aluminum, resulting in a mass saving of 260 g.

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