Showing papers on "Prime mover published in 2007"

Aircraft engine starter/generator and controller

Abstract: An aircraft starting and generating system includes a starter/generator that includes a main machine, an exciter, and a permanent magnet generator. The system also includes an inverter/converter/controller that is connected to the starter/generator and that generates AC power to drive the starter/generator in a start mode for starting a prime mover of the aircraft, and that converts AC power, obtained from the starter/generator after the prime mover have been started, to DC power in a generate mode of the starter/generator. The exciter includes a stator and a rotor, and wherein the exciter rotor includes a three-phase AC winding.

Dual-structured aircraft engine starter/generator

Abstract: An aircraft starting and generating system includes a first starter/main machine assembly that includes a first exciter and a first main machine, and second starter/main machine assembly that includes a second exciter and a second main machine. The system also includes a permanent magnet generator (PMG) that is connected to the first and second starter/main machine assemblies. The system further includes a first inverter/converter/controller (ICC) that is connected to the first starter/main machine assembly and to the PMG, and a second ICC that is connected to the second starter/main machine assembly and to the PMG. The first and second ICCs generate AC power to respective drive the first and second starter/main machine assemblies in a start mode of the starting and generating system for starting a prime mover of the aircraft, and the first and second ICCs convert AC power, respectively obtained from the PMG after the prime mover has been started, to DC power in a generate mode of the starting and generating system.

Measurements of acoustic streaming in a looped-tube thermoacoustic engine with a jet pump

Abstract: This paper reports on the acoustic streaming in a looped-tube thermoacoustic prime mover equipped with an asymmetric constriction called a jet pump. The time-averaged mass flow velocity was determined using visualization methods and using acoustic field measurements. It was demonstrated that the magnitude and the direction of the velocity were dependent on the orientation of the jet pump. From the observed velocities, we estimated the heat carried away from the hot heat exchanger by the mass flow. It was shown that the heat loss was decreased from 30 W to 6.5 W by reversing the orientation of the jet pump, when the input heat power supplied to the prime mover was 100 W. The influence of the acoustic streaming was also studied from the cooling temperature of the looped-tube cooler.

Hydraulic energy recovery system with dual-powered auxiliary hydraulics

Abstract: A power transfer system for a vehicle that comprises a an internal combustion engine, one or more drive wheels, and power transfer apparatus transfers power from the prime mover to the wheels for propelling the vehicle. The system further comprises an auxiliary hydraulic pump that has a drive shaft that coupled to a power take-off unit driven by engine, and to an auxiliary hydraulic motor powered by hydraulic fluid supplied from a hydraulic energy storage device such as an accumulator. As a result, the auxiliary hydraulic pump can be powered by hydraulic fluid from the accumulator when the prime mover is not operating, or by the prime mover when operating. A tandem arrangement of one way clutches can be employed to avoid the need to disconnect the auxiliary hydraulic pump from the prime mover during operation of the auxiliary hydraulic motor, and vice versa.

Hybrid propulsion system and method

Abstract: A hybrid propulsion system includes a prime mover system, a driving system, an energy storage system, a regenerative braking system, and a control system usable to control operation of the prime mover, driving, energy storage, and regenerative braking systems. The control system receives inputs of geographic location, speed, and terrain features, and manages energy discharge and charge operations.

Transmission System for Pump Drive

Abstract: A transmission system for use in a pump system comprising a prime mover driving a pump, the transmission system comprising: an epicylic gear system comprising a sun gear and a ring gear, and a planet gear engaged between the sun gear and ring gear; a main input drive arranged to be driven by the prime mover; an auxiliary input drive arranged to be driven by the prime mover; and an output drive arranged to drive the pump; wherein the main input drive is connected to the sun gear and either (i) the auxiliary input drive is connected to the ring gear and the output drive is lead from the planet gear; or (ii) the auxiliary input drive is connected to the planet gear and the output drive is lead from the ring gear.

Drive system for electrically driven dump truck

Abstract: A drive system for an electrically driven dump truck is capable of enabling electric motors for traveling to make full use of the output horsepower of the prime mover up to an output limit of the prime mover. A target motor horsepower corresponding to an operation amount of an accelerator pedal is calculated and an available maximum horsepower for the electric motors out of the maximum output horsepower of the prime mover is calculated in response to the actual revolution speed of the prime mover. The horsepower coefficient corresponding to the instantaneous revolution speed deviation is calculated. The available maximum horsepower for the electric motors is modified by the horsepower coefficient to determine a second target motor horsepower. The target motor horsepower is limited to not exceed the second target motor horsepower so as to control the torque of the electric motors.

Electric power generation system with multiple alternators driven by a common prime mover

Abstract: An apparatus includes a vehicular electric power generation system comprising a variable speed internal combustion engine, a first variable speed electric power generator driven by the engine, a second variable speed electric power generator driven by the engine, a first inverter to receive electric power from the first generator a provide a first controlled electric output, a second inverter to receive electric power from the second generator and provide a second controlled electric output, and a controller coupled to the engine The controller is responsive to variation in electrical loading of the first inverter and the second inverter and a degree of electrical load imbalance between the first inverter and second inverter to provide one or more engine control signals The engine is responsive to the one more engine control signals to change rotational operating speed to adjust for the variation in electrical loading and the degree of electrical load imbalance

Regenerative breaking system

Abstract: A power transmission system that comprises a prime mover (1), a flywheel (2) and an epicyclic gear set with clutches (4, 9, 10 and 12) by which either the prime mover or the flywheel can be connected co-axially to the input of an infinitely variable transmission (15). The prime mover (1) may be an internal or external combustion engine. The flywheel system may comprise at least one flywheel, and optionally an electrical machine, and optionally a second flywheel which is arranged to rotate in opposite direction to the first flywheel. The transmission may be fitted with the various auxiliaries that are frequently used in vehicles and these auxiliaries may be driven by a shaft from the transmission, even with the vehicle at rest, and with the prime mover stopped. The electrical machine may also be independent of the flywheel, attached and connected to the transmission and auxiliaries via a clutch, and operated by a control system. The flywheel structure may be optionally metallic or composite.

Mixed propulsion system

Abstract: A mixed propulsion system for a seagoing vessel such as a liquid natural gas carrier including a gas turbine engine is described. The vessel has at least one electric propulsion drive and a plurality of prime movers of different types each coupled directly to drive an electrical generator. The outputs of the several generators are connected t at least two electricity distribution switchboards to supply the power requirements of the vessel, and each electric propulsion drive is cross-coupled to receive power selectively from either switchboard such that in the event of a single failure in a switchboard or prime mover or both power can be maintained to both propulsion drives.

Heat-to-electricity thermoacoustic-magnetohydrodynamic conversion

Abstract: A design for the conversion of heat into electricity is proposed. The conversion is based on the combined effects of a thermoacoustic prime mover coupled to a magnetohydrodynamic generator where different working fluids can be optimally chosen for each process. The results of preliminary experiments are presented.

System and method for managing a powertrain in a vehicle

Abstract: A vehicle include a first disconnect disposed between a prime mover of the vehicle and a certain one of the vehicle drive wheels. The first disconnect is operable to connect and disconnect the prime mover to and from the certain one of the drive wheels. A second disconnect is disposed between the powertrain and the certain one of the drive wheels, and is operable to connect and disconnect the certain one of the drive wheels to and from the powertrain when the first disconnect is engaged. A control system and method are configured to control operation of at least the first and second disconnects. Through selective control of the disconnects, the system can be automatically placed in a four-wheel-drive mode based on predetermined criteria, or the desirability of the four-wheel-drive mode can be indicated to the vehicle operator in a passive version of the control system and method.

Fuel life monitor and engine management for plug-in hybrid electric vehicles

Abstract: An engine management system for a hybrid vehicle may include a hybrid vehicle controller that selects a power source to be one of an electric propulsion system and a combustion engine. The hybrid vehicle controller may include an engine operation module configured to determine when operation of the combustion engine is required based on a predetermined set of operating parameters associated with the combustion engine.

A combined cycle system for gas turbines and reciprocating engines and a method for the use of air as working fluid in combined cycle power plants

Abstract: A combined cycle power plant comprising: a first cycle comprising: a prime mover; a prime mover exhaust in fluid communication with the prime mover; a second cycle comprising: a liquid air supply; a heat exchanger in fluid communication with the liquid air supply and the prime over exhaust; a turbo expander in fluid communication with the heat exchanger; wherein liquid air is heated to gaseous air by the heat exchanger, and the gaseous air is expanded in the turbo expander thereby producing work. A liquid air combined cycle method comprising: providing pressurized liquid air; heating the pressurized liquid sir to pressurized gaseous air; expanding the pressurized gaseous air with a turbo expander; using work from the expansion of the pressurized gaseous air to compress ambient air; heating the expanded pressurized gaseous air; and sending the heated expanded air to a turbine combustion chamber.

Experimental observation on a small-scale thermoacoustic prime mover

Abstract: A miniature thermoacoustic prime mover, consuming heat to radiate sound, may be considered as a potential way of heat management in microcircuits because of its simplicity and stability. A prototype with variable resonant tube length of 10 to 25 cm was built, and experiments were carried out to observe its performance, such as onset temperature, oscillation amplitude and operating frequency. The results with atmospheric air showed that proper structures and operating conditions can make the system start an oscillation at a temperature lower than 100 °C, which proves the feasibility of potential usage in electronic units. The influences of stack position, heat input power or tube inclination on the oscillation amplitude, onset temperature and operating frequency are also presented.

The Cause Analysis of Turbine Power Disturbance Inducing Power System Low Frequency Oscillation of Resonance Mechanism

Abstract: Resonance mechanism is one of the theories that interpret power system low frequency oscillation. According to the resonance mechanism, power disturbance of prime mover can arouse power system forced low frequency oscillations. Therefore, the causes of turbine power disturbance were analyzed. The coupling model between thermodynamic system of plant and power system was set up by MATLAB. The possibility of combustion ratio of boiler and control valve of governing system disturbance inducing the variation of turbine power was researched in detail. The simulation results indicate that power system low frequency oscillations of resonance mechanism might be caused by the disturbance of control valve, when it’s frequency is consistent with or close to power system natural oscillations frequency. Because of the biggish inertia of boiler, the disturbance of combustion ratio cannot invoke power system low frequency oscillation of resonance mechanism.

Modulation of sound field in looped-tube thermoacoustic cooling system with membrane

Abstract: A design of the looped-tube thermoacoustic cooling system with an insertion of rubber membrane is proposed. When the membrane to block mass flow due to acoustic streaming is located at a position different from a sound pressure loop, the membrane changes the distribution of the phase difference between pressure and particle velocity. This accompanies the phase difference change in the stack of the prime mover. Since efficient energy conversion is attained when the pressure and particle velocity are in phase, the prime mover of this experiment is shifted to a new in-phase position. Then, collaborating with the enhanced sound intensity due to mass flow blocking, the energy conversion efficiency is significantly enhanced and a high cooling quality is attained.

Electric power generation with magnetically geared machine

Abstract: A power generation system includes: a prime mover; an electrical machine coupled to the prime mover and configured for converting mechanical power to electrical power, the electrical machine having a power factor of less than or equal to 0.7; a reactive power supply assembly coupled to the electrical machine and configured to supply reactive power to the electrical machine; and a power electronic converter coupled to the reactive power supply assembly and configured for transferring power from the electrical machine to a grid.

Generator with quadrature AC excitation

Abstract: A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required.

An empirical analysis of the off-balance sheet activities of Indian banks

Abstract: The article traces the determinants of off-balance sheet activities in the Indian banking sector. Using data for the period 1996 to 2004, the article finds that not only regulatory factors, but also market forces captured by banks-specific characteristics and macro-economic conditions are at work in the diffusion pattern of off-balance sheet (OBS) activities. From the regulatory standpoint, while capital adequacy is dominant in the case of public sector banks, non-performing assets seem to he a prime concern for foreign banks, in addition to public sector banks. Among others, at the bank-specific level, size is an important consideration for public sector and foreign banks, while profits are a prime mover only for new private banks. Finally, the macro-economic environment seems to have played an important role in affecting OBS diffusion, more so for public sector and new private banks.

Voltage and Frequency Regulation of a Stand-Alone Self-Excited Induction Generator

Abstract: This paper discusses the regulation of the voltage and frequency of a stand-alone self-excited squirrel-cage induction generator (SEIG) connected to an unregulated prime mover by means of a single voltage source inverter (VSI) connected in shunt with the stator of the generator A battery bank is used at the dc side of the VSI so that it can deal active and reactive power and affect the frequency and magnitude of the generated voltage The focus of this paper is on the experimental results obtained for a 4-pole 2 HP SEIG with an unregulated prime- mover with a linear torque versus speed characteristic typical of impulse type hydro turbines It shows that active and reactive power control yields a better voltage and frequency regulation to load variations than reactive power alone

Analysis of asymmetrical shaft power increase during tight manoeuvres

Abstract: In the present work the phenomenon of asymmetrical shaft power increase during tight maneuvers is investigated by means of the analysis of turning circle maneuvers at different speeds and rudder angles performed during sea trials for a series of twin screw naval ships; this analysis has allowed to underline a common trend for asymmetrical shaft power increase despite significant differences in ships considered; possible reasons for this shaft power increase have been examined, and data about an asymmetrical variation of wake fraction during maneuvers are reported, showing again a common trend but with larger scatter of data. In this view, a first investigation about the possibility of performing dedicated free running model tests and scaling their results to full scale, in order to improve prediction accuracy for a specific ship in preliminary design phases, has been carried out. It is believed that, for unconventional propulsion plant arrangements, in which for instance two shaft axes are powered by the same prime mover via a unique reduction gear, automation plant will need to monitor carefully these effects, in order to avoid possible problems.

Vibration control of free piston machine through frequency adjustment

Abstract: A method and apparatus for minimizing the amplitude of mechanical vibrations of a mechanical apparatus including a linear, freely reciprocating, prime mover coupled to and driving a reciprocating mass of a driven machine in reciprocation at a driving frequency. The coupled prime mover and driven machine have a spring applying a force upon the reciprocating mass to form a resonant main system having a main system resonant frequency of reciprocation. A driving frequency range over which the driven machine operates at an acceptable efficiency of operation is determined and stored. A parameter of the operation of the mechanical apparatus, such as the amplitude of vibrations or an operating temperature, is sensed and the prime mover is driven in response to the sensed parameter at a driving frequency that is offset from the main system resonant frequency of reciprocation, is within the driving frequency range of acceptable efficiency of operation and reduces or minimizes the amplitude of mechanical vibration of the mechanical apparatus under existing operating conditions.

Non-inverter based distributed energy resource for use in a dynamic distribution system

Abstract: A microsource is provided, which includes a generator, a prime mover, and a controller. The prime mover includes a shaft connected to drive the generator to generate power at a frequency controlled by a rotation rate of the shaft. The controller calculates an operating frequency for the generator based on a comparison between a power set point and a measured power flow. A requested shaft speed for the prime mover is calculated by combining a maximum frequency change, a minimum frequency change, and the calculated operating frequency. A shaft speed adjustment is calculated for the prime mover based on a comparison between the requested shaft speed and a measured shaft speed of the prime mover. A fuel command for the prime mover is calculated based on the shaft speed adjustment. A rotation rate of the shaft of the prime mover is adjusted based on the calculated fuel command to control the frequency.

Application of Battery Energy Operated System to Isolated Power Distribution Systems

Abstract: This paper deals with model of battery energy operated system for a 425kVA DG set using Simulink and Power System Block-set in MATLAB environment Battery Energy Storage System (BESS) is employed for compensation along with a small synchronous generator of 425kVA capacity coupled to a diesel engine as a prime mover The DG set feeds a wide variety of loads The performance of the system is simulated for linear, non-linear balanced and unbalanced loads Simulation results justify enhanced power quality of the system with BESS application

Multifunction integrated portable power and utility apparatus

Abstract: An integrated multi-function, portable power and utility apparatus having a single prime mover device having a single engine device having at least two opposite extending rotary output devices wherein the engine device turns one output device clockwise and the other counterclockwise without belts, pulleys, chains or gears. An electric generator device is directly connected to one of the two rotary output devices and has a plurality of electric output devices. A fluid pumping device is directly connected to the other rotary output device. The fluid pumping device is preferably a rotary screw-type air compressor.

Power Systems and Methods Using an Induction Generator in Cooperation with an Uninterruptible Power Supply

Abstract: A power system includes a load bus configured to be connected to a power source, a generator and an uninterruptible power supply (UPS). The generator is operated as an induction generator to provide power to the load bus while providing reactive power to the load bus from the UPS. In some embodiments, prior to operating the generator as an induction generator, the generator is operated as an induction motor while the load bus is receiving power from the power source. Responsive to loss of the power source, the UPS may be used to maintain operation of the generator as an induction motor while the prime mover accelerates up to a speed sufficient to drive the generator as an induction generator.

Modelling and Analysis of Electro-Mechanical Interactions between Prime-Mover and Load in a Marine IFEP System

Abstract: This paper reports on the simulation of a marine Integrated Electric Full Electric Propulsion (IFEP) system to assess its ability to absorb variations in propulsion or auxiliary load without excessive degradation of the electrical supply quality or imposing excessive demands on the prime movers. IFEP systems are expected to yield economic benefits to ship operators by permitting the capacity of ship engines in use to be more closely tailored to the electrical demand of auxiliary and propulsion systems. However, the extent to which these savings can be realised at times of low demand is dependent on the ability of the shipboard electrical system to absorb disturbances. In this paper, simulations are conducted for a variety of frequencies of load variation, and the results assessed. Measures which might be taken to reduce the observed effects are suggested.