Showing papers on "Prime mover published in 1994"

Power System Stability and Control

Abstract: Part I: Characteristics of Modern Power Systems. Introduction to the Power System Stability Problem. Part II: Synchronous Machine Theory and Modelling. Synchronous Machine Parameters. Synchronous Machine Representation in Stability Studies. AC Transmission. Power System Loads. Excitation in Stability Studies. Prime Mover and Energy Supply Systems. High-Voltage Direct-Current Transmission. Control of Active Power and Reactive Power. Part III: Small Signal Stability. Transient Stability. Voltage Stability. Subsynchronous Machine Representation in Stability Studies. AC Transmission. Power System Loads. Excitation in Stability Studies. Prime Mover and Energy Supply Systems, High-Voltage Direct-Current Transmission. Control of Active Power and Reactive Power. Part III: Small Signal Stability. Transient Stability. Voltage Stability. Subsynchronous Oscillations. Mid-Term and Long-Term Stability. Methods of Improving System Stability.

Dynamics models for combines cycle plants in power system studies

Abstract: This paper is the third of a series of papers prepared by the Working Group on Prime Mover and Energy Supply Models for System Dynamic Performance Studies. It describes various aspects of combined cycles made up of gas turbine, waste heat recovery boiler and steam turbine and develops models designed to simulate the response of the combined cycle plant for use in system dynamic performance studies

Stability curves for a thermoacoustic prime mover

Abstract: The purpose of this paper is to investigate the stability curves of the fundamental and second modes in a helium filled prime mover. The predicted and measured stability limits are in reasonable agreement for both modes at most mean pressures. There is, however, evidence that the stability of one mode is affected by the presence of the other. It is also observed that one mode can suppress the other. Measurements are also reported on a prime mover modified to selectively inhibit the fundamental mode. Results indicate that the reduced fundamental amplitude allows the stability curve for the second mode to extend into the regions where the fundamental mode previously dominated. This produces a region where both modes are simultaneously excited. Analysis of the waveforms show that the resulting oscillations are quasiperiodic.

Improvements in or relating to continuously-variable-ratio transmissions

Abstract: A continuously-variable-ratio transmission ('CVT'), especially of the toroidal-race rolling-traction type, in which the prime mover is connected to the ratio-varying component ('variator') by a torque converter (1) or other starting device capable of slip. The CVT output (36) is connected both to the variator output (23) and also, by way of fixed ratio gearing (37, 38) and a one-way clutch (53), to the output of the starting device. At low speeds drive is transmitted from primer mover to the CVT output by way of the fixed ratio gearing in both forwards and reverse. In forward drive, as the speed of the variator output rises, operation of the one-way clutch (53) causes the drive transmission path to change from the fixed ratio gearing to the variator output once the speed of the latter exceeds the former. Where the variator is of the toroidal-race type, further one-way clutch means (54) may be included to ensure that the fixed ratio gearing components can rotate in one direction only, thus preventing them from imposing reverse rotation upon the essentially unidirectional variator components.

Analysis of the initial buildup of oscillations in a thermoacoustic prime mover

Abstract: Previously, the evolution of the quality factor Q of a prime mover below onset of self‐oscillation as a function of the temperature difference applied across the prime mover stack was discussed [A. A. Atchley, H. E. Bass, T. J. Hofler, and H. T. Lin, ‘‘Study of a thermoacoustic prime mover below onset of self‐oscillation,’’ J. Acoust. Soc. Am. 91, 734–743 (1992) and A. A. Atchley, ‘‘Standing wave analysis of a thermoacoustic prime mover below onset of self‐oscillation,’’ J. Acoust. Soc. Am. 92, 2907–2914 (1992)]. In this paper, these measurements are extended through onset. Above onset Q is determined from measurements of the rise time of the initial buildup of the acoustic oscillations. These measurements, coupled with those previously reported for below onset conditions, show the complete evolution of Q for an individual prime mover from below to above onset. The measurements are in good agreement with the predictions of a standing wave analysis of prime movers discussed in the earlier work. It is sugge...

Non-railbound vehicle with an electric motor and an internal combustion engine powered generator wherein a low voltage source and capacitors are used to operate the generator as a starter to start the engine

Abstract: A non-railbound vehicle in which at least one driving wheel is coupled with an electric motor which is supplied with electric current via power electronics influenced by an electronic control depending on the power requirement selected by the driver via an accelerator pedal. The current is produced by a generator (2) which is coupled with an internal combustion engine. The current for driving the generator is supplied with an operating voltage in the medium-voltage range. Additionally, there is a vehicle power supply in the low-voltage range which ensures the supply of power to accessory electrical consumers. The low-voltage power supply has a vehicle battery and is supplied with current obtained by transforming a portion of the mechanical energy generated by the internal combustion engine. The generator can also be operated as an electric motor for starting the internal combustion engine. A DC-voltage intermediate circuit outfitted with capacitors is connected downstream of the generator, and powers the electric motors. The electronic control is programmed to provide for a charging of the capacitors of the DC-voltage intermediate circuit from the vehicle battery before starting the internal combustion engine, and the current for motor operation (starter operation) of the generator is drawn from the DC-voltage intermediate circuit.

Input compounding torque converter

Abstract: An input compounding torque converter is provided for converting and multiplying torque from a prime mover to an input shaft for a transmission. The input compounding torque converter includes an impeller operatively connected for rotation with a prime mover. The input compounding torque converter also includes a turbine fluidly connected in driving relationship with the impeller for receiving torque from the impeller and planetary gearset interconnecting the turbine and an input shaft of a transmission for multiplying torque from the turbine to the input shaft. The planetary gearset includes an annulus gear connected to the turbine, a planetary carrier connected to the input shaft, a sun gear, and a plurality of planetary pinion gears rotatably supported on the planetary carrier and engaging the sun and annulus gears. The input compounding torque converter also includes first and second one way clutches which are radially spaced with respect to one another and including a stationary reaction member having an intermediate portion disposed between the radially spaced first and second one way clutches.

Tunnel operation for self-propelled traction vehicles

Abstract: In a tunnel control system for traction vehicles, the normal deration function is suppressed to delay deration in a tunnel. The traction vehicle is provided with a controller having a normal operation mode and a tunnel operation mode. A tunnel indicator connected to the controller provides an indication of when the vehicle is approaching a tunnel and causes the controller to switch into the tunnel operation mode. In this mode, the controller increases cooling to reduce the temperature of the vehicle's prime mover and the control electronics prior to entering the tunnel. As the traction vehicle enters the tunnel, the controller monitors the engine oil temperature and the ambient air temperature. If the ambient air temperature exceeds a predetermined value, then the cooling of the control electronics is discontinued. If the oil temperature exceeds a threshold (which is about 10° C. higher than the normal deration threshold), then power to the prime mover is derated. After the vehicle exits the tunnel, the prime mover and control electronics are gradually cooled to avoid thermal shock.

Electro-mechanical hybrid powertrain with self-engaging brakes for starting the engine

Abstract: An electro-mechanical hybrid powertrain uses the electric motor during engine starting. A planetary gear arrangement is disposed in torque transmitting relation between the prime mover, the electric motor and the transmission output. A pair of brake members, which are self-engaging, are provided to establish reaction members in the planetary gear arrangement during engine starting. A fluid-operated piston selectively enforces disengagement of the brakes after the engine has started.

Aristotle' identification of the Prime Mover as God

Abstract: There is a certain conventional interpretation of Aristotle's argument, in Metaphysics Λ.7, for the identification of the first unmoved mover as God, according to which that argument has the following outline

Method and apparatus for controlling pump operations in artificial lift production

Abstract: A method and apparatus for controlling an artificial lift system is described and claimed. Preferably, the control system includes at least one sensor for detecting at least one mechanical attribute during pumping operations, and a controller for receiving the electrical signal as an input, and analyzing it to determine if a pumped-off condition is occurring. Additionally, the controller member provides command signals to control the prime mover and to suspend operation of the prime mover if it is determined that a pumped-off condition is occurring. The controller maintains the suspension of the prime mover for an idle interval having a duration which is calculated by the controller from (1) at least one preceding pumping interval, and (2) a predefined pump cycle duration. Preferably, the controller operates to maintain a substantially constant and predetermined pumping cycle duration by continuously adjusting the idle interval duration.

Standby generator pulse excitation system and electric power generating system for use therein

Abstract: A back-up electric power generating system comprises a first variable speed synchronous generator drivably coupled to a first prime mover, a second variable speed synchronous generator drivably coupled to a second prime mover, a converter having a first and a second input coupled to the first and second generators respectively, and an output, and a logic circuit in controlling communication with the converter for designating one of the first or second generators as a primary power source and one as a standby power source, exclusively. The system further comprises a primary voltage regulator selectably coupled to the primary power source generating a controlled current signal to maintain its output voltage at a given level, and a pulse exciter selectably coupled to the standby power source for verifying the operational readiness of the standby power source. This pulse exciter generates a current pulse signal to the exciter field of said standby power source and monitors the output voltage generated thereby. The converter produces a constant frequency voltage output. The method of verifying the operational readiness of a generator drivably coupled to a prime mover, the generator having an exciter field, a rotor, and a poly-phase wound stator forming an output, comprises the steps of a) providing a current pulse to the exciter field, b) monitoring the generator output, and c) indicating the operational status as ready upon detecting a voltage pulse on the generator output in response to the current pulse, or as not ready upon detecting the lack of a voltage pulse on the generator output in response to the current pulse.

Portable power blower

Abstract: A portable power blower includes a body and a handle mounted on a top of the body. The body includes a prime mover, a fan volute chamber, a fan housed in the fan volute chamber and attached to one end of an output shaft of the prime mover, and an air inlet of the fan volute chamber formed in front of the fan. A main guard member is so mounted as to cover one side surface of the fan volute chamber on which the air inlet is formed, and a gap for radially introducing external air into the air inlet is formed between a rear side of the main guard member and the one side surface. The gap is in open communication with atmosphere at a top portion of the body. A bottom guard member connected to the main guard member and the fan volute chamber covers bottom portions of the fan volute chamber and the prime mover, and a sub-guard member connected to the bottom guard member and the fan volute chamber covers sides of the prime mover which oppose the main guard member and the bottom guard member, respectively.

Engine starting systems and methods

Abstract: Systems and methods for starting a prime mover (21), such as a gas turbine engine of an aircraft auxiliary power unit (APU), are disclosed herein whereby an electromagnetic machine (10) is operated as a motor during operation in a self starting mode to bring the prime mover (21) up to selfsustaining speed. The same electromagnetic machine (10) is thereafter operated as a generator during operation in a generating mode.

Jet propulsion unit and prime mover therefore

Abstract: A pair of small watercraft powered by a combined jet propulsion and prime mover unit so as to eliminate the use of separate impeller drive shafts passing through the water inlet duct. The prime mover may comprise either an electric motor or an internal combustion engine and is supported within a nacelle to the rear of the impeller.

System for controlling operation of turbo type fluid machinery

Abstract: A system for controlling the operation of a turbo-type fluid machine driven by a variable speed prime mover, which enables the characteristics of the fluid machine to be improved so as to become favorable for actual use while allowing the prime mover to exhibit its capacity to the maximum even at an operating point other than the rated point. The operation control system includes a turbo-type fluid machine driven by a driving machine, and a device for detecting an operating head or operating pressure of the fluid machine. The operation control system further includes a device for arithmetically outputting a rotational speed which gives a preset characteristic of the fluid machine in corresponding relation to the operating head or operating pressure, and a device for changing the rotational speed of the driving machine in response to the output rotational speed, so that even when the operating head or operating pressure of the fluid machine changes, the rotational speed of the fluid machine is controlled so as to maintain the preset characteristic of the fluid machine.

Engine/generator set especially for a motor vehicle

Abstract: An engine/generator set, especially for use in driving a hybrid motor vehicle, in which an internal combustion engine is equipped with free flying pistons. The internal combustion engine operates in a two-stroke cycle with asymmetrical electrically controlled gas exchange with an exhaust gas turbine driving a turbocompressor. The power excess is fed back via a synchronous alternating current machine to the generator so that the vehicle is driven with high efficiency with an apparatus of reduced volume and weight per unit output.

Suppression oscillation along automobile longitudinal axis

Abstract: Characteristic oscillation periods and overall drive take-up times, experimentally determined, are entered in control unit memory. The unit receives operational input every e.g. 10ms covering e.g. instantaneous acceleration, accelerator pedal position, and prime mover variables, and controls engine or electric motor torque. If, e.g., decelerating (al) the driver calls for an acceleration (a2), the control unit initially raises the torque till it becomes slightly positive (CaO, ta1), maintaining this level by closed loop control for a period (Pal) corresponding to the drive take-up time under the conditions then obtaining. This period is previously determined experimentally; opt., its termination (ta2) is recognised from changed operational parameters. The torque is then (ta2) raised till the required acceleration (a2) is achieved(ta3).

Ground rod driver

Abstract: An ground rod driver including a tubular ground rod receiver engaging a prime mover at one end and having a ratcheting ground rod driving member and a clamping setscrew disposed at an opposite end wherein a ground rod may be inserted, clamped at an initial position and subsequently be driven by releasing clamp forces and operating the prime mover in a repetitive series of downward thrusting moves whereby the ground rod is installed. The clamping setscrew of the ground rod driver may be additionally employed to remove embedded ground rods by clamping an exposed end of an embedded ground rod to the ground rod receiver wherein the prime mover extracts the ground rod from the earth by repetitively performing an upward motion followed by clamp release, and a downward motion followed by reclamping until the ground rod is freed from the earth.

Jet propulsion unit for a watercraft

Abstract: A number of compact jet pump and prime mover propulsion units for watercraft. In each embodiment the jet propulsion unit impeller shaft is driven by a prime mover that is disposed at least in part below the jet propulsion unit and which has its output shaft disposed no higher than the jet propulsion unit impeller shaft axis. Various transmission arrangements are disclosed, as are in-line and V-type engines.

Design of a radial mode thermoacoustic prime mover (sound source) and experimental observations

Abstract: Experimental thermoacoustics has been limited in the past to plane wave systems. Swift briefly discussed the radial mode thermoacoustic engine, but no working models have been built. Radial modes of a cylindrical resonator are naturally anharmonic; thus harmonic generation at high sound‐pressure levels by nonlinear processes tend to be less resonance enhanced in the radial mode, potentially leading to higher sound‐pressure levels in the fundamental radial mode of oscillation. A radial mode prime mover which is theoretically optimized for a 60% helium, 40% argon gas mixture (mole fraction) at atmospheric pressure has been constructed. Details of the design and construction, measurement of the power dissipated in the hot heat exchanger (required for onset of self oscillation) as a function of ambient pressure, and harmonic distortion of the fundamental mode of oscillation will be presented. [Work supported by ONR.]

Speed-limited adjustable hydraulic torque variator

Abstract: The utility model relates to a speed-limited adjustable hydraulic torque variator The utility model is characterized in that the speed-limited adjustable hydraulic torque variator is provided with a two-shaft speed-limited mechanism on the basis of existing torque variators The mechanism comprises two rotary solid shafts and two pairs of drive gears The speed-limited and regulating effect can be realized through changing the installation position of a one-way clutch and using a secondary shaft as the output end Consequently, the limiting rotary speed can not exceed the designed value in light loading or empty loading, and a prime mover can obtain partial unloading The utility model can fundamentally eliminate the problems of mechanical over-speed danger, prime motor overload and energy consumption explosion generated simultaneously, etc

Driving coupler with rotational vibration shock absorber in driving linkage system of car with prime mover

Abstract: PURPOSE: To provide a drive combining device capable of providing rotational oscillation cushioning by properly measuring a special spring and a frictional element. CONSTITUTION: This drive combining device in a drive linking system of a vehicle with a prime mover has a special spring member and a frictional member for rotational oscillation cushioning so as to precisely measure the cushioning of rotational oscillation. Consequently, a thin plate laminated body 8 energized by a spring is useful, and this laminated body 8 connects a driving disc 1 and a driven shaft 4 to each other so as to be engaged with each other by frictional force.

Universal mount for a compressor prime mover

Abstract: An apparatus is provided for adjustably mounting a prime mover in belt driving relation to a reciprocating compressor to facilitate proper tensioning, locating and aligning of a reciprocating compressor drive belt. The apparatus includes a base plate and a support plate which mounts the prime mover. A pivotal mounting means, which defines an axis of rotation, is connected to the support plate. At least one pair of locators are fixedly attached to the base plate. The at least one pair of locators removably receive the pivotal mounting means to adjustably locate the support plate with respect to the base plate. A pivotal adjustment assembly adjustably positions the support plate in a predetermined position along an arcuately shaped path of travel about the axis of rotation.

Main prime moving device for cableway

Abstract: PURPOSE:To decrease the downtime due to falling of a thunderbolt and enhance the safety of a cableway main prime mover device which drives circulatively a cable to tow transport unit on the cableway, by installing in line a DC motor and an AC motor to be controlled by respective controllers, arranging in series their rotary shafts with possibility of mounting and removing, and providing possibility of changing over between the two motors. CONSTITUTION:On the floor 17 of a car stop 1, a reduction gear frame 11 and a motor base 15 are installed in line along the line of a cableway 20. A reduction gear 10 is installed on the frame 11, and the output shaft 10b which is vertical is coupled with a planetary reduction gearing 8. From the reduction gear 10, a DC motor 13 and an AC motor 14 are installed in series on the base 15, and the rotary shaft 13a of the DC motor 13 is connected with the input shaft 10a of the reduction gear 10 through a universal joint 12. The two motors 13, 14 are coupled through a chain coupling 16. The motors 13, 14 are connected and disconnected by setting a chain on and off from a sprocket wheel. A changeover device CE switches a main circuit MC and a control circuit CC between the two motors 13, 14.

Controllable drive unit with internal combustion engine and a generator

Abstract: The invention relates to a controllable drive unit for a drive device, comprising an internal combustion engine (VM) and a prime mover (AM) which is driven thereby, the drive power being controlled in relation to a prescribed desired value for a control variable in the working method by means of an actual value measurement sensor (M1) for the control variable. For this purpose, the respective power requirement is determined in each case from a difference in the measured actual value (IW) and from the parameters (PW) which influence the control variable and are continuously measured with corresponding parameter value measurement sensors (M2), and from power-requirement coefficients assigned to these measured values. By means of a control device (ST), an optimum desired engine speed is then determined, the said optimum desired engine speed then being fed to an engine speed final control element (DRS) of the internal combustion engine (VM). An electric three-phase generator (G) which feeds electrical consumers (V1, V2) via at least one converter circuit (UF1, UF2) is coupled to the internal combustion engine (VM).

Driven wheel torque control system

Abstract: A driven wheel torque control system includes a slip-reduction output torque control device for adjusting the output torque from a prime mover of a vehicle in accordance with the slipping state of a driven wheel driven by the prime mover in order to reduce an excessive slipping of the driven wheel, an operation quantity detecting device for detecting the operation quantity of an operating element for adjusting the output torque from the prime mover, a grip force detecting device for detecting a grip force of a road surface, an output torque gain changing device for changing the output torque control gain from the prime mover with respect to the output from the operation quantity detecting device on the basis of the output from the grip force detecting device, and a gain variable output torque control device for adjusting the output torque from the prime mover on the basis of the output torque control gain changed by the output control gain changing device. Thus, it is possible to positively control the slipping state of the driven wheel on the basis of a driver's will.

Guard attachment for power take-off shaft

Abstract: A guard attachment (1) for a wide-angled joint on a PTO shaft located between a prime mover and an accessory or implement comprises: a pair of flexible hollow cone-shaped members (10, 11) each capable of axial bending but resistant to radial compression, each cone-shaped member being provided at its narrower diameter end with a first connector means (14, 15), the first connector means either (a) being adapted to connect the cone-shaped member to a housing of the prime mover or of the accessory or implement; or (b) being adapted to connect the cone-shaped member to another PTO shaft guard attachment; or (c) comprising bearing means adapted to be locatable about a PTO output/input stub of a prime mover, implement or accessory and a second connector means (18, 19) adapted to connect the cone-shaped members together at their wider diameter ends.

Hybrid type driver

Abstract: PURPOSE:To simplify the structure of the field system of a hybrid type driver in which a prime mover, a generator and a motor are combined. CONSTITUTION:A hybrid exciting type permanent magnet generator (HPG) 51 to be rotted by a prime mover 52 regulates a current flowing to its exciting winding 51a thereby to regulate its field, thereby controlling an output voltage value. The output of the HPG 51 is rectified by a rectifier 52 to DC, which is converted to an AC and fed to a motor 56, which rotatably drives a motor 56. A chopper circuit 58 chopper-controls a DC rectified from the AC of the HPG 51 by a rectifier 57, and supplies it to the exciting winding 51a of the HPG 51. The chopper operation of the circuit 58 is controlled by a voltage controller of command unit 64, 66, etc., and the HPG 51 is field controlled to control its output voltage.