In figure 1 a schematic view of a simple point absorber type wec is depicted. Development and validation of linear alternator models for the advanced stirling convertor jonathan f. It consists of the calculation of th e process of scavenging, compression, combustion, expansion and exhaust. Experimental evaluation of a prototype free piston engine. Linear reciprocating generator sizing equations and. An alternator is a type of alternating current ac electrical generator. Above figure shows the comparison of field analysis between the previous model 2airgaps and the new model 1airgap. They can be identified because they have 4 stator lead ends. Because of this ability, this type of permanent magnet alternator is suitable for tidal action and production of electricity from that motion. Some alternator manufacturers have managed to do this while actually increasing the life span of the alternator. The generator has a long translator and a permanent magnet mover as magnetic field source. Permanent magnet linear alternator magnetic field analysis.
Parallel development plan inhouse sandia magsoft electromagnetic modeling flux2d describe velocity profile, anisotropic. The effects of various resistance loads and equivalence ratios are studied. The design and construction of the firing circuit for the avr. Performance of a free piston engine was investigated using a rapid compression expansion machine and a full cycle. The design for sandia s engine, developed by retired sandian peter van blarigan, called for homogeneous charge compression ignition hcci combustion, a highly efficient technology that compresses a mixture of fuel and air to the point of autoignition, obviating the need for the spark plug. Maury white s presentation discusses infinia s 30kw maintenancefree solar dish engine. Halbach array linear alternator for thermoacoustic engine. The alternator design was described in 2008 by the shanghai jiaotong university. A pragmatic approach for comparative analysis of linear. Moses contractor abstract this report describes the experimental evaluation of a prototype free piston engine linear alternator fpla system developed at sandia national laboratories. Occasionally, a linear alternator or a rotating armature with a stationary magnetic field is used.
A linear generator power takeoff system for the vivace. The opposed piston design wa developed to investigate its potential for use in. So called because the piston is not mechanically linked to other engine systems, such as the crankshaft, the freepiston engine may provide greater efficiency than its conventional diesel and gasoline counterparts. The linear joule engine generator ljeg incorporates the joule engine technology and the permanent magnet linear alternator design, which is a promising power generation device for the applications of range extenders for electric vehicles, combined heat and power chp systems, or. This paper describes the experimental evaluation of a prototype free piston engine linear alternator fpla system developed at sandia national laboratories. The freepiston linear generator fplg uses chemical energy from fuel to drive magnets through a stator and converts this linear motion into electric energy. Obviously the choice of the generator system highly depends on the wec characteristics such as sizing, design sea state climate and working principle. The model will be validated with respect to sandia fpe. Their problem, as i see it, has little to do with the alternator design, rather the energy losses when reversing the mass of the moving magnet or. According to the discussion above, several research groups have made the numerical simulation for the working process.
Magnet volume is defined by the cost target but the tradeoffs between output power, operating frequency, coil displacement and efficiency of the thermoacoustically driven linear alternator need to be addressed. In principle, any ac electrical generator can be called. In this paper, the excitation control for the synchronous generator is designed by using silicon controlled. A linear alternator is most commonly used to convert reciprocating i. Because of its versatility, low weight and high efficiency, it can be used in a wide range of applications, although it is of special interest to the mobility industry as range extenders for electric vehicles. Colgate the work of gm is based on the pescarasigma freepiston engine and the history as gm ordered the hyprex engine for their xp500 firebird at s. Development of a low inductance linear alternator for stirling power convertors steven m. The linear joule engine generator ljeg incorporates the joule engine technology and the permanent magnet linear alternator design, which is a promising power generation device for the applications of range extenders for electric vehicles, combined heat and power chp systems, or as a standalone power unit.
Dlrs freepiston linear generator redesigns the range extender. Design study of a 15 kw freepiston stirling enginelinear. Modeling and design analysis of a permanent magnet linear. Preliminary designs for 25 kwe advanced stirling conversion. Since are design consist of optimizing a linear generator it is useful to know the fundamentals of its design. Xin niu engineering system design lab university of illinois at urbanachampaign august 25, 20 abstract ocean wave energy conversion is a popular research area due to the increasing scarceness of nonrenewable energy resources.
Dimensionless parametric analysis of s park ignited freepiston linear alternator 277 2. National power and energy conference pecon 2003 proceedings, bangi, malaysia 306 linear generator. Understanding the alternator wye design wye wound stators have three windings with a common neutral junction. Simulation of a twostroke freepiston engine for electrical power generation by qingfeng li, jin xiao, and zhen huang the quote below about freepiston linear alternator is from this paper which describes all acronyms the freepiston linear alternator fpla is a newly emerged energy converter. The law of inductions demands high speed for the moveable electrical parts, on the contrary mechanical parts like low sliding speeds to avoid excessive wear. The basic mice design consists of a free piston twostroke engine, a spring, and an alternator in a linearly oscillating configuration. This was already done in ervin carrillos senior project and can be located in the. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.
The model will be validated with respect to sandia fpe experimental data and used to explore conditions. Sandia s concept, illustrated in figure 1, employs a free piston linear alternator combination to facilitate direct electrical generation, thus enabling electronic control of the hcci process and therefore the performance of the fuel cell. The sandia alternator design and prototype will be finished, and the magnequench design will be tested. Optimizing the scavenging system for a twostroke cycle. The patent explains how can two cylinders are used in the creation of a. Design and modeling of free piston linear alternator. The output power and cost of the linear alternator is fixed for the score project application and used as a basis for the electrical design. Development of a low inductance linear alternator for. Dimensionless parametric analysis of spark ignited free. Itroduction two motivators for the use of hydrogen as an energy carrier today are. Modeling and experimental characterization of a permanent. The new model has achieved the same level of performance as shown in right figure with only a half mass of magnets by reducing the magnetic resistances due to air gaps.
Work on the scavenging system consists of learning to use kiva3v, and designing the scavenging experiment. The sandia alternator design and prototype will be finished, and the sandia and magnequench designs will be tested. Finally, it is stated that this thesis solves the problem of developing a linear engine to the point of feasibility. Linear alternators are at the heart of those batteryless flashlights that you shake back and forth to light the led. The cummins design incorporates a linear alternator to provide the electrical output, while the stc design generates electrical power indirectly through a hydraulic pumpmotor coupled to an induction generator. A singleacting design with flat type linear alternator. In order to accomplish this they have improved 1 fan designs for better cooling, 2 rectifier and regulator designs for increased durability,3 and stator design to maximize the amount of wire that can be fit into the alternator. The linear generator is designed such that electricity is generated directly from the pistons oscillating motion, as permanent magnets fixed to the piston are driven back and forth through the alternators coils. Effect of electromagnetic force on the design of a linear. Several linear alternator designs such as moving iron, moving magnet and moving coil were studied and the moving iron linear alternator was selected as the design because of its advantages.
Bourke engine specifications bourke engine project llc. One of the most debatable fields of application of linear electric machine now is a generator with direct drive from an internal combustion engine stroke 412. The engine has a single combustion chamber and an opposite bouncer chamber. Structural integrity for high peak pressures, design simplicity and cost. The opposed piston design was developed to investigate its potential for use in hybrid electric vehicles hevs. The low speed alternator design will take an alternator, and through a few tweaks of the generator, will be usable for low speed applications. The field poles are made to rotate at synchronous speed n s 120 fp for effective power generation. Design, modelling and validation of a linear joule engine.
Similar engines were built by innas and tu dresden. A pragmatic approach for comparative analysis of linear and rotary generators. Where, f signifies the alternating current frequency and the p represents the number of poles. Conclusion design and modeling free piston linear alternator has been successfully completed. In the following different options for linear generators in wecs are introduced, discussed and compared. Diy magnetic linear electricity generator 08152018 8. The main components of an alternator are the rotor, the stator, and the rectifying circuit. A sixslot tubular permanent magnet linear generator is designed, simulated, fabricated and tested. Sandia national laboratories was investigating the use of a free piston linear alternator one moving part figure 1, page 5 of the presentation document utilizing hcci operation. Sandia national laboratories is developing a prototype 30kw freepiston internalcombustionbased linear generator for vehicular applications. Schifer2 nasa glenn research center, cleveland, ohio, 445 the freepiston stirling power convertor is a promising technology for highefficiency heattoelectricity power conversio n in space. Sandia national laboratories, nm developmenttest, 2009.
The avr maintains the constant voltage up to certain level of the load current which is independent of the generator speed and load. Gmum crl will assess sandia freepiston engine fpe potential with a model built in a matlabsimulink framework featuring 0d thermodynamics, a linear alternator model, a bounce chamber air control model, and dynamic force balance. Sandias concept, illustrated in figure 1, employs a free pistonlinear alternator combination to facilitate direct electrical generation, thus enabling electronic control of the hcci process and therefore the performance of the fuel cell. The opposed piston design wa developed to investigate. Such a generator is expected to obtain advanced efficiency and robustness. In order to turn the alternator into a low speed generator all of the original alternator specifications will need to be measured. This presentation does not contain any proprietary, confidential, or otherwise restricted information. An experimental and theoretical investigation of a homogeneous charge compression ignition hcci free piston powered linear alternator has been conducted to determine if improvements can be made in the thermal and conversion efficiencies of modern electrical generator systems. Paper open access simulation of the incylinder working. Homogeneous charge compression ignition free piston.
Design of a linear generator for wave energy plant, uppsala university school of engineering, uptec f 03 003. Mice is inherently an electric power generator, since there is no mechanical linkage with which to extract power. The motion differences between the fpla and the internal combustion engine ice are also presented. Wye wound stators are used in alternators that require high voltage output a low alternator speed. Most papers are devoted to tubular design of linear generator, which has permanent magnets on an. May 31, 20 dlrs freepiston linear generator recharges an electric vehicles battery to increase range 4 7 the fuelair mix ignites in the freepiston linear generators central combustion chamber. An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. Work on the scavenging system consists of using kiva3v to investigate loop and uniflow configurations. A power generation system that utilizes a hydrogenfuelled free piston engine fpice and a linear generator are under development. Sep 29, 2010 sandia national laboratories is developing a prototype 30kw freepiston internalcombustionbased linear generator for vehicular applications. Toward the development of a thermodynamic fuel cell.
Figure 2 shows the same rotary linear generator from figure 1, but now with a mechanical slanted bearing 16 supporting the slanted magnetic bearing in case the magnetic bearing is not accurate enough on the shaft 6 is a slanted bearing 16 accommodating a nonrotating ring 17 connected via a strong pin 9 to a ball 8 in a stationary embedment 7. This paper describes the development and experimental validation of a mathematical model for the permanent magnet linear alternator that will be used by the prototype. Replacing the rotor is a translator consisting of pennanent magnets and a shaft. A conceptual design of a free piston solar stirling engine linear alternator which can be designed and developed to meet the requirements of a nearterm solar test bed engine with minimum risks was developed. This paper present our experience in the design of a permanent magnet generator. A linear alternator is essentially a linear motor used as an electrical generator. The presentation document outlined the advantages of this free piston linear alternator as. The avr maintains the constant voltage up to certain.
Homogeneous charge compression ignition free piston linear alternator peter van blarigan, scott goldsborough, nicholas paradiso engineering for emerging technology janson wu exploratory systems technologies sandia national laboratories p. Modeling and design analysis of a permanent magnet linear synchronous generator technical report uiucesdl201. The conceptual design was calculated to have an overall system efficiency of 38% and provide 15kw electric output. Linear alternator electricity out power piston cooling flexure bearings concentrated. The linear alternator was initially designed using manual calculation from equations obtained from research papers. Both preliminary designs for the ascss will use technology which can reasonably be expected to be available in the early 1990s. The finite element method is used in calculation and simulation to get the accurate results.
Sandia and nrel have weathered the storm and are helping on many levels. The model will be validated with respect to sandia. The free piston linear alternator illustrated in figure 2 has been designed in hopes of approaching ideal otto cycle performance through hcci operation. A sandia team is pursuing a novel route to hybridelectric vehicles. Lewandowski2 nasa glenn research center, cleveland, oh 445 two models of the linear alternator of the advanced stirling convertor asc have been developed using the sage 1d modeling software package. It is concluded that free piston linear alternator is working properly under the specified working condition. Linear permanent magnet generators i dc generators, pm. Principle of linear alternator figure 2 is a cross section view of a singleslot singlephase cylindrical permanent magnet linear alternator.
Perreault vahe caliskan massachusetts institute of technology abstract this paper introduces a new design for alternator systems that provides dramatic increases in peak and average power output from a conventional lundell alternator, along with substantial improvements in efficiency. The principal difference is in how they are used and which direction the energy flows. The first motivation requires a little discussion while the second one is selfevident. A fpice gives power output more efficiently compared with conventional reciprocating piston engines, because it utilizes many benefits such as low friction loss and inherently variable compression ratio apart from the low emission of hazardous exhaust gases. In livermore, california at sandia national laboratories, an innovative and practical use for linear generators is being developed. Combustion occurs alternately at each end of the piston and a modern twostroke. Development and validation of linear alternator models for. While running of free piston linear alternator we found it produce about 4v of electricity per stroke. Single phase automatic voltage regulator design for.
Experimental evaluation of the free piston engine linear. Freepiston engine could be twice as fuel efficient as. Pure linear motion is ensured by the use of a unique double helix or multiple helix spring. The linear generator has six slots, six coils, and a set ofpemlanent magnet translator.
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