The present paper introduces the free piston linear generator fplg a compact electricity generation unit, which is being developed at the german aerospace center dlr. This allows a free piston linear engine to easily adjust the compression ratio and optimize the combustion process. The simple construction of a free piston engine in combination with a linear alternator represents the theoretically simplest possible construction of a power generator. Jan 12, 2017 free piston engine range extender technology duration. The key difference is how it captures the power of combustion. Principal, design and characteristics of a free piston linear.
Colgate the work of gm is based on the pescarasigma freepiston engine and the history as gm ordered the hyprex engine. An application of the free piston generator in a series hybrid vehicle is also proposed. A free piston linear generator fplg is an electric generator which. Its called the free piston engine linear generator fpeg. A free piston linear generator utilizes the power produced from hydrogen fuel and transmits it to the powertrain of a vehicle. 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. The effect of nonlinear thermofluiddynamic terms on freepiston stirling machine stability integrated design of linear alternatorengine system for hev auxiliary power unit a unique starting scheme of linearengine tubular pm linear generator system using position feedback controlled pwm inverter.
The free piston linear generator fplg uses chemical energy from fuel to drive magnets through a stator and converts this linear motion into electric energy. Without the limitation of the crankshaft mechanism, as known for the conventional engines, the piston is free to oscillate between its. The freepiston gasoline engine linear generator fpglg is a new kind of power plant consisting of freepiston gasoline engines and a linear generator. Reported modern freepiston engine applications modern freepiston engines are mainly of the single piston or dual piston type. Us7318506b1 free piston engine with linear power generator. Pdf linear generator for a free piston stirling engine. Oct 28, 2017 researchers in china have developed a novel free piston linear generator fplg to recover exhaust waste heat efficiently from a vehicle engine.
Decoupling design and verification of a freepiston linear. Unique features of the freepiston engine are presented and their e. A free piston engine with a linear power generation system with a variable stroke piston and improved construction and control is provided. Linear generator for a free piston stirling engine article pdf available in journal of electrical and electronics engineering 71. Starting of a free piston linear engine generator by mechanical resonance and rectangular current commutation conference paper pdf available october 2008 with 754 reads how we measure reads.
E the free piston linear generator development of an innovative, compact, highly efficient rangeextender module. Free piston linear generator for low grid power generation. However, since engine control conventionally relies heavily on crankshaft, an alternative control system is required for fpe. The free piston linear generator is a device converting energy from all different kinds of fuels gasoline, natural gas, syntethic gas, ethanol, diesel, hydrogen among others to electric energy. In a standard engine, fuel and air are injected into. In this study, a prototype fplg, the twostroke engines were developed and a linear generation system was incorporated in between the cylinders to get the electricity and the start of the engine as well. Examples include the stelzer engine and the free piston power pack manufactured by pempek systems based on a german patent. Although it seems that in practice it is not quite that simple, as some examples will reveal in the following. Development of a freepiston linear generator for use in an. Notably, most of the systems use rotating generators and engines, therefore, linear electric generators connected directly to free piston engine is a viable solution. The pistonshaft assembly consists of two pistons and a shaft where one piston is connected to each end of the shaft and a linear.
Download pdf 168 kb abstract the free piston linear generator fplg is a compact electricity generation unit, which is being developed since the year 2003 at the german aerospace center dlr. Jun 30, 2014 its called the free piston engine linear generator fpeg. Development of a freepiston linear generator for use in an extendedrange electric vehicle cornelius ferrari1, horst e. Download limit exceeded you have exceeded your daily download allowance.
The free piston linear generator fplg is a kind of linear freepiston engine and has many advantages over the conventional internal. This paper proposes a decoupling design approach for a freepiston linear generator fplg constituted of three key components, including a combustion chamber, a linear generator and a gas spring serving as rebounding device. An implementation assessment study performed indicates that the free piston solar stirling enginelinear alternator can be manufactured at a reasonable price cost direct labor plus material of 2,500 per engine in production quantities of 25,000 units per year. Design study of a 15 kw freepiston stirling enginelinear. Piston motion control of a freepiston engine generator. Researchers developing freepiston linear generator for. Linear electric generator several linear electrical machines were considered for using with a free piston engine. Free refers to the fact that the piston isnt attached to a crankshaft. Introduction free piston linear engine is nothing but an engine which works without crankshaft instead of crankshaft, here an turbine and linear alternator is used to convert the rotary motion into reciprocatory motion this crank less engine reduce the losses due the crankshaft. Pdf starting of a freepiston linear enginegenerator by.
The piston is reciprocated within the cylinder between the opposed combustion chambers. Figure 4 shows the same rotary linear generator from figure 1, but the slanted magnetic bearing is now replaced by a conventional linear generator comprised of a stator 25, and a moveable part 26. Piston dynamics of a single piston freepiston engine. The invention relates to a hydraulic highspeed free piston linear generator and belongs to the field of energy power. Why free piston engines could power your next plugin hybrid. Its closest competitor is the diesel engine which is 35% efficient, while conventional gasoline engines are below even that number.
The key technologies to realize stable continuous operation are lubricating, cooling, and control logic. Pdf a freepiston linear generator control strategy for. Feb, 2017 a driving force behind the interest and researches in free generators is the increasing interest in hybridelectric vehicle technology and all fig. Therefore, studies are conducted on a free piston linear generator fplg prototype evaluating the optimum control and operation parameters to obtain best performance. The freepiston linear generator fplg uses chemical energy from fuel to drive magnets through a stator and converts this linear motion into electric energy. The approach is based on the distribution of the system power and efficiency, which provides a theoretical design method from the viewpoint of the overall. The approach is based on the distribution of the system power and efficiency, which provides a theoretical design method from the viewpoint of the overall power and. Fplg is a freepiston combustion engine with an integrated linear generator. It is designed as a freepiston combustion engine with integrated linear. The free piston engine is classified into three main types. Introduction extensive use of fossil fuels as an energy source. This paper proposes a decoupling design approach for a free piston linear generator fplg constituted of three key components, including a combustion chamber, a linear generator and a gas spring serving as rebounding device. Hydraulic energy from accumulator pushes the piston thereby compressing the gases in the combustion with the.
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. Researchers in china have developed a novel freepiston linear generator fplg to recover exhaust waste heat efficiently from a vehicle engine. In this study, a prototype fplg, the twostroke engines were developed and a linear generation system was incorporated in between the cylinders to get the electricity and the. The linear generator is designed such that electricity is generated directly from the pistons oscillating motion, as rare earth permanent magnets fixed to the piston are driven back and forth through the alternators coils. Linear permanent magnet electric generator for free piston. Pdf the free piston linear generator fplg is a compact electricity generation unit, which is being developed since the year 2003 at the. The fpeg consists of a twostroke combustion chamber, a linear generator and a gas spring chamber. Cn102418600a hydraulic highspeed free piston linear. Free piston linear generator in comparison to other range. Illustration of the principle of the freepiston linear generator.
In order to compare the range extender systems, fuel cells, micro gas turbine and ottowankel combustion, will briefly be presented, before being compared to the. A freepiston linear generator control strategy for. Freepiston engine range extender technology duration. Pdf linear permanent magnet electric generator for free. 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. The freepiston engine is classified into three main. Freepiston engine linear generator for hybrid vehicles. Analysis of freepiston stirling enginelinear alternator.
A freepiston linear generator is a novel energy converter which normally consists of an internal. Introduction nowadays the power generator systems for transportation and energy generation use thermal engines as primary sources of energy. Freepiston engine generator fpeg is a new kind of energy conversion device, which integrates a linear combustion engine and a linear electrical machine into a single unit. Furthermore the generator comprised of a stator 22, and a rotor 23 runs now as an electrical motor to add the rotation synchronized to the stroke motion. Dlrs freepiston linear generator recharges an electric vehicles battery to increase range 4 7 the fuelair mix ignites in the freepiston linear generator s central combustion chamber. A power generation system that utilizes a hydrogenfuelled free piston engine fpice and a linear generator are under development. Uk startup improves free piston linear technology, generating power with no drive shaft. Historical development of the freepiston linear alternators. A freepiston linear generator fplg is be ing developed at the german aerospace center. The hydraulic highspeed free piston linear generator mainly comprises a free piston internal combustion engine, a hydraulic transmission mechanism and a linear generator, wherein the hydraulic transmission mechanism comprises a first hydraulic piston, a first hydraulic cavity.
The engine can be used as a rangeextending device in an electric vehicle. Performance characteristics of free piston linear generator on. 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. Colgate the work of gm is based on the pescarasigma free piston engine and the history as gm ordered the hyprex engine. It is designed as a free piston combustion engine with integrated linear generator. Free piston engine linear generator fpeg with features of thin and compact build, high efficiency and high fuel flexibility is developed. Investigation of the starting process of freepiston. Development of a free piston linear generator for use in an extendedrange electric vehicle cornelius ferrari1, horst e. In this paper, the combustion characteristics during the stable generating process of a. Seminar report on free piston engine linkedin slideshare. Design and analysis of hydrogen free piston linear generator. Friedrich2 12institute of vehicle concepts, german aerospace center, pfaffenwaldring 3840, 70569 stuttgart, germany abstract this paper presents the development methodology of the free piston linear generator fplg. A twostroke of utp high pressure freepiston linear generator fplg engine is invented as a new source of green power generation.
The free piston engine includes a single doubleended piston located within a cylinder having opposed combustion chambers positioned at opposite ends of the cylinder. The freepiston linear generator is a device converting energy from all different kinds of fuels gasoline, natural gas, syntethic gas, ethanol, diesel, hydrogen among others to electric energy. Dlrs freepiston linear generator redesigns the range extender. Freepiston linear generators that eliminate a heavy crankshaft with electrical coils in the piston and cylinder walls are being investigated by multiple research groups for use in hybrid electric vehicles as range extenders. Examples include the stelzer engine and the free piston power pack manufactured by pempek systems based on a german. The first free piston generator was patented in 1934. Without the limitation of the crankshaft mechanism, as known for the conventional engines, the piston is free to oscillate between its dead centres. A free piston has most of the same components as any internal combustion engine. A linear engine coupled to a linear alternator consists of permanent magnet and stator assembly becomes a lineargenerator.
Dlrs free piston linear generator fplg development of an innovative linear power unit. An implementation assessment study performed indicates that the free piston solar stirling engine linear alternator can be manufactured at a reasonable price cost direct labor plus material of 2,500 per engine in production quantities of 25,000 units per year. As an alternative to conventional engines, fpeg is a promising power generation system and has attracted considerable research interests recently all over the world 1. A freepiston linear generator is a novel energy converter which normally consists of an internal combustion engine ice, a linear electric. The load device can be a hydraulic cylinder, as shown in the. The free piston linear generator development of an. A freepiston linear generator utilizes the power produced from hydrogen fuel and transmits it to the powertrain of a vehicle. Nov, 2014 a free piston has most of the same components as any internal combustion engine. May 31, 20 dlrs free piston linear generator recharges an electric vehicles battery to increase range 4 7 the fuelair mix ignites in the free piston linear generator s central combustion chamber.
Free piston engines a combustion engine is referred to as a free piston if the linear movement of the pistons is not transformed into rotational motion by using the crankshaft. Freepiston engine linear generator for hybrid vehicles modeling study t. Friedrich2 12institute of vehicle concepts, german aerospace center, pfaffenwaldring 3840, 70569 stuttgart, germany abstract this paper presents the development methodology of the freepiston linear generator fplg. Development of free piston engine linear generator system. The fplg can be used in a smallscale organic rankine cycle orc system and can directly convert the thermodynamic energy of working fluid into electricity. A driving force behind the interest and researches in free generators is the increasing interest in hybridelectric vehicle technology and all fig. Research on the combustion characteristics of a free. Free piston linear generator for low grid power generation matec. The freepiston linear generator potentials and challenges. Supercharge pump intake air valve bounce chamber exhaust gas receiver. Free piston four stroke linear engine with generator duration. Due to the elimination of the crankshaft mechanism, the piston motion process and the combustion heat release process affect each other significantly. Fl max stroke x fc fr a b tdcn bdcn ml ml b free body diagram of the mover in a single piston freepiston engine.
Pdf a freepiston linear generator control strategy for improving. Development of a freepiston linear generator for use in. Therefore, studies are conducted on a freepiston linear generator fplg prototype evaluating the optimum control and operation parameters to obtain best performance. This allows a freepiston linear engine to easily adjust the compression ratio and optimize the combustion process. Dlrs freepiston linear generator redesigns the range.
The free piston linear generator fplg is a novel energy converter which can generate electrical energy and is regarded as a potential technology for solving the restriction of the short driving. The freepiston engine fpe is a linear energy conversion system, and the term freepiston is widely used to distinguish its linear characteristics from those of a conventional reciprocating engine. Historical development of the free piston linear alternators. 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. Principal, design and characteristics of a free piston.
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