KR20150055160A - Scaffold Energy harvester using Electromagnetic Induction - Google Patents

Abstract

Disclosed is a scaffold type energy harvester using an electromagnetic induction method. The scaffold type energy harvester using the electromagnetic induction method includes a bottom frame (120) which includes a plurality of press springs (130) formed on the outside of the surface thereof with a preset interval, a first energy harvest module (200) which is located on the bottom frame (120), a second energy harvest module (300) which is located on the bottom frame (120) and is arranged to face the first energy harvest module (200), and a top frame (110) which is located on the first energy harvest module (200) and the second energy harvest module (300). The first energy harvest module (200) and the second energy harvest module (300) compress the springs by performing a falling operation by a vertical force supplied from the outside. the first energy harvest module (200) and the second energy harvest module (300) generate electromagnetic induction energy by a rotation motion by converting a vertical displacement into the rotation motion after the vertical displacement is generated by the rising and falling operations by performing the rising operation by the elastic force of the press spring (130) If the vertical force disappears.

Description

{Scaffold Energy harvester using Electromagnetic Induction}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy harvester, and more particularly, to a scaffold type energy harvester using an electromagnetic induction method.

Korea is a representative resource poor country with less than 3% of energy independence. The remaining 97% depends on imports and is the fifth largest energy importer in the world, following the US, Japan and Italy.

In addition, electric power demand is increasing every year due to the increase in the proportion of electronic devices in modern life. In this year, Korea's electric power consumption has reached 7300kWh in one hour as of July.

On the other hand, nuclear power generation and thermal power generation, which account for most of the existing power generation, can secure a large amount of power generation but cause environmental problems such as smoke, waste and high temperature cooling water. In addition, there are technologies such as fuel cells and biomass that are being illuminated by next-generation alternative energy technologies. However, fuel cells have the problem of reducing green spaces while reforming fossil fuels and petroleum, and biomass has a problem of increasing carbon dioxide emissions. There is a difficulty in solving the problem.

Therefore, the recent global power market, which is required to secure stable future energy resources, and to cope with global environmental problems and increase in electric power demand, is focused on advanced countries such as USA, Japan, Europe, (energy harvesting) technology is being developed rapidly and domestic efforts are being made to cope with global warming by promoting the New Deal project which is motivated by "low carbon green growth".

Energy Harvest is sometimes referred to as energy scavenging, or power harvesting, because it takes energy that disappears naturally in a way that acquires energy scattered around. This energy harvesting technology is one of representative clean energy systems, and it does not cause any environmental pollution. It is an environment-friendly energy utilization technology that can utilize natural and surrounding energy as it is.

Energy Harvest technology has been on the rise for over 50 years, but recently the technology has attracted much attention because of the energy forms and environments that can be harvested from the environment and the emergence of a variety of portable devices that can harness these energy harvest technologies This is because the practicality of harvest technology is increasing, and the structure and performance of energy harvesting equipment are constantly evolving.

- Piezoelectric energy harvest system -

Energy harvesting using piezoelectric is the most common method for energy harvesting, centering on several US and European universities, including the University of California, USA. Generally, energy harvest using a piezoelectric body is made in the form of a cantilever in which one end of a bar is fixed. In the cantilever type piezoelectric energy harvest, unimorphs in which a piezoelectric body is disposed only on a support bar supporting a cantilever ) Type and a bimorph type in which a piezoelectric body is arranged at the upper and lower parts, and a mass of mass is suspended at the end. When the cantilever is bent downward, tensile is formed on the upper surface, compression is caused on the lower surface, and voltage is generated on both sides. Therefore, when the cantilever vibrates up and down, an AC voltage is generated.

Fig. 2 (a) is a piezoelectric energy harvest cage developed by Southampton University in England, and (b) is a bimorph piezoelectric energy harvest developed by the University of California, USA.

The Bimorph piezoelectric energy Harvest produced by this method is able to generate electric power of up to 120 kW using a test apparatus, and it has been reported that electric power is generated up to 375 kW by controlling the concentrated mass and the size of the cantilever. In addition to the cantilever piezoelectric energy harvest, piezoelectric energy harvesting in the form of a circular membrane is also being studied. However, piezoelectric energy harvesting can be easily broken due to the use of piezoelectric ceramics (PZT). In the case of cantilever piezoelectric energy harvest, it is necessary to design the resonance frequency of the structure. In addition, Can be generated.

In addition, since the mechanical-electrical energy conversion efficiency is low compared to the size, the application range is not so high as compared with the electric power required by the electronic device.

Examples of practical applications of piezo-electric systems are in the United States, with the support of DARPA (Defense Advanced Research Projects Agency), researching the output characteristics of human vibrations using PVdF and PZT materials. This is a structure in which energy is generated by using a shock wave at the time of walking or a vibration generated by the machine, and Fig. 3 shows an example of application to a shoe.

However, this method is not yet satisfactory in terms of energy efficiency and is being developed in a large area.

FIG. 4 (a) shows an energy harvesting plate manufactured by Soundpower, which includes a plurality of piezoelectric loudspeakers inside the power generating plate, so that the loudspeakers generated from the diaphragm are generated through the piezoelectric loudspeaker.

It is reported that about 5 mW of power can be generated when 10 Hz of vibration is applied. At present JR, a railway company in Japan, is experimenting to drive automatic ticket gates by using the vibration generated when people pass through a subway turnstile,

At this time, it can produce 6000Ws of power per day. INNOWATTECH, Israel has developed a piezoelectric energy harvesting system in which several lattice-shaped piezoelectric bodies are erected by using the principle that electricity is generated when a piezoelectric body is subjected to a load, as shown in FIG. 4 (b) And is currently conducting research to produce electrical energy from these devices.

INNOWATTECH believes it can generate up to 200 kWh per hour on a 1 km road. As described above, macro scale energy harvest systems are applied to various applications due to high energy generation. However, external environmental factors such as initial installation cost and great kinetic energy have been pointed out as drawbacks.

- Electromagnetic induction energy harvest system -

Electromagnetic induction energy harvesting systems are under active research centering on MIT in the United States, Southampton University in England and Chinese University in Hong Kong.

The electromagnetic induction type energy harvesting system currently being studied is based on Faraday's law that an electric field is formed around a conductor when a magnetic field passing through a conductor (electric circuit) changes and an electric current flows.

At this time, the change of the magnetic field can be realized by a starting magnet, a fixed coil, a fixed magnet, and a starting coil, but most of them use a starting magnet and a fixed coil method. Generally, if the other conditions are the same, the number of times the wire is wound on the coil, that is, the more the number of windings, the better the performance.

FIG. 5 (a) is an electromagnetic energy harvest developed by MIT, USA. When a coil connected to a spring makes a vertical motion by hanging on a concentrated mass, the coil moves the inside and outside of the circular magnet and generates a current.

Another electromagnetic energy harvest is a method in which a circular pattern (coil) is wound on a printed circuit board (PCB) as shown in FIG. 5 (b) and a via hole is connected to a PCB on the lower layer, It is a way to get the effect of winding the coil on the PCB. Unlike piezoelectric energy harvesting, electromagnetic energy harvesting does not need to match the resonant frequency, and it is reported that electric power (100 to 400 psi) similar to piezoelectric energy harvesting occurs at 330 to 500 kHz.

However, the electromagnetic energy harvest developed up to now has a disadvantage that it is difficult to miniaturize and there is a limitation in the generation amount in the low frequency range.

- Electrostatic energy harvest system -

An electrostatic generator developed by Meninger et al. At MIT has a MEMS-type variable capacitor structure that changes the distance of the capacitor to change the capacitance of the capacitor.

For electrostatic energy conversion, they proposed a parallel capacitor structure operating at a constant charge amount and a comb type capacitor structure operating at a constant voltage.

Among these two types of structures, a capacitor structure operating at a constant voltage showed higher energy efficiency than a capacitor operating at a constant charge amount. However, a capacitor structure operating at a constant voltage has a disadvantage in that it initially requires a large voltage source. In order to solve this problem, a method of connecting an additional capacitor in parallel to a MEMS capacitor to obtain a relatively large energy while using a capacitor structure operating at a constant charge amount is proposed. However, it is also necessary to increase the size of the initial voltage source, The switching system for efficiently transferring the stored energy has a problem in that it needs to be synchronized with the vibration characteristic of the kinetic energy of the generator.

- Current Status of Energy Harvest System in Korea -

In the case of micro energy harvest technology, researches on application as a direct power source for small devices such as sensor nodes are being actively carried out in the United States. However, in the case of domestic micro energy harvest technology, This is a reality that is still in the early stage of research due to its weak relationship with the related technology.

As shown in Figure 5 (a), in 2007, ETRI conducted a study on a piezoelectric single-crystal MEMS structure element that generates a voltage by vibrating with a sound wave to generate a power of about 13.2 mW at a frequency of 10.8 kHz, Energy harvest system with high energy conversion efficiency was developed. In addition, KIST developed a cantilever-type PZT-based MEMS structure as shown in Fig. 5 (b), and developed a piezoelectric-type energy harvest device that generates power of about 0.74 mW at a frequency of 13.9 kHz per square centimeter We are conducting basic research.

As described above, domestic researches are mainly focused on the method using piezoelectric bodies. However, in consideration of the fact that the present level of technology development is the starting point, various approaches are used to diversify the generation methods and increase the possibility of technological development There is a need to be studied.

On the other hand, energy harvest structures that utilize piezoelectric methods are widely used in domestic and overseas energy harvest. In the case of such a piezoelectric method, a piezoelectric ceramic method in which a generated current is small but a generated voltage is large is used. However, the piezoelectric ceramics are made of a material similar to ceramics, and are susceptible to breakage or deformation due to pressure, resulting in poor durability. In addition, the piezoelectric type has a disadvantage in that it is necessary to design the resonance frequency of the structure in order to increase the energy efficiency and to generate the active power only in a very limited frequency range.

Korean Patent Registration No. 10-1067019 entitled ENERGY HARVEST UNIT MODULE, MULTI-CHAIN ENERGY HARVEST ASSEMBLY CONJUGATED THEREOF, AND MULTI-SHAFT ENERGY HARVEST MULTILE ASSEMBLY CONJUGATED THEREFOR

SUMMARY OF THE INVENTION It is an object of the present invention to provide a foot type energy harvester using an electromagnetic induction method.

In addition, it is possible to install a scaffolding type energy harvester, which can be installed close to a living space, enable efficient use of electric power, be installed in India and be able to generate power without any ambience, and can be applied to various applications such as roads, underground parking lots, The purpose is to provide.

In order to achieve the above object, a foot type energy harvester using an electromagnetic induction method according to an embodiment of the present invention includes a lower frame 120 having a plurality of press springs 130 formed at a predetermined interval on a surface outer surface thereof; And a first energy harvesting module (200) located on the lower frame (120); A second energy harvesting module (300) located on the lower frame (120) and arranged to face the first energy harvesting module (200); And an upper frame (110) located on the first energy harvesting module (200) and the second energy harvesting module, wherein the first energy harvesting module (200) and the second energy harvesting module (300) , And a plurality of springs are compressed by a vertical force externally provided to compress the plurality of springs. When the vertical force is extinguished, the lifting operation is performed by the elastic force of the press spring (130) The vertical displacement is converted into a rotational motion to generate electromagnetic induction energy generated by the rotational motion.

The first energy harvesting module 200 and the second energy harvesting module 300 perform a descending operation by a vertical force provided by the upper frame 110 to compress the plurality of press springs 130, An up-down module 310 for performing up-and-down movement by the elastic force of the press spring 130 when the vertical force is extinguished to generate a vertical displacement in accordance with the up-down operation; A speed increasing gear module 320 for converting the vertical displacement of the lifting / lowering module 310 into rotational motion; And a generator module (330) for generating AC energy according to the direction of the rotational motion provided by the speed increasing gear module (320).

And a rectifying circuit for converting the AC energy into DC energy.

And an energy accumulator for storing the direct current energy.

는 수학식 2로 표현되는 것을 특징으로 하며,The speed increasing gear module 320 is composed of at least one one-stage spur gear and at least one two-speed spur gear, the number of gears is adjusted according to the increased number of rotations,

Is expressed by Equation (2)

 &Quot; (2) "

는 평기어의 잇수이며,

는 평기어의 회전수, 속도 전달비

의 크기가 1보다 작으면(

) 증속 기어이며,

이면 등속 기어,

이면 감속 기어를 의미한다.here,

Is the number of teeth of the spur gear,

Is the number of revolutions of the spur gear, the speed transmission ratio

Is smaller than 1 (

) Incremental gear,

Back gear,

Side reverse gear.

The two-stage spur gear is characterized in that two spur gears having different diameters are combined.

The vertical movement of the rack gear 311 induces a rotation angle of the driving gear 321. The vertical movement of the rack gear 311 causes the vertical movement of the driving gear 321, .

The rotation angle is obtained by the following equation (1)

[Equation 1]

,

,

,

은 각각 랙기어의 이동량, 구동 기어의 잇수, 구동 기어의 이각도, 기어의 피치를 의미한다.
here,

,

,

,

Respectively denote the movement amount of the rack gear, the number of teeth of the driving gear, the pitch angle of the driving gear, and the pitch of the gear.

The generator module 330 includes a cylindrical housing 331; A magnetic body 332 provided on an inner surface of the cylindrical housing 331; A rotating shaft 334 provided at an inner center of the cylindrical housing 331 and rotated in accordance with rotation of the speed increasing gear module; And a solenoid coil 333 wound on the rotary shaft 334 in a single direction a plurality of times so that the induction electromotive force is generated due to the rotation direction of the solenoid coil 333 varying with the rotation of the rotary shaft 334 .

The foot type energy harvester using the electromagnetic induction method according to the embodiment of the present invention does not need to be designed in consideration of the resonance frequency in comparison with the piezoelectric type which is widely used in the past and produces a relatively large electric power even at a small frequency .

In addition, the miniaturization of the structure and the socket-type design allow the same structure to be easily combined and installed on the floor, which is advantageous in that the installation range for the energy harvest is not restricted.

In addition, if it is manufactured in a socket shape according to the miniaturization of the structure, it can be installed microscopically on a sneaker floor of a person to produce electric power, and it can be installed as a peripheral power supply device by installing it on a floor where a lot of people are walking like a subway .

FIG. 1 is a diagram illustrating a harvest technique, in which (a) is a rotor energy harvest technique and (b) is an energy harvest technology developed by KIST.
Fig. 2 (a) shows a cantilever-shaped piezoelectric energy harvest, and Fig. 2 (b) shows an example of a bimorph piezoelectric energy harvest.
Fig. 3 shows an example of a piezoelectric energy harvest system applied to a shoe.
4 (a) shows a Harvest system using the sound power of the present Soundpower, and (b) shows a piezoelectric harvest system manufactured by Israel INNOWATTECH.
Figure 5 shows an example of an energy harvest of electromagnetic type.
6 (a) shows a single-crystal energy harvest device developed by ETRI, and FIG. 6 (b) shows an energy harvest device developed by KIST.
7 is a block diagram showing the kind of the energy harvest.
8 is a perspective view of a scaffold type energy harvester using an electromagnetic induction method according to an embodiment of the present invention.
Fig. 9 is an actual view of the foot type energy harvester shown in Fig. 8. Fig.
10 is an exemplary view showing a rectifying circuit.
11 is an exemplary view showing the first energy harvest module shown in FIG.
12 is an exemplary view showing the rotation distance and rotation angle of the driving gear according to the vertical displacement of the rack gear.
13 is an exemplary view showing a connection relationship between a generator module and a speed increasing gear module.
Figure 14 is an exemplary diagram illustrating 2D and 3D simulations of a generator module.
15 is a graph showing the generated voltage of the entire harvester generated from the four generator modules.
16 is a graph showing the generated power analysis according to the resistance at a frequency of 1 Hz and a 1:29 speed-increasing gear module.
FIG. 17A is a graph for analyzing the generated power according to the frequency and the incremental gear ratio when the load resistance is 33 OMEGA, and FIG. 17B is a graph for analyzing the power generation according to the frequency and the gear ratio at the load resistance 1 KΩ .
FIG. 18 is a photograph of a light-emitting diode (LED) illuminated by attaching a rectifying circuit chip to a foot type energy harvester of the present invention and using a capacitor having a capacity of 3,200 .mu.m.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Embodiments in accordance with the concepts of the present invention can make various changes and have various forms, so that specific embodiments are illustrated in the drawings and described in detail in this specification or application. It is to be understood, however, that it is not intended to limit the embodiments according to the concepts of the present invention to the particular forms of disclosure, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises ",or" having ", or the like, specify that there is a stated feature, number, step, operation, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Hereinafter, a foot type energy harvester using an electromagnetic induction method according to an embodiment of the present invention will be described in detail with reference to the drawings.

8 is a perspective view of a scaffold type energy harvester using an electromagnetic induction method according to an embodiment of the present invention.

Fig. 9 is an actual view of the foot type energy harvester shown in Fig. 8. Fig.

10 is an exemplary view showing a rectifying circuit.

11 is an exemplary view showing the first energy harvest module shown in FIG.

12 is an exemplary view showing the rotation distance and rotation angle of the driving gear according to the vertical displacement of the rack gear.

13 is an exemplary view showing a connection relationship between a generator module and a speed increasing gear module.

Figure 14 is an exemplary diagram illustrating 2D and 3D simulations of a generator module.

15 is a graph showing the generated voltage of the entire harvester generated from the four generator modules.

16 is a graph showing the generated power analysis according to the resistance at a frequency of 1 Hz and a 1:29 speed-increasing gear module.

FIG. 17A is a graph for analyzing the generated power according to the frequency and the incremental gear ratio when the load resistance is 33 OMEGA, and FIG. 17B is a graph for analyzing the power generation according to the frequency and the gear ratio at the load resistance 1 KΩ .

FIG. 18 is a photograph of a light-emitting diode (LED) illuminated by attaching a rectifying circuit chip to a foot type energy harvester of the present invention and using a capacitor having a capacity of 3,200 .mu.m.

8 and 9, a scaffold type energy harvester 100 according to an embodiment of the present invention includes two energy harvest modules 200 and 300, And 300 each convert the vertical displacement generated according to the magnitude of the vertical force provided from the outside into the rotational displacement and then convert the rotational kinetic energy according to the rotational displacement into electric energy.

More specifically, the scaffold type energy harvester 100 includes an upper frame 110, a lower frame 120, a first energy harvesting module 200, and a second energy harvesting module 300.

The scaffold type energy harvester 100 may further include a rectifier circuit for rectifying induced electromotive force generated in the first energy harvesting module 200 and the second energy harvesting module 300, respectively.

Referring to FIG. 10, the rectifier circuit is designed using a rectifier circuit chip (KBPC808). In connection with the generator, four generator modules are connected in series and the AC power is converted into DC power through a rectifier circuit chip.

The foot type energy harvester 100 may further include an energy storing unit (not shown) such as a capacitor for storing electric energy rectified in the rectifying circuit (not shown).

The upper frame 110 is located at the upper end of the first energy harvesting module 200 and the second energy harvesting module 300 and the lower frame 200 is connected to the first energy harvesting module 200, And a plurality of press springs (130) located at a lower end of the second energy harvesting module (300) and arranged at regular intervals around the surface, wherein the elastic modulus of the plurality of press springs (130) May vary depending on the size of the light source 100 and the magnitude of the vertical force.

The lifting frames 310 provided in the first energy harvesting module 200 and the second energy harvesting module 300 are connected to each other through the frame spring 140.

The first energy harvesting module 200 and the second harvesting module 300 are formed in the same structure and each includes a lifting frame 310, a speed increasing gear module 320 and a generator module 330.

In the present invention, the first energy harvest module 200 and the second energy harvest module 300 have the same structure, so that only the first energy harvest module 200 will be described as an example.

The lifting frame 310 of the first energy harvesting module 200 performs a downward movement in the vertical direction by a vertical force applied to the upper frame 110. The lifting frame 310 that performs the lowering motion is lowered by a predetermined length due to the press spring 130 supporting the lower frame 120 and the vertical force is removed by the elastic force of the press spring 130 And performs a vertical movement by performing the vertical movement.

At this time, the linear motion generated by the upward / downward movement of the lifting frame 310 is changed to the rotational motion through the rack gear 311, and the rack gear 311 is connected to the speed increasing gear module 320, .

More specifically, the lifting frame 310 is provided with a rack gear 311 on one side thereof in the height direction.

The rack gear 311 is connected to the driving gear 321 of the speed increasing gear module 320. Therefore, when the lifting frame 310 is lowered by, for example, about 5 mm due to the force exerted vertically from the outside, it causes vertical displacement of the rack gear 311, (See FIG. 12)

The relationship between the moving distance of the rack gear 311 and the angular displacement of the driving gear 321 is defined by the following equation (1).

[Equation 1]

,

,

,

은 각각 랙기어(311)의 이동량, 구동 기어의 잇수, 구동 기어(321)의 이도, 기어의 피치를 의미한다. At this time,

,

,

,

Means the amount of movement of the rack gear 311, the number of teeth of the driving gear, the distance of the driving gear 321, and the pitch of the gear.

을 0.5로 설정하고 구동 기어(321)의 지름을 16 ㎜로 설정한다. In the present invention, the distance between the teeth and the teeth of the driving gear 321 and the rack gear 311

Is set to 0.5, and the diameter of the drive gear 321 is set to 16 mm.

은 60이며, 승하강 프레임(310)의 눌림에 의해 랙기어(311)가 5 ㎜ 이동했다고 가정하면 구동 기어(321)는 약 38.46 °의 회전을 갖는다.
At this time

60, and assuming that the rack gear 311 has moved by 5 mm due to the pressing of the lifting frame 310, the driving gear 321 has a rotation of about 38.46 degrees.

The plurality of press springs 130 have a Young's modulus according to the moving distance of the rack gear 311. In the present invention, assuming that a plurality of springs connected to the lifting frame 310 are six, The number of teeth of the drive gear 321 defined in the following Equation 1 is calculated on the premise that the lifting frame 310 has a Young's modulus of 5 mm when the adult male of 60 kg body weight is lifted, The rotation angle range of the drive gear 321 can be obtained.

Next, the speed-increasing gear module 320 performs a function of converting the vertical displacement of the up-down module 310 into rotational motion through a plurality of gears provided therein.

는 아래의 수학식 2와 같다.More specifically, referring to FIG. 13, the speed increasing gear module 320 is composed of a single-stage spur gear and a double-speed spur gear, and is designed so that the number of gears can be adjusted according to the increased number of rotations. Speed transmission ratio of two spur gear meshed with each other

Is expressed by the following equation (2).

 &Quot; (2) "

는 평기어의 회전수를 의미한다. 여기서 속도 전달비

의 크기가 1보다 작으면(

) 증속 기어이며,

이면 등속 기어,

이면 감속 기어를 의미한다. Here, z is the number of teeth of the spur gear,

Means the number of revolutions of the spur gear. Here,

Is smaller than 1 (

) Incremental gear,

Back gear,

Side reverse gear.

와

은 같다. In the case of the second gear such as Gear # 2 and Gear # 3 in FIG. 13 (b)

Wow

Is the same.

The number of gears of the speed increasing gear module 320 varies according to the gear ratio. When designing the speed increasing gear module at a ratio of 1:77, two single spur gears and six double spur gears are used as shown in FIG. 13 (a).

을 먼저 설정하고, 그 후 기어지름에 따른 잇수를 설정하게 된다. 잇수를 설정하면 증속비율에 따라 기어의 개수를 결정하게 되는데 잇수와 기어의 개수에 따른 증속비율

는 아래의 수학식 3과 같은 관계식을 갖는다.Therefore, depending on the speed increasing ratio and the size of the speed increasing gear module,

Is set first, and then the number of teeth is set according to the gear diameter. When the number of teeth is set, the number of gears is determined according to the speed increasing ratio. The number of gears and the rate of increase

Has a relationship as shown in the following equation (3).

&Quot; (3) "

Where z is the number of teeth of the gear and m is the number of gears.

을 0.5로 설계하고 기어의 잇수와 개수를 조절하는 방식으로 1:29, 1:50, 1:77의 증속비율을 갖는 증속기어 모듈을 설계하였다. 제작된 증속기어 모듈은 도 13의 (c)와 같이 발전기 모듈과 결합되어 증속기어가 결합된 발전기 형태로 제작된다.
In the present invention,

0.5, and the number of teeth and the number of gears were controlled to design a speed increasing gear module with the speed increasing ratio of 1:29, 1:50, 1:77. The manufactured speed increasing gear module is assembled with a generator module as shown in FIG. 13 (c), and is manufactured as a generator in which a speed increasing gear is coupled.

Next, the generator module 330 generates an induced electromotive force through rotational displacement according to the rotational speed ratio of the gears provided in the speed increasing gear module 320.

More specifically, the generator module 330 generates an induction electromotive force through an electromagnetic induction method, and a cylindrical housing 331, a magnetic body 332, a solenoid coil 333, and a rotary shaft (not shown) 334).

The cylindrical housing 331 is designed to have a receiving space therein so as to include the magnetic body 332, the solenoid coil 333, and the rotating shaft 334 therein.

The magnetic body 332 is accommodated in the cylindrical housing 331 and has a receiving space for accommodating a plurality of the solenoid coils 333.

One end of the rotation shaft 334 is connected to the speed increasing gear module 320 to rotate the magnetic body 332.

The solenoid coil 333 is accommodated in the accommodating space provided in the magnetic body 332.

Accordingly, the generator module 330 can generate the induced electromotive force due to the rotation direction of the solenoid coil 333, which varies according to the rotation of the rotation shaft 334 through the above-described configurations.

Hereinafter, a process of generating an induced electromotive force in the generator module 330 will be described in more detail.

The generator module 330 generates the induced electromotive force using an electromagnetic induction method. Herein, the induced electromotive force (V) is defined through Faraday's law defined by the following equation (4).

&Quot; (4) "

,

및

는 각각 코일의 권선수, 총 쇄교자속 및 코일의 회전당 평균자속을 나타낸다. here,

,

And

Represents the average flux per revolution of the coil, the total flux linkage, and the coil.

)은 아래에 기재된 수학식 2와 같이 코일의 각 권선당 자속밀도(magnetic flux density)

[T]를 자속밀도가 작용하는 코일의 면적에 대해 적분한 후, 적분값에 코일의 권선수를 곱하여 구할 수 있다.
At this time,

Is the magnetic flux density per coil of the coil as shown in Equation (2)

[T] is integrated with respect to the area of the coil in which the magnetic flux density acts, and then the integral value is multiplied by the winding amount of the coil.

&Quot; (5) "

At this time, assuming that the magnetic flux density is uniform with respect to the entire area of the coil, the integral can be transformed into a simple product.

Therefore, the magnitude of the induced electromotive force (V) induced in the generator module using Equations (4) and (5) can be obtained as shown in Equation (6) below.

&Quot; (6) "

와 자계강도(magnetic field intensity)

[A/m])와의 관계식으로 표현할 수 있다.
Also, the magnetic body provided in the cylindrical housing has magnetic flux density

And magnetic field intensity.

[A / m]).

&Quot; (7) "

는 자기투자율(magnetic permeability),

는 자성재료의 비 투자율(relative permeability),

은 내부 자기화(internal magnetization),

는 자화율(magnetic susceptibility)을 나타낸다.
here,

Magnetic permeability,

The relative permeability of the magnetic material,

Internal magnetization,

Represents magnetic susceptibility.

Here, when the generator module 330 is applied to Multiphysics, which is an analysis tool using the finite element method, the intensity of an electric field due to magnetic induction can be internally calculated.

In this case, the voltage generated in the generator module 330 can be expressed by the relationship between the intensity of the electric field intensity due to magnetization of the magnetic body and the sensed conductor as shown in Equation (8).

&Quot; (8) "

는 z방향에 대한 전계강도의 크기이며,

은 도선의 길이,

는 도선의 면적을 각각 나타낸다.
here,

Is the magnitude of the electric field intensity in the z direction,

The length of the conductor,

Represents the area of the conductor.

Hereinafter, results of an experiment on the dynamical efficiency and the efficiency of the generator according to the difference in gear ratio will be described in relation to the generator module in the foot type energy harvester using the electromagnetic induction method of the present invention.

1. Generator Modeling (Simulation)

Before the actual experiment of the generator module provided in the present invention, the dynamic relationship of the generator was modeled by the finite element method using Multiphysics provided by COMSOL.

For the simulation, the model for the inside of the generator module was designed in 2D and 3D as shown in FIG. 14, and the simulation was performed by setting the variables as shown in Table 1 shown below.

[Table 1]

The magnitude of the generator is set equal to the size designed for Φ30 × 40 ㎜, the solenoid coil is 0.2 ㎜ copper wire, the winding number is 1,400 times, the magnitude of the magnet is 0.54 T, the frequency is 0.5 ~ And the simulation was carried out.

14 (a), a method of rotating the magnet with the core outside is used, and the rpm of the rotating body is adjusted in consideration of the speed increasing ratio of the speed increasing gear module. If the gear increment ratio is 1:77, the generator core is rotated 8.26 times when the frame moves 5 mm, and the rpm of the core is determined by calculating the number of revolutions at that time.

In this case, it is assumed that the rpm is the same as when the rising / falling frame is pressed, and the rotation direction is set to the opposite direction.

Figure 14 (b) shows the distribution of Magnetic flux density, Magnetic field, and Magnetic potential using the finite element method. To confirm that the generator operates normally under the above conditions.

2. Results of efficiency analysis

After verifying the internal structure of the generator through finite element analysis, the efficiency of the generated voltage was verified by modeling the generated voltage

When the electric field intensity according to the magnetic induction is calculated for the generator module proposed in the present invention, the voltage generated in the generator module is expressed by Equation (8), and the intensity of the electric field intensity It can be expressed as a relational expression according to the conductor.

Multiphysics, which is an analysis tool using the finite element method, defines the generator module of the energy harvester proposed in Fig. 14 (b), the internal variables including the magnitude of the magnet, and the structural changes due to the external motion, The intensity of the electric field due to the magnetic induction is internally calculated.

As a result of the simulation in this manner, it was confirmed that an AC voltage of sine curve type was periodically generated as shown in FIG.

The analysis result of FIG. 15 shows the generated voltage of the entire harvester generated from the four generators, and it is assumed that there is no load resistance. From the analysis results, it was confirmed that voltage of about 18 V was generated when the footstep (frame) was pressed twice per second (2 Hz), and about 4.5 V was generated in the lowest frequency band of 0.5 Hz. Also, it can be seen that as the frequency of pressing the foot plate is increased, that is, as the power generation frequency is increased, the generated voltage is also increased.

3. Generated power experiment of energy harvester

In order to test the generated power of the foot type energy harvester provided in the present invention, three acceleration gear modules having ratios of 1:29, 1:50, 1:77 were prepared, and the number of times per second when the actual person stepped on the harvester The frequency was increased by 0.5 Hz from 0.5 to 2 Hz.

In order to analyze the generated power of the foot type energy harvester according to the load resistance, a total of 7 resistors were connected to analyze the generated power at that time.

The generated power value is calculated by using Equation (9) described below, and the effective power value is calculated by Equation (10) using the calculated effective voltage value. Also, since there are four generator modules in the harvester, the power generated in the entire harvester is verified by multiplying the effective power calculated by Equation (11) by four.

&Quot; (9) "

&Quot; (10) "

&Quot; (11) "

은 실험횟수이며,

은 부하 저항이다.here,

Is the number of experiments,

Is the load resistance.

In order to analyze the power generated by the load resistance, the load resistance was changed in a frequency environment of 1 Hz using a 1:29 ratio speed gear module and the power generated at that time was analyzed.

The resistances were similar to those of the internal resistors, considering that the internal resistance was 33 Ω in total of 7 resistances used (10 Ω, 23 Ω, 27 Ω, 33 Ω, 39 Ω, 51 Ω and 1 kΩ).

The generated voltage was measured using an oscilloscope, and the power value was calculated using the measured voltage value after the rectifier circuit.

As a result, as shown in FIG. 16, a maximum power of 2.38 W was generated at a load resistance of 33 Ω, and maximum power was generated when the internal resistance and the load resistance were the same according to the maximum power transfer condition.

17 (a) is an analysis of generated power according to the frequency and the incremental gear ratio when the load resistance is 33 OMEGA. (B) is an analysis of power generation according to the frequency and the gear ratio at a load resistance of 1 K? It is a graph.

From the analysis results, the generated power increases linearly as the gear ratio increases, and it is confirmed that power increases as the frequency increases.

The maximum power of the foot type energy harvester proposed in the present invention was a power of 1:77 at the increased gear ratio, 33 Ω at the load resistance, and 25.36 W at the maximum at the frequency of 2 Hz.

Here, the energy harvester proposed in the present invention is designed such that effective power is generated even in a low frequency band because a frequency generated when a human is stepped on is extremely low as compared with other energy sources.

Therefore, the experiment also proceeded in the lower frequency band. Table 2 below shows the data summarizing the generated power measured according to the speed increasing gear ratio, the load resistance, and the frequency.

[Table 2] Unit (W)

FIG. 18 is a photograph of lighting a light emitting diode (LED) using a capacitor having a capacity of 3,200 부착 by attaching a rectifying circuit chip to the energy harvester proposed in the present invention. When a footstep is stepped once, 15 light emitting diodes It was able to light for about 20 seconds.

Therefore, the energy harvester proposed in the present invention does not need to match the resonance frequency, and it is expected that it can be applied to various fields because it can generate active power even at low frequency. Particularly, it is possible to utilize semi-permanent power generation as an emergency power source such as fire in public facilities and power-free power indicator, as well as being able to harvest energy from buildings, subways,

Therefore, the energy harvester using the electromagnetic induction method according to the present invention can be constructed by a solenoid coil and an electromagnet using a electromagnetic induction method, and the gear ratio of the spur gears provided in the gear module are designed differently, And to generate electrical energy in the power generation module according to the rotational displacement by changing the vertical displacement due to the movement of the module 310 to the rotational displacement through the gear module.

More specifically, the footbed-type energy harvester proposed in the present invention changes the vertical motion generated at the time when the footrest is pressed by an external load to a rotary motion using a rack gear, and the changed rotary motion is transmitted through a speed- In order to verify the efficiency of the proposed stepped-type energy harvester, the modeling is done by simulation and the gear ratio (1:29, 1:50, 1 : 77) and the generated power according to the frequency. Also, the maximum power transfer condition was analyzed by measuring the generated power according to the load resistance.

In addition, the footbed type energy harvester proposed in the present invention generates a power of 33.3 W at a load of 1:77 and a frequency of 2 Hz at a maximum of 25.36 W, and the LED is turned on by connecting a capacitor and an LED to the rectifier circuit. Therefore, the scaffold type energy harvester was developed for the purpose of installation in a place where the floating population such as the entrance of a building or a subway turnstile is high, and has a high energy conversion efficiency even at a low frequency. Therefore, It is expected that it will be possible to use as.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

100: scaffold type energy harvester 110: upper frame
120: lower frame 130: press spring
140: frame spring 200: first energy harvesting module
300: second energy harvesting module 310: ascending / descending module
311: Rack gear 320: Incremental gear module
321: drive gear 330: generator module
331: Cylindrical housing 332: Magnetic body
333: solenoid coil 334: rotating shaft

Claims (9)

A lower frame (120) having a plurality of press springs (130) formed at regular intervals on a surface outer surface; And
A first energy harvest module (200) located on the lower frame (120);
A second energy harvesting module (300) located on the lower frame (120) and arranged to face the first energy harvesting module (200); And
A first energy harvesting module (200) and an upper frame (110) located on the second energy harvesting module,
The first energy harvesting module 200 and the second energy harvesting module 300,
The pressing force is applied to the plurality of springs by the vertical force externally provided to compress the plurality of springs, and when the vertical force is extinguished, the pressing spring 130 performs a vertical movement by the elastic force of the press spring 130, Wherein the electromagnetic induction energy generated by the rotary motion is generated by converting the vertical displacement into the rotary motion after generating the displacement.
The method according to claim 1,
The first energy harvesting module 200 and the second energy harvesting module 300,
A vertical movement of the upper frame 110 is performed to lower the plurality of press springs 130. When the vertical force is extinguished, Up / down module 310 for generating a vertical displacement in accordance with a rising / falling operation;
A speed increasing gear module 320 for converting the vertical displacement of the lifting / lowering module 310 into rotational motion; And
And a generator module (330) generating AC energy according to the direction of the rotational motion provided by the speed increasing gear module (320).
The method according to claim 1,
Further comprising a rectifying circuit for converting the alternating-current energy into direct-current energy.
The method of claim 3,
Further comprising an energy accumulator for storing the DC energy. ≪ RTI ID = 0.0 > 11. < / RTI >
The method according to claim 1,
The speed increasing gear module 320,
Wherein the number of gears is adjusted in accordance with the number of revolutions to be increased and the speed transmission ratio of the two spur gears

Is expressed by Equation (2). ≪ EMI ID = 1.0 >
&Quot; (2) "

Here, z is the number of teeth of the spur gear,

Means the number of revolutions of the spur gear, and the speed transmission ratio

Is smaller than 1 (

) Incremental gear,

Back gear,

Side reverse gear.
6. The method of claim 5,
In the two-stage spur gear,
Wherein a pair of spur gears having different diameters are combined with each other.
6. The method of claim 5,
The ascending / descending module 310,
Wherein a rack gear (311) is provided in a height direction on a work surface, and the vertical displacement generated in the rack gear (311) induces a rotation angle of the driving gear (321) Type energy harvester.
8. The method of claim 7,
The rotation angle
And is derived from Equation (1) below. ≪ EMI ID = 1.0 >
[Equation 1]

At this time,

,

,

,

Means the amount of movement of the rack gear 311, the number of teeth of the driving gear, the tooth surface of the driving gear, and the pitch of the gear.
3. The method of claim 2,
The generator module (330)
A cylindrical housing 331;
A magnetic body 332 provided on an inner surface of the cylindrical housing 331;
A rotating shaft 334 provided at an inner center of the cylindrical housing 331 and rotated in accordance with rotation of the speed increasing gear module; And
And a solenoid coil 333 wound on the rotating shaft 334 a plurality of times in one direction,
And the induction electromotive force is generated due to the rotation direction of the solenoid coil (333) varying with rotation of the rotation shaft (334).

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