Study on Energy Harvester Using Dynamic Vibration Absorber ...Œ¯動/RotO...Study on Energy Harvester Using Dynamic Vibration Absorber for Automotive Applications Yasuyuki Takamura,

Study on Energy Harvester Using Dynamic Vibration Absorber for Automotive Applications

◎Yasuyuki Takamura, Katsuhiro Hirata,

Noboru Niguchi, Masayuki Kato (Osaka University)

Yuki Tojima, Takeshi Tojo,

Hiroki Koguchi, Keisuke Ushida (AISIN SEIKI CO,.Ltd)

EM10

26th July 2018

2Contents

◎Introduction

◎Simulation on drive train components・Frequency characteristics・Decision of the engine speed range harvesting

◎Proposal of the power generation device

◎Power generation simulation of the simple model・Operating theory・Investigation of the effectiveness of the proposed device

◎Conclusion

3Contents

◎Introduction




◎Conclusion

Problem of noise

Noise during driving

4

Generating mechanism of muffled sound

Engine T/M

Diff

Tire

Driveshaft

Clutch

5

Torque fluctuation(3-cylinders engine)

Inhalation Compression Explosion Exhaust

Vibration control of driving system6

Frequency characteristic of driveshaft

・Muffled sound generates at frequencies higher 15 Hz・All the energy of vibrations is converted into losses such as a heat andsound

Technique

Problem

・Design drive train components not to resonate with the torque fluctuation

General measure against muffled sound

(FF,MT)

Torsional vibration of shaft

→Energy of vibration is consumed as loss of heats

→Decrease the vibrations generated bythe engine torque

Engine T/M

Diff

Tire

Driveshaft

Clutch

Muffled sound

7

Damper

Measure using damper clutch

Torque fluctuation

Proposed device harvesting energy

(FF,MT)

Torsional vibration of shaft

Torque fluctuation Engine T/M

Diff

Tire

Driveshaft

Clutch

Muffled sound

8

Development of a power generation device harvesting energy of vibrations→Decrease muffled sound without losses of

energy→ Utilization electric power generated

Purpose

Power generation device

9Contents

◎Introduction




◎Conclusion

Simulation on drive train components

In order to simulate the torsional vibrations simply, we use a 2-inertia system model

・Effectiveness harvesting energy utilizing a mechanical resonance

・Relationship between the engine speed and harvested energy

Examination

10

T

1I 2IK

D

1 2

(Engine) (Generation device)

Frequency characteristics

Moment of inertia of the engine [kgm2] I1=0.14

Moment of inertia of the generation device [kgm2] I2=0.07

Synthetic inertia [kgm2] 1

𝐼=

1

𝐼1+

1

𝐼2

Spring constant [Nm/rad] K=Iω2=414(15Hz)

Viscosity coefficient [Nms/rad] D=K/1000=0.414

Frequency of the excitation force is changed from 1Hz to 30Hz,Amplitude of the excitation force is 2Nm, the offset is 5Nm

The excitation force（15Hz）

11

T

1I 2IK

D

1 2


Mathematical model

gen212111 TDKTI

gen212122 TDKI

121gen

2

21

2

21

2

11

2

222

1

2

1

2

11 TTDKII

dt

Torque of the generation device ※ Gain21gen T

12

T

1I 2IK

D

1 2


Frequency characteristics

121gen

2

21

2

21

2

11

2

222

1

2

1

2

11 TTDKII

dt

Input power Harvested energy

It is effective to harvest energy utilizing a mechanical resonance

13

Resonance frequency (15Hz)

Decision of the engine speed harvesting energy

The moment of inertia of the engine [kgm2] I1=0.14

The moment of inertia of the generation device[kgm2] I2=0.007~0.07

The synthetic inertia [kgm2] 1

𝐼=

1

𝐼1+

1

𝐼2

The spring constant [Nm/rad] K=I･ω 2

The viscosity coefficient [Nms/rad] D=K/1000

The frequency of the excitation force is changed from 15Hz, 75Hz,162.5HzThe amplitude of the excitation force is 2Nm, the offset is 5Nm.

Excitation force（15Hz）

14

T

1I 2IK

D

1 2


・harvesting in the lower engine speed ・designing the device so that I2 becomes large

Harvested energyTorsional vibration (I2=0.07)

15Decision of the engine speed harvesting energy

The harvested energy increases

16Contents

◎Introduction




◎Conclusion

Structure of the proposed device

Yoke 50JN400/JFE Steel

Magnet N42SH/Shin-Etsu Chemical

Number of pole 8

Number of slots 8

Coil turns per teeth 40

Iron stack length[mm] 50

Shaft diameter[mm] 16

Inner rotor length[mm] 6

Teeth length[mm] 16

Teeth width[mm] 10.7

Air gap length[mm] 0.5

Magnet length[mm] 3

Outer rotor[mm] 11

Basic specifications

Outer rotor

Inner rotor

Permanent magnet

Coil

Outer yoke

Inner yoke

Shaft

Generation device

17

Analysis model and conditions

Analysis model(Stable point)

Analysis conditions

Number of elements 35460

Number of nodes 13946

Number of steps 91

Remanence of Magnet[T] 1.3

CoilsNumber of turn per

teeth40

18

Analysis result

Cogging torque Flux linkage coils

Peak torque[Nm] 12.24

Spring constant[Nm/rad] 77.29

Magnet Flux[Wbp-p] 0.502

The device can utilize the Cogging torque as the spring constant

19

Problem of the proposed device

In the stable point, the proposed device can not output

20

In the unstable point

In the stable point

21Contents

◎Introduction




◎Conclusion

Power generation simulation

Moment of inertia of the engine [kgm2] I1=0.14

Moment of inertia of the generation device [kgm2] I2=0.013

Synthetic inertia [kgm2] 1

𝐼=

1

𝐼1+

1

𝐼2

Spring constant [Nm/rad] Km=105

Viscosity coefficient [Nms/rad] D=K/1000

Coil resistance [W] R=1.04

The frequency of the excitation force is 15HzThe amplitude of the excitation force is 2Nm, the offset is 5Nm

Excitation force (15Hz）

22

T

1I 2I

1 2

genT

(Generation device)(Engine)

Operating theory

gen2111 TDTI

gen2122 TDI

motion equations

0b KiLRi

Circuit equation

cgen TTT i

electromagnetic torque

※Ti: current torque，Tc: cogging torque

※L: Inductance，Kb: back EMF constant

T

1I 2I

1 2

genT

23

21 ，

Mathematical model of simulations

Simulation of the power generation due to torsional vibrations

θ1,2 i

𝑇𝑖，𝑇𝐶θ1,2T

1I 1I

1I 2I

2I

24

Motion equations Circuit equation

・Induced voltage

・Inductance

Magnetic equation

Electromagnetic Torque

・Current torque

・Cogging torque

Result of simulations

Voltage and Current

・The proposed device can convert the energy of torsional vibrations to magnetic energy and output as electric energy

・The amount of power generation is small

25

Amount of power generation

Adjusting the phase 26

・The phase difference is about 90 degrees・The amount of power generation decreases

tan𝜓 = −𝜔𝐿

𝑅∝ 𝑁

𝜓：the phase angle𝜔：frequency of vibration

𝐿：Inductance𝑅：Coil resistance(1.04W)

𝑁:the number of coils

Inductance

wL

R実軸

虚軸

Y

𝜓 ≒ 84

The amount of power generation increases by adjusting the phase

27Contents

◎Introduction




◎Conclusion

28Summary

◎Simulation on drive train components・Frequency characteristics➡It is effective to harvest energy utilizing a mechanical resonance

・Decision of the engine speed range harvesting➡The harvested energy increases and the amount of generation

power increases by harvesting in the lower engine speed


◎Power generation simulation of the simple model・Investigation of the effectiveness of the proposed device➡The proposed device can convert the energy of torsional vibrations

to magnetic energy and output as electric energy➡The amount of power generation increases by adjusting the phase

Documents

Study on Energy Harvester Using Dynamic Vibration Absorber ...Œ¯動/RotO...Study on Energy Harvester Using Dynamic Vibration Absorber for Automotive Applications Yasuyuki Takamura,