OPTIMIZATION OF SPEED PROFILE AND QUICK CHARGING

OF A CATENARY FREE TRAIN WITH ON-BOARD ENERGY STORAGE

19th October 2010

M. Miyatake and H. Haga Sophia University, Japan

INTRODUCTION

BackgroundApplication of energy storage devices to railwayIt enables effective use of regenerative energy. Some attempts for energy storage on-board can be seen.

Objective

catenary free sections

quick charging

terminal

catenary line

fast slow

a tramcar with small energy storage

Eco-driving and charging on the catenary-free sections saving energysmaller storage capacityAssumed scenario

downtown (transit mall etc.)

ContentsIntroductionModelingmain circuittrack profilenumerical optimizationResults of simulationsConclusion

MATHEMATICAL MODELING

Main Circuit

Electric Double Layer Capacitor (EDLC)

traction motor/inverter!"#$

!"

#$

$"!%

%internal resistance

weight: 300kgenergy density: 6.7Wh/kg

0.1[!]

40[F]

! "! #! $!

!%"!%#!%$!%&'%!'%"

!()**+,-./012

3456378*,9:46*,)*4,

654,;

*7<13,-=0.<2

tractive effort influenced by Vc

Track Conditions

short stop with quick charging

long stop with charging

running in section A

running in section B

T1 T2Ts Tt

t

Vc(t) IqcVc_max

x0m L1mT1 T2

Ts

section A section BL2m

terminal

The tramcar runs so as to minimize energy consumption.

variable

Optimal Eco-drivingu

0t

acc./dec.

t

v

T0

boundary conditions

t0

x

L

speed

!"#$%&'()(*+'"$,

$"-(

!

"#

Bellman’s Dynamic Programming (DP) is applied.

control input

speed profile

Strategy for Quick Charging

charging currentlarger currentlarger losseasier driving with higher SOC

charging time = stopping timelong charging timeshorter running time with higher SOC

RESULTS OF SIMULATIONS

time [s]

EDLC

volta

ge [V

]ve

locity

[km/

h]

Speed and Voltage Profiles

example of case AIqc=100[A]

length of sections 500[m]Ts =5,10,15,20,25 and 30 [s]

fixed conditions

Relation between Charging Time & Energy Consumption

optimal

Ts=5[s]

Ts=15[s]

time [s]

EDLC

vol

tage

[V]

case Csevere voltage drop

CONCLUSIONS

ConclusionSummaryThe rational train speed profile and quick-charging time and current can be discussed with the proposed optimization model. Future scope analyses under various conditionssystem implementation