railtokyo 2015railtokyo2015.cs.it-chiba.ac.jp/pres/135p.pdfshoichiro watanabe (ph.d. candidate)...

Shoichiro WATANABE (Ph.D. Candidate)

Takafumi KOSEKI (Professor)

RailTokyo 2015,

6th International Conference on Railway Operations Modelling and Analysis

Oral Session: Energy-efficient driving and driver advisory systems

Outlines

Introduction & Purpose

(1) Energy-Saving Operation for A Train

Power-limiting Brake

Advantages of ATO

(2) Energy-Saving Train Scheduling

Basic Approach

Application to Practical Train Scheduling with Proposed Methods

Analysis for Energy-saving Scheduling

Conclusions & Future Work

2015/3/25 2

Outlines

Introduction & Purpose

(1) Energy-Saving Operation for A Train

Power-limiting Brake

Advantages of ATO

(2) Energy-Saving Train Scheduling

Basic Approach

Application to Practical Train Scheduling with Proposed Methods

Analysis for Energy-saving Scheduling

Conclusions & Future Work

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Introduction & Purpose

A Key to Solving Environment Problems

Some technologies have been developed

Hardware side Storages, Power device, Conversion control

Software side

(1) Energy-saving operation Optimal energy-saving running curve between two station Best use of regenerative braking with ATO

(2) Energy-saving scheduling Optimisation to change running time between every pairs of stations

based on (1) Energy-saving operation

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Purpose

Outlines

Introduction & Purpose

(1) Energy-Saving Operation for A Train

Power-limiting Brake

Advantages of ATO

(2) Energy-Saving Train Scheduling

Basic Approach

Application to Practical Train Scheduling with Proposed Methods

Analysis for Energy-saving Scheduling

Conclusions & Future Work

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What is Energy-Saving Operation?

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Energy-saving operation(11) was

i. Restriction of running time for scheduling

ii. Max accelerating, coasting and power-limiting braking

The best use of the regenerative brakes

[11] S. Watanabe and T. Koseki, “Train group control for energy-saving DC-electric railway operation,” 2014 International

Power Electronics Conference (IPEC-Hiroshima 2014-ECCE-ASIA), pp. 1334–1341, 2014.

Relationships of energy consumption

A < B

Advantages of ATO in Operation

The railway car is controlled by on-board computers

(1) Install optimised energy-saving operation in ATO

ATO system can keep running times with accuracies on the

order of seconds

(2) Design the optimised schedule between every pairs of stations

based on this energy-saving operation

2015/3/25 7 Human driver ATO

Advantages of ATO in Operation

The railway car is controlled by on-board computers

(1) Install optimised energy-saving operation in ATO

ATO system can keep running times with accuracies on the

order of seconds

(2) Design the optimised schedule between every pairs of stations

based on this energy-saving operation

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How to design the optimised schedule

based on (1) energy-saving operation?

Next Chapter

Outlines

Introduction & Purpose

(1) Energy-Saving Operation for A Train

Power-limiting Brake

Advantages of ATO

(2) Energy-Saving Train Scheduling

Basic Approach

Application to Practical Train Scheduling with Proposed Methods

Analysis for Energy-saving Scheduling

Conclusions & Future Work

2015/3/25 9

Basic Approach –Change The Running Time-

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Station A

Station B

Station C

Station D

Station A

Station B

Station C

Station D

Running time Running time

60 sec

120 sec

180 sec

50 sec

130 sec

180 sec

60

60

60

50

80

50

Total running time is not changed

Conventional schedule Optimal schedule

Energy-Saving

Basic Approach and Our Modification

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Basic approaches(15) are as follows:

1. Calculate the relationship between energy consumption and running

time for each section

2. Differentiate each curve of each section.

3. Choose the same differentiated value for each section.

The result obtained is some

decimal-point value

Accomplish scheduling in a

practical manner with

integer value

Modifying

[15] M. Miyatake, “A simple mathematical model for energy-saving

train scheduling,” IEEJ Transactions on Industry Applications, vol. 131,

pp. 860–861, 2011. (in Japanese)

Practical Scheduling with Proposed Methods

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Step1 •Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

Calculate the running curve based on energy-saving

operation.

Energy consumption Ei and running time ti

in the i-th section are determined.

Practical Scheduling with Proposed Methods

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Change the notch-off speed and calculate the

running curve.

Ei and ti in the i-th section will change.

Step1 •Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

①

①

②

②

③

③

Practical Scheduling with Proposed Methods

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Plot a graph with ti on the x axis and Ei on the y axis. Step1

•Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

Practical Scheduling with Proposed Methods

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Differentiate energy consumption with respect to

running time

Calculate the slope of the straight line that can be

drawn between any two points.

𝜽𝒊 =𝝏𝑬𝒊

𝝏𝒕𝒊 is energy time sensitivity in the i-th section

Step1 •Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

Practical Scheduling with Proposed Methods

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Plot each θi and ti value on a graph with

θi on the x axis and ti on the y axis

Step1 •Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

Practical Scheduling with Proposed Methods

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Calculate the sum of the ti values for each θi

The summation of ti is a total running time T.

𝛩 is common energy time sensitivity for all sections.

Step1 •Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

Practical Scheduling with Proposed Methods

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Given the limitation on the total running time T

Determine the optimal running time ti in each section

Step1 •Calculate Ei & ti

Step2 •Change notch-off speed

Step3 •Plot Ei & ti

Step4

•𝜃𝑖 =𝜕𝐸𝑖

𝜕𝑡𝑖

Step5 •Plot θi and ti

Step6 •Sum up a total running

time T

Step7 •Determine the optimal

running time ti

Scheduling in A Practical Manner With Integer Value

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START

Round the optimal running time to an integer value.

The total running time T is changed to T’.

T > T’ Choose the largest energy time

sensitivity and add 1 s in this section.

T < T’Choose the smallest energy time

sensitivity and subtract 1 s in this section.

FINISH

Outlines

Introduction & Purpose

Energy-Saving Operation for A Train

Power-limiting Brake

Advantages of ATO

Energy-Saving Train Scheduling

Basic Approach

Application to Practical Train Scheduling with Proposed Methods

Analysis for Energy-saving Scheduling

Conclusions & Future Work

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Calculation Conditions

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Parameters Remarks column

Number of cars 4 4M0T

Capacity ratio 100% Load-compensating device is

considered

Operation ATO

Single way

Not a round trip

Environment Subway Platform doors are installed

Number of sections 10

Total running time 713 s

Pantograph voltage DC 1500 V

DC 1650 V

In acceleration

In regeneration

Results of Common Energy Time Sensitivity

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Optimal Running Time from a Practical Point of View.

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0.1525

Analysis of Energy Consumption

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Cases Basic Optimised

Total running time 713 s 713 s

Changed sections - 10

Energy consumption 53.40 kWh 52.40 kWh

Energy savings - 1.00 kWh

Percent energy savings - 1.9 %

Outlines

Introduction & Purpose

Energy-Saving Operation for A Train

Power-limiting Brake

Advantages of ATO

Energy-Saving Train Scheduling

Basic Approach

Application to Practical Train Scheduling with Proposed Methods

Analysis for Energy-saving Scheduling

Conclusions & Future Work

2015/3/25 25

Conclusions & Future Work

(1) Energy-saving railway operation Power-limiting braking

(2) Energy-Saving train scheduling Optimisation of running time in track sections between stations

Practical scheduling method

Analysis for Energy-saving Scheduling Energy saving effects : 1.9%

Additional timetabling strategies for saving energy Reducing dwell and turnaround times and increasing running time

margins

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Future Work

Conclusions

Shoichiro WATANABE

The University of Tokyo

shoichiro@koseki.t.u-tokyo.ac.jp

2015/3/25 27