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
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
2015/3/25 3
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
2015/3/25 20
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