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Collaborative Energy Conservation in a Microgrid Mohit Jain [email protected] IBM Research India
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Page 1: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Collaborative Energy Conservation in a Microgrid

Mohit Jain [email protected]

IBM Research India

Page 2: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

KBFSC Kuala Belalong Field Studies Centre In Brunei, a country in SE Asia, close to Malaysia A research centre located in a tropical evergreen rainforest Visited by biologists and ecologists from all over the world.

Page 3: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

KBFSC

Page 4: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

KBFSC

India ! Bandar Seri Begawan ! Bangar ! Temburong ! KBFSC 1 day of travel with 4 different modes of transportation

Page 5: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

State-of-the-art 40 occupants (30 researchers+10 staff)

Primary Appliances: lights, fans Secondary Appliances: dryer, washer, heater, lab equipment

Page 6: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

State-of-the-art 40 occupants (30 researchers+10 staff)

Primary Appliances: lights, fans Secondary Appliances: dryer, washer, heater, lab equipment

No direct grid connection

3 diesel generators (DG) for 5 buildings

DG hours: 6-9am and 4-11pm (~10 hrs)

DG consumption: ~30 L/day

Page 7: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

State-of-the-art 40 occupants (30 researchers+10 staff)

Primary Appliances: lights, fans Secondary Appliances: dryer, washer, heater, lab equipment

No direct grid connection

3 diesel generators (DG) for 5 buildings

DG hours: 6-9am and 4-11pm (~10 hrs)

DG consumption: ~30 L/day

Transporting diesel is difficult

Page 8: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Objective Increase Power Availability

Page 9: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Objective

Reduce Diesel Consumption

Increase Power Availability

Page 10: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Objective

Reduce Diesel Consumption

Increase Power Availability

Minimize Visitor Inconvenience

Page 11: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Further Constraints

Only about 1-2 hrs of direct sunshine per day

River too shallow Wind speed too low

Page 12: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

State-of-the-art Analysis Underutilized DG

"  Loaded to only 30% of its capacity "  DG fuel efficiency characteristics is non-linear "  At KBFSC, DG is sized for worst load

Page 13: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

State-of-the-art Analysis Underutilized DG

"  Loaded to only 30% of its capacity "  DG fuel efficiency characteristics is non-linear "  At KBFSC, DG is sized for worst load

Fixed (unrequired) DG hours "  DG being ON even with no (or small) loads "  Increasing DG hours can lead to inadvertent wastage, while

decreasing DG hours can lead to visitor inconvenience

Inconvenient DG hours

No DG = No load (not even fans or lights)

Page 14: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Solution

Page 15: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Solution Battery bank

To supply power to small but convenience (primary) loads, such as lights and fans

Page 16: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Solution Battery bank

To supply power to small but convenience (primary) loads, such as lights and fans

Collaborative Scheduler Provides visitor a UI to choose when they want to use a particular secondary appliance

Page 17: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Solution Battery bank

To supply power to small but convenience (primary) loads, such as lights and fans

Collaborative Scheduler Provides visitor a UI to choose when they want to use a particular secondary appliance

DG Optimizer A software that uses load of secondary appliances and battery status, to suggest optimal DG hours

Page 18: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Solution

Page 19: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

I. Battery Bank

Supply power to small primary loads

Lead acid batteries were deployed

Extra advantage: High loaded DG is efficient Battery bank can act as load aggregator

Page 20: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

II. Collaborative Scheduler

Select Activity

Select Duration

Recommended time (2:30-4 PM)

Admin login

Selected time (2-5 PM)

Feedback (Green-ness, your contribution)

Walk-up-and-use kiosk | Minimal interaction

Page 21: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

II. Collaborative Scheduler

Select Activity

Select Duration

Recommended time (2:30-4 PM)

Admin login

Selected time (2-5 PM)

Feedback (Green-ness, your contribution)

Walk-up-and-use kiosk | Minimal interaction | Minimal learning curve

Page 22: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

II. Collaborative Scheduler

Type 4: 1800 W Duration: 2 hrs

Time period: 6-12

Page 23: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer Schedule running time of each request Compute DG running schedule

corresponding fuel consumption for the diesel generator, ascalculated from the relevant DG consumption data sheet [1].Note that the energy received by the battery is a function ofits state of charge and dynamics in the battery model [14],and hence drives the fuel consumption of the generator. Asexplained previously, the battery lifetime depreciation is in-cluded in the system model [6]. The objective function forthe optimisation procedure is,

J =N

Â1

ui [FB(c(i))+FS(i)+(1�ui�1)Fstart] . (1)

Here, ui 2 {0,1} is the binary decision taken at time i,controlling the operation or otherwise of the DG. PS(i) is theexpected power profile of secondary appliances in time stepi derived from the first optimisation step, and FS(i) is the cor-responding diesel usage. The spool-up cost Fstart is countedonly if the DG is running in the current time period, and wasnot running in the previous time period. It is assumed that itsinitial state is u0 = 0. The optimal schedule can be computedby using Dijkstra’s algorithm to solve a shortest path prob-lem [5] from the initial state (i = 0 and battery charge equalto the initial charge level) to each feasible final state (i = Nand the battery’s final state of charge lower bounded by itsinitial state of charge). The optimisation algorithm beginsfrom a known initial state at i = 0. It explores each of twooptions: battery charging (generator ON) or battery discharg-ing (generator OFF), and arrives at two potential destinationstates accordingly. The cost to reach each state is the dieselconsumed by the sequence of decisions culminating in thecurrent state of charge at the current time. This cost is savedby the algorithm, along with the battery state in the previoustime step and the decision taken at the previous time step.The algorithm proceeds in this way to the end of the timewindow, where it is constrained to only consider final statesthat replenish the battery levels to their starting values, orhigher.

The optimal control computation algorithm is given inAlgorithm 1. We define the following matrices of sizeM2 ⇥ (N + 1), with rows representing state of charge of thetwo batteries and columns representing time. Note that the(N +1)th column represents the end of the final time period.

• F , with each element containing the minimum fuel toreach state ( j, i) where i is an integer, 0 i N,

• C , with each element containing the charge level at timestep (i � 1) on the optimal path from (c(0),0) to ( j, i),and

• D , containing the decision taken at time step (i�1) onthe optimal path from (c(0),0) to ( j, i).

This procedure is illustrated schematically in Fig. 7, withtime on the X-axis, and potential combinations of charge lev-els on the Y-axis. The starting state is well defined, whilethe acceptable final charge levels form a subset of all thepotential charge levels. By accounting for battery dynam-ics, a feasible region such as the one depicted in Fig. 7is automatically defined and explored by the dynamic pro-gramming algorithm. If the level of each charge well in theKiBaM [14] battery model is divided into M intervals, themaximum number of reachable states at any time step is M2,

Recommended DG run timing

Feedback (power consumption and diesel usage)

Admin selected DG run timing

Selected DG run timings

Activity bar

Visitor input

Figure 9: Administrator Interface of Collaborative Scheduler

in the current time period, and was not running in the previous timeperiod. It is assumed that its initial state is u0 = 0. The optimalschedule can be computed by using Dijkstra’s algorithm to solve ashortest path problem [5] from the initial state (i = 0 and batterycharge equal to the initial charge level) to each feasible final state(i = N and the battery’s final state of charge lower bounded by itsinitial state of charge). The optimisation algorithm begins from aknown initial state at i = 0. It explores each of two options: batterycharging (generator ON) or battery discharging (generator OFF),and arrives at two potential destination states accordingly. The costto reach each state is the diesel consumed by the sequence of deci-sions culminating in the current state of charge at the current time.This cost is saved by the algorithm, along with the battery state inthe previous time step and the decision taken at the previous timestep. The algorithm proceeds in this way to the end of the timewindow, where it is constrained to only consider final states thatreplenish the battery levels to their starting values, or higher.

The optimal control computation algorithm is given in Algo-rithm 1. We define the following matrices of size M2 ⇥(N+1), withrows representing state of charge of the two batteries and columnsrepresenting time. Note that the (N + 1)th column represents theend of the final time period.

• F , with each element containing the minimum fuel to reachstate ( j, i) where i is an integer, 0 i N,

• C , with each element containing the charge level at time step(i�1) on the optimal path from (c(0),0) to ( j, i), and

• D , containing the decision taken at time step (i � 1) on theoptimal path from (c(0),0) to ( j, i).

This procedure is illustrated schematically in Fig. 10, with timeon the X-axis, and potential combinations of charge levels on theY-axis. The starting state is well defined, while the acceptable fi-nal charge levels form a subset of all the potential charge levels.By accounting for battery dynamics, a feasible region such as theone depicted in Fig. 10 is automatically defined and explored bythe dynamic programming algorithm. If the level of each chargewell in the KiBaM [14] battery model is divided into M intervals,the maximum number of reachable states at any time step is M2,and the number of decisions available at any state of charge is atmost 2. Thus, the maximum number of computations required tofind the optimum generator schedule is 2NM2. The computationalcomplexity thus scales linearly with the time dimension.

5 Results5.1 DG Optimizer Evaluation

In this section, we estimate the benefits delivered by the optimi-sation procedure using simulations that extrapolate from empirical

Algorithm 1 Optimal control computation

1. Initialize: Time i = 0, all elements of F set to � except forinitial state F (c(0),0) = 0, all elements of C and D set to-1

2. For all i in {0,N �1}:3. For all j such that F ( j, i) < �:

(a) Evaluate j+i+1, charge at time (i+1) with ui = 1(b) Evaluate stage cost F+( j, i) from ( j, i) to ( j+i+1, i+1)

(c) If state ( j+i+1, i+1) satisfies problem constraints andF ( j, i)+F+( j, i) < F ( j+i+1, i+1):

(d) **New optimal path found**i. Set F ( j+i+1, i+1) = F ( j, i)+F+( j, i)

ii. Set C ( j+i+1, i+1) = jiii. Set D( j+i+1, i+1) = 1

EndIf(e) If PS(i) = 0:(f) **DG in OFF state is feasible**

i. Evaluate j�i+1, charge at time (i+1) with ui = 0ii. Stage cost F�( j, i) = 0 from ( j, i) to ( j�i+1, i+1)

iii. If state ( j�i+1, i+1) satisfies problem constraintsand F ( j, i)+F�( j, i) < F ( j�i+1, i+1):

iv. **New optimal path found**A. Set F ( j�i+1, i+1) = F ( j, i)+F�( j, i)B. Set C ( j�i+1, i+1) = jC. Set D( j�i+1, i+1) = 0EndIf

EndFor4. EndFor5. Find j⇤ such that F ( j⇤,N) = min j2Jfin F ( j,N), where Jfin

is the set of feasible final charge levels6. Trace backward from C ( j⇤,N) and D( j⇤,N) to compute

optimal decision vector

and the number of decisions available at any state of chargeis at most 2. Thus, the maximum number of computationsrequired to find the optimum generator schedule is 2NM2.The computational complexity thus scales linearly with thetime dimension.

5 Results5.1 DG Optimizer Evaluation

In this section, we estimate the benefits delivered by theoptimisation procedure using simulations that extrapolatefrom empirical data. DG and battery model (KiBaM) pa-rameters used in this section were taken from vendor datasheets. It is assumed that users use the interface described

0"

5"

10"

15"

20"

25"

30"

35"

40"

45"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Case"571" Case"572" Case"573" Case"2571" Case"2572" Case"2573" Case"2574"

Fuel"Cost"($)" Ba@ery"Cost"($)"

Figure 8: Cost comparison between Only DG, Hybrid & C-Hybrid

Problem

Page 24: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer Schedule running time of each request Compute DG running schedule Minimize the diesel consumption Scheduling requests

power rating, usage duration, selected time period

Current battery charge level

corresponding fuel consumption for the diesel generator, ascalculated from the relevant DG consumption data sheet [1].Note that the energy received by the battery is a function ofits state of charge and dynamics in the battery model [14],and hence drives the fuel consumption of the generator. Asexplained previously, the battery lifetime depreciation is in-cluded in the system model [6]. The objective function forthe optimisation procedure is,

J =N

Â1

ui [FB(c(i))+FS(i)+(1�ui�1)Fstart] . (1)

Here, ui 2 {0,1} is the binary decision taken at time i,controlling the operation or otherwise of the DG. PS(i) is theexpected power profile of secondary appliances in time stepi derived from the first optimisation step, and FS(i) is the cor-responding diesel usage. The spool-up cost Fstart is countedonly if the DG is running in the current time period, and wasnot running in the previous time period. It is assumed that itsinitial state is u0 = 0. The optimal schedule can be computedby using Dijkstra’s algorithm to solve a shortest path prob-lem [5] from the initial state (i = 0 and battery charge equalto the initial charge level) to each feasible final state (i = Nand the battery’s final state of charge lower bounded by itsinitial state of charge). The optimisation algorithm beginsfrom a known initial state at i = 0. It explores each of twooptions: battery charging (generator ON) or battery discharg-ing (generator OFF), and arrives at two potential destinationstates accordingly. The cost to reach each state is the dieselconsumed by the sequence of decisions culminating in thecurrent state of charge at the current time. This cost is savedby the algorithm, along with the battery state in the previoustime step and the decision taken at the previous time step.The algorithm proceeds in this way to the end of the timewindow, where it is constrained to only consider final statesthat replenish the battery levels to their starting values, orhigher.

The optimal control computation algorithm is given inAlgorithm 1. We define the following matrices of sizeM2 ⇥ (N + 1), with rows representing state of charge of thetwo batteries and columns representing time. Note that the(N +1)th column represents the end of the final time period.

• F , with each element containing the minimum fuel toreach state ( j, i) where i is an integer, 0 i N,

• C , with each element containing the charge level at timestep (i � 1) on the optimal path from (c(0),0) to ( j, i),and

• D , containing the decision taken at time step (i�1) onthe optimal path from (c(0),0) to ( j, i).

This procedure is illustrated schematically in Fig. 7, withtime on the X-axis, and potential combinations of charge lev-els on the Y-axis. The starting state is well defined, whilethe acceptable final charge levels form a subset of all thepotential charge levels. By accounting for battery dynam-ics, a feasible region such as the one depicted in Fig. 7is automatically defined and explored by the dynamic pro-gramming algorithm. If the level of each charge well in theKiBaM [14] battery model is divided into M intervals, themaximum number of reachable states at any time step is M2,

Recommended DG run timing

Feedback (power consumption and diesel usage)

Admin selected DG run timing

Selected DG run timings

Activity bar

Visitor input

Figure 9: Administrator Interface of Collaborative Scheduler

in the current time period, and was not running in the previous timeperiod. It is assumed that its initial state is u0 = 0. The optimalschedule can be computed by using Dijkstra’s algorithm to solve ashortest path problem [5] from the initial state (i = 0 and batterycharge equal to the initial charge level) to each feasible final state(i = N and the battery’s final state of charge lower bounded by itsinitial state of charge). The optimisation algorithm begins from aknown initial state at i = 0. It explores each of two options: batterycharging (generator ON) or battery discharging (generator OFF),and arrives at two potential destination states accordingly. The costto reach each state is the diesel consumed by the sequence of deci-sions culminating in the current state of charge at the current time.This cost is saved by the algorithm, along with the battery state inthe previous time step and the decision taken at the previous timestep. The algorithm proceeds in this way to the end of the timewindow, where it is constrained to only consider final states thatreplenish the battery levels to their starting values, or higher.

The optimal control computation algorithm is given in Algo-rithm 1. We define the following matrices of size M2 ⇥(N+1), withrows representing state of charge of the two batteries and columnsrepresenting time. Note that the (N + 1)th column represents theend of the final time period.

• F , with each element containing the minimum fuel to reachstate ( j, i) where i is an integer, 0 i N,

• C , with each element containing the charge level at time step(i�1) on the optimal path from (c(0),0) to ( j, i), and

• D , containing the decision taken at time step (i � 1) on theoptimal path from (c(0),0) to ( j, i).

This procedure is illustrated schematically in Fig. 10, with timeon the X-axis, and potential combinations of charge levels on theY-axis. The starting state is well defined, while the acceptable fi-nal charge levels form a subset of all the potential charge levels.By accounting for battery dynamics, a feasible region such as theone depicted in Fig. 10 is automatically defined and explored bythe dynamic programming algorithm. If the level of each chargewell in the KiBaM [14] battery model is divided into M intervals,the maximum number of reachable states at any time step is M2,and the number of decisions available at any state of charge is atmost 2. Thus, the maximum number of computations required tofind the optimum generator schedule is 2NM2. The computationalcomplexity thus scales linearly with the time dimension.

5 Results5.1 DG Optimizer Evaluation

In this section, we estimate the benefits delivered by the optimi-sation procedure using simulations that extrapolate from empirical

Algorithm 1 Optimal control computation

1. Initialize: Time i = 0, all elements of F set to � except forinitial state F (c(0),0) = 0, all elements of C and D set to-1

2. For all i in {0,N �1}:3. For all j such that F ( j, i) < �:

(a) Evaluate j+i+1, charge at time (i+1) with ui = 1(b) Evaluate stage cost F+( j, i) from ( j, i) to ( j+i+1, i+1)

(c) If state ( j+i+1, i+1) satisfies problem constraints andF ( j, i)+F+( j, i) < F ( j+i+1, i+1):

(d) **New optimal path found**i. Set F ( j+i+1, i+1) = F ( j, i)+F+( j, i)

ii. Set C ( j+i+1, i+1) = jiii. Set D( j+i+1, i+1) = 1

EndIf(e) If PS(i) = 0:(f) **DG in OFF state is feasible**

i. Evaluate j�i+1, charge at time (i+1) with ui = 0ii. Stage cost F�( j, i) = 0 from ( j, i) to ( j�i+1, i+1)

iii. If state ( j�i+1, i+1) satisfies problem constraintsand F ( j, i)+F�( j, i) < F ( j�i+1, i+1):

iv. **New optimal path found**A. Set F ( j�i+1, i+1) = F ( j, i)+F�( j, i)B. Set C ( j�i+1, i+1) = jC. Set D( j�i+1, i+1) = 0EndIf

EndFor4. EndFor5. Find j⇤ such that F ( j⇤,N) = min j2Jfin F ( j,N), where Jfin

is the set of feasible final charge levels6. Trace backward from C ( j⇤,N) and D( j⇤,N) to compute

optimal decision vector

and the number of decisions available at any state of chargeis at most 2. Thus, the maximum number of computationsrequired to find the optimum generator schedule is 2NM2.The computational complexity thus scales linearly with thetime dimension.

5 Results5.1 DG Optimizer Evaluation

In this section, we estimate the benefits delivered by theoptimisation procedure using simulations that extrapolatefrom empirical data. DG and battery model (KiBaM) pa-rameters used in this section were taken from vendor datasheets. It is assumed that users use the interface described

0"

5"

10"

15"

20"

25"

30"

35"

40"

45"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Only"DG

"Hy

brid"

C"Hy

brid"

Case"571" Case"572" Case"573" Case"2571" Case"2572" Case"2573" Case"2574"

Fuel"Cost"($)" Ba@ery"Cost"($)"

Figure 8: Cost comparison between Only DG, Hybrid & C-Hybrid

Problem

Objective

Input

Page 25: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer Step 1: Schedule running time of each request DG efficiency is highest when DG is loaded close to its capacity Heuristic: Run as many appliance as possible, at any given time (Bin Packing problem).

a.  Start with the most constrained appliance (with minimal padding between usage duration and selected time period).

b.  Schedule successive appliances by maximizing the overlap with already scheduled appliances.

Page 26: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer Step 2: Compute DG running schedule Use the aggregate power profile generated in Step 1. Objective function: J = Σ ui [ FB(c(i)) + FS(i) + (1 - ui-1)Fstart ]

This formulation is solved using DP approach (full algorithm in paper)

N

1

{0,1} Binary decision

at time i

Fuel usage by Battery

c(i): State of battery charge

at time i

Fuel usage by secondary appliances

Spool-up Cost

Page 27: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer

0000" 0300" 0600" 0900" 1200"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Primary App !0000"1500" 1800" 2100"

Original Scenario

Page 28: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer

0000" 0300" 0600" 0900" 1200"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Primary App !

!

0000"1500" 1800" 2100"

!

Original Scenario

Page 29: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer

Altered Scenario

0000" 0300" 0600" 0900" 1200"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Primary App !

0000" 0000"0300" 1200" 1500"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Battery Charge

Primary App

!

0000"1500" 1800" 2100"

!

0600" 0900" 1800" 2100"

Original Scenario

c"

Page 30: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer

Altered Scenario

0000" 0300" 0600" 0900" 1200"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Primary App !

0000" 0000"0300" 1200" 1500"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Battery Charge

Primary App

!

0000"1500" 1800" 2100"

!

0600" 0900" 1800" 2100"

Original Scenario

Page 31: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

III. DG Optimizer

Altered Scenario

0000" 0300" 0600" 0900" 1200"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Primary App !

0000" 0000"0300" 1200" 1500"

Fuel Use

DG Max

DG

Secondary App A

Secondary App B

Battery Charge

Primary App

!

0000"1500" 1800" 2100"

!

0600" 0900" 1800" 2100"

Less Fuel Consumption

High Power Availability

Original Scenario

Page 32: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Results Run"DG"whenever"there"is"non9zero"demand"(state9of9the9art)"Run"all"appliances"from"baDery;"run"DG"opGmally"to"recharge"the"baDery"Run"primary"appliances"from"baDery,"and"secondary"appliances"from"DG"

Only&DG&Hybrid&

C&Hybrid"

Page 33: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Results Run"DG"whenever"there"is"non9zero"demand"(state9of9the9art)"Run"all"appliances"from"baDery;"run"DG"opGmally"to"recharge"the"baDery"Run"primary"appliances"from"baDery,"and"secondary"appliances"from"DG"

Only&DG&Hybrid&

C&Hybrid"

Page 34: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Results C Hybrid performs almost as good as pure Hybrid Hybrid: both primary and secondary loads run from the battery, and DG is used only to recharge the battery

–  Higher wear and tear of the battery –  As electricity is freely available from the battery at any

time of the day, users may tend to be less economical in their usage

Page 35: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Results

0"

10"

20"

30"

40"

50"

60"

70"

80"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W" 1000"W"1500"W"2000"W"5000"W"0"

10"

20"

30"

40"

50"

60"

70"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W"1000"W"1500"W"2000"W"5000"W"

Only%DG%

Hybrid%

C%Hybrid%

A B

33.3% 20.1%

Primary Load Primary Load Fu

el C

ost (

$)

Tota

l Cos

t ($)

0"

10"

20"

30"

40"

50"

60"

70"

80"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W" 1000"W"1500"W"2000"W"5000"W"0"

10"

20"

30"

40"

50"

60"

70"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W"1000"W"1500"W"2000"W"5000"W"

Only%DG%

Hybrid%

C%Hybrid%

A B

33.3% 20.1%

Primary Load Primary Load

Fuel

Cos

t ($)

Tota

l Cos

t ($)

Page 36: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Results

0"

10"

20"

30"

40"

50"

60"

70"

80"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W" 1000"W"1500"W"2000"W"5000"W"0"

10"

20"

30"

40"

50"

60"

70"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W"1000"W"1500"W"2000"W"5000"W"

Only%DG%

Hybrid%

C%Hybrid%

A B

33.3% 20.1%

Primary Load Primary Load Fu

el C

ost (

$)

Tota

l Cos

t ($)

0"

10"

20"

30"

40"

50"

60"

70"

80"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W" 1000"W"1500"W"2000"W"5000"W"0"

10"

20"

30"

40"

50"

60"

70"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W"1000"W"1500"W"2000"W"5000"W"

Only%DG%

Hybrid%

C%Hybrid%

A B

33.3% 20.1%

Primary Load Primary Load

Fuel

Cos

t ($)

Tota

l Cos

t ($)

0"

10"

20"

30"

40"

50"

60"

70"

80"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W" 1000"W"1500"W"2000"W"5000"W"0"

10"

20"

30"

40"

50"

60"

70"

10"W" 20"W" 50"W" 100"W" 200"W" 500"W"1000"W"1500"W"2000"W"5000"W"

Only%DG%

Hybrid%

C%Hybrid%

A B

33.3% 20.1%

Primary Load Primary Load

Fuel

Cos

t ($)

Tota

l Cos

t ($)

Page 37: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Summary Solution designed for reducing diesel consumption at KBFSC, a remote ecological field study centre in Brunei

The system consists of "  a battery bank to increase power availability to primary loads "  a collaborative scheduler for access to power for secondary loads "  a DG optimizer ensures that the DG run at the appropriate times to

minimize diesel consumption while keeping the batteries charged and meeting user needs

Simulations modeled on real data suggest that our system: "  provides uninterrupted power, oppose to 10 hours in the past "  reduces diesel consumption by 33.3% and total cost by 20.1%

Page 38: Collaborative Energy Conservation Microgridmjain/BuildSys-2014-PPT.pdf · 2014-11-10 · III. DG Optimizer Schedule running time of each request Compute DG running schedule corresponding

Thank You!

Mohit Jain [email protected]

Harshad Khadilkar Neha Sengupta

Zainul Charbiwala Deva P. Seetharam

Kushan U Tennakoon Rodzay bin Haji Abdul Wahab

Liyanage Chandratilak De Silva

IBM Research India

Institute for Biodiversity & Environmental Research

Universiti Brunei Darussalam


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