2. Power Distribution Network
Cassandra Project 1st Workshop September 11, 2013
Small Industry
MV/LV Power
Transformer
Commercial
MV/LV Power
Transformer
MV/LV Power
Transformer
Residential
Residential
Commercial
Commercial
Overhead or Underground
Power Lines
HV/MV Power
Substation
Residential
3. Power Distribution Network
• Consumer Side (Demand Side)
• Demand Side Management
– Consumption optimization
– Energy efficiency
– Profit
• Problems
– Which is the profile of each
consumer?
– How to cluster/categorize
consumers?
– Which DSM program/incentive to offer
to each consumer?
Cassandra Project 1st Workshop September 11, 2013
4. Cassandra as a solution
• A helping hand in order to:
– Simulate the consumption of consumer populations,
– Understand behaviors that drive consumption,
– Cluster consumers into groups for more efficient incentivisation,
– Simulate consumer response to specific Demand Response programs
• Two modeling approaches:
– Input based on demographic data → aggregate results for a consumer
population
– Input based on consumer level measurements → bottom-up approach
with results regarding individual consumers and/or consumer
populations
Cassandra Project 1st Workshop September 11, 2013
5. Basic modeling concepts
• Reality:
– Installation (the aggregation of all the appliances installed within the
premises of a consumer)
– Person(s) performing activities by the use of appliances according to
their utility
– Person(s) have habits (recurrent behaviour)
– Person(s) receive incentives to modify consumption, and choose either
to respond or not according to their utility
Cassandra Project 1st Workshop September 11, 2013
6. Basic modeling concepts
• Modeling:
– An Installation consists of its Appliances
– Measurements of the installation are used in order to determine its
Appliances, as well as the consumer Activities (Disaggregation
procedure)
– Appliances are described by Consumption Models
– Consumer utility is modelled through Utility Models
– Consumer response to specific incentives is modelled through Response
Models
– Auxiliary Models:
• Pricing Schemes Models
• CO2 Emission Calculation
• Prosumer Generation
Cassandra Project 1st Workshop September 11, 2013
7. Functionality according to quality of input
• Basic simulation rule: The more information you offer as input,
the more accurate results you will obtain
• Demographic data input: The simulation will be based on statistics,
thus it will not produce accurate individual consumer results
• Measurement data input:
– The Cassandra modeling is based on per minute measurements of
active and reactive power for an installation (loss of information)
– Accuracy of results depends on information compensation
Cassandra Project 1st Workshop September 11, 2013
8. Appliance Consumption Models
• They define mathematically the active and reactive power
demand of an appliance for a specified time of operation
• Example: Refrigerator active power
Cassandra Project 1st Workshop September 11, 2013
𝑐 𝑝 𝑡 =
𝑘=1
𝑁
99.8 ∙ 𝑢 𝑡 − 𝑘2520 − 𝑢 𝑡 − 620 − 𝑘2520 , 𝑡 < 𝑑0
9. Activity Models
• They describe mathematically the occurrence, duration and
composition of an activity
𝐴 → 𝒂, 𝑓𝑠 𝑡 , 𝑓𝑑 𝑡 , 𝑓𝑁 𝑛
A set of appliances
associated with the
activity
The probability density
function (pdf) of the activity
start time(s) within a day
The pdf of the number of
times the activity is
performed during a day
The pdf of the activity
duration
𝑓𝑎 𝑖
𝑡 𝐴 : The probability that an appliance will be triggered at a
time t after the activity initiation (may differ according to
day type and/or season)
Cassandra Project 1st Workshop September 11, 2013
10. Activity Models
• Procedure:
– Correlation of Appliances and Activities (installation modelling phase):
Each Appliance may be correlated with a single Activity
– Determination of Appliances and respective Activities within
measurements (Disaggregation phase)
– Training of the Activity Modelling procedure
Cassandra Project 1st Workshop September 11, 2013
11. Response Models
• The aim of the CASSANDRA platform in this case is to estimate
whether a consumer will respond to a specific incentive or not
• Factors affecting behavioural change are:
– Pricing
– Environmental impact
– Awareness and Sensitivity
• Time shifting models describe the changes of the probability
density function fs(t) of the activity start time(s) within a day, as a
result of the change of price
• Consumers may also respond by reducing the number of times
they perform some activities
Cassandra Project 1st Workshop September 11, 2013
12. Disaggregation Methodology
• Aims to provide information regarding the appliances that
produce a given set of active and reactive power curves.
• Step 1: Determination of background demand
Cassandra Project 1st Workshop September 11, 2013
15. Disaggregation Methodology (cont.)
• Step 4: Determination of individual appliances
– Slope Percentage Vector (SPV) calculation from active power
measurements vector Px
– Combination of Points of Interest (POIs) leads to POI vector
– Aggregated consumption curved is decomposed into events
Cassandra Project 1st Workshop September 11, 2013
16. B. Disaggregation Methodology (cont.)
• Step 5: Identification (clustering) of individual appliances
– Classification according to specific parameters:
• Active power
• Reactive power (power factor)
• Differentiation of active/reactive power during operation
• Typical (average) time of use for each appliance
– Matching in appliance library
Cassandra Project 1st Workshop September 11, 2013
17. Results in Pilot Cases (Lulea – 40 days)
Background
45,86 %
Refrigeration 9,79%
Cooking
18,79 %
Entertainment 6,67 %
Cleaning
9,31 %
Lighting
0,65 %
Unidentified 8,93 %
Percentage Energy Per Activity for Installation A
Cassandra Project 1st Workshop September 11, 2013
18. Results in Pilot Cases (Lulea – 40 days)
Background
6,36 %
Refrigeration
13,76 %
Cooking
16,17 %
Entertainment
3,78 %
Cleaning
48,08 %
Lighting
0,32 %
Unidentified
11,53%
Percentage Energy Per Activity for Installation B
Cassandra Project 1st Workshop September 11, 2013
19. Load identification - Lulea installation B
Cassandra Project 1st Workshop September 11, 2013
0
200
400
600
800
1000
1200
1400
1600
1800
2000
TV1 TV2 Refrigerator Freezer Extra Freezer PC Cooker Microwave
Oven
Vacuum
Cleaner
TimesofUSe
Installed Appliance
20. Related Conference Papers
1. A Framework for the Implementation of Large Scale Demand Response
G. T. Andreou, A. L. Symeonidis, C. Diou, P. A. Mitkas and D. P. Labridis, IEEE
International Conference on Smart Grid Technology, Economics and Policies (SG-TEP
2012), December 3-4, 2012, Nürnberg, Germany.
2. Redefining the Market Power of Small-Scale Electricity Consumers through
Consumer Social Networks
K. C. Chatzidimitriou, K. N. Vavliakis, A. L. Symeonidis and P. A. Mitkas, 10th IEEE
International Conference on e-Business Engineering (ICEBE 2013), September 11-13,
2013, Coventry, UK.
3. Event Detection for Load Disaggregation in Smart Metering
A. N. Milioudis, G. T. Andreou, V. N. Katsanou, K. I. Sgouras and D. P. Labridis, 4th IEEE
European Innovative Smart Grid Technologies (ISGT 2013) Conference, October 6 - 9,
2013, Copenhagen, Denmark.
4. Agent-based Small-Scale Energy Consumer Models for Energy Portfolio
Management
A. Chrysopoulos, C. Diou, A. L. Symeonidis and P. A. Mitkas, 2013 IEEE/WIC/ACM
International Conference on Intelligent Agent Technology (IAT-13), November 17-20,
2013, Atlanta, Georgia, USA.
Cassandra Project 1st Workshop September 11, 2013
21. Professor Dimitris P. Labridis
Director of Power Systems Laboratory (PSL)
Department of Electrical and Computer Engineering
Aristotle University of Thessaloniki (AUTh)
P.O. Box 486
54124 Thessaloniki, Greece
tel: +302310996374
fax: +302310996302
e-mail: labridis@auth.gr
Skype: labridis
URL: http://users.auth.gr/labridis/index_en.htm
PSL: http://power.ee.auth.gr/index.php?page=intro&action=lnchange&lnid=124&lnsym=EN
AUTh: http://www.auth.gr/
Cassandra Project 1st Workshop September 11, 2013
Authors affiliations
22. Lecturer Georgios T. Andreou
Power Systems Laboratory (PSL)
Department of Electrical and Computer Engineering
Aristotle University of Thessaloniki (AUTh)
P.O. Box 486
54124 Thessaloniki, Greece
tel: +302310996118
fax: +302310996302
e-mail: gandreou@auth.gr
URL: http://power.ee.auth.gr/index.php?page=andreou
Cassandra Project 1st Workshop September 11, 2013
Authors affiliations (cont.)
23. Dr. Apostolos N. Milioudis
Power Systems Laboratory (PSL)
Department of Electrical and Computer Engineering
Aristotle University of Thessaloniki (AUTh)
P.O. Box 486
54124 Thessaloniki, Greece
tel: +302310996379
fax: +302310996302
e-mail: amilioud@auth.gr
URL: http://power.ee.auth.gr/index.php?page=milioudis
Cassandra Project 1st Workshop September 11, 2013
Authors affiliations (cont.)
