| heal.abstract |
The mass rollout of smart electricity meters by the Hellenic Electricity Distribution
Network Operator (HEDNO/DEDDIE), produces per-consumer hourly consumption time
series that enable a range of analytics tasks. This thesis addresses one such task: the au-
tomatic classification of electricity consumers into behavioural categories based on their
consumption signature, rather than their self-declared registry label. The work pursues
two complementary goals: a verification use case, in which a mismatch between a con-
sumer’s declared category and the category inferred from actual usage is flagged as a
potential case of misdeclaration or non-technical loss; and a general-purpose categorisa-
tion use case supporting tariff design, demand forecasting, and network planning.
Using two years of hourly active-load data for tens of thousands of HEDNO con-
sumers, the thesis classifies six behavioural groups: the four registry-native categories
Agricultural, Industrial, Commercial, and Public Services, together with Tourism and
Food Service. An unsupervised cluster analysis (UMAP, DBSCAN, k-means) is first used
to characterise class separability in raw feature space, followed by an extensive feature-
engineering stage, statistical, temporal, seasonal, and activity-based descriptors, reduced
from 373 to 174 features via SHAP-guided selection. Classification is then approached
with both classical machine-learning models (LightGBM, Random Forest, Logistic Regres-
sion) and deep time-series architectures (PatchTST, with weekly/daily/ monthly patch
branches and self-supervised pretraining, TimesNet, MiniRocket, InceptionTime), and fi-
nally combined through a soft-vote ensemble and a confidence-gated cascade that routes
only the consumers LightGBM itself flags as ambiguous to binary PatchTST experts.
The tabular-fused cascade of LightGBM and PatchTST is the best-performing config-
uration overall, reaching a test Macro-F1 of 0.8648 (86.6% accuracy) on the four-class
dataset, a gain of 4.67 Macro-F1 points over standalone LightGBM and larger than the
corresponding soft-vote ensemble’s improvement. Notably, plain LightGBM already out-
performs every deep-learning model trained from scratch while requiring only CPU train-
ing, underscoring that careful data handling and feature fusion matter more than archi-
tectural sophistication on this dataset. These results support the proposed pipeline as
both an accurate general-purpose classifier and a practical, interpretable tool for flagging
declared-versus- behavioural consumption mismatches for distribution-operator review. |
en |