Reliability Assessment
Electric Utility
Mapping
Maged Yackoub
Eva Szatmari
Veridian Connections
Toronto, October 2015
Agenda
•
Introduction
•
About Veridian Connections
•
Veridian’s GIS platform
•
Reliability assessment
A case study for wood poles
•
Electric utility mapping
Schematics
•
Conclusions and future directions
•
Q&A
2
3
4
Veridian’s GIS platform
5
Reliability assessment
A case study on utility
wood poles serviced by Veridian
Connections
6
Electrical Equipment Reliability
•
Electrical equipment is subject to aging and deterioration
•
Every component has different
failure behaviour
•
Overhead lines are exposed to
damage from a wide range of
causes
•
In general, the failure rate of
electrical equipment follows the
famous bathtub-shaped curve.
The bathtub curve
7
Weibull Model
•
a=0.5
Two parameter Weibull distribution function
𝛽 𝑡
𝑓 𝑡 =
𝛼 𝛼
𝛽−1
𝑡 𝛽
−
𝑒 ∝
𝐹 𝑡 = 1−
𝑡 𝛽
−
𝑒 𝛼
f(t) - the probability density function,
F(t) - the cumulative distribution function CDF
b>0 - the shape parameter
a>0 - the scale parameter
•
Failure rate function
𝑓(𝑡) 𝛽𝑡 𝛽−1
ℎ 𝑡 =
=
𝑅(𝑡)
𝛼𝛽
•
Reliability function
𝑅 𝑡 =1−𝐹 𝑡 =
•
𝑡 𝛽
− 𝛼
𝑒
Estimation of parameters a and b can be
obtained from the linearized form of the CDF
by linear least square regression
8
Data Collection & Analysis
Data sources
•
•
Pole failure data
Historical pole inspection data
GIS
DATABASE
EXTRACT POLE
FEATURES
EXTRACT DATA FOR
ANALYSIS
DATA PREPARATION
MODEL PARAMETER
ESTIMATION
CALCULATE RELIABILITY
FUNCTION
Data analysis
•
•
Age of failed wood poles
Age of substandard poles
MAP
RESULTS
9
ArcGIS Implementation
10
Results of the Analysis
Poles failed
a=50.20 years
b =3.49
Substandard Poles
a=47.11 years
b =3.54
11
Reliability Function Mapping
12
Reliability Function Mapping
13
Reliability Function Mapping
14
Conclusions
• Weibull analysis provide consistent estimates of wood pole reliability
for true failure and inspection data
• Model-based reliability analysis can be applied to the study of failure
patterns of other components of power distribution system.
• Predictive results of different modelling strategies can be further
integrated into decision making processes in maintenance planning
and replacement programs
• Include covariate factor to analysis (e.g., environmental factors)
15
Electric Utility Mapping
Schematics
16
Maps in Electric Utility Companies
•
Maps are the most common method to communicate
spatial information
•
GIS technology has transformed conventional mapping
•
Electric utility maps are essential at different levels of the
utility company:
System Control Centre
Asset Managers
Engineers and technicians
Field Crew
17
Different Types of Maps
Geographic
Geo-Schematic
Pure Schematic
18
Schematic Diagrams at Veridian
Connections
• Two systems: CAD and GIS
• Challenges
• Data redundancy
• Separate data source
• Error-prone system
19
Our Requirements for Schematics
•
Schematic representation of the power distribution network
•
Geographic reference
•
Network visualization from source to load
•
Detailed information with optimized placement of features for map
legibility
•
Efficient updates each time required
•
Automatic or semi-automatic generation of the schematic
20
Our Approach to Schematics
Previous approach
•
Map books and
schematic diagrams created
with ArcGIS Desktop
Current approach
•
•
•
GIS data organized into a geometric network.
Geo-Schematic map is created using ArcGIS Schematics
Extension tools
Semi-automated methods to update schematics
21
GIS
DATABASE
Geo-Schematics
Workflow
CREATE FEATURE
DATASET
CORRECT
ERRORS
CREATE GEOMETRIC
NETWORK
NETWORK
ERRORS ?
YES
NO
GENERATE NEW
SCHEMATIC DIAGRAM
Non optimized layout
Latest GIS data
NO
UPDATE
?
SCHEMATIC DATASET
DIAGRAM
TEMPLATE
YES
IMPORT EXISTING
SCHEMATIC GEOMETRY
INTO NEW SCHEMATIC
DIAGRAM
APPLY ESRI SCHEMATIC
LAYOUT ALGORITHMS
IDENTIFY (visually)
OVERLAPPED, CLUTTERED
&SCATTERED FEATURES
EXISTING
SCHEMATIC
Optimized layout
Old GIS data
IDENTIFY NEW FEATURES
since last update
MANUALLY REPOSITION
SCHEMATIC
FEATURES
SCHEMATIC
DIAGRAM
22
Challenges
•
Dealing with different network connectivity rules in ArcGIS
geometric network and other GIS platforms
•
Schematic layout algorithms (e.g., linear dispatch, compression)
are applicable only to parts of diagram
•
Manual labor still required (e.g., when first time generating the
schematic)
23
Port Hope Schematic in CAD format
24
Port Hope Geo-Schematic
25
Gravenhurst Grid Maps
26
27
Conclusions
•
Unique data source: GIS database
•
A single schematic template for all service areas
•
Schematics are generated from a dataset in geometric network
•
Automated update process
•
Less error prone (e.g., new elements/changes are highlighted
in the map document)
•
More detailed information captured on the map
•
Multiple visualization
•
Customized solutions using the schematic layout algorithms
29
Thank you for
your attention.
30