Download DG Conference, Clemson, SC March 13

Software Aspects of PQ
in a DG Context
By
Dr. Siri Varadan
Overview

Introduction
– PQMS
– Basic Components of a PQMS

Modular System Design
– Benefits
– Functional Design
– Data Flow, Analysis, Reporting


DG Specific Applications
Conclusions
DG Conference, Clemson, SC
March 13-15, 2002
2
Power Quality Monitoring
Systems

Integrated systems of several PQ monitors
are being set up
– increasing number of monitors
– emerging computer technologies on hardware
and software area
– different architectures that serve all PQ
monitors with a single large database
» client-server
» Intranet/Internet
DG Conference, Clemson, SC
March 13-15, 2002
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Power Quality Monitoring
Systems

Advantages
–
–
–
–
–
–
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efficient and fast analysis of large volumes of data
establish centralized PQ data
usage of standard PQ indices within the utility
standardization of customer complaint evaluation
modular, expendable and portable system design
reduction in system maintenance and expansion costs
standard data analysis tools on LAN/WAN, Intranet,
etc.
– centralized security system
DG Conference, Clemson, SC
March 13-15, 2002
4
Main PQ Monitoring System
Components
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Communication System - physical media (fibre
optics, copper, wireless, etc), modems (DSL,
telephone, etc.), Ethernet network components
(switches, routers, etc), etc.
Information Technology (IT) System - computers
(data servers, polling stations, client stations, etc),
system software (operating system, etc), database
system, protocol converters, user applications
(GUI, analytical applications, alarm and
information dispersal software, web publishing,
etc.), etc.
DG Conference, Clemson, SC
March 13-15, 2002
5
Main PQ Monitoring System
Components

Monitoring System - instrumentation (PQ
monitors, RTUs, sensors, etc), data retrieval and
configuration software, etc
DG Conference, Clemson, SC
March 13-15, 2002
6
PQ Monitoring System
Components
Monitoring system
Polling
server
IT system
Communication system
ODBC
database
Database/Application
server
WAN
End users
PQ Monitors
DG Conference, Clemson, SC
March 13-15, 2002
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Modular System Design Benefits


Removes vendor dependencies - The best
alternatives, specific to meet all of the utility’s
requirements, are used
Easy implementation of analysis applications
– Analytical applications can be written that use the
‘standardized databases
– Industry standard and vendor independent applications,
each best suited to meet utility’s requirements
DG Conference, Clemson, SC
March 13-15, 2002
8
Modular System Design Benefits


Ease in implementation of web reporting
applications - Latest web hosting and interactive
site technologies can be used.
Economic benefits - With several alternative
systems, price of the individual modules is more
competitive
DG Conference, Clemson, SC
March 13-15, 2002
9
Modular System Design Benefits

Maintenance of a standard database
– Allows cheap and regular maintenance. Facilitates easy
database expansion. Single database ensures that there
is no duplication of data from all current and potential
future power quality monitors.

Existing trained personnel can quickly come up to
speed with the operation & maintenance of the
system - No new elaborate training is necessary
DG Conference, Clemson, SC
March 13-15, 2002
10
Modular System Design Benefits
Future subsystem components can be
selected solely on their merit - ‘Vendorindependence’
 Modular design allows

– utilization of future advances in
instrumentation, communication, and software
technologies
– utilization of upgrading without a major
investment in a complete system overhaul
DG Conference, Clemson, SC
March 13-15, 2002
11
Conceptual Design

Future expandability; plug-and-play concept
Instrumentation
Required software
- Communication
- Data logging
- Configuration
Meter server
Database
Database server
LAN
End user
Fiber Optics and
DSL modems
Current PQ meters
Leased Lines or other
media
Future PQ meters
DG Conference, Clemson, SC
March 13-15, 2002
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Functional Design
Applications Software
Polling & Downloading
Proprietary
Database
Data Managing, Analysis
& Reporting
WEB Reporting
ODBC
Database
PQ System
Characterization
Future
Applications
User Interface
DG Conference, Clemson, SC
March 13-15, 2002
13
Software Modules
3F component
analysis
Data from
Communication server
Harmonic
analysis
‘Basic’ software
is installed on the
Communication server
Web reporting
ODBC
database
Event reporting
Application
server
PQ characterization
Independent software
modules, each of which
can be modified/upgraded
independently
Import/Export of data
to other formats
(PQDIF , COMTRADE , etc)
DG Conference, Clemson, SC
March 13-15, 2002
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Data Flow
Polling
Alarms
Proprietary
Database
Basic Software
3F Component Analysis
Harmonics Analysis
Data Managing &
Reporting
SQL
Standard
Interfaces
User
Interface
Data Analysis &
Reporting
ODBC
Database
WEB Reporting
PQ System
Characterization
DG Conference, Clemson, SC
March 13-15, 2002
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Data Analysis and Reporting
Data Managing
& Reporting
Data Analysis
& Reporting
ODBC compliant database
Oracle or SQL server
Disturbance reports
Event-based reports
Periodic reports
Trending reports
Rule-based
Expert
System
system
rules
ODBC data
Calculation
Modules
Display
Extract
DG Conference, Clemson, SC
March 13-15, 2002
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Data Analysis and Reporting
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Calculation Modules
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RMS, Root Mean Square, (voltage or current)
SARFI
Fundamental voltages and currents of Fourier series
Total voltage harmonic RMS, etc.
Expert system rules constitute a simple if-and-then
logic for combining windowed time data with
relational and topological data
Extract module basically extracts the required
portion of the data from database tables
Display is in the form of graphs, tables and text
DG Conference, Clemson, SC
March 13-15, 2002
17
DG Specific PQ Applications ?
Event Aggregation
 Use of Intelligent schemes for postprocessing
 Centralized data analysis
 Cross-communication between different
measuring units for real-time diagnostics;
classification etc.

DG Conference, Clemson, SC
March 13-15, 2002
18
DG Specific Needs
Protection issues – How and what caused
the problem?
 Potential conflicts with PQ design and DG
objectives
 Operational conflicts
 Ability to analyze conditions leading to
resonance etc.

DG Conference, Clemson, SC
March 13-15, 2002
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Conclusions
Modular – system components can be
changed without major modifications
 Expandable – new monitoring systems can
be added without a complete system
overhaul
 Easier to maintain
 Standard unified set of tools across the users
 Customizable PQ applications with DG
systems

DG Conference, Clemson, SC
March 13-15, 2002
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