1. Software Aspects of PQ in a DG Context By Dr. Siri Varadan

2. DG Conference, Clemson, SC March 13-15, 2002 2 Overview Introduction Introduction –PQMS –Basic Components of a PQMS Modular System Design Modular System Design –Benefits –Functional Design –Data Flow, Analysis, Reporting DG Specific Applications DG Specific Applications Conclusions Conclusions

3. DG Conference, Clemson, SC March 13-15, 2002 3 Power Quality Monitoring Systems Integrated systems of several PQ monitors are being set up 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

4. DG Conference, Clemson, SC March 13-15, 2002 4 Power Quality Monitoring Systems Advantages Advantages –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

5. DG Conference, Clemson, SC March 13-15, 2002 5 Main PQ Monitoring System Components Communication System - physical media (fibre optics, copper, wireless, etc), modems (DSL, telephone, etc.), Ethernet network components (switches, routers, etc), etc. 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. 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.

6. DG Conference, Clemson, SC March 13-15, 2002 6 Main PQ Monitoring System Components Monitoring System - instrumentation (PQ monitors, RTUs, sensors, etc), data retrieval and configuration software, etc Monitoring System - instrumentation (PQ monitors, RTUs, sensors, etc), data retrieval and configuration software, etc

7. DG Conference, Clemson, SC March 13-15, 2002 7 PQ Monitoring System Components Monitoring system WAN Polling server ODBC database Database/Application server Communication system IT system End users PQ Monitors

8. DG Conference, Clemson, SC March 13-15, 2002 8 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

9. DG Conference, Clemson, SC March 13-15, 2002 9 Modular System Design - Benefits Ease in implementation of web reporting applications - Latest web hosting and interactive site technologies can be used. 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 Economic benefits - With several alternative systems, price of the individual modules is more competitive

10. DG Conference, Clemson, SC March 13-15, 2002 10 Modular System Design - Benefits Maintenance of a standard database 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 Existing trained personnel can quickly come up to speed with the operation & maintenance of the system - No new elaborate training is necessary

11. DG Conference, Clemson, SC March 13-15, 2002 11 Modular System Design - Benefits Future subsystem components can be selected solely on their merit - ‘Vendor- independence’ Future subsystem components can be selected solely on their merit - ‘Vendor- independence’ Modular design allows 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

12. DG Conference, Clemson, SC March 13-15, 2002 12 Conceptual Design Future expandability; plug-and-play concept Database Leased Lines or other media Fiber Optics and DSL modems Instrumentation Database server Meter server LAN End user Required software - Communication - Data logging - Configuration Current PQ metersFuture PQ meters

13. DG Conference, Clemson, SC March 13-15, 2002 13 Functional Design

14. DG Conference, Clemson, SC March 13-15, 2002 14 Software Modules Data from Communication server ODBC database Application server 3  component analysis ‘Basic’ software is installed on the Communication server Harmonic analysis Web reporting Event reporting PQ characterization Independent software modules, each of which can be modified/upgraded independently Import/Export of data to other formats (PQDIF,COMTRADE, etc)

15. DG Conference, Clemson, SC March 13-15, 2002 15 Data Flow

16. DG Conference, Clemson, SC March 13-15, 2002 16 Data Analysis and Reporting

17. DG Conference, Clemson, SC March 13-15, 2002 17 Data Analysis and Reporting Calculation Modules Calculation Modules –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 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 Extract module basically extracts the required portion of the data from database tables Display is in the form of graphs, tables and text Display is in the form of graphs, tables and text

18. DG Conference, Clemson, SC March 13-15, 2002 18 DG Specific PQ Applications ? Event Aggregation Event Aggregation Use of Intelligent schemes for post- processing Use of Intelligent schemes for post- processing Centralized data analysis Centralized data analysis Cross-communication between different measuring units for real-time diagnostics; classification etc. Cross-communication between different measuring units for real-time diagnostics; classification etc.

19. DG Conference, Clemson, SC March 13-15, 2002 19 DG Specific Needs Protection issues – How and what caused the problem? Protection issues – How and what caused the problem? Potential conflicts with PQ design and DG objectives Potential conflicts with PQ design and DG objectives Operational conflicts Operational conflicts Ability to analyze conditions leading to resonance etc. Ability to analyze conditions leading to resonance etc.

20. DG Conference, Clemson, SC March 13-15, 2002 20 Conclusions Modular – system components can be changed without major modifications Modular – system components can be changed without major modifications Expandable – new monitoring systems can be added without a complete system overhaul Expandable – new monitoring systems can be added without a complete system overhaul Easier to maintain Easier to maintain Standard unified set of tools across the users Standard unified set of tools across the users Customizable PQ applications with DG systems Customizable PQ applications with DG systems