Advanced Decision Support Tools Very Large System Operators (VLSO) Working Group #3 Beijing, October 2005

Presentation Outline  WG#3 Objectives for 2005  List of Investigated Topics  Current Situation among the VLSO  Anticipated VLSO Needs  Recommendations of WG#3  Conclusions

Working Group #3  WG-1: Identify causes of blackouts and ways to prevent them (Lead: TEPCO)  WG-2: EMS architectures of the 21 st century (Lead: PJM/MISO)  WG-3: Advanced Decision Support Tools (Lead: RTE)

WG Contributors  CAISO USA (Yuri Makarov)  NCPG China (Xie Xu)  PJM USA (Chantal Hendrzak, Ken Huber)  Power Grid India (SK Soonee)  REE Spain (Eduardo Prieto Garcia, Cristina Gomez Simon)  RTE France (Christian Lemaître)  TEPCO Japan (Yasuyuki Tada)

WG-3 Objectives WG #3 ‘Advanced Decision Support Tools in Real Time’ was assigned to investigate the technologies that are currently used and those emerging, advanced technologies that show great potential to assist dispatchers in the operation of their ever increasingly complex and essential interconnected grid The objectives of the group are summarized as: 1. Identify the decision support tools in use today, and to describe the effectiveness and limitation of those tools 2. Describe the current and emerging needs of the participating Very Large System Operators 3. Draw conclusions and recommend a course of action for advancing the development and use the most needed and most effective decision support tools Nine topic areas have been investigated within WG members

List of Investigated Topic Areas (1) Topic#1Real-time tools to monitor the stability of the system (Dynamic Stability Assessment). Topic#2Real-time tools to monitor the voltage stability of the system (Voltage Stability Assessment). Topic#3Utilization of PMU (Phasor Measurement Units) in network operation and capabilities of these devices to enhance system safety. Development of decision support tools using a Wide Area Measuring System. Topic#4Real-time tools in the field of corrective switching in case of constraints (e.g. knowledge-based system, neuronal network) Topic#5Lessons learned from utilization of classical real-time tools such as state estimation, OPF, security analysis,... Different ways to improve their efficiency (e.g. hierarchical state estimation)

List of Investigated Topic Areas (2) Topic#6Development of complex operating rules (for dispatchers) based on a probabilistic risk assessment Topic#7Lessons learned with regard to reliability of data (used in decision support tools). In particular, problem of knowledge of neighbouring systems. Topic#8Visualization methods, techniques and tools that will enhance the decision support capabilities of the dispatchers in use of the above tools and others in the control room. Topic#9Intelligent Alarm Processing and its use as a decision support tool.

Lessons Learned from Utilization of Classical Real-Time Tools The “classic” EMS has been developed and installed in control centers for more than 20 years  Classic real-time tools such as State Estimation, Optimal Power Flow, and Security Analysis are now considered as essential  These tools have grown increasingly complex and difficult and expensive to maintain  their performance is critical  Data quality is essential  A more intuitive visualization is necessary WG#3 identified opportunities for using new technologies like  Parallelization and hierarchical computing (State Estimation)  Stability analysis  Visualization software tools  Bad data detectors  Open architecture (cf. WG#2 White Paper)

Data Reliability Data reliability is a foremost concern for VLSOs, the various decision support tools mentioned previously require accurate and updated data A big effort is being undertaken to improve real-time data (measurements and network topology model) as well as the modelling of network components Importance of RTU data synchronization and labelling, and the need for increased operator awareness when data is missing, not updated, or a communications failure occurs In addition, VLSO need reliable tools to identify bad data (real time data as well as network modeling data) and the associated cause especially in case of intentionally corrupted data (hacking or terrorist attack) REE has developed such a tool (GESTIME), a system based on a statistical analysis of real time measurements and state estimator results

Dynamic Stability Assessment Currently, there are no instances of a DSA simulation tool performing real-time assessments in the control room Each VLSO member-company expects that the needs for the real- time DSA will increase (transient stability problems have occurred in real time operation, massive insertion of wind energy) Regarding small signal stability, CAISO has now a real- time system that provides operators with dominant power oscillation modes Regarding transient stability, instead of using the conventional time domain simulation, studies on the application of techniques using the energy function method are proceeding (e.g. BCU technique TEPCO)

Voltage Stability Assessment Most of VLSO dispatchers utilize VSA tools for real time operations in order to consider the margins to the voltage collapse. There is a diversity of situations among VLSO regarding voltage stability depending on the structure of power system VLSO research in this area has come to a head as it is basic in real time operation. Mainly two different techniques are used (static methods and time-domain simulation method) Further functionalities have been added such as the decision on load shedding, determination of optimal post-contingency corrective actions and evaluation of security indices Alternative ways of determining distance to voltage collapse are studied (e.g. non-iterative power flow algorithms REE)

Phasor Measurement units (PMU) Utilization of PMU and WAMS in network operation is one of the most promising research areas to be further developed Currently, the number of installed PMUs is relatively small. PMU/WAMS are not utilized in the operation decision process, but are mainly gathering real-time network data applied for post analysis events and validation of system models Some real-time advanced tools have been developed by VLSO to assist operators in assessing system security VLSOs are expecting benefits from this technology in the future : 1. Real time system stability monitoring and assessment 2. Regular monitoring of inter-area oscillations 3. Supplying phase angle measurements to a state estimator 4. Development of decision support tools 5. Integration of PMU/WAMS technology with classical EMS

Intelligent Alarm Processor  One of the major challenges facing any VLSO is the overwhelming amount of data presented to the system operator  Intelligent Alarm Processing (IAP) addresses this challenge by increasing the operator’s ability to process large sets of information  Currently, almost every VLSO uses the Alarm Processor based on EMS built-in simple rules, which seems to be enough to handle daily operation. Nevertheless, most of the VLSO agree that it is necessary to provide processors with intelligence (e.g. Artificial intelligence, Fuzzy logic, and Neuronal networks)  The implementation of this type of advanced technology has not yet occurred within any of the VLSOs, though the interest is high. Several of the VLSOs have tried to develop or to implement an IAP system of some sort. Most of them express interest in continuing to explore this way in the future

Visualization Methods There is a need of advanced visualization method and tools to enable quick and intuitive decision making and to assess large amounts of data in real time operations, particularly in critical situations Some research that seems to be interesting in this area is to transfer the visual representations used in several planning phases or off-line studies into the real-time operation, for instance map technologies using Geographic Information System (GIS) Besides GIS, visualization capabilities that are emerging include: 3- dimensional displays, data levelling, animation and virtual reality Improvements need to focus on three elements: standardization, integration and cognition

Corrective Switching  VLSOs agree that there is a need to develop real-time decision support tools to help dispatchers to find the optimal corrective actions in case of constraints and that this need will likely increase as power systems are operated closer to their limits  Researches is being done today and has been done in the past by some VLSOs but there is no successful implementation yet. In general these tools are based on an optimal generation re-dispatch (based on an OPF algorithm) and/or one or several topology manoeuvres (equipment switching and busbar reconfiguration)

Probabilistic Risk Assessment  Up to now, all the operating rules used in real-time by dispatchers are defined in a deterministic way. Development of operating rules based on a probabilistic risk assessment has been identified as an important issue to be considered by the VLSO.  Research works are currently in progress today in this domain. The most advanced application in this domain is the determination of operating rules to protect the system against voltage collapse (RTE), usable in real-time by dispatchers.  Among the expected applications, the following are of great interest for VLSOs:  elaboration of operating rules for security enhancement,  study of the impact of wind power generation on the operating procedures,  determination of transfer capacities between adjacent areas.

Recommendations of WG#3 VLSOs should continue to share information about methodologies and lessons learned regarding their advanced decision support tools projects VLSO should work together, coordinate and co-fund research efforts VLSO should promote standardization (visualization tools, intelligent alarm processor) More precisely the proposed next steps are the following…

Next Steps Regarding projects of common interest: Develop a common format for sharing the lessons learned and results of these projects Issue a semi-annual consolidated documentation of the submitted projects Hold quarterly workshops focused on tools for the control room and invite some industry vendors to discuss available products and services Publish an advanced schedule of workshops Proposed first workshop on Visualization in 2006 Coordinate 2006 work plans for WG #2 and WG #3 Develop joint white paper between both WG for presentation at CIGRE Other cooperation initiatives between VLSO members could be: Assign each VLSO a focus area Professionals exchange within certain projects Look for opportunities to joint fund initiatives

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