draft advanced voltage control technology roadmap

DraftAdvanced Voltage ControlTechnology Roadmap

Robert Entriken, Senior Project ManagerJohn Wharton, Executive Director

Friday, 20 May 2011

2© 2011 Electric Power Research Institute, Inc. All rights reserved.

Agenda

• Future Statements• Current Status…• Functional Gaps• Next Steps


Future Statement Question

• In the future, AVC will be implemented.What does this world look like?

•Example:My system automatically reacts and corrects

for voltage anomalies


Future Statements


• The AVC system will be automatic and can supportrequirements for on-line control under all Real Timeconditions– All real-time scenarios (seasonal, peak/off-peak)– Control loop will be in seconds

• Understand the baseline for documenting benefits• The AVC system will support transmission and distribution

needs


Future Statements


• Transmission owners will be fully supportive and engagedto make the system and its operation as a robust andefficient process

• The AVC system will increase transfer capability to utilizetransmission capacity to its fullest extent

• The AVC system helps enable a reactive power market ofsome kind that is competitive on a local basis

• There is an interactive process for TOs and SOs toreconcile their own AVC objectives.


Future Statements


• The AVC system supports efficiency in the electricitymarket.

• The AVC system can handle a wide variety of goals andobjectives. This can be adapted over time.

• The AVC system supports VAR and control for DistributedEnergy Resources.

• The AVC system enables the efficient and maximalcapacity utilization of all system resources.


Future Statements


• The tertiary AVC level will be fully integrated into themarket clearing mechanism and/or energy scheduling (DA& RT set points).

• The economic incentives resulting from the AVC systemobjective and operation will be aligned with social welfare.

• There will be a common control framework allowing plug-and-play capability regardless of the hierarchical level ofcontrol.


Future Statements


• There will be coordination between voltage and protectioncontrol that aligns for safety and reliability.

• The coordinated protection and AVC systems willenhance local system stability under key contingencies.

• The AVC system enhances and support power quality,system security, and efficient economics.

• The AVC system will be self-contained and modularallowing anomalies to be narrowed down to a local area.


Future Statements


• The AVC system will support system restoration.• The AVC system will enhance and support voltage

stability to better avoid blackouts with this root cause. Itwill enable system operators to better control the systemfor voltage stability.

• The AVC system will enable more efficient scheduling andsettlement business processes.

• The AVC system will have measurements and reporting inReal Time will present a transparent view of the reactivepower in the system.


Future Statements


• The tertiary AVC system will utilize as much system detailand accurate information as possible.

• The AVC system will enable corrective action to becomeroutine.

• The AVC system will ensure the coordination ofdistributed resources at each hierarchical level.

• The centralized coordination of the AVC system will yieldbenefits over and above decentralized voltage control.


Current Status…

Imagine where your system is today,relative to the Future Statement vision.


Functional Gap Question

• What Functional Capability enables progresstoward the Future State vision?

• Example:Seamless integration of AVC

with surrounding business systems


Functional Gaps


• Robust computation of optimal control based on an acmodel

• Accurate modeling of the real and reactive power of theac model

• Direct measurement of power flow with less than 0.5%error

• Accurate measurement and reporting of systemcongestion.

• Process sequences of system states to estimate systemparameters.


Functional Gaps


• Installation and operation of an extensive network ofmeters for reactive power.

• Create a methodology for verification of an AVC systembefore it is implemented in practice.

• Create a methodology for benchmarking AVC systemperformance.

• Create a methodology for cost/benefit analysis of AVC inorder to understand the limits of regional and hierarchicaldevelopment .


Functional Gaps


• Methods for interactively exchanging relevant AVCinformation between hierarchical layers and regions.

• Implement situation awareness for System Operatorssufficient to support AVC decision making.

• Define the interface between the AVC and protectionsystems.

• Coordinate protection control schemes with dynamic AVCsub-regions. (Possible centralized protection control.)


Functional Gaps


• Acceptance of GOs and TOs of the AVC system.• Protocol for issuing AVC setpoint instructions.• An independent, extremely reliable, secure, and accurate

communications.• Ability to dynamically adapt sub-region boundaries and

control points to existing system conditions.• A methodology for “fairly” allocating voltage control

responsibility across large regions that aligns root causeand response.


Functional Gaps


• A common communication framework to enable propercommunication and plug-and-play modular design.– Standard data interfaces for measurements and

instructions• Automatic execution of control signals for voltage control.• A method for coordinating transmission and distribution

voltage control.• A method for adjusting AVC performance objectives that

adapts to existing system conditions.


Functional Gaps


• Identify the right objectives to use under different systemconditions, system designs, and at each level of thehierarchy.

• A method for designing AVC systems that utilizesDistributed Energy Resources for voltage control.


Next Step Question

• Which Functional Gap(s) should we address first?

• Example:Conduct a feasibility study for expanding AVC capability

from single area to multi-area


Next Steps

• Which Functional Gap(s) should we address first?

1. Robust OPF computation with AC model2. Engaging operators and demonstrating benefits of AVC3. Develop a tool for planners to incorporate AVC in their design4. Engaging operations planners to use AC OPF for developing

(seasonal) voltage schedules5. Sufficient metering of reactive power to implement AVC6. Robust (validated) method for defining subareas for voltage control7. Predict and validate performance of AVC8. Work with vendors to incorporate AVC capabilities into their

products9. Develop a method for relaing improved voltage stability to

reductions in the risk of cascade10.Engage TOs to assess their benefits from participating in AVC


Appendix


Technologies 1

• Real Time Conditions– Observability and Forecasting– Reactive Power Demand/Flow, Losses, Voltage

• Optimal Power Flow– Full AC, Decoupled, Real Only, Reactive Only– Discrete control decisions

• Adaptive Zone Division– Electrical distance from bus sensitivities is fed to a

clustering algorithm


Technologies 2

• Coordination of Multiple FACTS– TBD

• Determining Sub-Areas– Identify generator contingencies that contribute to

instability– The relations between these contingencies is nested

and hierarchical• Robustness

– Measurement errors• Coordination of Area Protection Schemes

– TBD


Technologies 3

• Distribution Voltage Control– TBD

• Transmission Voltage Control– TBD

• Transmission and Distribution Coordination– Transmission uses generators, transformers,

capacitors, and reactors– Distribution does not use generators– Coordination by separating Q and V supply/demand


Technologies 4

• Interface Specifications– TBD

• TBD– TBD

draft advanced voltage control technology roadmap

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