Applying the Distribution System in Grid Restoration/NERC CIP-014 Risk Assessment Srijib Mukherjee, Ph.D., P.E. UC Synergetic.

Applying the Distribution System in Grid Restoration/NERC CIP-014 Risk

Assessment

Srijib Mukherjee, Ph.D., P.E.UC Synergetic

Classic Power System Restoration

Distributed Generation in System Restoration

• Ramp-in a Distributed Generation resource– Is the DG resource capable of generation-load balance?– Is it tied to a storage device with sufficient ramp and

regulation capability? • Find an initial low to medium voltage path to energize• Energize line and pick up load• Synchronize to bulk power grid– Outline energized switching sequence path– How do I avoid false tripping of feeder breakers?• Consider short circuit contributions for DG resources

– Do I build upward, build downward, other variations?

The Big Picture

Reverse Flow and Grid Support

Distribution System Grid Restoration

• What’s the status of the radial system– How can we maximize our DER resources that

meet the “black start criteria requirement”?–What is the capability of power transfer in our

distribution network?– Are there any operating constraints?– How do we pick up load and maintain

frequency balance?

Frequency balance - California’s Duck Curve

What is NERC CIP-014

• A Critical Infrastructure Protection standard to identify and protect Transmission stations and substations, and their associated primary control centers, that if rendered inoperable or damaged as a result of a physical attack could result in widespread instability, uncontrolled separation, or Cascading within an Interconnection.

Applicability

• Today’s standard requires:– Any Transmission Owner that owns:• Transmission Facilities 500 kV or higher.• Collector bus for a generation plant is not considered a

transmission facility. Instead it is a part of the generation interconnection facility• Transmission Facilities operating between 200 kV and

499 kV at a single station or substation, where the station or substation is connected at 200 kV or higher to three or more other Transmission stations or substations

How may it change if we used the Distribution System for System Restoration?

• Functional entities would now be considered:– Distribution Owners– Generator Owners of Renewable Resources

• DER resources that are critical in the grid restoration process would need to go through a risk assessment evaluation– Contribution to frequency stability– Contribution to voltage stability– Applicable threat conditions on that asset– A vulnerability assessment of that asset

Risk w.r.t. CIP-014. Consider ..

• Event Driven Risk Indicators– Prioritize applicable events based on distribution

system integrity, equipment performance, and/or engineering judgment

– Consider applying a ranking methodology in association with TO’s input and CIP-014 requirements

• Condition Driven Indicators– Assess on a set of measurable conditions for reliability.

Examples: abnormal topology, alternative generation dispatches, power transfer between systems, etc.

Threat defense mechanisms

• Transmission systems are planned and operated to withstand N-1 contingency conditions– Should Distribution resources be studied in the same

fashion? • Think of proposing a system that has the ability to defend

against attacks of multiple components including bulk power transformers.

• Example: Attack detection tools that monitor traffic patterns simultaneously correlates events at multiple substations can help in early detection of coordinated attack scenarios.

Conclusion

• Consideration of Distribution System assets in system restoration efforts

• Advantages to doing this :– Diversification of risk to critical assets• Multiple black start points

– Greatly reduces vulnerability of the system to terror threats

– More robust alternatives to restoring load effectively

Questions?

• Contact Information:– Srijib Mukherjee– Email: [email protected]– Cell: (919)302-4956