1. Transmission-Distribution Interface Working Group Meeting
June 21, 2017

2. Today’s Agenda: Introductions
Brief updates on related efforts (15 minutes):
White Paper published + upcoming outreach
CPUC Grid Modernization – June 5
ESDER
FERC Storage/DER Rulemaking
Other?
Presentation on CPUC/CAISO Multi-Use Application Staff Proposal (30 minutes) – Lorenzo Kristov, CAISO
Implications on operations at T-D interface
Discussion of relevance to WG efforts
Working Group Exercise: Two Master Problem: Evaluating Conflicts When Providing Wholesale AND Distribution Services (90 minutes) – Matthew Tisdale, MTS
Lunch Break (30 minutes)
Presentation on Implementation of Use Cases A & B + Discussion (60 minutes) -- Mark Esguerra, PG&E
Presentation on Stem deployments and perspective from NYISO (30 minutes) – Ted Ko, Stem
Discuss future meeting dates, meeting agendas, and next steps (15 minutes)
Surprise sendoff

3. Orientation to 2017 Work Plan
Prepare an initial white paper that summarizes the 2016 effort, including description of existing coordination procedures, anticipated operational challenges with high DER, and communication and coordination improvements identified to date
Educate the WG on grid modernization from IOU perspective (using 1/24 DRP workshop presentations) and consider implications of operational coordination needs on grid modernization
Develop example use-cases reflecting likely DER integration scenarios to ground discussion in practical implications. Consider how future pilot proposals may stem from identified use cases.
Specify potential real-time coordination procedures to manage potential conflicts between DO needs and ISO dispatches. Begin with scenario approach and then broaden as needed
Identify principles for a DO approach to DER curtailment resulting from distribution level constraints
Consider any unique perspectives or challenges for municipal utilities w/in ISO footprint
Describe the process and timeline for integration of a new DERA into the wholesale market, including utility process for 30-day review of DERA under ISO DERP tariff as well as ISO integration process
Develop methods for short-term DER forecasting and impacts at T-D Interface (IOUs)
Develop method for DO feasibility assessment of ISO’s day-ahead DER schedules and real-time dispatches
Explore how various DSO models would impact design of the T-D interface coordination framework

4. The Two Masters Problem:
Problem Definition: Will DER receive competing dispatch signals from wholesale and distribution service operators? If so, how will the conflict be resolved?
Identified by working group members as a priority question at May meeting.
Agreed to further consideration by matrix of services and situations, allowing for identification of potential conflicts.
The following draft matrix created by AMS and MTS.
The following exercise intended to facilitate population of the matrix.

5. Distribution - Wholesale Grid Services Conflict Matrix
Two Masters?
Distribution - Wholesale Grid Services Conflict Matrix
Distribution Services
Wholesale Services
Energy
Regulation Up
Regulation Down
Spinning Reserve
Non-Spinning Reserve
Energy Up
Energy Down
Capacity Up
Capacity Down
VAR Up
VAR Down

6. Working Group “Conflict Identification and Resolution” Exercise:
Steps:
Hold hands
Discuss threshold questions on next slide, level-set
Populate matrix by identifying conflicts
Populate matrix by identifying opportunities
Think, Repeat
Behold

7. Does the following correctly state the task at hand?
Threshold Questions:
Does the following correctly state the task at hand?
The Working Group is analyzing when providing two or more services — one at wholesale, one at distribution — could result in a DER receiving conflicting dispatch signals. There are some situations where a conflict would be created between two dispatch signals for two services, while the same two services may not create a conflict in other situations. Our task is to identify the situations where conflicts exist and for which services.
Identified conflicts would be the same under Use Cases C-1, C-2, D-1, and D-2. Conflicts are not resolved through bifurcated capacity or aggregations. Use Cases E and F considered at a later date. Correct?
Matrix enables analysis of conflicts between wholesale and distribution services identified in most recent version of “T-D Interface Working Group Use Cases.” Customer services (e.g., demand charge management) and RA not included. Correct?
Other questions?

8. PG&E DO Activities Assessing High DER Penetration Use Cases
Distribution Operations performed assessment of high DER penetration feeders
Identify any impacts to operation of distribution grid
Discuss key operational considerations for assessing high DER penetration feeders
Selected two feeders in PG&E system that are currently experiencing high penetration of DERs
Feeder Name
Feeder ID
Feeder Capacity (MW)
Peak Load (MW)
Average Node ICA (kW)
Feeder ICA (kW)
Penetration
DG Customers
Feeder A
12.33
6.63
569
2,565
120%
127
Feeder B
6.09
3.38
356
798
114% 98

9. High DER Penetration Preliminary Screening Criteria applied

10. Examples of Existing Use Case A in PG&E System
October 2013
October 2016
Market participation of large DERs providing regulation complicates online power flow calculations and makes load forecasting very difficult
DERs providing regulation service may have multiple changes in power flow direction
For specific circuit, DER penetration level relatively low and is considered to be a robust feeder. Therefore, no voltage or power quality issues recorded
Managing and Integrating 3rd party DER aggregations into utility systems has proven to be very complex technically. Standards are immature and business rules are not yet established for distribution services.
4MW Battery Output October 2016

11. Background Slides

12. Services in Red have been preliminarily deemed “reliability”
Source: CPUC, June 2 Workshop Presentation

13. Use Cases Use Case Configuration Grid Services Provided A
Single Resource
Wholesale (only) B
Aggregated Resource – consider single-feeder and multi-feeder sub-cases
C-1
Wholesale + Distribution using separate portions of capacity for each (Multiple Use Application)
C-2
Wholesale + Distribution using the same capacity
D-1
D-2
Aggregated Resource E
Wholesale + Distribution: enhanced DO/DSO functionality F