ISO-NE PUBLIC

Al McBride D I R E C T O R , T R A N S M I S S I O N S T R A T E G Y & S E R V I C E S

The Interconnection Process in New England – Status Update

S E P T E M B E R 1 6 , 2 0 1 5 | W E S T B O R O U G H , M A

Planning Advisory Committee

ISO-NE PUBLIC

Purpose of This Presentation

• Provide an update regarding the status of the processing of new interconnections in New England – Discussion in the context of issues regarding the processing of wind

generation in Maine

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ISO-NE PUBLIC

Summary of Issues

• The time taken to complete system impact studies for new wind generators – Particularly in Maine

• Curtailment and performance issues in system operations for inverter-based generators

• Modeling and performance requirements being introduced by new NERC standards

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ISO-NE PUBLIC

Agenda

• Brief history of interconnection process developments in New England

• Discussion of the current status throughout New England

• Issues with inverter-based generators

• Discussion of the backlog in Maine

• Future considerations

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ISO-NE PUBLIC

ISO-NE INTERNAL USE

ISO-NE PUBLIC

BRIEF HISTORY OF INTERCONNECTION PROCESS DEVELOPMENTS IN NEW ENGLAND

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ISO-NE PUBLIC

Timeline of Interconnection Standard Development in New England

1998

• Minimum Interconnection Standard

2003/2004

• FERC Proforma LGIA/LGIP

2009

• FCM/Queue Reforms

2015

• Elective Transmission Upgrades

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ISO-NE PUBLIC

Minimum Interconnection Standard

• Minimum required upgrades, consistent with: – No degradation in transfer capability – Maximum one-for-one displacement of existing/proposed generation – All reliability standards must be met – ISO can still operate and maintain the system

• Minimum Interconnection Standard – More stringent than “plug and play” – Does not assure incremental capacity to serve load – Assures no degradation to load-serving capability of the system – Consistent with market and Tariff constructs for Network Resources

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ISO-NE PUBLIC

Observations on the Application of the MIS

• New generators are competing with conventional generators for transmission access

• New inverter-based generation has very different voltage support and inertial characteristics than conventional generators – Many are more distant from the stronger parts of the grid

• Hence, new inverter-based generators are not ready substitutes for many of the conventional generators they are competing with

• Many upgrades may still be required for basic interconnection pursuant to the MIS

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ISO-NE PUBLIC

2008 FCM-Q Reforms: Summary of Objectives

• Improved coordination between the requirements of the Forward Capacity Market and the Generator Interconnection Process

• Addressed Intra-Zonal Deliverability in New England

• Addressed Interconnection Queue processing issues that had been observed across the industry and discussed at FERC

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ISO-NE PUBLIC

Observations on the Implementation of FCM-Q

• Capacity Network Resource Interconnection Service (CNRIS) is achieved through successful participation in the FCM – Annual CNR Group study in FCA qualification to test for overlapping

impacts

• Integrating the Interconnection Queue with the FCM is a very complex undertaking for both the ISO and participants – There is more emphasis than ever on processing queue positions as

quickly as possible

• Queue processing reforms (increased deposits/requirements at key decision points) were successful in achieving queue discipline – Projects move to the next stage of the process, or withdraw

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ISO-NE PUBLIC

Elective Transmission Upgrades

• In April 2015, FERC approved the interconnection procedures for Elective Transmission Upgrades (ETUs) – New Schedule 25 in the ISO OATT that governs the interconnection of

all forms of ETUs to the New England system • Closely modeled on, and integrated with, the generator interconnection

procedures

– Established interconnection service rights for certain ETU types • New controllable External ETUs

– Enabled an Internal ETU to become directly associated with a specific Generating Facility seeking CNRIS • So that it can be studied together with the Generating Facility and thereby

increase the Generating Facility’s ability to qualify for the FCM

– Did not alter the existing Tariff structure • ETUs must function within the existing dispatch, market and tariff

structure of the New England system

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ISO-NE PUBLIC

ISO-NE INTERNAL USE

ISO-NE PUBLIC

DISCUSSION OF THE CURRENT STATUS OF THE INTERCONNECTION PROCESS THROUGHOUT NEW ENGLAND

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ISO-NE PUBLIC

Current Queue Status

• At this time, with very specific exceptions, queue processing is up-to-date

• With the exception of the North and Western Maine portion of the system (which has experienced a backlog of mostly wind interconnection requests), substantially all the generator interconnection requests made through 2014 have completed the system impact study phase or have moved to the Interconnection Agreement and commercialization phases

• Note that the ISO has also identified other parts of the system that would face significant challenges to adding new generation – Northern Vermont – Northern New Hampshire

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ISO-NE PUBLIC

Status of Queued Requests

2012 2013 2014

Wind Project In Maine 3 4 12

Not a Wind Project In Maine 1 1

0

2

4

6

8

10

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Co

un

t

Year of Original Interconnection Request

Active Interconnection Requests Without a Completed System Impact Study

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Other Recent Queue Observations

• Recent upturn in proposals in Southern New England – Appear to have been timed with FCM Show of Interest window – Many new proposals in Southeast New England (SEMA/RI) – Mostly gas-fired (primary fuel) – Studies proceeding well overall

• Recent activity with large solar project applications – ~20 MW and larger

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ISO-NE PUBLIC

Drivers of the Backlog in Maine

1. Issues with Inverter Based Generators

2. Characteristics of the Maine system

3. Requests far beyond the capability of the existing Maine system

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ISO-NE PUBLIC

ISO-NE INTERNAL USE

ISO-NE PUBLIC

ISSUES WITH INVERTER BASED GENERATORS

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ISO-NE PUBLIC

New Wind Farms are located far from the transmission system

Electrical Distance

Large reactive losses incurred with flow over long distances This results in the addition of significant reactive upgrades for voltage and stability FERC exemption on Wind reactive requirement means that every wind farm study must individually identify the reactive requirement (there is no reactive margin left on the Maine system)

Low short circuit ratios of remote locations mean that wind farm models often do not perform as expected This results in the need to perform electromagnetic transient analysis (PSCAD) in addition to steady state and dynamic stability analysis

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ISO-NE PUBLIC

Wind Farms provide little inertia or voltage support

Wind Performance

Changes to wind generator parameters are frequently proposed because of a change in manufacturer or a change in technology/control design

Upgrades needed for earlier wind farms, such as series capacitor and/or dynamic reactive devices, further complicate the analysis of later wind farms

•Sub-synchronous analysis •PSCAD analysis

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ISO-NE PUBLIC

Interconnection Process – Basic Flow

Interconnection Request

Scoping Meeting

Feasibility Study (Optional)

System Impact Study

Facilities Study (Optional)

Construction

Interconnection Agreement Development

Commercial Operations

Interconnection Agreement

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ISO-NE PUBLIC

System Impact

Study Process

“Conventional” Generation

Identify system

upgrades

Create load

flow base cases

Create Stability

base cases

Identify Issues

Affected Parties

review results

Create

contingency list

Define potential

solutions

Identify Issues

Define potential

solutions

Identify system

upgrades

Create

contingency list

Develop detailed

SIS technical

assumptions

Draft System

Impact Study

Report

Customer signs

SIS Agreement

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ISO-NE PUBLIC

System Impact

Study Process

Wind/Inverter-based Generation

Identify system

upgrades

Create load

flow base cases

Create Stability

base cases

Identify Issues

Affected Parties

review results

Create

contingency list

Define potential

solutions

Identify Issues

Define potential

solutions

Identify system

upgrades

Create

contingency list

Develop detailed

SIS technical

assumptions

Draft System

Impact Study

Report

Customer signs

SIS Agreement

Collector System Design

Address Low Short Circuit

Solve Interactions Between Upgrades & Generators

PSCAD Analysis

Address Issues with Dynamic Model Performance

Identify Required Reactive Capability

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ISO-NE PUBLIC ISO-NE PUBLIC

REACTIVE PERFORMANCE REQUIREMENTS Considerations to improve study time-frames for inverter-based generators

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ISO-NE PUBLIC

Reactive Performance Requirements

• Recently approved PJM requirement1 – All new non-synchronous resources should: (1) have the capability to

autonomously provide dynamic reactive support within a range of 0.95 leading to 0.95 lagging at inverter terminals; (2) adhere to NERC Reliability Standard PRC-024-1 with respect to voltage and frequency ride-through capabilities, irrespective of resource size • Previously, in accordance with FERC Order No. 661, wind resources were

not required to provide reactive power unless a system impact study shows that reactive power is needed from that resource to maintain grid reliability

• ERCOT requirement – Power factor capability of +/-0.95 (or less) determined at the

generating unit's maximum net power to be supplied to the ERCOT Transmission Grid and at the transmission system Voltage Profile established by ERCOT, both measured at the POI

1. Docket No: ER15-1193-000: Conditionally Approved May 05, 2015

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ISO-NE PUBLIC

Benefits of Reactive Performance Requirement

• Reduce the reliance on the design of reactive solutions in the interconnection system impact study – Expected to help to reduce time to complete studies

• Capture the benefits of widely available technology improvements

• Can result in fewer operating restrictions

• Anticipate the increasing number of non-synchronous interconnection requests (combined with anticipated resource retirements) – Necessitates the availability of reactive power on a presumptive basis

to ensure the safety and reliability of the transmission system as a whole

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ISO-NE PUBLIC ISO-NE PUBLIC

DEFINING A COMPLETE INTERCONNECTION REQUEST Considerations to improve study time-frames for inverter-based generators

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ISO-NE PUBLIC

Detailed Representation of Wind Farms

• System Impact Studies have required full modeling of the wind farm in steady state analysis – Single-turbine equivalents are

used in stability analysis

• A standard wind farm data set has been drafted and has been used in the collection of data from some existing and new wind farms

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ISO-NE PUBLIC

Initial Steps in Wind Farm Electrical Design

• Identify tap settings for the unit step-up transformers and the station step-up transformers – Tap settings correspond to the most reasonable voltage conditions on

the collector system and the turbine terminals for a range of different voltage conditions at the POI

• The detailed representation provides direction to the tap settings to be used in the equivalent models used in stability analysis

• These analyses can be time-consuming and have been included in the ISO system impact study analysis

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ISO-NE PUBLIC

Inverter-Based Interconnections in Weak Portions of the System

• A low short circuit ratio (SCR) is a commonly used indicator of a “weak” system

• In a weak system, the following problems can be associated with inverter-based interconnections: – Steady state voltage violations – Voltage instability – Oscillations

• Power system analysis models provided by manufacturers do not represent actual performance under weak system conditions – Reduced confidence in the models – Reduced confidence in the ability of turbines to operate reliably in these weak

conditions

• Customized generator-specific changes are typically inadequate due to operational system changes and system evolution

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ISO-NE PUBLIC

Appropriate Design level of an Interconnection Request for an Inverter-Based Generator

• The detailed project design could be provided by the developer as part of Interconnection Request – Developer would provide comprehensive documentation demonstrating

conformance with performance requirements

• Interconnection Request submittal could address weak grid performance – Certify the lowest acceptable level of short circuit ratio, or provide

correction to an acceptable level – Provide electromagnetic transient (PSCAD) model – Provide documentation of acceptable power system analysis model

performance • Verify using benchmark comparison with PSCAD

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ISO-NE PUBLIC

Benefits of Up-Front Design

• Increased readiness to initiate the system impact analysis of the effect of the project on the network – Expected to help to reduce time to complete studies

• Reduced need to consider modifying the project after the interconnection process has begun

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ISO-NE PUBLIC ISO-NE PUBLIC

STANDARDIZED MODELS Applicable to all generator types

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ISO-NE PUBLIC

NERC Proposal for Standardized Models

• In November 2013, NERC issued a “Proposal for Use of Standardized Component Models in Powerflow and Dynamics Cases”

• NERC Planning Committee (PC) directed the NERC Modeling Working Group (MWG) to develop, validate, and maintain a library of standardized component models and parameters for powerflow and dynamics cases

• The proposal requires that user‐defined models should be placed on a swift path to inclusion in the library of standardized models – Once a corresponding standardized model is developed and validated,

the regions should shift to the standardized model

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ISO-NE PUBLIC

Benefits of Using Standardized Models

• Reduces the time required to set-up new study cases – Expected to help to reduce time to complete studies

• Eliminates the need for generator owners to update user models when power system analysis software is updated

• Eliminates the use of ISO/Transmission Provider engineering resources in the testing and troubleshooting of user models

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ISO-NE PUBLIC ISO-NE PUBLIC

MATERIAL MODIFICATION Applicable to all generator types

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ISO-NE PUBLIC

Material Modification Background

• In response to customer requests and to address the backlog in its generator interconnection queue, ISO has reviewed how it administers the process of making a Material Modification determination

• ISO has been implementing procedural rules to add more structure to the process that should expedite the studies of projects in the queue and provide notification to customers on key times to update the technical data for their project

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ISO-NE PUBLIC

Material Modification Background, cont.

• Interconnection Customers request changes to their existing or proposed generating facilities for a wide variety of reasons

• These changes can have no impact, can have a large impact on the studies of other proposed projects or can have a significant impact on the reliability of the New England’s transmission system

• Proposed changes that may cause a large/significant impact are deemed to be Material Modifications and require submission of a new Interconnection Request and a new queue position

• ISO’s Tariff provides a definition of Material Modification in Schedule 22 and provides further information on modifications in Section 4 of the LGIP and Article 5.19 of the LGIA

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ISO-NE PUBLIC

Data Refresh at the beginning of the System Impact Study

• ISO-NE will notify the Interconnection Customer 30 days before the study begins and allow the Interconnection Customer 30 days to refresh its data to the degree allowed under the same materiality standards for changes prior to execution of the System Impact Agreement

• Once the System Impact Study Study has started, it will be completed without making any changes except those based on study results that were not anticipated and are agreed to by the System Operator and the Interconnecting Transmission – Screening criteria on the following slide

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ISO-NE PUBLIC

Screening Criteria for Project Changes

• Changes will be deemed material and require a new Interconnection Request when: – A restudy is needed to determine if the change has a significant

impact on the reliability of the transmission system, or, – A restudy is needed to re-determine the system upgrades and/or the

allocation of system upgrade costs, or, – A restudy will result in a delay of the study of a later-queued project

• Changes will not be deemed material and will not require a new Interconnection when: – There are no performance problems that may be affected by the

change to the project that is found in any base cases for the most severe N-1 and N-1-1 contingencies, and,

– Similar or better performance can be confirmed based on a very limited review

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ISO-NE PUBLIC

Benefits of Additional Structure in Material Modification Determinations

• Reduced delay in the conduct of queued studies – Expected to help to reduce time to complete studies

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CONSIDERATION OF NETWORK UPGRADES Applicable to all generator types

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ISO-NE PUBLIC

Consideration of Network Upgrades

• The selection and design of reactive upgrades can take a significant amount of study effort – Sufficient descriptive detail of the proposed reactive upgrades must be

available for modeling and analysis – Must coordinate with other existing and proposed devices – Long time to collect cost estimates

• A request by the developer to consider a different reactive upgrade than the proposed upgrade can cause a significant amount of study re-work

• Static shunt compensation can be inoperable for intermittent resources due to quickly changing output conditions and can be infeasible from an operating standpoint due to frequent switching operations

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ISO-NE PUBLIC

Benefits of Focusing on Operable Solutions

• Reduced iterations in the study of upgrade alternatives – Expected to help to reduce time to complete studies

• Some scalability of upgrades to build upon in the evaluation of later queue positions – Expected to help to reduce time to complete studies

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ISO-NE PUBLIC ISO-NE PUBLIC

THE STANDARD SCOPE OF A FEASIBILITY STUDY

Applicable to all generator types

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ISO-NE PUBLIC

Feasibility Study Scope

• In New England, the Feasibility Study scope has corresponded to a complete steady-state portion of the overall System Impact Study – Complete thermal analysis – Complete steady state voltage analysis – Complete short circuit analysis

• Propose to modify the standard scope of Feasibility Studies to provide screening analysis of the expected areas of concern – Benefit is expected to be a high-level study in a shorter amount of

time that focuses on the expected problems

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ISO-NE PUBLIC

Examples of Reactive Power Screening Tools

• Surge Impedance Loading and VAR Losses – Overview of the VAR burden introduced by the interconnection

• “PV” (Power-Voltage) Analysis – Voltage feasibility pretest – Worst scenario and contingency screening – Critical voltage location (bus) searching – Understand the voltage profile in the facility and the region

• “QV” (Reactive-Voltage) Analysis – Evaluate reactive margin and high/low voltage potential – Evaluate the amount and type of reactive compensation needed

• Short Circuit Ratio – Evaluate potential issues and recommend focus of study

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ISO-NE PUBLIC

ISO-NE INTERNAL USE

ISO-NE PUBLIC

DISCUSSION OF THE BACKLOG IN MAINE

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ISO-NE PUBLIC

Multiple Communications Regarding the Severe Challenges in Maine

• “New England Wind Integration Study” (the “NEWIS”) – to assess the effects of large-scale wind penetration in New England (2009)

• Northern Maine System Performance, Planning Advisory Committee (PAC) presentation (September 21, 2010)

• Wind Development in Constrained Areas, PAC presentation (March 21, 2013)

• Strategic Transmission Analysis: Wind Integration Study, PAC Presentation (December 18, 2013)

• Strategic Transmission Analysis: Wind Integration Study – Stage 1- Maine, Regional Constraints, PAC Presentation (May 21, 2014)

• Strategic Transmission Analysis: Wind Integration Study – Stage 2- Maine, Interface Constraints, PAC Presentation (December 18, 2014)

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ISO-NE PUBLIC

–

The Existing Maine System Three existing Special Protection Systems (SPS) associated with actions to reduce North-South flows under contingency conditions

Maine corridor experiences severe voltage sags for faults in Southern New England

Maine Voltages

The Maine system has long transmission lines with relatively little load

Multiple Major Interfaces to manage North-South flows

Multiple Local Interfaces to manage local constraints (Not Shown)

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ISO-NE PUBLIC

Requests Far Beyond the Existing Capability of the Maine Transmission System

Maine System Approximate (MW)

Forecast 2015 Summer Peak Load1 (net) 2,300

Maine Export Capability 1,900

Load + Export Capability 4,200

Existing Generation Capacity (Summer 2015) 3,100

New Brunswick Import Capability 1,000

New Requests (September 2015)1 3,600

Resource Totals 7,700

1. Note that most of the proposals are located north of Orrington – where there is only approximately 300 MW of load

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ISO-NE INTERNAL USE

ISO-NE PUBLIC

FURTHER CONSIDERATION

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ISO-NE PUBLIC

Considerations

• Interconnection issues in the identified remote areas of the system are not caused by, nor can they be addressed by, queue process changes – The existing transmission system was built to serve minimal system load

and is at its limit • As noted above, studies since 2009 have shown the need for significant

transmission system expansion • Even if small incremental amounts of wind can be added, it is clear that the

existing system cannot support hundreds or thousands of proposed MWs – If individual projects are not able or willing to make the scale of system

upgrade investments now required; key issue becomes infrastructure

• How to address the infrastructure issues? – Additional wind integration analysis to identify the overall upgrades

required to interconnect the levels of MW that are proposed? • Such an approach is essentially a clustering study and only appears to be a way

forward if coupled with cost allocation to queue projects to share costs • Interconnection cost allocation alternatives?

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Next Steps

• Introduce proposed Tariff changes at the September Transmission Committee

• Transmission Committee action in October

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APPENDIX - PHASOR MEASUREMENT UNITS Discussed at the July Reliability/Transmission Committee

Applicable to all generator types

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ISO-NE PUBLIC

Model Validation: NERC MOD-026 and MOD-027

• MOD-026 will require generators equal to or greater than 100 MVA to verify the generator excitation control system or plant volt/var control function model (including the power system stabilizer model and the impedance compensator model) and the model parameters used in dynamic simulations accurately represent the generator excitation control system or plant volt/var control function behavior when assessing Bulk Electric System reliability

• MOD-027 will require generators equal to or greater than 100 MVA to verify the turbine/governor and load control or active power/frequency control model and the model parameters, used in dynamic simulations that assess BES reliability, accurately represent generator unit real power response to system frequency variations

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ISO-NE PUBLIC

Model Validation: MOD-033

• Requirement

Each Planning Coordinator shall implement a documented process to validate steady-state and dynamics Planning models by comparing performance with actual system behavior

• Compliance measure

Each Planning Coordinator shall provide evidence that it has a documented validation process according to Requirement R1 as well as evidence that demonstrates the implementation of the required components of the process

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ISO-NE PUBLIC

PJM Tariff Language

• 8.5.3. Phasor Measurement Units (PMUs):

An Interconnection Customer entering the New Services Queue on or after October 1, 2012 with a proposed new Customer Facility that has a Maximum Facility Output equal to or greater than 100 MW shall install and maintain, at its expense, phasor measurement units (PMUs). PMUs shall be installed on the Customer Facility low side of the generator step-up transformer, unless it is a non-synchronous generation facility, in which case the PMUs shall be installed on the Customer Facility side of the Point of Interconnection. The PMUs must be capable of performing phasor measurements at a minimum of 30 samples per second which are synchronized via a high-accuracy satellite clock. To the extent Interconnection Customer installs similar quality equipment, such as relays or digital fault recorders, that can collect data at least at the same rate as PMUs and which data is synchronized via a high-accuracy satellite clock, such equipment would satisfy this requirement. As provided for in the PJM Manuals, an Interconnection Customer shall be required to install and maintain, at its expense, PMU equipment which includes the communication circuit capable of carrying the PMU data to a local data concentrator, and then transporting the information continuously to the Transmission Provider; as well as store the PMU data locally for thirty days.

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ISO-NE PUBLIC

PJM Tariff Language (Cont’)

Interconnection Customer shall provide to Transmission Provider all necessary and requested information through the Transmission Provider synchrophasor system, including the following: (a) gross MW and MVAR measured at the Customer Facility side of the generator step-up transformer (or, for a non-synchronous generation facility, to be measured at the Customer Facility side of the Point of Interconnection); (b) generator terminal voltage; (c) generator terminal frequency; and (d) generator field voltage and current, where available. The Transmission Provider will install and provide for the ongoing support and maintenance of the network communications linking the data concentrator to the Transmission Provider. Additional details regarding the requirements and guidelines of PMU data and telecommunication of such data are contained in the PJM Manuals.

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ISO-NE PUBLIC

Benefits of PMUs

• The traditional off-line staged generator tests are costly and time consuming

• With high-resolution PMU data from generators, model validations may more readily be performed online or using system disturbance data, without taking generation outages – Opportunity to detect failures, changed adjustments, drifting, and

improper operation of equipment

• Enhanced ability to verify dynamic models using PMU measurements

• Validation and benchmarking system wide models (MOD-033)

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