ERCOT Nodal Operating Guides - Section 3

ERCOT and Market Participant Responsibilities

3.1 System Control Interfaces with ERCOT

3.1.1 Introduction
- Defines responsibilities between Qualified Scheduling Entities (QSEs) and Transmission Service Providers (TSPs) for ERCOT System security and reliability.
- Resource Entities can communicate directly with ERCOT during emergencies and specific scheduling activities.
- All other entities communicate with their QSE or TSP.
- [NOGRR177 Update]: Includes Direct Current Tie Operators (DCTOs) in the responsibilities.
3.1.2 Compliance with Dispatch Instructions
- QSEs and Transmission Operators (TOs) must comply fully and promptly with valid Dispatch Instructions as per Protocol Section 6.5.7.9.
3.1.3 Dispatch Instructions
- Applies to Real-Time operations Dispatch Instructions intended to change or preserve the state of an element or facility of the ERCOT System.
- Verbal Dispatch Instructions (VDI) Issuance and Receipt:
  - ERCOT actions when issuing a VDI:
    - (A) Confirm Market Participant's response if correct.
    - (B) Reissue if incorrect or requested.
    - (C) Reissue or take alternative action if not understood.
  - QSE actions when re-issuing VDI to Resource:
    - (A) Confirm Resource's response if correct.
    - (B) Reissue if incorrect or requested.
    - (C) Coordinate alternative action with ERCOT if no response or not understood.
  - TO actions when re-issuing the ERCOT VDI to the appropriate Distribution Service Provider (DSP) or Resource:
    - (A) Confirm the DSP’s or Resource’s response if the repeated VDI is correct.
    - (B) Reissue the VDI if the repeated VDI is incorrect or requested by the DSP or Resource.
    - (C) Coordinate an alternative action with ERCOT, as required in the ERCOT Protocols, if a response is not received or if the VDI was not understood by the DSP or Resource.
    - [NOGRR177 Update]: Includes DCTOs in TO actions.
  - Market Participant actions after receiving a VDI:
    - (i) Repeat the VDI and receive confirmation of correctness.
    - (ii) Request a reissue of the VDI.
  - ERCOT confirms receipt of Hotline VDI by at least one Market Participant on the Hotline call.
  - When issuing or re-issuing a Dispatch Instruction, ERCOT, QSEs, and TOs shall specify the time using a 24-hour clock in Central Prevailing Time (CPT) if the Dispatch Instruction is not to be acted upon immediately.
  - ERCOT, QSEs, and TOs shall use ERCOT Network Operations Model nomenclature when issuing Dispatch Instructions for Transmission Elements and Transmission Facilities.

3.2 Qualified Scheduling Entities

3.2.1 Operating Obligations
- QSEs must maintain a scheduling center with qualified personnel who have the authority to commit and bind the QSE, as specified in Protocol Section 16.2.
- QSEs must communicate with ERCOT to fulfill their obligations under the Protocols and Operating Guides.
- Each QSE designates an Authorized Representative as defined in Protocol Section 2.1.
- Each QSE must submit a written back-up control plan to ERCOT by March 15 annually, describing how they will continue operations if their scheduling center becomes inoperable.
  - Submitted via secured webmail or encrypted data transfer to shiftsupervisors@ercot.com.
- Back-up control plan requirements:
  - (a) Actions to avoid placing a prolonged burden on ERCOT and other Market Participants.
  - (b) Description of functions and responsibilities to be performed from an alternate location.
  - (c) Procedures for maintaining basic voice communications with ERCOT.
  - (d) Procedures for back-up control function testing and personnel training.
- The back-up control plan may include arrangements with another Entity to provide minimum back-up control functions.
- Connectivity requirements for back-up sites are detailed in Section 7.
3.2.2 Changes in Resource Status
- QSEs must verbally notify ERCOT of unplanned changes in Load and Generation Resource status as soon as practicable per Protocol Section 6.5.5.1.
  - [NOGRR268 Update]: Refers to changes in the status of a Resource.
- QSEs must verbally notify ERCOT and/or TSP of equipment changes affecting the reactive capability of an operating Generation Resource.
  - [NOGRR268 Update]: Includes Energy Storage Resources (ESRs).
- QSEs must submit a Current Operating Plan (COP) in accordance with Protocol Section 3.9.
3.2.3 Regulatory Required Incident and Disturbance Reports
- QSEs and TSPs (or their Designated Agents) must provide required reports to ERCOT, DOE, and/or NERC in the event of a system incident or disturbance as defined by NERC and DOE.
  - [NOGRR177 Update]: Includes Direct Current Tie Operators (DCTOs).
- Types of incidents that trigger reporting:
  - (a) Uncontrolled loss of Load
  - (b) Load shed events
  - (c) Public appeal for reduced electricity usage
  - (d) Actual or suspected attacks on the transmission system
  - (e) Vandalism
  - (f) Actual or suspected cyber attacks
  - (g) Fuel supply emergencies
  - (h) Loss of electric service to large customers
  - (i) Loss of bulk transmission component that significantly reduces integrity of the transmission system
  - (j) Islanding of transmission system
  - (k) Sustained voltage excursions
  - (l) Major damage to power system components
  - (m) Failure, degradation, or misoperation of Remedial Action Schemes (RASs) or other operating systems.
- Full descriptions of DOE and NERC reports are available on their websites.
3.2.4 Ancillary Service Qualification and Testing Program
- Resources providing Ancillary Services must qualify with ERCOT before participating in the Ancillary Service market.
- ERCOT will reject Ancillary Service offers from unqualified Resources and notify the QSE.
- ERCOT may provisionally qualify Load Resources for Ancillary Services for 90 days without a qualification test.
- ERCOT evaluates the performance of Resources providing Ancillary Services per Protocol Section 8.
  - QSEs are notified of Resources failing to meet performance requirements.
  - Resources failing for two consecutive months must develop and implement a corrective action plan as per Protocol Section 8.4.
- ERCOT may revoke the qualification to provide Ancillary Services for Resources failing an Ancillary Service performance standard for four consecutive months, as per Protocol Section 8.4.
- Re-testing after qualification revocation is at ERCOT's discretion, only after demonstrating and implementing a corrective action plan as described in Protocol Section 8.4.

3.3 Resource Entities

Operation of Generation Resources and Energy Storage Resources (ESRs) must conform to Protocols, NERC Reliability Standards, and Operating Guides.
QSEs and Resource Entities must provide modeling information to ERCOT and the TSP for each Generation Resource, ESR, and Load Resource as prescribed in Protocol Sections 3.7.1.1, 3.7.1.2, 3.7.1.3, and 3.10.7.2.
Resource Entities will provide information on Transmission, Main Power Transformers (MPTs) and Generation Resource Step-Up Transformers to TSPs as prescribed in Protocol Section 3.10.7.1.4.
QSEs must provide operational information for generation facilities greater than 10 MW per Protocol Sections 3.10.7.5, 6.5.5.2, and 8.
Minimum notifications from a Resource Entity to ERCOT and the QSE:
- (a) 60 days prior to planned equipment changes affecting reactive capability of a Generation Resource or ESR.
- (b) Prior ERCOT approval is needed for changes that decrease reactive capability below required levels or decrease voltage ride-through capability.
- (c) As soon as practicable when high reactive loading or reactive oscillations on Generation Resources or ESRs are observed.
- (d) As soon as practicable when a Generation Resource or ESR trips Off-Line due to voltage or reactive problems.
Resource Entities scheduled to ERCOT must be staffed or monitored 24x7 by personnel capable of making operating decisions.
- Each Resource Entity designates an Authorized Representative per Protocol Section 2.1.
- Applies to:
  - (a) Generation Resources or ESR greater than 10 MW.
  - (b) Load Resources.
Resource Entity responsibilities include implementing the following in a reliable and safe manner according to the TSP's switching procedure:
- (a) Synchronizing generation to the ERCOT System.
- (b) Performing transmission switchyard switching or clearances.
An agreement with the Transmission Operator (TO) is required for any Resource or Customer-owned switching device (60 kV or greater) that can interrupt flow through network transmission equipment, to schedule Outages on, and perform emergency switching of, the device.
Generation Resources or ESRs specifically licensed by a federal regulatory agency must provide applicable grid interconnection and performance licensing requirements to ERCOT and the connected TSP (through its QSE representative).
The TSP must incorporate these licensing requirements into its planning and operations, with ERCOT supporting such requirements.
- Procedures include provisions to notify the facility licensee through its QSE if any requirements cannot be satisfied.
Licensees must be given the opportunity to review and respond to any proposal to revise this Operating Guide or the procedures incorporating the licensee requirements that would diminish the obligation or ability of ERCOT or the TSP to support these requirements.
- Any such proposal that is approved, as a result of which the licensee is required to implement changes to meet its license requirements or to seek amendment to its license, shall become effective no sooner than six months following the approval.
Resource Entities must provide Resource-owned Transmission Elements data requirements as prescribed in Protocol Section 3.10.7.
- Additional distribution voltage level devices and connectivity may be required to adequately represent the modeling of the Resource within ERCOT computer systems.

3.3.1 Unit Capability Requirements

If a QSE fails to meet Protocol Section 8.1.1.2 (General Capacity Testing Requirements), ERCOT will notify the QSE via email and telephone.
- [NOGRR268 Update]: Applies to the QSE representing the Generation Resource or ESR.
The QSE has three days to correct the omission with ERCOT approved test results.
- If the generating resource is operated during these three days, without providing test results, the QSE will be disqualified from providing Ancillary Services.
- [NOGRR268 Update]: Applies to the Resource.
If the generating Resource is not operated and included in a QSE Current Operating Plan (COP) after the notification of the Protocol violation, then ERCOT shall not disqualify the Ancillary Service provider unless or until the Generation Resource is operated and included in the COP that might be depended upon for Ancillary Services.
- [NOGRR268 Update]: Applies to the Resource.

3.3.2 Unit Reactive Capability Requirements

3.3.2.1 Corrected Unit Reactive Limits (CURL)

A reactive capability curve and associated data for each unit on the ERCOT System must be submitted to ERCOT through the Market Information System (MIS) Certified Area.
- Must contain the most limiting elements for the leading and lagging reactive output.
- Limiting factors include under-excitation limiters, over-excitation limiters, ambient temperature limitations across the MW range of the unit at the unit terminals or any other factor that limits the reactive output of the unit and is verifiable through engineering calculations or testing
The corrected reactive capability curve establishes the Corrected Unit Reactive Limits (CURL) at the unit terminals that ERCOT Planning and ERCOT Operations, and TSPs will use for their studies.
- For Intermittent Renewable Resources (IRRs), CURL data should be reported at the low side of the MPT.
Resources provide updated curves and test data by submitting test information to the Net Dependable Capability and Reactive Capability (NDCRC) application on the MIS Secure Area.
Once approved by ERCOT per Section 3.5, Resources provide updated data by submitting changes to the appropriate ERCOT Resource Registration information in accordance with Planning Guide Section 6.8.
Before including submitted data in the Network Operations Model, ERCOT notifies the TSP to which the Resource Entity is interconnected that the test data is posted on the MIS Secure Area.
- ERCOT and TSPs may review and comment within ten Business Days.
ERCOT includes changes in the future Network Operations Model and forwards them to TSPs and the Steady State Working Group (SSWG).
The CURL data should be available in the Resource Entities’ control room where the tests are conducted and at the QSE’s Real-Time generation dispatch desk.
During any test, the Generation Resource must maintain its generator cooling system at normal operating conditions, the Automatic Voltage Regulator (AVR) in service and all auxiliary equipment in service that is needed for expected normal operation.
[NOGRR204 Update]: Generation Resource or ESR must maintain its generator cooling system at normal operating conditions, the Automatic Voltage Regulator (AVR) in service and all auxiliary equipment in service that is needed for expected normal operation.

3.3.2.2 Reactive Testing Requirements

Reactive testing can be