NERC Footnote b / 12 – Load Loss

Joe SeabrookElectric Transmission Contracts

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TPL-002-0, footnote b and TPL-001-3, footnote 12 Non-Consequential Load Loss: Non-Interruptible Load

loss that does not include: (1) Consequential Load Loss, (2) the response of voltage sensitive Load, or (3) Load that is disconnected from the System by end-user equipment. (Defined in TPL-001-3)

Footnote b and 12 is about conditional requirements for some contingencies when Non-Consequential Load Loss might be allowed

Footnote b and 12 with respect to some N-1 outages, and generator followed by N-1 outages

Footnote 12 in TPL-001-3 is applied for the same contingencies in HV and EHV (above 300 kV)

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TPL-001-3, footnote 12, Table 1 P1 – Loss of one of the following:

1. Generator2. Transmission Circuit3. Transformer4. Shunt Device5. Single Pole of a DC line

P2 – Opening of a line section w/o a fault P3 – Loss of generator, system adjustments,

then loss of:1. Generator2. Transmission Circuit3. Transformer4. Shunt Device5. Single Pole of a DC line

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TPL-001-3, footnote 12, Table 1 Note that for P2, Non-Consequential Load Loss

is not allowed for EHV for:1. A Bus Section Fault2. A non-Bus-tie Breaker Internal Breaker Fault

But could allow Non-Consequential Load Loss for EHV for loss of:1. Generator2. Transmission Circuit3. Transformer4. Shunt Device5. Single Pole of a DC line6. Opening of a line section w/o a fault

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TPL-001-3, footnote 12, text12. An objective of the planning process should be to minimize the likelihood and magnitude of Non-Consequential Load Loss following Contingency events. However, in limited circumstances Non-Consequential Load Loss may be needed to ensure that BES performance requirements are met. When Non-Consequential Load Loss is utilized within the planning process to address BES performance requirements, such interruption is meets the conditions shown in Attachment 1. In no case can the planned Firm Demand interruption under footnote 12 exceed ‘x’ MW.

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The Conditions shown in Attachment 1.

Attachment 1 labeled “I. Stakeholder Process” Meetings for all affected stakeholders Requirements for notifications Procedures to involve stakeholders Dispute resolution for questioning and concerned

stakeholders. Extensive reporting requirements Future plans to mitigate Firm Demand interruption Alternatives considered Regulatory approval required if EHV, or if ≥ 25 MW Regional Entity verification of no Adverse Reliability

Impact is required.

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Conclusion An alternative would be to leave customers on

radial connections. ‘x’ MW is not defined in:

“In no case can the planned Firm Demand interruption under footnote 12 exceed ‘x’ MW.”

The SDT is expected to define ‘x’ MW