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NPRR #562 · Revision Request

NPRR562  Subsynchronous Resonance

Approved sponsor ERCOT posted 2013-08-12 ercot.com
  1. PRS Apr 13 '17
  2. TAC May 25 '17
  3. BOARD Jun 13 '17
  4. PUCT —
ReasonSSR is a potentially harmful phenomenon involving coincident oscillation between two or more Transmission Elements or Generation Resources at frequencies lower than the normal operating frequency (60 Hz) of the ERCOT System. The ERCOT System has recently become more vulnerable to SSR because of the introduction of series capacitors for voltage support, although other Transmission Elements (including poorly tuned power electronic devices) and generator control systems can also create SSR. Without proper mitigation, SSR can quickly destroy resonating Transmission Elements and/or Generation Resources and lead to cascading Outages. It is therefore essential to carefully study and mitigate this risk. This NPRR is intended to create a process for investigating and addressing SSR risk and to clarify the responsibilities of the various Entities affected.
Created2013-09-19
Approved2017-06-13
Sections Affected
2.12.23.1.13.1.5.113.22 (new)3.22.1 (new)3.22.1.1 (new)3.22.1.2 (new)3.22.1.3 (new)3.22.1.4 (new)3.21.2 (new)and 3.22.3 (new)
Summary
This Nodal Protocol Revision Request (NPRR) creates new requirements for the identification, study, mitigation of, and protection against Subsynchronous Resonance (SSR).
Timeline