{"id":1701,"date":"2018-10-25T00:00:00","date_gmt":"2018-10-25T00:00:00","guid":{"rendered":"https:\/\/www.trccompanies.com\/insights\/nerc-addresses-single-points-of-failure-in-protection-systems-among-other-ferc-concerns\/"},"modified":"2025-02-13T14:33:18","modified_gmt":"2025-02-13T14:33:18","slug":"nerc-addresses-single-points-of-failure-in-protection-systems-among-other-ferc-concerns","status":"publish","type":"news-and-insights","link":"https:\/\/www.trccompanies.com\/fr\/insights\/nerc-addresses-single-points-of-failure-in-protection-systems-among-other-ferc-concerns\/","title":{"rendered":"NERC Addresses Single Points of Failure in Protection Systems Among Other FERC Concerns"},"content":{"rendered":"\n\n
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Under the proposed NERC TPL-001-5 standard, utilities with transmission planning responsibilities will be required to identify reliability risks related to protection system failures and take mandatory corrective action. It will be critical to have an in depth understanding of your company\u2019s protection system settings and to perform the system studies necessary to identify where single points of failure may result in cascading tripping of transmission elements. Mitigation actions may require the installation of redundant protection systems which in turn may lead to significant substation redesign. Transmission planners and planning coordinators should begin preparing for any necessary protection system changes.<\/p>\n

TPL-001-5 Overview<\/h2>\n

NERC began studying the reliability risk associated with single points of protection system failure starting in 2011\u00a0as directed in FERC Order 754. TPL-001-5 will bring significant changes for Planning Coordinators and Transmission Planners as they perform annual Planning Assessments. There is a new obligation to adequately account for the reliability risk posed by single point of protection system failure via risk-based Assessment.<\/p>\n

This reliability risk management approach will be implemented through modifications to the Category P5 Planning Event which is described in Table 1 of the TPL-001-5 standard<\/a>.<\/p>\n

NERC believes that the most cost-effective Corrective Action Plans to address unacceptable system performance for the P5 Planning Events will likely be to add protection system component redundancy in certain cases. Protection system redundancy changes to address Category P5 Event system performance violations should reduce or even negate non-redundant component related risks that need to be considered in assessing transmission system performance. These risks will be identified during simulations of certain extreme events as required under the standard.<\/p>\n

TPL-001-5 also addresses reliability risks related to outage management as directed in FERC Order 786. The standard requires utility planners to consider maintenance outages of significant facilities as well as outages for critical long lead time to repair or replace equipment. Specifically, it addresses stability analysis to assess system performance for conditions expected during possible unavailability of long lead time equipment. Although it is not a NERC defined term, it is believed that a \u201cspare equipment strategy will be sufficient to allow flexibility for utilities to conduct both steady state and stability analysis required by TPL-001-5. For example, a utility\u2019s spare equipment strategy may include the warehousing of a replacement transformer to be installed given the failure of an in service transformer. When a utility\u2019s spare equipment strategy may prevent major transmission equipment from being out-of-service for one year or more, this possible equipment unavailability need not be assessed as part of TPL-001-5.<\/p>\n <\/div>\n

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