FRTPSPS (Helms RAS) Modification of Cottle 230kV Bus Substations Addition of Distribution Transformer March 2018

Southern PG&E Area Including Greater Fresno Area Gregg Panoche Helms Gates Los Banos Moss Landing Morro Bay Diablo Canyon Midway Bellota Tesla Kings River McCall Arco To Southern California Bellota-Gregg #1 & #2 230KV Los Banos-Panoche #1 & #2 230KV Dos Amigos-Panoche 230KV Coburn Gates - Panoche #1 & #2 230kV Gates-McCall 230kV Gates-Gregg 230kV Mc Call Midway #1 & #2 115kV Tranquillity Mustang 2

FRTPSPS Background Outage detection devices are located at the following stations with the addition of Mustang and Tranquillity: Bellota Borden Cottle Gates Gregg Helm Herndon Kearney McCall Panoche Wilson Warnerville (CCSF) New Melones (WAPA) Mustang (Dec 2015) Tranquillity (Feb 2016)

FRTSPS Station Locations The location of the monitoring station locations is listed below: COTTLE SUBSTATION VICINITY WARNERVILLE SUBSTATION VICINITY NEW MELONNES SUBSTATION VICINITY WILSON SUBSTATION VICINITY BELLOTA SUBSTATION VICINITY BORDEN SUBSTATION VICINITY GREGG/HERNDON SUBSTATION VICINITY HELMS PSP PH VICINITY MCCALL SUBSTATION VICINITY KEARNEY SUBSTATION VICINITY HELM SUBSTATION VICINITY PANOCHE SUBSTATION VICINITY GATE SUBSTATION VICINITY FOC VICINITY MUSTANG SUBSTATION VICINITY TRANQUILLITY SUBSTATION VICINITY

FRTPSPS Background (cont.) The Greater Fresno Area load is served by a network of 230 and 115 kV import lines and by local generation. The area load, including the Helms PGP facility while in pump mode is constrained by the capacity of the import lines. The forced outage of any of several import lines or of the Gates 500/230 kV bank can cause thermal overloads on the remaining lines. Three SPS / RAS were installed in the Fresno Area to increase the available hours that Helms can pump. The initial HRAS was placed in service in the early 1990’s with the HTT-RAS installed in early 1994. The Gates TB11 SPS was installed in 2007. The FRTPSPS has replaced and combined the HTT-RAS, Gates TB-11 SPS and portions of the HRAS (except the Pacific Inter Tie, the Helms 230kV Line #2 Transfer Trip for generation tripping and the SFGO Manual Pump trip) into one fully redundant scheme utilizing C37.94 fully redundant digital communication paths.

FRTPSPS Background/Modifications This scheme was presented to WECC in July 2014 and approved in November 2014 as a LAPS scheme. This modification is installing a new 45MVA 230kV/17kV Distribution Transformer Bank to Cottle Substation. The installation will include an additional 230kV breaker. The addition of the 230kV breaker modifies the existing Cottle Ring Bus and requires a change to outage detection logic. The expected on-line date for the 230kV breaker installation is 4/5/2018. Existing devices located at Cottle Substation will be rewired and outage detection logic will be modified to include the addition of the new 230kV breaker. No logic changes are required to the main controller.

FRTPSPS Cottle Modification Over all single line of the system before the Cottle CB 2042 TB-3 Addition:

FRTPSPS Cottle Modification Over all single line of the affected system:

Response To Detected Event Line/Element Outage is detected. Data is sent to the FOC main controller. FOC main controller sends appropriate trip signal to Helms PGP Selected Helms PGP pump/pumps will trip via normal shutdown (86N) in approximately 5 – 10 seconds. If the Selected Helms PGP unit breaker is not opened within 20 seconds the scheme will trip the selected unit (86E) tripping relay.

System Control/Monitoring Field Elements Cut-in/Cut-out feature. In cutout mode the train is un-available. Test Feature Allows for outage signal to be sent via front panel pushbutton. Alarms* Communication channel failure alarm, IRIG-B Clock Failure, line status disagreement (CB indicates open with current present) Device failure * Alarms are sent to GCC and FOC.

FRTPSPS Cottle Modification Existing Cottle Line Outage Detection Logic.

FRTPSPS Cottle Modification Propose Cottle Line Outage Detection Logic

FRTPSPS Cottle Cottle Modification PG&E requests approval from the RASRS Committee for the modifications to the FRTP SPS at Cottle to incorporate the installation of CB 2052 in conjunction with the new 230kV/17kV 45MVA distribution transformer. This scheme was classified as LAPS in 2014, however the WECC database indicates the classification is a WAPS, the WECC database should be corrected. Mention DOO, Scada Screens, and training are being addressed.

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