RFI - Webbers Falls Exciters Options for Commissioning.pdf

Webbers Falls Excitation System Replacement – Request for Information (RFI)

Current Project Scope Overview

Component Scope of Work

AC supply connection:

To be replaced with new cable/conduit system for all three units, including the close-coupled cable connection between the Unit 1 bus tap and the high side fuse disconnect switch cabinet of the PPT. The contractor will be responsible for pulling the new cable and making the connections at both ends.

Power Potential Transformer (PPT):

To be replaced with new PPT.

PPT to exciter AC connection:

New close-coupled configuration, to be determined by contractor. Close coupled connections can be made by either cable or bus. The contractor will be responsible for all aspects of this work.

Exciter cabinets:

All exciter cabinets to be replaced, with size as limited by contract drawings.

Redundant bridges will be specified to match existing equipment capabilities.

Redundant Controllers will be specified.

Exciter DC field connection:

Replace with new cables, which will consist of DLO cable of specified sizes.

Conduit to be replaced where necessary. The contractor will be responsible for pulling the new cable and making the connections at both ends.

Collector ring: Collector ring inspection with optional (in place) collector ring refurbishment.

Collector ring brushes: No collector ring brush work will be part of this contract.

Shaft grounding brush: No shaft grounding brush work will be part of this contract.

Field ground detection:

New SEL-2664 field ground modules to be installed in new exciter, fiber to splitter in control room to redundant SEL-300G relays. Remove and retain existing field ground modules as spares.

Control room switchboard devices:

Replace two Exciter control switches for each Unit.

Provide and install new Satellite Clock in Main Board cubicle 1F.

Provide and install all equipment necessary for proper operation, including terminal block(s), signal converters, signal splitters, wire to BNC converters, and power supplies. Re-use existing antenna and cable.

Connect each Units Exciter MODBUS signal to the Plants Remote Monitoring and Annunciation system (Lookout). Re-use existing ADAM-4250 and install two new ADAM-4250 signal converters in the same location.

Annunciation:

Provide new Annunciation light in Lightbox, to read “Exciter Trouble.” Remove “Voltage Regulator” light and replace with this new light. Work to be done at all three Mainboard locations, and all three Governor Board locations. Plant annunciation points will remain the same, and new wires will be wired to the same terminal blocks. Excitation system outputs going to plant and SCADA annunciation will land at the same terminal blocks as before

Data Connections: Modbus RTU using RS-485 protocol to be provided for future use.

Generator CTs for exciter use:

Reuse existing Generator CTs

Wiring (for Control, Annunciation, and Metering):

Contractor to supply all new cable and wiring and will be responsible for pulling the new cable to the appropriate locations in the powerhouse and connecting all external cable in the excitation cubicles only. The government will be responsible for connecting any new wire external coming from the excitation and PPT cubicles, to the plant.

Commissioning and Testing

[SEE PATHS 1 -3 BELOW]

Component Scope of Work

NERC Model Verification Testing

The following will be performed on Units 2 and 3 only:

MOD-025: Unit capability verification MOD-026: Generator/Exciter/PSS/UEL/OEL dynamic modeling MOD-027: Turbine/Governor dynamic modeling PRC-019: Coordination of protection and limiters

Structural Structural scope of work items to include an assessment of floor loading for equipment to be installed, concrete demolition and repair of surfaces, and seismic anchoring of all provided excitation equipment, as necessary.

PROBLEM STATEMENT:

Unit 1 Issue

Unit 1 is currently out of service due to a failure of the gear that converts the lower speed of the turbine to a higher rotational output required by the generator. It is unknown when this will be fixed. Unit 1 cannot be spun up and run until this issue is resolved.

COMMISSIONING OPTION PATHS:

Path 1a: Two Contracts – Second Contract for Completing Commissioning of Unit 1

First Contract o Complete above scope for all three Units o Commissioning and Testing

Units 2 and 3: Fully commissioned under first contract Unit 1: Partially test and commission Excitation System for Unit 1 to the extent possible (standstill operation), match all settings to Unit 2 and Unit 3, and ensure, with reasonable certainty, that the excitation can operate to it's full capabilities.

Second Contract o Sole-Source Contract to finish commissioning and testing of Unit 1 Excitation System

(Offline and Online) o Complete Model Validation Testing

Path 1b: One Contract – Rolling notice to proceed (NTP) on each unit

Complete above scope for all three Units Commissioning and Testing o Units 2 and 3: Fully commissioned under first NTP Delay second NTP on Unit 1 for up to 5 years, to allow for Unit 1 to become operational again

Path 2: One Contract – Commissioning and Testing of Unit 1 Excitation System using Unit 2 Generator

Complete above scope for all three Units Commissioning and Testing o Commissiong and Test Unit 3 normally o Commissiong and Test Unit 1 Excitation System, using Unit 2 Generator. Added scope to include:

Route AC cables from Unit 2 bus tap at Switchgear to Unit 1 PPT Route DC cables from Unit 1 Exciter to Unit 2 collector ring housing

Connect Unit 2 CTs and PTs to Exciter 1 Run multiwire cable from Unit 1 Exciter to Unit 2 Lift all external wires in Exciter 1 and land wires from the cable to Exciter 2 lift all internal connections that connect to external wire in Unit 2, and land corresponding wires from the cable from Exciter 1 Use all of Unit 2 Exciter controls, indication, annunciation, and protection for

Exciter 1.

Perform Model Validation on Excitation System for Unit 1, with all these connections After Commissioning, testing, and model validation of Exciter 1, using Generator

2, reconnect all connections in Exciter 1 and Exciter 2, and remove multiwire cable from Exciter 1 to Exciter 2

Trim and connect AC cables from Unit 1 PPT to Unit 1 Switchgear Trim and connect DC cables from Unit 1 Exciter to Unit 1 Collector Ring Trim and connect PTs and CTs from Unit 1 Exciter to Unit 1 switchgear Perform standstill testing and commissioning on Unit 1 o Commissioning and Test Unit 2 normally (Unit 2 Exciter will be installed after commissioning of Unit 1)

Path 3: Two Contracts – First for Unit 2 and Unit 3; second contract will be a Sole Source Selection for entire Unit 1 Excitation System

First Contract o Complete above scope for Units 2 and 3 o Commissioning and Testing

Fully commission and test Unit 2 and 3 Second Contract o Use new threshold for approving sole-source justifications (up to $10 million) to Sole- Source Unit 1 Excitation System to previous contractor o Complete above scope for Unit 1 o Commissioning and Testing

Fully commission and test Unit 1

QUESTIONS FOR INDUSTRY:

1. When would Warranty begin for each potential path?

2. Which potential path presents the least risk?

3. Are any of the potential paths unbiddable? If so, why?

4. Which potential path in your estimation would be the least costly?

5. Which potential path would you recommend?

6. Is there a commissioning option we haven’t considered?

7. What path would produce the most accurate bid price?