James Cropper plc are British master papermakers based in Kendal who create some of the world’s most distinctive and technically advanced paper products, using materials from cotton and wood to carbon fibre.
Operating a legacy Ruston Gas Turbine package, the site had a GEC type C10/120 AVR system fitted with GEC Midos type Generator Protection Relays and Synchronisers. The generator is critical to operations at site and would be difficult to remove in the event of a breakdown, making it imperative that it is fully protected.
With the OEM no longer manufacturing the AVR for stock and with some of the protection relays being obsolete, OEM support in the event of a breakdown was becoming limited and any spares requirement was likely to be on a long lead time.
With this in mind, the client decided to upgrade the complete system to a modern digital equivalent and having serviced the generator and control equipment for many years, the client could rely on Quartzelec to work with them to provide the required outcome.
Quartzelec provided a new, dual channel, Basler DECS-250 based excitation system, providing; design (including new drawings), build and test (including dynamic AVR test using Quartzelec's in-house test capability) and installation and commissioning services.
The system was back-plate mounted for installation into the existing cubicle frame and also included new cubicle doors, consisting of a new generator protection relay, metering, HMI and a circuit breaker mimic board with synchronising facility for generator and grid circuit breakers.
The dual channel excitation aspect allows the client to generate in the unlikely event of a failure of one of the Basler units and the new design incorporates the original control philosophy using modern components with increased functionality, performance and reliability.
In an ideal situation, with a job of this magnitude, the entire cubicle would be replaced, however, due to very limited access, where the control room had been built around the equipment, the existing cubicle had to be fully stripped out and reused, making installation a challenge.
With access to the original design data for this generator, Quartzelec were able to provide protection settings, more finely tuned than on the existing equipment as well as providing additional features with the new relay.
Due to our previous experience, working on legacy AVR systems including GEC / Alstom / Converteam / GE and associated packages from Ruston Gas Turbines / European Gas Turbines / Alstom / Siemens Lincoln Gas Turbines and coupled with our ability to design the system to meet client requirements, the project was a success.
With the new, finely tuned protection system, dual channel AVRs and annual generator maintenance by Quartzelec, James Cropper are well placed for uninterrupted operations.