Renovation of a paper mill steam driven turbine-generator

This paper highlights a renovation project involving replacement of an M-H (mechanical-hydraulic) turbine governor and replacement of an in-line shaft-driven rotating exciter. The turbine generator is an early 1960 vintage and is a double automatic extraction condensing unit. The generator voltage is 13800 volts AC and the exciter voltage is 250 volts DC. The turbine governor was replaced with an E-H (electro-hydraulic) governor system. The rotating exciter and regulator were replaced with a solid state exciter and static voltage regulator. The reasons for the renovation were the physical condition of the existing equipment, the lack of spare parts, the continuous maintenance, and the potential operating improvements with the up-to-date modern equipment. Hardware and software were installed for communications between the replacement equipment and the mill distributed control system. The DCS personnel monitor and direct the operation of the new systems from the mill DCS central control area. The control cubicles, control panels, electrical wiring, hydraulic power unit, hydraulic tubing, DCS hardware and software, and additional power protective relays were physically installed as completely as possible prior to the turbine-generator outage. The outage was scheduled for around-the-clock installation as required to keep the turbine-generator outage hours to a minimum.<>