SMUD's Camp Far West (CFW) Hydroelectric facility was supervised by a PC-based level/flow control system that was no longer reliable or maintainable. Parts were no longer available, and program logic was not accessible by current SMUD staff. IEC's project team investigated the controller and provided a Preliminary Design Report in which alternative refurbishment options were suggested. Our team was then contracted to research and develop an upgrade path to incorporate the existing Woodward governor functionality into the new programmable logic controller (PLC) to be implemented in the project.

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‍Topics of review for governor refurbishment included:

• Speed sensing and unit speed switch functions.
• Wicket gate position sensing and feedback.
• Wicket gate hydraulic servo control valve.
• Wicket gate hydraulic emergency shutdown function.
• Hydraulic system controls, oil filtering, water-in-oil due to air-over-oil accumulator, etc.

‍Our team also reviewed options for improved station instrumentation and control including:

• Flow metering options including hydro tailrace weir and turbine scroll case differential-pressure method.
• Reservoir level elevation monitoring.
• Howell-Bunger bypass valve (BPV) position indicating instrumentation.
• Downstream diversion dam level monitoring and surge suppression.
• Digital power metering with digital communication to new PLC.
• BPV modulation to sustain desired flow during both “flow control” and “level control” modes.