A Sensor Specification and Deployment Framework for Condition Monitoring of Existing Hydraulic Turbines

Abstract

Hydraulic turbines increasingly operate under variable hydraulic regimes, creating a need for condition monitoring (CM) systems that support diagnostics and predictive maintenance, rather than only protection or threshold-based alarms. However, sensor selection in hydropower monitoring studies is often reported as an experimental detail, with limited guidance on how monitoring objectives, degradation mechanisms, measurable signatures, sensor modalities, data acquisition (DAQ) requirements and field constraints should be linked. This paper presents a sensor specification and deployment framework for hydraulic turbine CM in practice. Its main contribution is an operational decision process that links monitoring objectives to mechanisms, signatures, sensor roles, DAQ requirements, deployment constraints and site-specific sensor-suite selection. The framework was verified on a laboratory pump-as-turbine (PAT) rig using flow, pressure, vibration and acoustic emission (AE) measurements under three quasi-steady regimes defined by Q/Qmax = 0.90, 0.63 and 0.33, where Qmax is the maximum measured PAT flow. Flow measurement separated the regimes with coefficients of variation of 2.47–7.61%; pressure measurements provided hydraulic-loading and fluctuation context; accelerometers showed direction-dependent vibration responses; and Hsu–Nielsen testing confirmed AE reproducibility within the ASTM E976 criterion. Field adaptation to five Pelton, Francis and Kaplan plants showed how the same specification logic produced site-specific sensor layouts.