Measuring uncertainty of hydraulic generator efficiency by calorimetric method

Abstract

Abstract Calorimetric method is generally performed on determination of hydraulic generator efficiency. Generator losses could be evaluated by measuring the heat taken by cooling medium or dissipated from a reference surface. To satisfy the requirements of measuring uncertainty in IEC 60034, special attention must be paid. An estimation method is proposed and performed on a hydraulic generator for calorimetric test. Estimation result shows that discharge of cooling water must be reduced to a rather low value to ensure the measuring uncertainty of calorimetry within 3%. Also, a lower cooling discharge can bring higher temperature rise then reduce the measuring uncertainty caused by temperature measurement. Furthermore, to reduce the measuring uncertainty of cooling discharge, flowmeters must be installed correctly.