Research of Generator Efficiency Test by Calorimetric Method for Bulb Tubular Unit

This paper carries out research on the generator efficiency test for the bulb tubular hydro-generator unit, which is based on the calorimetric method in IEC60034-2-2. It introduces the test method and how to implement it on-site. According to the characteristics of the tubular unit, it discusses the selection of reference surface and difference between tubular unit and other type units, then analyzes the effect of different selection to the calculation and test procedure. To the difficulty of thermal loss measurement from the generator to bulb head cover, then to the river water, the paper tries to find a solution to get the loss step by step, which is by the heat exchange sequence. In the last part of the paper, a test case performed in Laos has been brought out as an example, which was applied with the optimized test and analysis method. From the test result of generator efficiency curve and weighted efficiency result, it can be proved that the optimized measurement method has good tolerance and uncertainty, which can be a reference for other generator efficiency tests in the bulb-type tubular hydropower plant.