Towards an Improved Model for Predicting Hydraulic Turbine Efficiency

Field performance testing of hydraulic turbines is undertaken to define the head-power-discharge relationship, which identify the turbine’s peak operating point. This relationship is essential for the efficient operation of a hydraulic turbine. Unfortunately, in some cases it is not feasible to field test turbines due to time, budgetary, or other constraints. Gordon (2001) proposed a method of mathematically simulating the performance curve for several types of turbines. However, a limited data set was available for the development of his model. Moreover, his model did not include a precise method of developing performance curves for rerunnered turbines. Manitoba Hydro operates a large network of hydroelectric turbines, which are subject to periodic field performance testing. This provides a large data set with which to refine the model proposed by Gordon (2001). Furthermore, since Manitoba Hydro’s data set includes rerunnered units, this provides an opportunity to include the effects of rerunnering in his model. The purpose of this paper is to refine Gordon’s model using Manitoba Hydro’s data set and to include the effects of rerunnering in the model. Analysis shows that the accuracy of the refined model is within ±2% of the performance test results for an “old” turbine. For a newer turbine or a rerunnered turbine, the error is within ±1%. For both an “old” turbine and a rerunnered turbine, this indicates an accuracy improvement of 3% over the original method proposed by Gordon (2001).