On 2 ÷ 3 of June 2024, the measurement of bulb Kaplan turbine (power 3 MW) at the Bulgarian hydroelectric power plant Prokopanik was performed. This power plant (property of company VEZ Svoge EOOD) is a part of cascade on the Iskar River, north of Sofia city.

The goal of test was to assess the correctness of the existing ON-CAM relation and, if necessary, to optimize it with regard to the maximum machine efficiency and acceptable cavitation emissions. The flow rate was determined by index method from the pressure difference values at the turbine. The noise level was also measured at selected locations in the plant at machine full power.

The results at HPP showed a significant deviations of existing ON-CAM, where its optimization can increase the efficiency of the unit by up to 7% over the entire power range.