Influence of Power Factor on the Performance of Bulb Tubular Turbine Generator

摘要

Background: In recent years, many patents have been dedicated to increasing the ratedpower factor of generators. However, hydro-generators often encounter uncontrollable factors,such as dry season, power network adjustment, and so on, resulting in low power factor operation.In other words, the generator is often in a low power factor operating state. In order to provide datareference for power plant in regulating power factor, it is necessary to analyze the performance ofgenerator in low power factor operation.Objective: The performance of the generator is analyzed when the power factor decreases, and theinfluence of low power factor operation on the generator is obtained. Methods: Taking a 24MWbulb tubular turbine generator as an example, a 2D transient electromagnetic field model is established.The correctness of the model is verified by comparing the test data and the simulation data.The torque, eddy current loss and air gap flux density of the generator under different power factorare calculated.Results: When the power factor deceases from 0.99 to 0.85, the air gap flux density increases from0.713 T to 0.749 T, the torque ripple increases from 150.5 kN⋅m to 179.9 kN⋅m, and the rotor eddycurrent loss increases from 17.48 kW to 18.15 kW.Conclusion: The results show that the torque ripple and eddy current loss will increase with thedecrease of power factor when the generator lagging phase operation. The torque ripple and eddycurrent loss increase by 3.8 % and 1 % respectively with the power factor decrease by 0.02 % withpower factor between 0.99 and 0.85.