Research on Control of Levitation Force and Torque of a Maglev Device for Water-Turbine Generator Set

Abstract

Hydropower generation is clean, pollution-free, and renewable, and has good social and economic benefits, so it is given priority for development throughout the world. The capacity of hydropower stations is increasing to 1000 MW from 700 MW. As the p value on the bearing reaches a new height, coupled with the original risk of easy damage, the thrust bearing faces new technical challenges. Maglev technology is studied and applied to a large vertical-shaft hydro-generator set to solve the bearing problem. The maglev device is designed, and the working principle is expounded, using active-control repulsive-suspension technology. The levitation-force addition and the torque cancellation are realized by controlling the frequency of the excitation power supply. The dynamic mathematical models of levitation force and torque are derived. Combined with the design and theoretical analysis, the vector-control strategy is developed and the simulation analysis is completed. According to the results, the controller is improved to enhance the response performance. Finally, a control experiment is carried out on the prototype, and the results verify the effectiveness of the design and control strategy.