Control Performance Improvement of Excitation System with Active Magnetic Bearing for Measurement of Rotordynamic Forces

In electrical plants, rotating machines have to maintain power supply for our life. Rotating machines such as turbines are main component of the electrical plants. Stability performance of the rotating machines is important design point. Rotordynamic force influences the stability performance, and the rotordynamic forces should be evaluated in the development. Theoretical analysis is difficult to evaluate the rotordynamic forces accurately, because the characteristic is complex due to coupling with mechanical and fluid dynamics. On the other hand, direct measurement of rotordynamic forces has a problem, because the measurement condition, namely the rotating speed, the whirling orbit of a rotor is difficult to realize in a test bench. This study proposes a control system to improve the performance of a active magnetic bearing in the test bench. The control system can realize the measurement condition accurately, and the rotordynamic forces can be measured at various frequencies simultaneously. In the feasibility study, the measured rotordynamic forces by using the proposed control system were matched to the simulation data.