Suspension Force Control for High-Speed Bearingless Doubly Salient Electromagnetic Motor Considering Advanced Angle and Commutation

With the increase of the speed of bearingless doubly salient electromagnetic motor (BDSEM), the armature currents affect the suspension force characteristics, thus affecting the suspension performance. In this article, first, the influence of suspension currents on torque characteristics is deduced. Second, the suspension force characteristics at high-speed are analyzed and illustrated under different drive control methods. Third, a suspension force control method is proposed to achieve stable suspension during advanced angle drive control and commutation at high-speed. The finite element (FE) results verify the effectiveness of the proposed suspension control method. An experimental platform of 12/8-pole BDSEMs is built. A system including a drive controller, a suspension controller, and a power generation unit is also developed. The experimental results show that the suspension performance is significantly improved.